{"id":12860,"date":"2025-09-24T06:52:08","date_gmt":"2025-09-24T05:52:08","guid":{"rendered":"https:\/\/mcqsadda.com\/?p=12860"},"modified":"2026-01-12T10:48:03","modified_gmt":"2026-01-12T10:48:03","slug":"human-heart-top-100-mcqs-with-answer-and-explanation","status":"publish","type":"post","link":"https:\/\/mcqsadda.com\/index.php\/2025\/09\/24\/human-heart-top-100-mcqs-with-answer-and-explanation\/","title":{"rendered":"Human Heart Top 100 MCQs With Answer and Explanation"},"content":{"rendered":"\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">1. The human heart is located in ___________.<br><\/mark><\/strong>A) Abdominal cavity<br>B) Thoracic cavity<br>C) Cranial cavity<br>D) Pelvic cavity<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  The heart lies in the thoracic cavity between the two lungs, in the mediastinum.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">2. Human heart is enclosed by a protective covering called<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Pleura<br>B) Peritoneum<br>C) Pericardium<br>D) Perichondrium<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  The pericardium is a double-layered sac that protects and anchors the heart.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">3. The human heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Two-chambered<br>B) Three-chambered<br>C) Four-chambered<br>D) Five-chambered<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  The human heart has 2 atria and 2 ventricles.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">4. The right atrium receives blood from<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Pulmonary vein<br>B) Superior and inferior vena cava<br>C) Aorta<br>D) Coronary artery<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Deoxygenated blood from the body enters the right atrium via venae cavae.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">5. The left atrium receives blood from<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Pulmonary artery<br>B) Pulmonary veins<br>C) Aorta<br>D) Superior vena cava<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Left atrium receives oxygenated blood from lungs via pulmonary veins.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">6. Which chamber of the heart pumps blood into the lungs?<br><\/mark><\/strong>A) Right atrium<br>B) Left atrium<br>C) Right ventricle<br>D) Left ventricle<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Right ventricle pumps deoxygenated blood into pulmonary artery \u2192 lungs.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">7. The strongest chamber of the heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Right atrium<br>B) Right ventricle<br>C) Left atrium<br>D) Left ventricle<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: D  <\/b><BR>\n<b>Explanation:<\/b>  Left ventricle has thickest walls to pump blood to whole body.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">8. The human heart weight in adults is about<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><\/mark><br><\/strong>A) 150 g<br>B) 250\u2013300 g<br>C) 500 g<br>D) 1000 g<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  The average heart weight is ~280 g (females slightly less).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">9. The number of valves in the human heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 2<br>B) 3<br>C) 4<br>D) 5<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Two atrioventricular valves (tricuspid, bicuspid) and two semilunar valves.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">10. The tricuspid valve lies between<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Left atrium and left ventricle<br>B) Right atrium and right ventricle<br>C) Left ventricle and aorta<br>D) Right ventricle and pulmonary artery<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   Tricuspid valve prevents backflow of blood.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">11. The bicuspid (mitral) valve lies between<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Right atrium and ventricle<br>B) Left atrium and left ventricle<br>C) Right ventricle and pulmonary artery<br>D) Left ventricle and aorta<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Mitral valve allows unidirectional blood flow.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">12. The pulmonary valve guards the opening of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Aorta<br>B) Pulmonary artery<br>C) Vena cava<br>D) Coronary vein<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary semilunar valve prevents backflow into right ventricle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">13. The aortic valve guards the opening of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Pulmonary artery<br>B) Aorta<br>C) Vena cava<br>D) Coronary sinus<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Aortic valve prevents backflow into left ventricle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">14. Which type of blood is found in the right side of the heart?<br><\/mark><\/strong>A) Oxygenated<br>B) Deoxygenated<br>C) Both<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Right atrium &#038; ventricle carry deoxygenated blood to lungs.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">15. Which type of blood is found in the left side of the heart?