Q150.Smoking increases the risk of which blood-vessel-related disease?
[RRB Group D 2025 cycle (held 25 Aug 2026, Shift 3) — 2026]
(a) Anaemia
(b) Diabetes
(c) Goitre
(d) Cardiovascular disease
Answer: (d) Cardiovascular disease
Explanation: Tobacco smoke damages blood-vessel lining and promotes atherosclerosis and clot formation. These processes raise the risk of heart attacks, stroke and peripheral arterial disease. Smoking cessation is a major preventable cardiovascular risk reduction measure. Timely recognition matters because reduced organ blood supply can become an emergency.
Q149.Which element is necessary for the thyroid gland to make thyroxine hormone?
[RRB Group D 2025 cycle (held 12 Aug 2026, Shift 2) — 2026]
(a) Iron
(b) Calcium
(c) Iodine
(d) Vitamin D
Answer: (c) Iodine
Explanation: Iodine is incorporated into thyroxine (T4) and triiodothyronine (T3), hormones made by the thyroid gland. Insufficient dietary iodine can enlarge the thyroid, producing goitre, and may impair thyroid function and development. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q148.Who received the first EASD Diabetes Global Impact Prize in 2025?
[RRB Group D (27 Dec 2025, Shift 2) — 2025]
(a) Dr Devi Shetty
(b) Dr Randeep Guleria
(c) Dr V. Mohan
(d) Dr Soumya Swaminathan
Answer: (c) Dr V. Mohan
Explanation: Indian diabetologist Dr V. Mohan was recognised for contributions to diabetes research and care. This is a current-affairs-linked diabetes question rather than a question about the biological mechanism of the disease. The exact mechanism determines which treatments and monitoring strategies are useful.
Q147.Which hormone requires iodine for its synthesis?
[MP Police Constable (1 Dec 2025, Shift 1) — 2025]
(a) Thyroxine
(b) Growth hormone
(c) Insulin
(d) Adrenaline
Answer: (a) Thyroxine
Explanation: The thyroid gland uses iodine to make T4 (thyroxine) and T3. These hormones help regulate metabolism, growth and development. Iodine deficiency may cause enlargement of the thyroid gland, known as goitre. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q146.Vitamin B12 is most useful for combating which condition?
[West Bengal Police Sub-Inspector (12 Oct 2025) — 2025]
(a) Night blindness
(b) Rickets
(c) Anaemia
(d) Goitre
Answer: (c) Anaemia
Explanation: Vitamin B12 supports red-blood-cell production and nerve function. Its deficiency can cause megaloblastic anaemia, while pernicious anaemia results specifically from impaired B12 absorption, often due to intrinsic-factor deficiency. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q145.Diabetes mellitus is caused by the inadequate secretion of which hormone?
[RRB NTPC Undergraduate CBT-I (29 Aug 2025, Shift 3) — 2025]
(a) Estrogen
(b) Insulin
(c) Adrenaline
(d) Thyroxine
Answer: (b) Insulin
Explanation: Insulin is produced by pancreatic beta cells and helps tissues take up glucose. Too little insulin raises blood glucose. Type 1 diabetes usually involves severe insulin deficiency, while type 2 often begins with insulin resistance. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q144.Which national initiative aims to prevent and control non-communicable diseases such as diabetes and hypertension?
[SSC Selection Post, Matriculation Level (1 Aug 2025, Shift 2) — 2025]
(a) Mission Indradhanush
(b) National Digital Health Mission
(c) Pradhan Mantri Jan Arogya Yojana
(d) National Programme for Prevention and Control of NCDs
Answer: (d) National Programme for Prevention and Control of NCDs
Explanation: The National Programme for Prevention and Control of Non-Communicable Diseases focuses on prevention, screening, diagnosis and management of conditions including diabetes, hypertension, cancer and cardiovascular disorders. Population-level screening supports earlier identification of health risks. Community screening complements individual clinical care and risk-factor management.
Q143.Which combination correctly matches a vitamin with its function and deficiency disorder?
[SSC Selection Post, Higher Secondary Level (31 Jul 2025, Shift 2) — 2025]
(a) Vitamin A—calcium absorption—scurvy
(b) Vitamin D—visual pigments—pellagra
(c) Vitamin B12—nerve function and red-cell formation—anaemia
(d) Vitamin C—blood clotting—night blindness
Answer: (c) Vitamin B12—nerve function and red-cell formation—anaemia
Explanation: Vitamin B12 is needed for DNA synthesis, normal red-cell production and nervous-system maintenance. Deficiency can cause megaloblastic anaemia and neurological symptoms. The other options mismatch the vitamins with the functions and deficiency conditions. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q142.Scurvy is characterised by swelling and bleeding of gums. Deficiency of which vitamin causes scurvy?
[RPF Constable 2024 cycle (held 7 Mar 2025, Shift 2) — 2025]
(a) Vitamin C
(b) Vitamin A
(c) Vitamin B1
(d) Vitamin D
Answer: (a) Vitamin C
Explanation: Vitamin C is essential for collagen synthesis. Prolonged deficiency weakens connective tissues and blood-vessel walls, causing swollen bleeding gums, bruising and poor wound healing. Fresh fruits and vegetables supply vitamin C. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q141.Match the deficiency diseases:
Vitamin A, D, B1 and C
with night blindness, rickets, beriberi and scurvy.
[SSC MTS (29 Oct 2024, Shift 1) — 2024]
(a) A–scurvy; D–rickets; B1–night blindness; C–beriberi
(b) A–night blindness; D–scurvy; B1–beriberi; C–rickets
(c) A–rickets; D–night blindness; B1–beriberi; C–scurvy
(d) A–night blindness; D–rickets; B1–beriberi; C–scurvy
Answer: (d) A–night blindness; D–rickets; B1–beriberi; C–scurvy
Explanation: Vitamin A contributes to vision, vitamin D to calcium metabolism, thiamine (B1) to energy metabolism and vitamin C to collagen synthesis. Their characteristic deficiencies are night blindness, rickets, beriberi and scurvy respectively. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q140.The National Prophylaxis Programme launched in 1970 targeted which nutritional problem?
[SSC MTS (15 Oct 2024, Shift 3) — 2024]
(a) Blindness
(b) Hypercalcaemia
(c) Goitre
(d) Beriberi
Answer: (a) Blindness
Explanation: India introduced the National Prophylaxis Programme against Nutritional Blindness to prevent vision loss associated with vitamin A deficiency, particularly among children. Severe deficiency can cause xerophthalmia, corneal injury and preventable blindness. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q139.Pellagra is caused by deficiency of which nutrient?
[SSC MTS (9 Oct 2024, Shift 2) — 2024]
(a) Vitamin E
(b) Niacin
(c) Iodine
(d) Riboflavin
Answer: (b) Niacin
Explanation: Niacin, or vitamin B3, deficiency causes pellagra. It is traditionally associated with dermatitis, diarrhoea and dementia, called the three Ds. Niacin is obtained from foods such as legumes, meat, fish and enriched cereals. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q138.Which of the following is a mineral-deficiency disease?
[SSC MTS (7 Oct 2024, Shift 2) — 2024]
(a) Rickets
(b) Marasmus
(c) Scurvy
(d) Goitre
Answer: (d) Goitre
Explanation: Goitre can result from insufficient iodine, a dietary mineral needed for thyroid-hormone production. Rickets is classically linked to vitamin D deficiency, scurvy to vitamin C deficiency and marasmus to severe energy deficiency. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q137.Deficiency of which nutrient causes beriberi?
[DSSSB Jail Warder (12 Jun 2024, Shift 1) — 2024]
(a) Vitamin K
(b) Fat
(c) Protein
(d) Vitamin B1
Answer: (d) Vitamin B1
Explanation: Beriberi results from thiamine (vitamin B1) deficiency. Dry beriberi mainly involves nerves and muscles, whereas wet beriberi involves cardiovascular problems and oedema. Diets dominated by polished rice may lack sufficient thiamine. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q136.Which vitamin–disease pair is incorrectly matched?
[JKSSB Sub-Inspector (Finance), 10 Mar 2024 — 2024]
(a) Vitamin A—xerophthalmia
(b) Vitamin D—rickets
(c) Vitamin K—beriberi
(d) Vitamin C—scurvy
Answer: (c) Vitamin K—beriberi
Explanation: Beriberi is caused by thiamine (vitamin B1) deficiency, not vitamin K deficiency. Vitamin K is important for activation of clotting factors; its deficiency can cause bleeding. The other three pairings are correct. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q135.Silicosis is primarily a disease of which organ?
[MP Police Constable (4 Sep 2023, Shift 2) — 2023]
(a) Bone
(b) Nerve
(c) Lung
(d) Liver
Answer: (c) Lung
Explanation: Silicosis develops after inhaling respirable crystalline silica, which can cause inflammation and irreversible scarring in the lungs. Mining, cutting stone and sandblasting are occupational exposure settings. The disease can impair breathing even after exposure ends. Reducing prolonged exposure is a major part of respiratory disease prevention.
Q134.Thyroid : iodine :: night blindness : ?
