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

In a portal system

  1. a vein starts from an organ and ends up in the heart

  2. a vein enters into an organ other than the heart and breaks up into capillaries

  3. an artery breaks up in an organ and restarts by union of its capillaries

  4. the blood from gut is brought into kidneys before it is poured into posterior vena cava

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

A portal vein system is characterized by a vein that originates from capillaries in one organ (e.g., capillaries in the gastrointestinal tract), travels to another organ without first returning to the heart, and then breaks into a second capillary network (e.g., in the liver). The hepatic portal system is the classic example.

Multiple choice

Arteries are

  1. thin walled and blood flows under diminished pressure

  2. thick walled and blood flows under high pressure

  3. thin walled and blood flows under high pressure

  4. thick walled and blood flows under diminished pressure
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Arteries are thick-walled vessels that carry blood away from the heart under high pressure generated by ventricular contraction. Their walls contain smooth muscle and elastic tissue to withstand and maintain this pressure, ensuring efficient distribution of oxygenated blood throughout the body.

Multiple choice

Which of the following statements is true?

  1. All veins carry deoxygenated blood.

  2. All arteries carry oxygenated blood.

  3. All veins except one carry oxygenated blood.

  4. All arteries except one carry oxygenated blood .
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The pulmonary artery is the exception among arteries, carrying deoxygenated blood from the heart to the lungs. Conversely, the pulmonary vein is the exception among veins, carrying oxygenated blood from the lungs back to the heart.

Multiple choice

Hypotension is

  1. low blood pressure

  2. high blood pressure

  3. low blood sugar level

  4. low WBCs count

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

Hypotension is the medical term for abnormally low blood pressure, typically defined as systolic pressure below 90 mmHg. It can cause dizziness, fainting, and inadequate blood flow to organs.

Multiple choice

In man which blood vessel takes away blood from the kidney?

  1. Afferent arteriole

  2. Efferent arteriole

  3. Renal vein

  4. Renal portal vein
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The renal vein carries deoxygenated blood away from the kidney toward the inferior vena cava. The afferent arteriole brings blood TO the glomerulus, and efferent arteriole carries blood away FROM the glomerulus (but still within kidney). Renal portal veins are found in lower vertebrates like birds and reptiles, not mammals. Renal vein is the correct answer for the vessel that 'takes away blood from the kidney.'

Multiple choice

Why does the blood in the veins flow only towards heart and not backwards?

  1. Because veins have valves.

  2. Because the veins are divided into capillaries which are attached to heart.

  3. Because the carbon dioxide rich blood tends to flow towards the heart.

  4. Because the slope of veins is toward the heart.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Yes, it is correct. The valves present in the veins allow blood to flow only towards the heart.

Multiple choice

Which of the following statements is/are false?

a. Sponges and coelenterates circulate water from their surroundings through their body cavities. b. Plasma is a viscous fluid that constitutes nearly 90 percent of the blood. c. Leucocytes are colourless as they lack haemoglobin.

  1. Only a

  2. Only a and b

  3. Only b

  4. Only b and c

  5. Only c
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

This is the correct option as this statement is false. Plasma is a viscous fluid that constitutes nearly 55 percent of the blood.

Multiple choice

Why is blood called a connective tissue?

a. It carries food and oxygen to all the cells. b. It connects bones and muscles. c. It collects waste from all the parts of the body to liver and kidney. d. It connects bones to bones.

  1. Only a and b

  2. Only c and b

  3. Only a and c

  4. Only b and d

  5. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Yes, it is correct. Both 'a' and 'c' are true. Blood carries food and oxygen to all the cells. It also collects waste from all the parts of the body and carries it to liver and kidney.