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

Mitral (bicuspid) valve in mammals guard the opening between

  1. left auricle and left-ventricle

  2. pulmonary vein and left auricle

  3. stomach and intestine

  4. liver and spleen
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The mitral (bicuspid) valve is located between the left atrium (auricle) and left ventricle of the heart. It prevents backflow of blood from the left ventricle to the left atrium when the ventricle contracts, ensuring one-way flow toward the aorta.

Multiple choice

Which of the following is true about arteries?

  1. They carry deoxygenated blood from different body parts to the heart.

  2. They carry oxygenated blood from heart to different body parts.

  3. In arteries, blood flows with low speed and under low pressure.

  4. They possess valves.

  5. Their lumens are thin and less elastic.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Arteries carry oxygenated blood from heart to various parts of the body.

Multiple choice

Why are semilunar valves present in the veins?

  1. To allow the movement of leucocytes through them

  2. To allow the diffusion of oxygen into the intercellular fluids

  3. To prevent the loss of nutrients form the blood

  4. To prevent the backward flow of blood

  5. To prevent the entry of pathogens into the veins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Veins are provided with semilunar valves, which prevent the backward flow of blood.

Multiple choice

Consider the following statements: (a) Portal veins carry blood directly to the heart and forms a network of capillaries. (b) In human beings, two main portal systems; hepatic and the hypophyseal portal systems are present. (c) A pair of hepatic veins carries blood from liver to the inferior vena cava. (d) The blood from intestine, pancreas and spleen is drained into liver via. the hepatic portal vein.

Which of the above statements is/are incorrect about portal system of a man?

  1. Only (a)

  2. Both (a) and (b)

  3. Only (d)

  4. Only (c)

  5. Both (b) and (d)

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Portal vein does not carry blood directly to the heart but forms a network of capillaries on another organ before reaching the heart.

Multiple choice

Which among the following is supplied with enormous blood vessels?

  1. Germinal epithelium

  2. Tunica albuginea

  3. Cumulus oophorus

  4. Stroma
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The stroma of the ovary is a particular soft tissue, particularly supplied with enormous blood vessels consisting of spindle-shaped cells with a small amount of ordinary connective tissue.

Multiple choice

Neutrophils squeeze through the pores of blood vessels by the process of

  1. chemotaxis

  2. diapedesis

  3. opsonization

  4. phagocytosis

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

It is the passage of blood cells through the unruptured wall of a blood vessel into the surrounding tissues. The white cells may exhibit diapedesis to fight infection in the tissues surrounding blood vessels. The neutrophils are the first to arrive through diapedesis at the site of an infection.

Multiple choice

Which of the following does not characterise the blood supply of the central nervous system?

  1. The vertebrobasilar system which constitutes the anterior circulation.

  2. At the core of the brain, the arteries form the circle of Willis.

  3. Abnormalities of blood flow in the carotid arteries frequently leads to the problems in the cerebral hemisphere .

  4. Abnormalities of blood flow in the vertebral arteries frequently leads to the defects in brainstem, cerebellum and posterior parts of the brain.

  5. Thrombus and emboli are the chief causes of blood flow obstructions in the brain.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

It is the incorrect statement. The carotid arteries form the anterior circulation to the brain, whereas the vertebral arteries merge to become the basilar artery (so called vertebrobasilar system), which constitutes the posterior circulation.

Multiple choice

In human beings, the pulmonary artery originates from the

  1. septomarginal trabecula

  2. conus arteriosus

  3. crista terminalis

  4. fossa ovalis

  5. limbus of the fossa ovalis
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

It is a conical extension of the right ventricle in the heart of mammals, from which the pulmonary artery originates.

Multiple choice

_______ carries away the filtered blood from the kidneys.

  1. Renal vein

  2. Pulmonary vein

  3. Aorta

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

Renal vein carries away the filtered blood from the kidneys. Nephron is the structural and functional unit in kidneys. Each nephron is made up of 2 main parts: malphigian body and renal tubule. Malphigian body comprises a cup-shaped Bowman's capsule and a network of blood capillaries, the glomerulus. The renal artery, after entering the kidney, divides and redivides forming various afferent renal arterioles. An afferent arteriole enters a Bowman's capsule to form glomerulus. The efferent renal arteriole has narrower lumen than the afferent renal arteriole. Thereafter, an efferent renal arteriole leaves the glomerulus. The efferent renal arteriole breaks up into capillaries around the tubules. All the capillaries, in turn, unite to form renal venules and the latter together form the renal vein, which leaves the kidney. Thus, after the process of filtration in the glomerulus, renal vein has the clean or filtered blood.