[SSC MTS 2022 cycle (20 Jun 2023, Shift 1) — 2023]
(a) Vitamin D
(b) Vitamin B
(c) Vitamin C
(d) Vitamin A
Answer: (d) Vitamin A
Explanation: Iodine is needed for thyroid hormones, while vitamin A is needed for normal visual-pigment function. Vitamin A deficiency typically first reduces adaptation to dim light, causing night blindness and sometimes xerophthalmia. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q133.Which vitamin helps the body use calcium for bones and teeth?
[SSC MTS 2022 cycle (19 Jun 2023, Shift 1) — 2023]
(a) Vitamin A
(b) Vitamin E
(c) Vitamin C
(d) Vitamin D
Answer: (d) Vitamin D
Explanation: Vitamin D promotes intestinal absorption of calcium and phosphate and enables normal bone mineralisation. Its deficiency causes rickets in children and can contribute to osteomalacia in adults. Sunlight exposure and foods are important sources. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q132.Which disease is caused by severe protein deficiency in the diet?
[SSC MTS 2022 cycle (16 Jun 2023, Shift 1) — 2023]
(a) Scurvy
(b) Jaundice
(c) Rickets
(d) Kwashiorkor
Answer: (d) Kwashiorkor
Explanation: Kwashiorkor is a form of severe malnutrition marked by bilateral pitting oedema and often skin and hair changes. It is classically associated with marked dietary protein inadequacy, usually alongside wider nutritional and environmental stresses. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q131.Goitre is most commonly associated worldwide with deficiency of which nutrient?
[SSC MTS 2022 cycle (18 May 2023, Shift 1) — 2023]
(a) Protein
(b) Vitamin A
(c) Iodine
(d) Iron
Answer: (c) Iodine
Explanation: Iodine is necessary for thyroid-hormone synthesis. In iodine-deficient populations, the thyroid may enlarge to compensate, producing goitre. Not every goitre is caused by iodine deficiency: autoimmune disease and nodules are other causes. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q130.Yellowing of the skin and eyes from raised bile pigment is called which condition?
[SSC CGL 2020 cycle (held 23 Aug 2021, Shift 3) — 2021]
(a) Diarrhoea
(b) Constipation
(c) Vomiting
(d) Jaundice
Answer: (d) Jaundice
Explanation: Jaundice refers to yellow discoloration caused by accumulation of bilirubin. It is a sign rather than a single disease. Causes include hepatitis, bile-duct obstruction and excessive red-blood-cell breakdown. Advanced liver impairment can affect fluid balance and other body systems.
Q129.Which organ is primarily associated with jaundice?
[DSSSB PGT Biology (16 Jul 2021, Shift 1) — 2021]
(a) Liver
(b) Heart
(c) Kidney
(d) Lungs
Answer: (a) Liver
Explanation: Jaundice is yellowing of skin and sclera caused by excess bilirubin. The liver normally processes and excretes bilirubin, so liver disorders often cause jaundice; increased red-cell breakdown and bile-duct obstruction can cause it too. Clinical assessment distinguishes problems of bilirubin production, processing and bile drainage.
Q128.Posthepatic jaundice is also called what type of jaundice?
[MP Lab Technician (7 Jan 2021, Shift 2) — 2021]
(a) Haemolytic
(b) Obstructive
(c) Toxic
(d) Neonatal
Answer: (b) Obstructive
Explanation: Posthepatic or obstructive jaundice occurs when bile drainage is blocked after bilirubin has been processed by the liver. Gallstones and tumours may obstruct bile ducts, producing conjugated hyperbilirubinaemia, pale stools and dark urine. Associated symptoms and blood tests help clinicians determine the underlying cause.
Q127.Which substance has traditionally been linked to muscle fatigue after intense exercise?
[UP R.O./A.R.O. (Mains) 2013 — 2013]
(a) Uric acid
(b) Pyruvic acid
(c) Benzoic acid
(d) Lactic acid
Answer: (d) Lactic acid
Explanation: Many older examination keys identify lactic acid. Modern physiology is more nuanced: lactate is also a useful metabolic fuel, and fatigue involves several factors including ionic disturbances and energy availability. It is inaccurate to treat lactate as the sole cause.
Q126.Deposition of which substance is characteristic of gouty arthritis?
[UPPCS (Mains) 2013 — 2013]
(a) Urea
(b) Uric acid
(c) Albumin
(d) Cholesterol
Answer: (b) Uric acid
Explanation: Gout is an inflammatory arthritis caused by monosodium urate crystal deposits in joints. Persistently elevated urate increases risk, and attacks commonly affect the big toe, ankle or knee. Not all arthritis is gout. A precise diagnosis matters because different forms of arthritis need different treatments.
Q125.High levels of uric acid in the blood are especially associated with which disease?
[UPPCS (Mains) 2009 — 2009]
(a) Arthritis in general
(b) Gout
(c) Rheumatic fever
(d) Rheumatic heart disease
Answer: (b) Gout
Explanation: Hyperuricaemia increases the likelihood of monosodium urate crystals forming in joints and causing gout. However, many people with high uric acid never develop an attack; clinical findings and sometimes crystal analysis establish diagnosis. Joint swelling alone does not reveal the cause without appropriate clinical assessment.
Q124.What is the main biological feature that distinguishes a malignant tumour from a benign tumour?
(a) Formation of a capsule
(b) Ability to invade nearby tissues
(c) Presence of any dividing cells
(d) Location only in skin
Answer: (b) Ability to invade nearby tissues
Explanation: Malignant tumours invade surrounding structures and may spread to distant organs. Benign tumours usually remain localised, although some can still cause harm by compressing vital tissues or secreting hormones. Tumour type and stage guide decisions about diagnosis and treatment options.
Q123.What is the term for the spread of cancer cells from a primary site to a distant organ?
(a) Metastasis
(b) Hypertrophy
(c) Metaplasia
(d) Homeostasis
Answer: (a) Metastasis
Explanation: Metastasis occurs when malignant cells leave the original tumour, enter lymphatic or blood vessels, and establish new growth elsewhere. Common secondary sites include the liver, lung, brain and bone. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q122.Leukaemia primarily involves abnormal proliferation of which cells?
(a) Muscle fibres
(b) Platelets alone
(c) Cartilage cells
(d) White blood cells or their precursors
Answer: (d) White blood cells or their precursors
Explanation: Leukaemia is a group of blood and bone-marrow cancers involving abnormal blood-forming cells, often white-cell precursors. Such cells can crowd out normal marrow, leading to anaemia, infections and bleeding tendencies. The effects depend on the tissue involved and extent of spread.
Q121.Which organ normally produces most blood cells in healthy adults?
(a) Thyroid
(b) Gallbladder
(c) Red bone marrow
(d) Spleen
Answer: (c) Red bone marrow
Explanation: In adults, red bone marrow produces red cells, many white cells and platelets from haematopoietic stem cells. Leukaemia and other marrow disorders can interfere with this process and reduce healthy blood-cell output. Tumour type and stage guide decisions about diagnosis and treatment options.
Q120.A carcinogen is best described as a substance or exposure that can do what?
(a) Cure all tumours
(b) Increase cancer risk
(c) Raise blood calcium
(d) Destroy all viruses
Answer: (b) Increase cancer risk
Explanation: Carcinogens can promote cancer through mechanisms including DNA damage and altered cell signalling. Examples of carcinogenic exposures include tobacco smoke, certain industrial chemicals, ultraviolet radiation and some infections. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q119.Which type of radiation is commonly associated with skin cancer risk after excessive sunlight exposure?
(a) Ultraviolet radiation
(b) Radio waves
(c) Audible sound
(d) Infrared only
Answer: (a) Ultraviolet radiation
Explanation: Ultraviolet radiation can damage DNA in skin cells. Repeated overexposure increases the risk of basal-cell carcinoma, squamous-cell carcinoma and melanoma. Protective clothing and avoiding excessive exposure reduce risk. The effects depend on the tissue involved and extent of spread.
Q118.A benign tumour is generally distinguished by which feature?
(a) It is always harmless
(b) It always metastasises
(c) It cannot contain dividing cells
(d) It usually remains confined to its original site
Answer: (d) It usually remains confined to its original site
Explanation: Benign tumours typically do not invade tissues or metastasise. Yet they may still produce serious effects by growing within the brain, blocking an organ, or secreting biologically active substances. Tumour type and stage guide decisions about diagnosis and treatment options.
Q117.Which virus is strongly associated with cervical cancer?
(a) Rabies virus
(b) Rotavirus
(c) Human papillomavirus
(d) Rhinovirus
Answer: (c) Human papillomavirus
Explanation: Persistent infection with certain high-risk human papillomavirus types is a major cause of cervical cancer. HPV vaccination and appropriate cervical screening substantially reduce the burden of this preventable malignancy. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q116.Which habit is an established major risk factor for lung cancer?
(a) Regular walking
(b) Tobacco smoking
(c) Washing hands
(d) Adequate sleep
Answer: (b) Tobacco smoking
Explanation: Tobacco smoke contains many carcinogenic compounds and is a major preventable cause of lung cancer. The risk generally rises with cumulative exposure; avoiding tobacco also protects against heart and lung diseases. The effects depend on the tissue involved and extent of spread.
