Biology · General Awareness

Human Circulatory System

818 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

Which vessel(s) is/are used for coronary artery bypass surgery?

  1. Saphenous vein

  2. Internal mammary artery

  3. Femoral artery

  4. Both 1 and 2
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Both the saphenous vein (from the leg) and the internal mammary artery (from the chest wall) are commonly harvested and used as grafts in coronary artery bypass surgery.

Multiple choice

In high mountain regions bleeding through nose occurs because -

  1. The pressure of the blood in capillaries is higher than the outside air pressure

  2. The air pressure at high altitudes is greater than that of the plains

  3. The blood pressure increases at high altitude

  4. The blood pressure fluctuates and causes the blood vessels to break
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

At high altitudes, atmospheric pressure drops significantly while blood pressure remains relatively constant. This pressure differential causes the blood pressure in capillaries to exceed the external air pressure, making delicate nasal capillaries more prone to rupture and bleeding. Option B is incorrect because air pressure decreases, not increases, at higher altitudes. Option C is misleading - blood pressure doesn't inherently increase, but the pressure differential becomes more significant.

Multiple choice

Which of the following provides blood supply to the penis?

  1. Greater palatine artery

  2. Femoral artery

  3. Pampiniform plexus

  4. Internal pudendal arteries

  5. Genitofemoral artery
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The internal pudendal arteries serve as the penile blood supply by entering the penis dorsally and running deep into the tissues of the corpora cavernosa. The internal pudendal artery becomes the penile artery.

Multiple choice

Pulmonary veins

  1. carry pure blood from heart to lungs

  2. carry pure blood from lungs to heart

  3. carry impure blood from lungs to heart

  4. carry impure blood from heart to lungs
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pulmonary veins carry pure blood from lungs to heart.There are four pulmonary veins, two from each lung. The pulmonary veins are among the few veins that carry oxygenated blood.

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 and blood flows under high pressure.

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

Option (4) is the correct answer.

Multiple choice

Blood pressure is measured in

  1. veins

  2. arteries

  3. venues

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

Blood pressure is measured in arteries,as it is the intra-arterial pressure generated by the pulsatile flow of blood through an artery.

Multiple choice

pH of blood in arteries and veins is

  1. more in veins and less in arteries

  2. more in arteries and less in veins

  3. same

  4. not definite
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

pH of blood in arteries is more and less in veins because of their gaseous combinations as ateries contain oygenated blood and veins contain deoxygenated blood.

Multiple choice

Blood capillaries are made of

  1. endothelium, connective tissue and muscle fibres

  2. endothelium and muscles fibres

  3. endothelium and connective tissue

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

Blood capillaries are made of endothelium only.The blood capillaries are where the important functions of the circulation take place: the exchange of material between circulation and cells.

Multiple choice

The pulmonary artery carries

  1. pure blood to lungs

  2. impure blood to lungs

  3. pure blood to the intestine

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pulmonary artery carries impure blood to lungs.It is one of the only arteries (other than the umbilical arteries in the fetus) that carries deoxygenated blood.