<br><\/mark><\/strong>A) Oxygenated<br>B) Deoxygenated<br>C) Mixed<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Left atrium &#038; ventricle carry oxygen-rich blood from lungs to body.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">16. The natural pacemaker of the heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) AV node<br>B) SA node<br>C) Purkinje fibers<br>D) Bundle of His<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Sinoatrial (SA) node initiates heartbeat (~70\u201375 beats\/min).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">17. The human heart is made of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Smooth muscle<br>B) Skeletal muscle<br>C) Cardiac muscle<br>D) Voluntary muscle<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>   Involuntary, striated, branched cardiac muscle forms heart wall.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">18. Wall of heart consists of three layers<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Endocardium, myocardium, pericardium<br>B) Epidermis, dermis, hypodermis<br>C) Mucosa, submucosa, serosa<br>D) Pleura, peritoneum, periosteum<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Myocardium is thickest muscular layer.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">19. The coronary arteries supply<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Lungs<br>B) Brain<br>C) Kidneys<br>D) Heart itself<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: D  <\/b><BR>\n<b>Explanation:<\/b>  Coronary arteries provide oxygenated blood to myocardium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">20. Failure of coronary circulation leads to<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Asthma<br>B) Heart attack<br>C) Paralysis<br>D) Stroke<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   Blockage of coronary artery \u2192 myocardial infarction (heart attack).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">21. The average size of human heart is comparable to<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) A fist<br>B) A football<br>C) A tennis ball<br>D) A brain<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer:  A  <\/b><BR>\n<b>Explanation:<\/b>  Human heart is roughly the size of a clenched fist..\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">22. The number of atria in the human heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 1<br>B) 2<br>C) 3<br>D) 4<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Right atrium and left atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">23. The number of ventricles in the human heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 1<br>B) 2<br>C) 3<br>D) 4<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Right ventricle and left ventricle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">24. Which side of the heart has thicker walls?<br><\/mark><\/strong>A) Right side<br>B) Left side<br>C) Both same<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Left ventricle pumps blood to whole body \u2192 thickest wall.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">25. The blood vessel that carries oxygenated blood from lungs to heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Pulmonary vein<br>B) Pulmonary artery<br>C) Aorta<br>D) Vena cava<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary vein carries oxygen-rich blood to left atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">26. Human heart shows<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Single circulation<br>B) Double circulation<br>C) Open circulation<br>D) No circulation<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Blood passes twice through the heart in one complete circuit \u2192 pulmonary and systemic circulation.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">27. Pulmonary circulation carries blood between<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Heart and body tissues<br>B) Heart and lungs<br>C) Lungs and tissues<br>D) Heart and brain<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary circulation = right ventricle \u2192 lungs \u2192 left atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">28. Systemic circulation carries blood between<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><\/mark><\/strong><br>A) Heart and lungs<br>B) Heart and whole body<br>C) Heart and kidneys only<br>D) Heart and brain only<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Systemic circulation = left ventricle \u2192 body \u2192 right atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">29. Which blood vessel carries deoxygenated blood from heart to lungs?<br><\/mark><\/strong>A) Pulmonary vein<br>B) Pulmonary artery<br>C) Aorta<br>D) Vena cava<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary artery carries deoxygenated blood from right ventricle to lungs.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">30. Which blood vessel carries oxygenated blood from lungs to heart?<br><\/mark><\/strong>A) Pulmonary artery<br>B) Pulmonary vein<br>C) Aorta<br>D) Coronary artery<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary vein carries oxygenated blood to left atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">31. Which valve prevents backflow of blood from ventricles to atria?