Q115.What is an oncogene?
(a) A gene that can promote cancer when abnormally activated
(b) A hormone from the pancreas
(c) A normal red-cell pigment
(d) A mineral needed for bones
Answer: (a) A gene that can promote cancer when abnormally activated
Explanation: An oncogene is a gene whose abnormal activation can drive excessive cell growth or survival. Proto-oncogenes are normal genes involved in regulated signalling, and mutations or increased expression may convert them into oncogenes. Tumour type and stage guide decisions about diagnosis and treatment options.
Q114.Which process, when defective, can allow damaged cells to survive and contribute to tumour formation?
(a) Filtration
(b) Transpiration
(c) Osmosis
(d) Apoptosis
Answer: (d) Apoptosis
Explanation: Apoptosis is programmed cell death, which helps remove damaged or potentially dangerous cells. Some cancers evade this protective mechanism, enabling abnormal clones to survive and multiply instead of being eliminated. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q113.Cancer cells travelling through the lymphatic system may initially spread to which structures?
(a) Tooth enamel
(b) Lens of the eye
(c) Lymph nodes
(d) Hair shafts
Answer: (c) Lymph nodes
Explanation: Lymph nodes filter lymph and are a frequent early site of spread for some cancers. Examining relevant nodes helps clinicians evaluate tumour stage, although patterns differ among cancer types and locations. The effects depend on the tissue involved and extent of spread.
Q112.Which radioactive isotope has historically been used in selected forms of cancer brachytherapy?
(a) Nitrogen-14
(b) Gold-198
(c) Oxygen-16
(d) Carbon-12
Answer: (b) Gold-198
Explanation: Gold-198 is a radioactive isotope that has been used in certain brachytherapy applications. Cancer radiotherapy uses carefully controlled ionising radiation to damage tumour cells while limiting exposure to surrounding tissues. Tumour type and stage guide decisions about diagnosis and treatment options.
Q111.What is the principal purpose of chemotherapy for cancer?
(a) Use medicines to kill or inhibit rapidly growing cancer cells
(b) Increase iodine intake
(c) Replace all hormones
(d) Correct colour blindness
Answer: (a) Use medicines to kill or inhibit rapidly growing cancer cells
Explanation: Chemotherapy uses anticancer drugs to kill cancer cells or interrupt their growth and division. Some drugs also affect normal rapidly dividing tissues, which helps explain adverse effects such as low blood-cell counts. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q110.Which blood component is often abnormally reduced because of bone-marrow failure in leukaemia?
(a) Synovial fluid
(b) Bile
(c) Tooth dentine
(d) Platelets
Answer: (d) Platelets
Explanation: Abnormal cells in leukaemia can crowd out normal marrow production. Reduced platelets cause easy bruising or bleeding; reduced red cells cause anaemia, while impaired normal white cells increase infection risk. The effects depend on the tissue involved and extent of spread.
Q109.Which examination technique uses tissue under a microscope to confirm many cancers?
(a) Height measurement
(b) Pulse counting alone
(c) Biopsy and histopathology
(d) Urine colour alone
Answer: (c) Biopsy and histopathology
Explanation: A biopsy removes cells or tissue for microscopic examination. Histopathology can identify malignant cells, tumour type and important characteristics. Imaging may suggest a tumour, but tissue diagnosis is often required. Tumour type and stage guide decisions about diagnosis and treatment options.
Q108.What is the term for cancer arising from epithelial tissue?
(a) Lymphoma
(b) Carcinoma
(c) Myeloma
(d) Sarcoma
Answer: (b) Carcinoma
Explanation: Carcinomas originate from epithelial cells lining the skin, glands and many organs. Sarcomas arise in connective tissues, while lymphomas and myelomas originate from different immune or blood-cell lineages. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q107.A sarcoma most commonly arises from which tissue category?
(a) Connective or supporting tissues
(b) Tooth enamel only
(c) Brain fluid
(d) Skin epithelium only
Answer: (a) Connective or supporting tissues
Explanation: Sarcomas are malignant tumours of connective or mesenchymal tissues such as bone, cartilage, fat and muscle. They differ from carcinomas, which begin in epithelial tissues such as the lung or intestine. The effects depend on the tissue involved and extent of spread.
Q106.Which cobalt isotope is widely known for use as a gamma-ray source in radiotherapy?
(a) Carbon-14
(b) Iodine-127
(c) Cobalt-59
(d) Cobalt-60
Answer: (d) Cobalt-60
Explanation: Cobalt-60 emits gamma radiation and has been used in external-beam radiotherapy. Modern treatment may also use linear accelerators. Radiation doses must be planned to destroy cancer cells while sparing healthy structures. Tumour type and stage guide decisions about diagnosis and treatment options.
Q105.Which inherited change can increase breast and ovarian cancer susceptibility?
(a) ABO blood group O
(b) Lactase persistence
(c) Pathogenic BRCA1 or BRCA2 variant
(d) Normal haemoglobin A
Answer: (c) Pathogenic BRCA1 or BRCA2 variant
Explanation: Certain pathogenic BRCA1 and BRCA2 variants impair DNA-repair pathways and increase susceptibility to several cancers. Carrying a variant raises risk but does not mean that cancer is inevitable. Early evaluation is important because clinical behaviour differs greatly between tumour types.
Q104.Insulin is secreted mainly by which pancreatic cells?
(a) Alpha cells
(b) Beta cells
(c) Acinar cells
(d) Delta cells
Answer: (b) Beta cells
Explanation: Pancreatic beta cells in the islets of Langerhans release insulin in response to rising blood glucose. Insulin facilitates glucose storage and uptake, helping maintain blood glucose within a healthy range. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q103.Which hormone generally raises blood glucose by stimulating glycogen breakdown?
(a) Glucagon
(b) Oxytocin
(c) Melatonin
(d) Insulin
Answer: (a) Glucagon
Explanation: Glucagon is secreted by pancreatic alpha cells. It helps maintain blood glucose between meals, especially by promoting liver glycogen breakdown and glucose production. Insulin generally has the opposite blood-glucose-lowering effect. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q102.What is the main underlying mechanism of type 1 diabetes mellitus?
(a) Abnormal collagen in skin
(b) Excess iodine consumption
(c) Lack of ADH alone
(d) Autoimmune destruction of pancreatic beta cells
Answer: (d) Autoimmune destruction of pancreatic beta cells
Explanation: In type 1 diabetes, immune-mediated destruction of pancreatic beta cells produces marked insulin deficiency. Individuals usually require insulin replacement. Type 2 diabetes more commonly involves insulin resistance alongside declining beta-cell function. The exact mechanism determines which treatments and monitoring strategies are useful.
Q101.Type 2 diabetes mellitus is most strongly associated with which metabolic abnormality?
(a) High ADH secretion
(b) Excess vitamin C
(c) Insulin resistance
(d) Absence of all digestive enzymes
Answer: (c) Insulin resistance
Explanation: Type 2 diabetes usually begins with reduced responsiveness to insulin in tissues, and pancreatic insulin secretion may later become insufficient. Genetics, adiposity, age and inactivity contribute to risk. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q100.What does hyperglycaemia mean?
(a) High blood calcium
(b) High blood glucose
(c) Low blood glucose
(d) Low blood oxygen
Answer: (b) High blood glucose
Explanation: Hyperglycaemia is an abnormally high concentration of glucose in blood. Persistent hyperglycaemia is characteristic of diabetes mellitus and can damage nerves, kidneys, eyes and blood vessels over time. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q99.Which test reflects average blood glucose over approximately two to three months?
(a) HbA1c
(b) ESR
(c) Serum sodium only
(d) Bleeding time
Answer: (a) HbA1c
Explanation: Glycated haemoglobin, or HbA1c, reflects glucose exposure of red blood cells over their lifespan, with greater weighting towards recent weeks. It assists in diagnosing and monitoring diabetes when clinically appropriate. The exact mechanism determines which treatments and monitoring strategies are useful.
Q98.Diabetes insipidus is mainly related to abnormal action or secretion of which hormone?
(a) Insulin
(b) Thyroxine
(c) Growth hormone
(d) ADH or vasopressin
Answer: (d) ADH or vasopressin
Explanation: Diabetes insipidus involves inadequate antidiuretic hormone secretion or kidney resistance to its action. It causes passage of large volumes of dilute urine and increased thirst, unlike diabetes mellitus, which concerns glucose regulation. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q97.Which organ is most directly targeted by antidiuretic hormone to conserve water?
(a) Pancreas
(b) Stomach
(c) Kidney
(d) Spleen
Answer: (c) Kidney
Explanation: ADH acts on collecting ducts in the kidneys and promotes water reabsorption through aquaporin channels. This concentrates urine and helps maintain fluid balance, explaining why ADH dysfunction causes excessive dilute urination. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q96.A typical early symptom of uncontrolled diabetes mellitus is which of the following?
