Free Circulation MCQs with Answers
695 Circulation MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The circulatory system covers the chambers, valves and conducting pathway of the human heart, along with the cardiac cycle and control of heartbeat. It compares arteries, veins and capillaries by structure and function, and explains how the lymphatic system returns tissue fluid, transports absorbed fats and supports immunity.
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Read the Circulation notesFree MDCAT chapter notes with key terms695 questions · page 4 of 35
- A. Plasma
- B. Matrix
- C. Lymph
- D. Blood
Explanation: Surplus tissue fluid that drains into the blind ending lymph capillaries is called lymph, and it travels one way through nodes and along…
Correct answer: Lymph- A. Arteries
- B. Capillaries
- C. Veins
- D. none of these
Explanation: Veins return blood towards the heart, using valves and surrounding muscle contractions to prevent backflow, although pulmonary veins are…
Correct answer: Veins- A. Capillaries
- B. Lumen
- C. Platelates
- D. Plasma
Explanation: The lumen is the hollow internal space of a blood vessel through which blood flows.
Correct answer: Lumen- A. hypochromia
- B. Anisocytosis
- C. Poikilocytosis
- D. Polychromatophilia
Explanation: Anisocytosis means variation in the size of red blood cells, whereas poikilocytosis means variation in their shape.
Correct answer: Anisocytosis- A. Arteries
- B. Veins
- C. Capillaries
- D. None of these
Explanation: Veins generally carry blood toward the heart and commonly transport deoxygenated blood from body tissues.
Correct answer: Veins- A. Neck
- B. Wrist
- C. Elbow
- D. Brain
Explanation: The carotid arteries run through the neck and supply oxygenated blood to the head and brain.
Correct answer: Neck- A. Decrease
- B. Increase
- C. Remain Same
- D. Becomes zero
Explanation: For a given blood flow, reducing vessel radius greatly increases resistance because resistance varies inversely with the fourth power of…
Correct answer: Increase- A. Hepatic artery
- B. Pulmonary artery
- C. Pulmonary vein
- D. Renal artery
Explanation: The pulmonary veins carry oxygenated blood from the lungs to the left atrium of the heart.
Correct answer: Pulmonary vein- A. Lacking globulins
- B. Lacking albumins
- C. Lacking clotting factors
- D. Lacking antibodies
Explanation: Serum is the liquid left after blood has clotted, so it lacks fibrinogen and other clotting components that were used or removed during…
Correct answer: Lacking clotting factors- A. Platelets in plasma
- B. Proteins in blood
- C. RBC and WBC in blood
- D. Sodium in serum
Explanation: Plasma proteins, especially fibrinogen and globulins, increase the internal friction of blood and therefore contribute substantially to…
Correct answer: Proteins in blood- A. Earthworm
- B. Cockroach
- C. Hydra
- D. Sponges
Explanation: In earthworms, haemoglobin is dissolved directly in the plasma rather than enclosed in red blood cells, and it transports oxygen through…
Correct answer: Earthworm- A. Red fluid
- B. Hemoglobin
- C. Fluid tissue
- D. Plasma
Explanation: Blood is classified as a fluid connective tissue because its plasma matrix transports cells and dissolved substances throughout the body.
Correct answer: Fluid tissue- A. 6.4
- B. 7.0
- C. 7.4
- D. 7.5
Explanation: Normal arterial blood is slightly alkaline, with a tightly regulated pH of about 7.35 to 7.45, commonly given as 7.4.
Correct answer: 7.474. It has been estimated that in a normal person plasma constitutes about ________ by volume of blood.
- A. 35%
- B. 45%
- C. 55%
- D. 75%
Explanation: Blood is composed of about 55% plasma and about 45% formed elements such as red blood cells, white blood cells and platelets.
Correct answer: 55%- A. There are 5-7 pairs of heart.
- B. They are present between 1-7th segments.
- C. They are present lateral to the oesophagus.
- D. They pump blood from ventral to dorsal vessel.Standardized & Admissions Tests
Explanation: Earthworms have several pairs of muscular aortic arches, commonly called hearts, located around the oesophagus in the anterior segments.
Correct answer: They are present lateral to the oesophagus.- A. Red Blood Cells
- B. White Blood Cells
- C. Haemoglobin
- D. All of these
Explanation: Open circulatory systems contain hemolymph, which may include circulating cells called hemocytes that perform functions comparable to…
Correct answer: White Blood Cells- A. Antibodies
- B. Hemoglobin
- C. Enzymes
- D. Proteins
Explanation: Haemoglobin makes up most of the dry protein content of a red blood cell and occupies much of its cytoplasm, allowing the cell to…
Correct answer: Hemoglobin- A. Nautrophils
- B. Basophila
- C. Monocyte
- D. Lymphocyte
Explanation: Monocytes leave the bloodstream and differentiate into macrophages in tissues, where they engulf and digest large particles and pathogens…
Correct answer: Monocyte- A. Leucemia
- B. Thalassaemia
- C. Sickle cell anemia
- D. None of these
Explanation: Cooley's anaemia is beta-thalassaemia major, an inherited disorder in which defective beta-globin production causes severe anaemia.
Correct answer: Thalassaemia- A. Arteries
- B. Veins
- C. Capillaries
- D. None of these
Explanation: Arteries have the thickest and most muscular and elastic walls because they receive blood at high pressure directly from the ventricles.
Correct answer: Arteries