<br><\/mark><\/strong>A) Semilunar valves<br>B) Bicuspid &amp; tricuspid valves<br>C) Coronary valves<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Atrioventricular (AV) valves prevent reverse blood flow.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">32. Tricuspid valve is located<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Between right atrium &amp; ventricle<br>B) Between left atrium &amp; ventricle<br>C) At pulmonary artery opening<br>D) At aorta opening<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>   Tricuspid = 3 cusps, regulates blood from RA \u2192 RV.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">33. Bicuspid (mitral) valve is located<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Between right atrium &amp; ventricle<br>B) Between left atrium &amp; ventricle<br>C) At pulmonary artery<br>D) At aorta<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Mitral valve = 2 cusps, regulates blood from LA \u2192 LV.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">34. Pulmonary semilunar valve is present at<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Right atrium<br>B) Pulmonary artery opening<br>C) Left ventricle<br>D) Left atrium<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Prevents backflow into right ventricle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">35. Aortic semilunar valve is present at<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Aorta opening<br>B) Pulmonary artery<br>C) Left atrium<br>D) Right atrium<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Prevents backflow into left ventricle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">36. Which chamber pumps blood to the whole body?<br><\/mark><\/strong>A) Right atrium<br>B) Right ventricle<br>C) Left atrium<br>D) Left ventricle<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: D  <\/b><BR>\n<b>Explanation:<\/b>  Left ventricle \u2192 thickest wall \u2192 pumps blood to systemic circulation.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">37. Which side of the heart carries oxygenated blood?<br><\/mark><\/strong>A) Right side<br>B) Left side<br>C) Both<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   Left atrium &#038; ventricle \u2192 oxygenated blood.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">38. Which side of the heart carries deoxygenated blood?<br><\/mark><\/strong>A) Right side<br>B) Left side<br>C) Both<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Right atrium &#038; ventricle \u2192 deoxygenated blood.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">39. Which vein brings deoxygenated blood from the lower body to the heart?<br><\/mark><\/strong>A) Superior vena cava<br>B) Inferior vena cava<br>C) Pulmonary vein<br>D) Coronary vein<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Inferior vena cava drains lower body into right atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">40. Which vein brings deoxygenated blood from the upper body to the heart?<br><\/mark><\/strong>A) Inferior vena cava<br>B) Superior vena cava<br>C) Pulmonary vein<br>D) Coronary sinus<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Superior vena cava drains head, neck, arms into right atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">41. Which blood vessel carries oxygenated blood from heart to body?<br><\/mark><\/strong>A) Pulmonary artery<br>B) Aorta<br>C) Pulmonary vein<br>D) Coronary vein<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Aorta carries oxygen-rich blood from LV to all body parts.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\"><strong>42. Coronary arteries supply<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/strong><\/mark>A) Kidneys<br>B) Brain<br>C) Heart muscle<br>D) Lungs<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Coronary arteries nourish myocardium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">43. Double circulation in humans ensures<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Mixing of oxygenated and deoxygenated blood<br>B) Complete separation of blood types<br>C) Less oxygen supply<br>D) Slow circulation<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   Four-chambered heart maintains separate oxygenated and deoxygenated blood flow.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">44. Which vein carries oxygenated blood?<br><\/mark><\/strong>A) Pulmonary vein<br>B) Pulmonary artery<br>C) Vena cava<br>D) Coronary sinus<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary vein is the only vein carrying oxygen-rich blood.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">45. Which artery carries deoxygenated blood?<br><\/mark><\/strong>A) Coronary artery<br>B) Aorta<br>C) Pulmonary artery<br>D) Carotid artery<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary artery is the only artery carrying deoxygenated blood.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">46. Which valves prevent backflow into atria during ventricular contraction?<br><\/mark><\/strong>A) Semilunar valves<br>B) Atrioventricular valves<br>C) Coronary valves<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Tricuspid and mitral valves close during ventricular systole.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">47. Which valves prevent backflow into ventricles during relaxation?