(a) Sudden hair greying
(b) Frequent urination
(c) Persistent inability to sweat
(d) Loss of all reflexes
Answer: (b) Frequent urination
Explanation: When blood glucose rises above the renal reabsorption threshold, glucose spills into urine and draws water with it. This can cause frequent urination, thirst and dehydration, although symptoms vary between individuals. The exact mechanism determines which treatments and monitoring strategies are useful.
Q95.Diabetic retinopathy mainly damages which structure?
(a) Retinal blood vessels
(b) Achilles tendon
(c) Salivary glands
(d) Outer ear
Answer: (a) Retinal blood vessels
Explanation: Diabetic retinopathy results from chronic damage to small vessels in the retina. Screening can detect changes before noticeable vision loss. Good glucose and blood-pressure control help reduce progression risk. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q94.Which complication of diabetes involves damage to kidney filtration structures?
(a) Osteomalacia
(b) Bronchiectasis
(c) Tonsillitis
(d) Diabetic nephropathy
Answer: (d) Diabetic nephropathy
Explanation: Diabetic kidney disease can damage glomerular filtration units over time, leading to albumin in urine and reduced kidney function. Regular kidney tests and management of glucose and blood pressure are important. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q93.Which term describes abnormally low blood glucose?
(a) Hyperbilirubinaemia
(b) Hyperuricaemia
(c) Hypoglycaemia
(d) Hypernatraemia
Answer: (c) Hypoglycaemia
Explanation: Hypoglycaemia means blood glucose below the normal range. It may cause sweating, tremor, hunger and confusion. Severe cases can impair consciousness and require prompt treatment with glucose or glucagon. The exact mechanism determines which treatments and monitoring strategies are useful.
Q92.Diabetic ketoacidosis occurs most commonly in association with what condition?
(a) Isolated hearing loss
(b) Marked insulin deficiency
(c) Excess vitamin D
(d) Mild iodine deficiency
Answer: (b) Marked insulin deficiency
Explanation: In severe insulin deficiency, the body increases breakdown of fat and generates acidic ketone bodies. This can produce dehydration, high glucose and metabolic acidosis. It is an emergency more common in type 1 diabetes. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q91.Insulin and glucagon are made in which part of the pancreas?
(a) Islets of Langerhans
(b) Gallbladder
(c) Duodenum
(d) Pancreatic duct
Answer: (a) Islets of Langerhans
Explanation: The endocrine islets contain beta cells secreting insulin and alpha cells secreting glucagon. These hormones have complementary roles in regulating blood glucose, unlike pancreatic digestive enzymes made by exocrine acinar cells. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q90.Which clinical finding is more suggestive of diabetes mellitus than diabetes insipidus?
(a) Increased urine volume
(b) Excessive thirst
(c) Frequent urination
(d) Glucose in urine
Answer: (d) Glucose in urine
Explanation: Glucosuria is characteristic of sufficiently high blood glucose, as may occur in diabetes mellitus. Both forms of diabetes can cause thirst and polyuria, but diabetes insipidus is primarily a water-balance disorder. The exact mechanism determines which treatments and monitoring strategies are useful.
Q89.What is the major role of insulin after a carbohydrate-rich meal?
(a) Raise blood uric acid
(b) Cause jaundice
(c) Facilitate glucose utilisation and storage
(d) Destroy red blood cells
Answer: (c) Facilitate glucose utilisation and storage
Explanation: Rising blood glucose stimulates insulin release, which promotes glucose uptake by muscle and fat and glycogen synthesis in the liver and muscle. These effects help return blood glucose toward baseline. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q88.Which historical scientist pair is associated with isolation of insulin in 1921–22?
(a) Watson and Crick
(b) Banting and Best
(c) Jenner and Pasteur
(d) Darwin and Wallace
Answer: (b) Banting and Best
Explanation: Frederick Banting and Charles Best carried out early insulin isolation experiments, working with John Macleod; James Collip helped purify insulin. Banting and Macleod received the 1923 Nobel Prize and shared credit with colleagues. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q87.Which lifestyle measure helps reduce risk of type 2 diabetes among susceptible adults?
(a) Regular physical activity
(b) Excess sugary drinks
(c) Tobacco smoking
(d) Long-term inactivity
Answer: (a) Regular physical activity
Explanation: Regular physical activity improves insulin sensitivity and can support healthy weight management. Balanced nutrition and avoidance of smoking also protect cardiometabolic health. Genetic susceptibility exists, but prevention can lower risk substantially. The exact mechanism determines which treatments and monitoring strategies are useful.
Q86.A patient with diabetes and numbness in both feet may have which complication?
(a) Goitre
(b) Cataract only
(c) Gallstones only
(d) Peripheral neuropathy
Answer: (d) Peripheral neuropathy
Explanation: Long-standing elevated glucose may injure peripheral nerves and cause tingling, burning or reduced sensation in feet. Loss of protective sensation increases the risk of unnoticed injury, infection and ulcers. Early recognition helps prevent avoidable metabolic and vascular complications over time.
Q85.Which plant seed, also called methi, is commonly mentioned in traditional discussions of glucose control?
(a) Cotton boll
(b) Neem flower only
(c) Fenugreek
(d) Pine seed
Answer: (c) Fenugreek
Explanation: Fenugreek seeds are used as food and in traditional approaches to diabetes. Evidence for glucose-lowering benefits is limited and variable, and seeds do not replace prescribed medicines, dietary planning or clinical monitoring. Long-term care also considers risks to eyes, nerves, kidneys and blood vessels.
Q84.Atherosclerosis involves formation of what within arterial walls?
(a) Extra teeth
(b) Lipid-rich plaques
(c) Excess bile in lungs
(d) Uric acid only
Answer: (b) Lipid-rich plaques
Explanation: Atherosclerosis is a chronic arterial disease with plaques containing cholesterol, inflammatory cells and fibrous tissue. Plaques can narrow arteries or rupture and trigger a clot, potentially causing a heart attack or stroke. Risk assessment also considers age, family history and associated metabolic conditions.
Q83.A heart attack most often results from interrupted blood flow in which vessels?
(a) Coronary arteries
(b) Portal vein
(c) Lymphatic ducts
(d) Pulmonary veins only
Answer: (a) Coronary arteries
Explanation: Myocardial infarction usually occurs when an atherosclerotic plaque ruptures or erodes in a coronary artery, producing a clot and blocking oxygen delivery to heart muscle. Immediate emergency treatment limits damage. Prevention generally combines lifestyle measures with treatment of modifiable risk factors.
Q82.Which term denotes death of heart muscle because of prolonged inadequate blood supply?
(a) Osteoporosis
(b) Cirrhosis
(c) Emphysema
(d) Myocardial infarction
Answer: (d) Myocardial infarction
Explanation: Myocardial infarction means death of a portion of heart muscle due to sustained ischaemia. Symptoms can include chest pressure, sweating and breathlessness, although presentations may be atypical. Timely recognition matters because reduced organ blood supply can become an emergency.
Q81.What is the basic purpose of coronary artery bypass grafting?
(a) Replace the thyroid
(b) Remove both kidneys
(c) Provide an alternative route for blood around blocked coronary segments
(d) Cure all arrhythmias
Answer: (c) Provide an alternative route for blood around blocked coronary segments
Explanation: CABG uses an artery or vein graft to direct blood beyond narrowed coronary segments. Internal thoracic arteries and leg veins may be used. The aim is to improve oxygen supply to affected myocardium. Risk assessment also considers age, family history and associated metabolic conditions.
Q80.Which vessel from the leg is commonly used as a graft in coronary bypass surgery?
(a) Femoral nerve
(b) Great saphenous vein
(c) Achilles tendon
(d) Bile duct
Answer: (b) Great saphenous vein
Explanation: Segments of the great saphenous vein can be harvested for coronary artery bypass grafting. Other common conduits include the internal thoracic artery and radial artery, depending on patient factors. Prevention generally combines lifestyle measures with treatment of modifiable risk factors.
Q79.What does an angiogram of the coronary arteries principally show?
(a) Coronary blood-vessel lumen and narrowing
(b) Thyroid hormone levels
(c) Bone marrow cell counts
(d) Liver bile production
Answer: (a) Coronary blood-vessel lumen and narrowing
Explanation: Coronary angiography uses contrast and X-ray imaging to assess the arterial lumen, identify important narrowing and guide treatment decisions. It does not directly measure every biological property of the plaque. Timely recognition matters because reduced organ blood supply can become an emergency.
Q78.A cardiac catheterisation laboratory is commonly called a what?
(a) Fertilisation lab
(b) Virology lab
(c) Dialysis lab
(d) Cath lab
Answer: (d) Cath lab
Explanation: A cath lab is a specialised procedure room used for catheter-based heart and vascular investigations and treatments. Coronary angiography, angioplasty and stent placement are common interventions performed there. Risk assessment also considers age, family history and associated metabolic conditions.
Q77.Which blood lipid is particularly involved in atherosclerotic plaque development?
