Biology · General Awareness

Human Circulatory System

846 Questions

The human circulatory system explores the network of blood vessels, heart valves, and structural pathways. Test items often target blood flow sequences and specific vascular functions. Mastering these details is vital for biology preparation.

Heart valves and chambersBlood vessels and venulesArteries of the bodyBlood supply to organsCentral nervous system supply

Human Circulatory System Questions

Multiple choice

As compared to artery, a vein has

  1. a thicker wall

  2. a narrower lumen

  3. more musculature

  4. less elastic tissue
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Veins have less elastic tissue than arteries.

Multiple choice

Directions: In the following question, some statements have been provided. These statements form a coherent paragraph when properly arranged. Select the alternative representing the proper and logical sequencing of these statements.

A. During the first twelve hours, the minute vessels in the vicinity of the wound dilate, and from them lymph exudes and leucocytes migrate into the tissues. B. When a wound is made in the integument under aseptic conditions, the passage of the knife through the tissues is immediately followed by an oozing of blood, which soon coagulates on the cut surfaces. C. In each of the divided vessels, a clot forms, and extends as far as the nearest collateral branch; and on the surface of the wound, there is a microscopic layer of bruised and devitalised tissue. D. If the wound is closed, the narrow space between its edges is occupied by a blood-clot, which consists of red and white corpuscles mixed with a quantity of fibrin, and this forms a temporary uniting medium between the divided surfaces.

  1. DCBA

  2. BCDA

  3. CBAD

  4. ACDB

  5. BDAC
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

‘Divided vessels’ in C refers to the cut in B. Closing of the wound in D has to follow both B and C. Hence, BCDA is correct.

Multiple choice

Oxygenated blood reaches heart by ________.

  1. pulmonary artery

  2. pulmonary vein

  3. aorta

  4. vena cava
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pulmonary artery carries de-oxygenated blood to the lungs, where it is supplied with fresh oxygen, and carbon-dioxide is removed. The blood, which is now rich in oxygen, returns to the heart through the pulmonary veins.

Multiple choice

Which of the following vessels is/are present in a human body?

  1. Capillaries

  2. Xylem

  3. Phloem

  4. Spleen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

On reaching the organ or tissue, the artery divides into smaller and smaller vessels to bring the blood in contact with all the individual cells. The walls of the small vessels are one-cell thick and are called capillaries. Exchange of material between the blood and surrounding cells takes place across this thin wall. The capillaries then join to form veins that take blood away from organ or tissue.

Multiple choice

As compared to arteries, veins have ________.

  1. thinner walls

  2. valves present in them

  3. wide lumen

  4. all of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The blood vessels that carry blood from different regions of the body towards the heart are called veins. The veins are usually thin walled with wide lumen. There are sets of semilunar valves inside the veins, which regulate the unidirectional flow of the blood. On the other hand arteries are the blood vessels that carry blood from the heart to different regions of the body. They are usually thick walled with narrow lumen.

Multiple choice

Pulmonary artery carries _______.

  1. oxygenated blood to lungs

  2. deoxygenated blood to heart

  3. deoxygenated blood to lungs

  4. oxygenated blood to heart
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Heart is divided into two halves: the right and left sides of the heart. The right side of the heart pumps deoxygenated blood to the lungs whereas the left side of the heart pumps oxygenated blood to the body. The right atrium pumps blood to right ventricle and the right ventricle pumps blood into the pulmonary artery. The pulmonary artery carries this deoxygenated blood to the lungs where it takes up oxygen and eliminates carbon dioxide.

Multiple choice

_______ prevents the backflow of blood in heart.

  1. Septa

  2. Valves

  3. Arteries

  4. Veins
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

There are four valves in the heart, which prevent blood from flowing backward in the heart. The valves open easily in the direction of blood flow but when the blood pushes the valve in the opposite direction, the valves close. 2 valves = Atrioventricular valves = located between atria and ventricles 2 valves = Semilunar valves = located between ventricles and arteries. Pulmonary valve - Between the right ventricle and pulmonary artery Aortic valve - Between the left ventricle and aorta

Multiple choice

Oxygen rich blood from the lungs first enters the _________ of heart.

  1. left atrium

  2. left ventricle

  3. right atrium

  4. right ventricle
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oxygenated blood from the lungs comes to thin walled upper chamber of the heart (left atrium). Left atrium is relaxed when it is collecting the oxygenated blood. After that, it contracts, while the next chamber (the left ventricle) expands. So, the blood is moved to left ventricle. If the left ventricle contracts, it pumps the oxygenated blood to different parts of the body.