<br><\/mark><\/strong>A) AV valves<br>B) Semilunar valves<br>C) Coronary valves<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Pulmonary and aortic valves close during diastole.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">48. Which side of the heart works under higher pressure?<br><\/mark><\/strong>A) Right<br>B) Left<br>C) Both equal<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Left ventricle pumps blood to whole body \u2192 high pressure.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">49. Which circulation brings oxygen and nutrients to heart tissue?<br><\/mark><\/strong>A) Pulmonary circulation<br>B) Systemic circulation<br>C) Coronary circulation<br>D) Lymphatic circulation<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Coronary arteries supply blood to myocardium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">50. Which is the correct sequence of blood flow in pulmonary circulation?<br><\/mark><\/strong>A) RA \u2192 RV \u2192 Pulmonary artery \u2192 Lungs \u2192 Pulmonary vein \u2192 LA<br>B) LA \u2192 LV \u2192 Aorta \u2192 Body \u2192 Vena cava \u2192 RA<br>C) LV \u2192 Aorta \u2192 Body \u2192 Vena cava \u2192 RA<br>D) RA \u2192 Pulmonary vein \u2192 LA<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  This is the correct pathway of pulmonary circulation.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">51. The number of heartbeats per minute in a healthy adult is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 40\u201350<br>B) 60\u201372<br>C) 80\u2013100<br>D) 120\u2013140<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Normal resting heart rate is about 72 beats\/minute.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">52. Each heartbeat lasts about<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 0.2 sec<br>B) 0.4 sec<br>C) 0.8 sec<br>D) 1.2 sec<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  One complete cardiac cycle (heartbeat) takes 0.8 seconds.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">53. Cardiac cycle consists of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Atrial systole, ventricular systole, joint diastole<br>B) Inspiration and expiration<br>C) Depolarization only<br>D) Systole only<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  These three phases complete one heartbeat.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">54. The \u201club\u201d sound of the heart is produced by closure of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Semilunar valves<br>B) AV valves (tricuspid and bicuspid)<br>C) Pulmonary valve only<br>D) Coronary valves<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  \u201cLub\u201d = closure of atrioventricular valves at start of ventricular systole.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">55. The \u201cdub\u201d sound of the heart is produced by closure of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) AV valves<br>B) Semilunar valves<br>C) Mitral valve only<br>D) Tricuspid valve only|<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   \u201cDub\u201d = closure of aortic and pulmonary valves at ventricular diastole.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">56. The cardiac pacemaker in the heart is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) AV node<br>B) SA node<br>C) Purkinje fibers<br>D) Bundle of His<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  SA node (sinoatrial node) initiates impulse \u2192 natural pacemaker.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">57. Artificial pacemaker is implanted when<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Valves are defective<br>B) SA node fails<br>C) Blood clotting decreases<br>D) Heart is enlarged<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Artificial pacemaker generates impulses when SA node fails.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">58. Which node delays the impulse to allow atrial contraction?<br><\/mark><\/strong>A) SA node<br>B) AV node<br>C) Purkinje fibers<br>D) Bundle of His<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  AV node introduces a delay before ventricles contract.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">59. Which fibers conduct impulses to ventricular walls?<br><\/mark><\/strong>A) Purkinje fibers<br>B) AV node<br>C) SA node<br>D) Coronary fibers<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>   Purkinje fibers spread impulse to ventricles \u2192 contraction.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><br><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\"><strong>60. ECG stands for<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/strong><\/mark>A) Electrocardiogram<br>B) Electrocardiograph<br>C) Both a and b<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  ECG = record (gram) and instrument (graph).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">61. The \u201cP wave\u201d in ECG represents<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Ventricular depolarization<br>B) Atrial depolarization<br>C) Ventricular repolarization<br>D) Heart relaxation<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  P wave = contraction (depolarization) of atria.