(a) Haemoglobin alone
(b) Albumin alone
(c) LDL cholesterol
(d) Bilirubin
Answer: (c) LDL cholesterol
Explanation: Low-density lipoprotein particles can enter artery walls and contribute to plaque formation. High LDL levels are a modifiable cardiovascular risk factor, and lowering them reduces heart attack and stroke risk. Prevention generally combines lifestyle measures with treatment of modifiable risk factors.
Q76.Hypertension means persistently elevated what?
(a) Blood platelet count
(b) Blood pressure
(c) Blood bilirubin
(d) Blood oxygen only
Answer: (b) Blood pressure
Explanation: Hypertension is chronic elevation of systemic arterial blood pressure. It increases risk of stroke, heart failure, heart attack and kidney disease, sometimes without warning symptoms. Measurement over time is important. Timely recognition matters because reduced organ blood supply can become an emergency.
Q75.Which medical instrument is routinely used to measure arterial blood pressure?
(a) Sphygmomanometer
(b) Lactometer
(c) Calorimeter
(d) Spirometer
Answer: (a) Sphygmomanometer
Explanation: A sphygmomanometer measures blood pressure, commonly using an inflatable cuff and automated sensor or stethoscope. Blood pressure is reported as systolic over diastolic pressure, usually in millimetres of mercury. Risk assessment also considers age, family history and associated metabolic conditions.
Q74.What is an important risk factor for coronary heart disease?
(a) Vaccination
(b) Normal exercise
(c) Adequate fibre intake
(d) Smoking
Answer: (d) Smoking
Explanation: Smoking promotes blood-vessel injury, clot formation and narrowing of arteries. Hypertension, high LDL cholesterol, diabetes, age and family history are additional important factors in coronary heart disease. Prevention generally combines lifestyle measures with treatment of modifiable risk factors.
Q73.Which substance is released from damaged heart muscle and used in diagnosing a heart attack?
(a) Pepsin
(b) Melanin
(c) Cardiac troponin
(d) Thyroxine
Answer: (c) Cardiac troponin
Explanation: Cardiac troponin rises in blood when heart muscle cells are injured. Clinicians interpret it together with symptoms, electrocardiograms and changes over time; not every elevated troponin level means a classic heart attack. Timely recognition matters because reduced organ blood supply can become an emergency.
Q72.What is the key difference between stable angina and myocardial infarction?
(a) Infarction never involves arteries
(b) Infarction involves heart-muscle injury or death
(c) Stable angina is always fatal
(d) Angina occurs only in children
Answer: (b) Infarction involves heart-muscle injury or death
Explanation: Stable angina typically results from temporary inadequate oxygen supply during exertion without myocardial cell death. Myocardial infarction involves acute injury or necrosis and often requires urgent reperfusion treatment. Risk assessment also considers age, family history and associated metabolic conditions.
Q71.Why is physical inactivity associated with cardiovascular risk?
(a) It can worsen metabolic and vascular risk factors
(b) It permanently stops blood production
(c) It creates cancer genes directly
(d) It destroys insulin in food
Answer: (a) It can worsen metabolic and vascular risk factors
Explanation: Regular exercise helps improve blood pressure, blood lipid profile, insulin sensitivity and cardiorespiratory fitness. Long-term inactivity may worsen several of these risk factors, increasing cardiovascular disease likelihood. Prevention generally combines lifestyle measures with treatment of modifiable risk factors.
Q70.What is the purpose of a coronary stent?
(a) Produce insulin
(b) Filter urine
(c) Store bile
(d) Hold a narrowed coronary artery open
Answer: (d) Hold a narrowed coronary artery open
Explanation: A stent is a small expandable mesh tube placed in an artery during angioplasty to maintain blood flow. Some stents release medication to reduce tissue growth that can re-narrow the vessel. Timely recognition matters because reduced organ blood supply can become an emergency.
Q69.Which chamber of the heart pumps oxygenated blood into the aorta?
(a) Right ventricle
(b) Left atrium
(c) Left ventricle
(d) Right atrium
Answer: (c) Left ventricle
Explanation: The left ventricle contracts to propel oxygenated blood through the aortic valve into the systemic circulation. Coronary arteries arise near the aortic root and supply blood to the heart muscle itself. Risk assessment also considers age, family history and associated metabolic conditions.
Q68.What is a thrombus?
(a) A type of vitamin
(b) A blood clot forming inside a vessel or heart
(c) A bile pigment
(d) An air sac in the lung
Answer: (b) A blood clot forming inside a vessel or heart
Explanation: A thrombus is a clot that forms within the circulation and can obstruct blood flow. A detached clot or fragment may become an embolus and lodge in a distant vessel. Prevention generally combines lifestyle measures with treatment of modifiable risk factors.
Q67.Emphysema is characterised by permanent enlargement of air spaces with destruction of what?
(a) Alveolar walls
(b) Nasal cartilage
(c) Vocal cords only
(d) Pleural fluid
Answer: (a) Alveolar walls
Explanation: Emphysema involves destruction of walls between alveoli and loss of elastic recoil. This traps air, impairs gas exchange and contributes to breathlessness. Cigarette smoking is a major cause. Pulmonary symptoms and lung-function tests are interpreted together during evaluation.
Q66.COPD is an abbreviation for what?
(a) Central oxygen pressure disorder
(b) Coronary obstruction pressure disease
(c) Chronic optic pigment disorder
(d) Chronic obstructive pulmonary disease
Answer: (d) Chronic obstructive pulmonary disease
Explanation: Chronic obstructive pulmonary disease causes persistent airflow limitation. It includes airway inflammation and emphysematous changes, often linked to tobacco smoke, biomass fuel exposure and occupational pollutants. Damage to the small airways or alveoli may progressively impair breathing.
Q65.Silicosis develops after prolonged inhalation of which dust?
(a) Pollen grains alone
(b) Sugar crystals
(c) Crystalline silica
(d) Table salt
Answer: (c) Crystalline silica
Explanation: Respirable crystalline silica dust can reach deep into the lungs and trigger progressive fibrotic scarring. Stone cutting, mining and sandblasting are common exposure settings. Protective controls reduce occupational risk. Reducing prolonged exposure is a major part of respiratory disease prevention.
Q64.What is the general term for lung disease caused by inhalation of certain occupational dusts?
(a) Osteomalacia
(b) Pneumoconiosis
(c) Haemophilia
(d) Polyuria
Answer: (b) Pneumoconiosis
Explanation: Pneumoconiosis refers to lung disorders associated with inhaled mineral or other occupational dusts, including silicosis and coal workers’ pneumoconiosis. Prolonged exposure may cause chronic inflammation and fibrosis. Pulmonary symptoms and lung-function tests are interpreted together during evaluation.
Q63.Coal workers are particularly at risk for which dust-related lung disorder?
(a) Coal workers’ pneumoconiosis
(b) Scurvy
(c) Goitre
(d) Gout
Answer: (a) Coal workers’ pneumoconiosis
Explanation: Inhaling coal-mine dust over many years can cause coal workers’ pneumoconiosis, sometimes called black lung. Exposure reduction, ventilation and respiratory protection are important occupational-health measures. Damage to the small airways or alveoli may progressively impair breathing.
Q62.Which structure is the principal site of oxygen–carbon dioxide exchange in lungs?
(a) Epiglottis
(b) Tracheal cartilage
(c) Vocal cords
(d) Alveoli
Answer: (d) Alveoli
Explanation: Alveoli are tiny air sacs surrounded by capillaries where oxygen diffuses into blood and carbon dioxide diffuses out. Emphysema destroys alveolar walls, decreasing effective gas-exchange surface. Reducing prolonged exposure is a major part of respiratory disease prevention.
Q61.What effect does loss of lung elastic recoil have in emphysema?
(a) Complete elimination of dyspnoea
(b) Increased number of alveolar walls
(c) Air trapping during exhalation
(d) Faster clearance of all airway secretions
Answer: (c) Air trapping during exhalation
Explanation: Loss of elastic tissue reduces the driving force for exhalation and makes small airways more likely to collapse. Air trapping and overinflation raise the work of breathing. Pulmonary symptoms and lung-function tests are interpreted together during evaluation.
Q60.Which habit is a major preventable cause of emphysema?
(a) Drinking clean water
(b) Cigarette smoking
(c) Reading
(d) Bathing
Answer: (b) Cigarette smoking
Explanation: Smoking causes chronic airway inflammation and injury to lung tissue, making it the leading preventable cause of emphysema in many populations. Other exposures and inherited alpha-1 antitrypsin deficiency can also contribute. Damage to the small airways or alveoli may progressively impair breathing.
Q59.An occupational disease caused by inhalation of asbestos fibres is called what?
(a) Asbestosis
(b) Itai-itai disease
(c) Beriberi
(d) Pellagra
Answer: (a) Asbestosis
Explanation: Asbestosis is a chronic fibrotic lung disease associated with inhaled asbestos. Asbestos exposure also increases the risk of lung cancer and mesothelioma, making control of occupational exposure essential. Reducing prolonged exposure is a major part of respiratory disease prevention.
Q58.Exposure to cotton dust in textile mills can cause which occupational airway disease?
(a) Cretinism
(b) Osteoporosis
(c) Goitre
(d) Byssinosis
Answer: (d) Byssinosis
Explanation: Byssinosis is associated with inhaling cotton and certain other organic textile dusts. It can cause chest tightness and airflow limitation, often noticed at the start of the working week. Pulmonary symptoms and lung-function tests are interpreted together during evaluation.
Q57.A person with COPD commonly experiences which symptom?
(a) Night blindness only
(b) Bleeding gums only
(c) Chronic breathlessness
(d) Painless swelling of thyroid only
Answer: (c) Chronic breathlessness
Explanation: COPD often produces progressive shortness of breath, cough and sputum production. Symptoms result from airflow obstruction and abnormal lung mechanics, and exacerbations may require urgent assessment. Damage to the small airways or alveoli may progressively impair breathing.
Q56.Which inherited protein deficiency can predispose to early-onset emphysema?
(a) Vitamin K excess
(b) Alpha-1 antitrypsin deficiency
(c) Insulin excess
(d) Iodine excess
Answer: (b) Alpha-1 antitrypsin deficiency
Explanation: Alpha-1 antitrypsin helps protect lung tissue from proteolytic injury. Severe inherited deficiency can lead to emphysema, especially when combined with smoking, and may also cause liver disease. Reducing prolonged exposure is a major part of respiratory disease prevention.
Q55.Which test measures airflow and helps diagnose chronic obstructive pulmonary disease?
(a) Spirometry
(b) Electroencephalography
(c) Audiometry
(d) Bone densitometry
Answer: (a) Spirometry
Explanation: Spirometry measures the volume and speed of air exhaled. Persistent airflow obstruction after bronchodilator testing supports COPD diagnosis when paired with symptoms and relevant exposure history. Pulmonary symptoms and lung-function tests are interpreted together during evaluation.
Q54.Cirrhosis of the liver is characterised by what?
(a) Uric acid crystals in joints
(b) Lack of thyroid iodine only
(c) Enlargement of alveoli
(d) Extensive fibrosis and regenerative nodules
Answer: (d) Extensive fibrosis and regenerative nodules
Explanation: Cirrhosis is advanced chronic liver injury with scarring and distorted architecture. It can impair liver function and cause portal hypertension, ascites and bleeding. Common causes include chronic viral hepatitis and alcohol-related liver disease. Clinical assessment distinguishes problems of bilirubin production, processing and bile drainage.
Q53.Which pigment causes yellow colour in jaundice?
(a) Insulin
(b) Haemoglobin itself
(c) Bilirubin
(d) Melanin
Answer: (c) Bilirubin
Explanation: Bilirubin is a yellow pigment produced mainly when haemoglobin from old red blood cells is broken down. Raised blood bilirubin causes yellowing of skin and sclera, termed jaundice. Associated symptoms and blood tests help clinicians determine the underlying cause.
Q52.Bilirubin is largely formed from the breakdown of which blood component?
(a) Thyroid colloid
(b) Haemoglobin in red blood cells
(c) Platelet membrane cholesterol
(d) Insulin in plasma
Answer: (b) Haemoglobin in red blood cells
Explanation: Macrophages recycle aged red blood cells, breaking down haemoglobin and its haem component. The resulting bilirubin travels to the liver for processing and excretion through bile. Advanced liver impairment can affect fluid balance and other body systems.
Q51.In healthy adults, processed bilirubin usually leaves the liver through what?
(a) Bile
(b) Saliva only
(c) Sweat glands only
(d) Tear glands
Answer: (a) Bile
Explanation: The liver conjugates bilirubin and secretes it into bile, which enters the intestine. Intestinal metabolism contributes to the brown colour of stool. Obstruction can produce pale stools and dark urine. Clinical assessment distinguishes problems of bilirubin production, processing and bile drainage.
Q50.Which symptom is commonly associated with liver cirrhosis and portal hypertension?
(a) Night blindness alone
(b) Bow legs
(c) Tooth decay only
(d) Ascites
Answer: (d) Ascites
Explanation: Ascites is accumulation of fluid in the abdominal cavity. In cirrhosis it often results from portal hypertension, altered kidney sodium handling and reduced plasma oncotic pressure. It needs medical evaluation. Associated symptoms and blood tests help clinicians determine the underlying cause.
Q49.What is the medical term for abnormally increased fluid in the abdomen?
(a) Anaemia
(b) Arrhythmia
(c) Ascites
(d) Arthritis
Answer: (c) Ascites
Explanation: Ascites is the accumulation of free fluid in the peritoneal cavity. Cirrhosis is a common cause, but cancers, heart failure and some infections can also produce ascites. Advanced liver impairment can affect fluid balance and other body systems.
Q48.Which laboratory measure reflects an important synthetic function of the liver?
(a) Pulse volume
(b) Serum albumin
(c) Visual acuity
(d) Hair colour
Answer: (b) Serum albumin
Explanation: Albumin is produced by the liver and contributes to plasma oncotic pressure. Low albumin can occur in severe liver disease, but it is not specific and also occurs with kidney loss, inflammation or malnutrition. Clinical assessment distinguishes problems of bilirubin production, processing and bile drainage.
Q47.Which condition is a common cause of obstructive jaundice?
(a) Gallstone blocking the common bile duct
(b) Vitamin A intake
(c) Tendon tear
(d) Mild short-sightedness
Answer: (a) Gallstone blocking the common bile duct
Explanation: A gallstone lodged in the bile duct can prevent bile drainage, causing bilirubin to accumulate in blood. Patients may develop jaundice, pale stools, dark urine and sometimes abdominal pain or fever. Associated symptoms and blood tests help clinicians determine the underlying cause.
Q46.Which organ stores and concentrates bile but does not produce it?
(a) Liver
(b) Pancreatic islet
(c) Spleen
(d) Gallbladder
Answer: (d) Gallbladder
Explanation: Hepatocytes in the liver produce bile; the gallbladder stores and concentrates it between meals. Bile salts help emulsify dietary fats and aid absorption of fat-soluble vitamins. Advanced liver impairment can affect fluid balance and other body systems.
Q45.Neonatal jaundice may occur partly because a newborn’s liver has what characteristic?
(a) Too many mature pancreatic beta cells
(b) Excess lung alveoli
(c) Immature bilirubin-conjugating capacity
(d) Excess bile ducts
Answer: (c) Immature bilirubin-conjugating capacity
Explanation: Newborns have high red-cell turnover and temporarily limited capacity to conjugate bilirubin. Most physiological jaundice is mild, but severe unconjugated hyperbilirubinaemia can injure the brain and needs prompt management. Clinical assessment distinguishes problems of bilirubin production, processing and bile drainage.
Q44.Oral submucous fibrosis is strongly linked with repeated use of which substance?
(a) Table salt
(b) Areca nut
(c) Plain water
(d) Rice starch
Answer: (b) Areca nut
Explanation: Oral submucous fibrosis is a potentially malignant fibrotic disorder strongly associated with areca-nut chewing, including betel-quid and gutkha products. Progressive tissue rigidity can restrict mouth opening. Persistent changes in the mouth should be assessed by a qualified professional.
Q43.A characteristic clinical feature of oral submucous fibrosis is what?
(a) Restricted mouth opening
(b) Enlarged thyroid
(c) Bow legs
(d) Loss of alveoli
Answer: (a) Restricted mouth opening
Explanation: Fibrosis in oral submucous tissues creates stiff mucosal bands and reduces mouth opening. The disorder is associated with areca nut exposure and requires evaluation because it carries an increased oral-cancer risk. Persistent changes in the mouth should be assessed by a qualified professional.
Q42.Which statement about jaundice is correct?
(a) It always means viral hepatitis
(b) It is caused only by vitamin C deficiency
(c) It is always harmless
(d) It is a clinical sign with multiple possible causes
Answer: (d) It is a clinical sign with multiple possible causes
Explanation: Jaundice is a visible sign of elevated bilirubin, not a single diagnosis. It may arise before the liver, within the liver, or because of bile-flow obstruction. Determining its cause guides treatment. Associated symptoms and blood tests help clinicians determine the underlying cause.
Q41.Which nutrient deficiency is the most common cause of nutritional anaemia worldwide?
(a) Vitamin K
(b) Fluoride
(c) Iron
(d) Iodine
Answer: (c) Iron
Explanation: Iron is essential for haemoglobin synthesis and oxygen transport. Inadequate iron intake, blood loss or poor absorption can produce microcytic anaemia with fatigue, pallor and reduced exercise tolerance. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q40.Which vitamin deficiency commonly causes megaloblastic anaemia and may produce nerve damage?
(a) Vitamin D
(b) Vitamin B12
(c) Vitamin C
(d) Vitamin K
Answer: (b) Vitamin B12
Explanation: Vitamin B12 is necessary for DNA synthesis and normal nervous-system function. Deficiency produces large abnormal red-cell precursors and can cause numbness or difficulty walking, even in some patients without severe anaemia. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q39.Deficiency of which vitamin can cause megaloblastic anaemia without the typical B12-related neuropathy?