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">62. The \u201cQRS complex\u201d in ECG represents<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Ventricular depolarization<br>B) Atrial repolarization<br>C) Ventricular repolarization<br>D) Atrial systole<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>   QRS complex = contraction of ventricles.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\"><strong>63. The \u201cT wave\u201d in ECG represents<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/strong><\/mark>A) Atrial systole<br>B) Ventricular repolarization<br>C) Ventricular depolarization<br>D) Atrial depolarization<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  T wave = relaxation of ventricles.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\"><strong>64. The duration of atrial systole is about<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/strong><\/mark>A) 0.1 sec<br>B) 0.3 sec<br>C) 0.5 sec<br>D) 0.7 sec<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Atria contract for ~0.1 sec during cardiac cycle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">65. The duration of ventricular systole is about<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 0.1 sec<br>B) 0.3 sec<br>C) 0.5 sec<br>D) 0.7 sec<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Ventricles contract for ~0.3 sec.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><br><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">66. The duration of joint diastole is about<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 0.1 sec<br>B) 0.3 sec<br>C) 0.4 sec<br>D) 0.7 sec<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Atria and ventricles relax together for ~0.4 sec.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">67. Average cardiac output of an adult human is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 1 L\/min<br>B) 2 L\/min<br>C) 5 L\/min<br>D) 10 L\/min<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Cardiac output = ~70 ml \u00d7 72 beats\/min \u2248 5 L\/min.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">68. Stroke volume is about<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 20 ml<br>B) 40 ml<br>C) 70 ml<br>D) 200 ml<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Each beat pumps ~70 ml of blood.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">69. Which factor does NOT increase heart rate?<br><\/mark><\/strong>A) Exercise<br>B) Adrenaline<br>C) Vagus nerve stimulation<br>D) Excitement<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Vagus nerve slows heart rate (parasympathetic).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">70. Normal blood pressure in humans is<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) 80\/60 mmHg<br>B) 100\/70 mmHg<br>C) 120\/80 mmHg<br>D) 140\/90 mmHg<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Normal systolic = 120 mmHg, diastolic = 80 mmHg.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">71. High blood pressure is called<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Hypotension<br>B) Hypertension<br>C) Atherosclerosis<br>D) Arrhythmia<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Hypertension = persistent BP above 140\/90 mmHg.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><br><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">72. Low blood pressure is called<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Hypotension<br>B) Hypertension<br>C) Bradycardia<br>D) Tachycardia<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Hypotension = BP below normal (e.g., 90\/60 mmHg).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">73. Bradycardia means<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Abnormally slow heartbeat<br>B) Abnormally fast heartbeat<br>C) Irregular rhythm<br>D) No heartbeat<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Bradycardia = <60 beats\/min.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">74. Tachycardia means<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Slow heartbeat<br>B) Fast heartbeat<br>C) Heart enlargement<br>D) Heart block<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Tachycardia = >100 beats\/min.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">75. Pulse rate is equal to<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Respiratory rate<br>B) Heartbeat rate<br>C) Blood pressure<br>D) Stroke volume<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Pulse rate (felt at wrist) = heart rate.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><br><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">76. Heart attack is medically known as<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Cardiac arrest<br>B) Myocardial infarction<br>C) Angina pectoris<br>D) Arrhythmia<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Heart attack occurs due to blockage of coronary arteries \u2192 death of cardiac muscle.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">77. Sudden stoppage of heartbeat is called<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Angina<br>B) Cardiac arrest<br>C) Stroke<br>D) Hypertension<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Cardiac arrest = sudden loss of heart function.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">78. Chest pain due to inadequate blood supply to heart is called<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Angina pectoris<br>B) Stroke<br>C) Asthma<br>D) Epilepsy<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Angina = pain during exertion due to poor oxygen supply.