(a) Folate
(b) Vitamin K
(c) Vitamin E
(d) Vitamin A
Answer: (a) Folate
Explanation: Folate, or vitamin B9, supports DNA synthesis and red-blood-cell production. Deficiency commonly causes megaloblastic anaemia. Adequate folate before and during early pregnancy also helps prevent neural tube defects. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q38.Which vitamin is essential for synthesis of several blood-clotting factors?
(a) Vitamin C
(b) Vitamin B1
(c) Vitamin A
(d) Vitamin K
Answer: (d) Vitamin K
Explanation: Vitamin K is required for activation of clotting factors II, VII, IX and X, among others. Deficiency may increase bleeding risk. Newborns routinely receive vitamin K prophylaxis in many health systems. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q37.Xerophthalmia is classically caused by deficiency of what?
(a) Vitamin B1
(b) Calcium
(c) Vitamin A
(d) Iron
Answer: (c) Vitamin A
Explanation: Vitamin A deficiency can dry the conjunctiva and cornea and impair night vision. Severe xerophthalmia may cause corneal injury and preventable blindness, especially among nutritionally vulnerable children. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q36.Which childhood bone disorder is classically related to lack of vitamin D?
(a) Pellagra
(b) Rickets
(c) Scurvy
(d) Beriberi
Answer: (b) Rickets
Explanation: Vitamin D deficiency impairs calcium and phosphate absorption, leading to poor mineralisation of growing bones. Rickets may produce bowed legs, widened wrists and delayed growth in children. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q35.Softening of bones due to defective mineralisation in adults is called what?
(a) Osteomalacia
(b) Leukaemia
(c) Silicosis
(d) Gout
Answer: (a) Osteomalacia
Explanation: Osteomalacia involves inadequate mineralisation of adult bone, often associated with vitamin D deficiency. It can cause bone pain, muscle weakness and fractures. Rickets refers to defective mineralisation in growing children. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q34.Which mineral is directly essential for normal bone mineralisation and muscle contraction?
(a) Chromium only
(b) Fluoride only
(c) Iodine
(d) Calcium
Answer: (d) Calcium
Explanation: Calcium contributes to bone and tooth structure, muscle contraction, nerve signalling and blood clotting. Vitamin D supports its absorption; disturbances in calcium balance can produce neuromuscular symptoms. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q33.Which common household measure helps prevent iodine-deficiency disorders?
(a) Drink excess sweetened beverages
(b) Avoid all vegetables
(c) Use adequately iodised salt
(d) Eat only polished rice
Answer: (c) Use adequately iodised salt
Explanation: Iodised salt is a population-level strategy to supply iodine needed for thyroid-hormone synthesis. Adequate iodine is especially important during pregnancy and childhood for normal growth and brain development. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q32.Keshan disease is historically associated with low intake of which trace element?
(a) Sodium
(b) Selenium
(c) Chloride
(d) Fluorine
Answer: (b) Selenium
Explanation: Keshan disease is an endemic cardiomyopathy historically associated with selenium deficiency in certain regions. Other environmental and infectious factors may contribute; it is not simply caused by low selenium in every case. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q31.Excess fluoride exposure over time may lead to which disorder?
(a) Skeletal fluorosis
(b) Beriberi
(c) Night blindness
(d) Scurvy
Answer: (a) Skeletal fluorosis
Explanation: Long-term excessive fluoride intake can cause dental fluorosis and, at higher cumulative exposure, skeletal fluorosis with bone and joint abnormalities. Fluoride also has protective effects against dental caries at appropriate levels. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q30.Which form of severe acute malnutrition commonly features bilateral pitting oedema?
(a) Rickets
(b) Pellagra
(c) Marasmus alone
(d) Kwashiorkor
Answer: (d) Kwashiorkor
Explanation: Kwashiorkor is classically an oedematous form of severe malnutrition. Affected children may develop swollen feet, skin changes and fatty liver. It arises from complex nutritional deficits and metabolic disturbances. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q29.Severe wasting with marked loss of body fat and muscle is characteristic of what?
(a) Hyperthyroidism
(b) Gout
(c) Marasmus
(d) Goitre
Answer: (c) Marasmus
Explanation: Marasmus is severe energy deficiency characterised by profound wasting and loss of subcutaneous fat. Unlike classic kwashiorkor, oedema is typically absent. Both conditions require carefully supervised nutritional rehabilitation. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q28.Pellagra is often remembered by which three symptoms?
(a) Dizziness, diplopia and dehydration only
(b) Dermatitis, diarrhoea and dementia
(c) Diabetes, dysphagia and depression only
(d) Dyspnoea, deafness and diplopia
Answer: (b) Dermatitis, diarrhoea and dementia
Explanation: The traditional three Ds of pellagra are dermatitis, diarrhoea and dementia. Pellagra results from inadequate niacin or its precursor tryptophan, and severe untreated cases may be fatal. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q27.Cracks at mouth corners and a swollen tongue may indicate deficiency of which vitamin?
(a) Riboflavin (B2)
(b) Vitamin K
(c) Vitamin D
(d) Vitamin A
Answer: (a) Riboflavin (B2)
Explanation: Riboflavin deficiency can cause angular cheilitis, glossitis and inflamed oral mucosa. Riboflavin is part of coenzymes involved in energy metabolism and is found in dairy products, eggs and leafy vegetables. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q26.Deficiency of pyridoxine may affect which biological process?
(a) Iodine production in thyroid
(b) Formation of bile ducts
(c) Synthesis of vitamin D from sunlight
(d) Amino-acid metabolism and neurotransmitter synthesis
Answer: (d) Amino-acid metabolism and neurotransmitter synthesis
Explanation: Vitamin B6, or pyridoxine, participates in amino-acid and neurotransmitter metabolism. Severe deficiency may cause neuropathy, dermatitis, anaemia or seizures, although these findings are not specific to B6 alone. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q25.Which deficiency is associated with dry beriberi and peripheral neuropathy?
(a) Zinc excess
(b) Iodine excess
(c) Thiamine deficiency
(d) Vitamin K excess
Answer: (c) Thiamine deficiency
Explanation: Thiamine (B1) is needed for carbohydrate energy metabolism. Dry beriberi primarily affects peripheral nerves and muscles, causing weakness, numbness and difficulty walking. Severe deficiency can also cause Wernicke encephalopathy. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q24.Wet beriberi mainly affects which system?
(a) Teeth enamel only
(b) Cardiovascular system
(c) Liver bile ducts only
(d) Visual pigments only
Answer: (b) Cardiovascular system
Explanation: Wet beriberi is thiamine deficiency with prominent cardiovascular effects, including oedema, rapid pulse and sometimes high-output heart failure. Prompt thiamine treatment is important when deficiency is suspected. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q23.Severe deficiency of vitamin E can sometimes cause which problem?
(a) Neuromuscular dysfunction
(b) Simple goitre due to iodine deficiency
(c) Scurvy
(d) Gout
Answer: (a) Neuromuscular dysfunction
Explanation: Vitamin E protects cellular membranes from oxidative damage. Severe deficiency, particularly in certain malabsorption disorders, may produce neuropathy, coordination problems and muscle weakness. It is uncommon with a balanced diet. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q22.Poor wound healing, growth impairment and impaired taste may be linked with inadequate what?
(a) Iodine alone
(b) Sodium chloride only
(c) Vitamin D alone
(d) Zinc
Answer: (d) Zinc
Explanation: Zinc is needed for many enzymes, immune functions, growth and tissue repair. Deficiency may impair wound healing and taste, delay growth, and increase infection susceptibility, especially in vulnerable populations. Characteristic clinical signs help distinguish overlapping deficiencies and guide further evaluation.
Q21.Which trace element helps enzymes involved in iron metabolism and connective-tissue formation?
(a) Argon
(b) Helium
(c) Copper
(d) Neon
Answer: (c) Copper
Explanation: Copper is a cofactor for enzymes involved in iron handling, energy production and connective-tissue cross-linking. Copper deficiency can contribute to anaemia and neurological abnormalities, although these findings have other causes too. Prevention often combines dietary diversity with targeted public-health nutrition measures.
Q20.Which process enables skin to synthesise vitamin D naturally?
(a) Drinking chlorinated water
(b) Exposure to ultraviolet-B radiation
(c) Absorbing infrared heat alone
(d) Exposure to loud sound
Answer: (b) Exposure to ultraviolet-B radiation
Explanation: UV-B radiation converts a cholesterol-derived precursor in the skin into vitamin D3. Diet and supplements are alternative sources. Appropriate sunlight advice depends on skin type, location and skin-cancer risk. The surrounding dietary pattern and nutrient absorption can also influence deficiency risk.
Q19.Itai-itai disease in Japan is historically linked with contamination by which heavy metal?
(a) Cadmium
(b) Mercury
(c) Zinc
(d) Magnesium
Answer: (a) Cadmium
Explanation: Itai-itai disease was associated with chronic cadmium pollution in Japan. Cadmium can damage kidneys and disrupt bone mineral metabolism, leading to severe bone pain, fragility and fractures. Exposure history and examination are important for distinguishing related conditions.
Q18.Epidemic dropsy has been associated with adulteration of edible oils by what?
(a) Vitamin D
(b) Coconut water
(c) Pure mustard seed
(d) Argemone oil
Answer: (d) Argemone oil
Explanation: Epidemic dropsy results from toxic alkaloids, including sanguinarine, found in Argemone mexicana oil used to adulterate edible oil. It may cause oedema and systemic toxicity; food quality control is essential. Prevention depends on identifying the underlying behavioural or environmental risk.
Q17.Which plant is a recognised source of toxic oil involved in epidemic dropsy?
(a) Pisum sativum
(b) Ocimum tenuiflorum
(c) Argemone mexicana
(d) Triticum aestivum
Answer: (c) Argemone mexicana
Explanation: Argemone mexicana, also called Mexican prickly poppy, contains toxic alkaloids in its seeds. Adulteration of edible oil with argemone seed oil has caused outbreaks of epidemic dropsy. Clinical context helps separate similar symptoms produced by very different causes.
Q16.Gout is caused by deposition of crystals of which compound in joints?
(a) Calcium chloride
(b) Monosodium urate
(c) Glucose
(d) Sodium bicarbonate
Answer: (b) Monosodium urate
Explanation: Gout involves inflammatory reactions to monosodium urate crystals within joints and tissues. Attacks typically produce sudden severe pain, redness and swelling; long-term urate-lowering therapy may be indicated. Some inflammatory conditions can cause long-term damage if treatment is delayed.
Q15.Which joint is classically affected in a first episode of gout?
(a) First metatarsophalangeal joint of big toe
(b) Shoulder only
(c) Elbow only
(d) Jaw joint only
Answer: (a) First metatarsophalangeal joint of big toe
Explanation: An acute attack of gout often affects the base of the big toe, a presentation known as podagra. However, ankles, knees and other joints can also be involved. A precise diagnosis matters because different forms of arthritis need different treatments.
Q14.Tophi are associated with which chronic joint disease?
(a) Emphysema
(b) Rickets
(c) Scurvy
(d) Gout
Answer: (d) Gout
Explanation: Tophi are deposits of monosodium urate crystals found in some people with longstanding gout. They may appear around joints, ear cartilage and other tissues and indicate substantial urate burden. Joint swelling alone does not reveal the cause without appropriate clinical assessment.
Q13.Which diet-related factor can increase gout risk in susceptible individuals?
(a) Balanced vegetable intake
(b) Normal physical activity
(c) Heavy alcohol intake
(d) Adequate hydration
Answer: (c) Heavy alcohol intake
Explanation: Alcohol, especially heavy consumption, can increase serum urate and trigger gout attacks in susceptible people. Genetic factors, kidney function, certain medications and some dietary patterns also influence risk. Some inflammatory conditions can cause long-term damage if treatment is delayed.
Q12.Rheumatoid arthritis is most accurately described as which condition?
(a) Vitamin C deficiency
(b) Autoimmune inflammatory joint disease
(c) Disease caused only by excess uric acid
(d) Lung disease from silica
Answer: (b) Autoimmune inflammatory joint disease
Explanation: Rheumatoid arthritis is an autoimmune disorder causing persistent inflammation of joints, often symmetrically in hands and wrists. Untreated disease can lead to damage and disability; it differs from gout. A precise diagnosis matters because different forms of arthritis need different treatments.
Q11.Which statement about arthritis is correct?
(a) It refers broadly to disorders involving joint inflammation or disease
(b) It only affects children
(c) It always has an infectious cause
(d) It is always caused by uric acid
Answer: (a) It refers broadly to disorders involving joint inflammation or disease
Explanation: Arthritis is an umbrella term for many joint disorders. Gout, rheumatoid arthritis, osteoarthritis and infections have different mechanisms. Uric-acid crystal deposition specifically characterises gout, not every type of arthritis. Joint swelling alone does not reveal the cause without appropriate clinical assessment.
Q10.Which bone condition is characterised by reduced bone strength and increased fracture risk?
(a) Leukaemia
(b) Angina
(c) Jaundice
(d) Osteoporosis
Answer: (d) Osteoporosis
Explanation: Osteoporosis involves low bone mass and deterioration of bone microarchitecture, increasing fragility fractures. Age, hormonal changes, inactivity and certain medicines may affect risk. It is distinct from osteomalacia. Exposure history and examination are important for distinguishing related conditions.
Q9.Bulimia nervosa is commonly characterised by what?
(a) Uric acid deposits in joints
(b) Vitamin A deficiency
(c) Episodes of binge eating followed by compensatory behaviours
(d) Lack of pancreatic beta cells from birth
Answer: (c) Episodes of binge eating followed by compensatory behaviours
Explanation: Bulimia nervosa involves recurrent binge-eating episodes, feelings of lost control and behaviours such as self-induced vomiting or misuse of laxatives to compensate. It is a serious eating disorder requiring professional care. Prevention depends on identifying the underlying behavioural or environmental risk.
Q8.Which feature is more characteristic of anorexia nervosa than bulimia nervosa?
(a) High bilirubin due to bile obstruction
(b) Persistent energy restriction leading to significantly low body weight
(c) Iodine-deficiency goitre
(d) Alveolar destruction
Answer: (b) Persistent energy restriction leading to significantly low body weight
Explanation: Anorexia nervosa involves restrictive intake, significantly low weight and intense fear of weight gain or disturbance in body-image experience. Bulimia nervosa involves recurrent binge eating and compensatory behaviours, often without marked underweight. Clinical context helps separate similar symptoms produced by very different causes.
Q7.An irrational or excessive fear of flowers is called what?
(a) Anthophobia
(b) Hydrophobia
(c) Claustrophobia
(d) Acrophobia
Answer: (a) Anthophobia
Explanation: Anthophobia means fear of flowers, a specific phobia that can provoke anxiety or avoidance. Specific phobias are anxiety disorders; treatment may include structured psychological approaches such as exposure-based therapy. Exposure history and examination are important for distinguishing related conditions.
Q6.Which current clinical term is often used for some conditions historically called hysteria?
(a) Haemophilia
(b) Coronary thrombosis
(c) Hepatic cirrhosis
(d) Functional neurological symptom disorder
Answer: (d) Functional neurological symptom disorder
Explanation: The older label hysteria is imprecise and largely abandoned in clinical practice. Some conditions historically placed under that label are now described as functional neurological symptom disorder, with genuine symptoms not explained by structural neurological damage.
Q5.Cadmium poisoning in Itai-itai disease is particularly associated with damage to which two systems?
(a) Heart valves and teeth
(b) Skin pigment and hair only
(c) Kidneys and bones
(d) Thyroid and eyes only
Answer: (c) Kidneys and bones
Explanation: Chronic cadmium exposure can injure renal tubules, disturbing calcium and phosphate balance and contributing to skeletal damage. The historically documented Itai-itai cases included severe bone pain and fractures. Clinical context helps separate similar symptoms produced by very different causes.
Q4.What does oedema mean in a medical context?
(a) Reduced blood glucose
(b) Excess fluid in tissues
(c) Yellow pigment in blood
(d) Enlarged alveoli
Answer: (b) Excess fluid in tissues
Explanation: Oedema is abnormal accumulation of fluid in interstitial spaces. Causes include heart, kidney and liver disease, venous problems, malnutrition and inflammatory conditions. Its distribution and associated findings guide investigation. Exposure history and examination are important for distinguishing related conditions.
Q3.Which term means abnormal fear of confined spaces?
(a) Claustrophobia
(b) Haemophobia
(c) Anthophobia
(d) Agoraphobia
Answer: (a) Claustrophobia
Explanation: Claustrophobia is marked fear or anxiety in enclosed spaces such as lifts or narrow rooms. It is a specific phobia and differs from anthophobia, which specifically refers to fear of flowers. Prevention depends on identifying the underlying behavioural or environmental risk.
Q2.Which condition is associated with calcium pyrophosphate crystal deposition rather than monosodium urate?
(a) Silicosis
(b) Beriberi
(c) Classic gout
(d) Pseudogout (CPPD disease)
Answer: (d) Pseudogout (CPPD disease)
Explanation: Calcium pyrophosphate deposition disease can cause acute inflammatory arthritis sometimes called pseudogout. Unlike gout, its crystals contain calcium pyrophosphate rather than monosodium urate and may affect the knee. Some inflammatory conditions can cause long-term damage if treatment is delayed.
Q1.Which statement about exercise-related muscle fatigue is most scientifically accurate?
(a) Lactate is always harmful waste
(b) Only uric acid produces fatigue
(c) Fatigue has multiple mechanisms and cannot be explained solely by lactate
(d) All fatigue is caused only by lactic acid
Answer: (c) Fatigue has multiple mechanisms and cannot be explained solely by lactate
Explanation: Muscle fatigue can involve changes in ion concentrations, excitation–contraction coupling, central nervous-system drive and energy availability. Lactate can serve as an important fuel and is not the sole explanation for fatigue. Clinical context helps separate similar symptoms produced by very different causes.Educational question bank • 150 questions • Q150 to Q1 • Original explanations • No source URLs inside questions