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">79. Which disease is caused by narrowing of coronary arteries?<br><\/mark><\/strong>A) Coronary artery disease (CAD)<br>B) Hypertension<br>C) Asthma<br>D) Stroke<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  CAD reduces blood flow to heart \u2192 angina\/heart attack.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">80. Which of the following is called \u201csilent killer\u201d?<br><\/mark><\/strong>A) Heart attack<br>B) Stroke<br>C) Hypertension<br>D) Atherosclerosis<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Hypertension shows no symptoms but damages heart, brain, kidneys.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">81. Atherosclerosis is caused by<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Accumulation of fat in arteries<br>B) Valve defects<br>C) High blood sugar<br>D) Infection<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>   Cholesterol deposition in arteries \u2192 narrowing &#038; hardening.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">82. Rheumatic heart disease is due to<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Bacterial infection<br>B) Viral infection<br>C) Fungal infection<br>D) Genetic defect<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>   Streptococcal infection can damage heart valves \u2192 rheumatic heart disease.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">83. Arrhythmia means<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Abnormal heart rhythm<br>B) High BP<br>C) Heart enlargement<br>D) Valve defect<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Arrhythmia = irregular heartbeat (too fast\/slow).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">84. Which test is used to detect electrical activity of the heart?<br><\/mark><\/strong>A) EEG<br>B) ECG<br>C) MRI<br>D) CT scan<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Electrocardiogram records electrical activity of heart.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">85. Pacemaker of the heart is located in<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><\/mark><\/strong><br>A) Right atrium<br>B) Left atrium<br>C) Right ventricle<br>D) Left ventricle<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  SA node (pacemaker) lies in right atrium.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\"><strong>86. Heart murmur is caused by<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><\/strong><\/mark><br>A) Valve defects<br>B) Coronary blockage<br>C) Arrhythmia<br>D) Hypertension<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Abnormal sounds (murmurs) occur due to improper valve closure.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">87. Which vitamin is essential for blood clotting, reducing bleeding risk?<br><\/mark><\/strong>A) Vitamin C<br>B) Vitamin D<br>C) Vitamin K<br>D) Vitamin E<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Vitamin K helps synthesis of prothrombin, prevents hemorrhage.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">88. Which lifestyle factor increases risk of heart disease?<br><\/mark><\/strong>A) Smoking<br>B) High-fat diet<br>C) Lack of exercise<br>D) All of these<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: D  <\/b><BR>\n<b>Explanation:<\/b>   Smoking, obesity, and sedentary lifestyle \u2192 major cardiac risk factors.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">89. Aspirin helps prevent heart attack by<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Lowering blood pressure<br>B) Preventing blood clot formation<br>C) Increasing heart rate<br>D) Strengthening heart muscle<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   Low-dose aspirin reduces platelet aggregation.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">90. Which ion is essential for normal heart contraction?<br><\/mark><\/strong>A) Sodium<br>B) Potassium<br>C) Calcium<br>D) Magnesium<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  Ca\u00b2\u207a plays key role in excitation-contraction coupling.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">91. Excess potassium in blood causes<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Hypertension<br>B) Arrhythmia and cardiac arrest<br>C) Atherosclerosis<br>D) Angina<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Hyperkalemia alters cardiac rhythm.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">92. Which side of the heart is more commonly affected in heart failure?<br><\/mark><\/strong>A) Right side<br>B) Left side<br>C) Both equally<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Left ventricular failure \u2192 pulmonary congestion, breathlessness.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">93. Stroke is caused by<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Brain hemorrhage or clot<br>B) Valve defect<br>C) Kidney failure<br>D) Heart enlargement<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  Stroke occurs when brain blood supply is cut off.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">94. Artificial valves are implanted in case of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Heart attack<br>B) Valve stenosis or regurgitation<br>C) Hypertension<br>D) Arrhythmia<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Artificial valves replace defective heart valves.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">95. First successful human heart transplant was performed by<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) William Harvey<br>B) Christian Barnard<br>C) Ronald Ross<br>D) Alexander Fleming<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Dr. Christian Barnard performed first heart transplant in 1967 (South Africa).\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">96. Discovery of blood circulation was made by<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Harvey<br>B) Malpighi<br>C) Leeuwenhoek<br>D) Pasteur<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: A  <\/b><BR>\n<b>Explanation:<\/b>  William Harvey (1628) described blood circulation.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">97. Malpighi is credited with discovery of<strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">___________.<\/mark><\/strong><br><\/mark><\/strong>A) Heart valves<br>B) Capillaries<br>C) Red blood cells<br>D) Platelets<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>   Malpighi discovered capillaries, linking arteries and veins.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">98. Which instrument is used to measure blood pressure?<br><\/mark><\/strong>A) Thermometer<br>B) Spirometer<br>C) Sphygmomanometer<br>D) ECC<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>  BP is measured in mmHg using sphygmomanometer.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">99. Which heart sound is abnormal?<br><\/mark><\/strong>A) Lub<br>B) Dub<br>C) Murmur<br>D) None<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: C  <\/b><BR>\n<b>Explanation:<\/b>   Murmurs are extra\/abnormal sounds indicating valve defect.\n <\/p>\n<\/div>\n\n\n\n<p class=\"has-large-font-size\"><strong><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-luminous-vivid-orange-color\">100. Which of the following statements about human heart is true?<br><\/mark><\/strong>A) It is a voluntary muscle<br>B) It pumps ~5 L blood per minute<br>C) It has 3 chambers<br>D) It pumps only deoxygenated blood<\/p>\n\n\n\n<button class=\"acc\">Show Answer<\/button>\n<div class=\"pnl\">\n  <p style=\"font-size: 22px;\"><b> Answer: B  <\/b><BR>\n<b>Explanation:<\/b>  Heart is an involuntary four-chambered pump circulating ~5 L\/min.\n <\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>1. The human heart is located in ___________.A) Abdominal cavityB) Thoracic cavityC) Cranial cavityD) Pelvic cavity Show Answer Answer: B Explanation: The heart lies in the thoracic cavity between the two lungs, in the mediastinum. 2. Human heart is enclosed by a protective covering called___________.A) PleuraB) PeritoneumC) PericardiumD) Perichondrium Show Answer Answer: C Explanation: The<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[16236,16221,16151,16133,16155,16154,16147,16158,16139,16234,16233,16232,16223,16228,16229,16135,16227,16230,16222,16218,16235,16225,16231,16237,10986,16156,5649,5652,5623,16226,16134,16220,16132,16219,16140,16224,16217],"class_list":{"0":"post-12860","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-biology","7":"tag-arteries-and-veins","8":"tag-atrium","9":"tag-biology-learning","10":"tag-biology-mcqs","11":"tag-biology-preparation-material","12":"tag-biology-questions-and-answers","13":"tag-biology-quiz","14":"tag-biology-revision","15":"tag-biology-study-material","16":"tag-blood-circulation","17":"tag-blood-vessels","18":"tag-capillaries","19":"tag-cardiac-cycle","20":"tag-chambers-of-heart","21":"tag-circulatory-system","22":"tag-competitive-exam-biology","23":"tag-deoxygenated-blood","24":"tag-ecg-basics","25":"tag-heart-function","26":"tag-heart-rate","27":"tag-heart-structure","28":"tag-heartbeat","29":"tag-human-circulation","30":"tag-human-heart","31":"tag-human-heart-top-100-mcqs-with-answer-and-explanation","32":"tag-mcqs-for-biology-exam","33":"tag-mcqs-for-pc-psi-sda-fda-pdo-vao-banking-kas-ias-ssc-gd-ssc-chsl-ssc-cgl-for-all-compitative-exams","34":"tag-mcqs-for-pc-psi-sda-fda-pdo-vao-banking-kas-ias-ssc-gd-ssc-chsl-ssc-cgl-for-all-compitative-examsin-kannada","35":"tag-mcqs-for-sda-fda-pdo-vao-banking-kas-ias-ssc-gd-ssc-chsl-ssc-cgl-for-all-compitative-exams","36":"tag-oxygenated-blood","37":"tag-psc-biology-mcqs","38":"tag-pulmonary-circulation","39":"tag-ssc-biology-mcqs","40":"tag-systemic-circulation","41":"tag-upsc-biology-mcqs","42":"tag-valves-of-heart","43":"tag-ventricle"},"_links":{"self":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12860","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/comments?post=12860"}],"version-history":[{"count":102,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12860\/revisions"}],"predecessor-version":[{"id":35772,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/posts\/12860\/revisions\/35772"}],"wp:attachment":[{"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/media?parent=12860"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/categories?post=12860"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mcqsadda.com\/index.php\/wp-json\/wp\/v2\/tags?post=12860"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}