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 cells line the entire circulatory system?

  1. Lymphatic endothelial cells

  2. Vascular endothelial cells

  3. Visceral mesothelium

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

Vascular endothelial cells line the entire circulatory system, from heart to the smallest capillaries.

Multiple choice

The correct pathway of flow of blood is

  1. ventricles, atria, veins, arteries

  2. atria, veins, arteries, ventricles

  3. atria, ventricles, arteries, veins

  4. ventricles, veins, arteries, atria

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

The blood flows from atria to ventricles to arteries and finally to veins. Oxygenated blood is carried through arteries and deoxygenated blood or impure blood is carried through veins.

Multiple choice

What happens to the oxygenated blood that comes from lungs?

  1. It enters the left atrium of the heart.

  2. It enters the right atrium of the heart.

  3. It enters the left ventricle of the heart.

  4. It enters the right ventricle of the heart.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Oxygen-rich blood from the lungs comes to the thin-walled upper chamber of the heart on the left, i.e. the left atrium. The left atrium relaxes when it collects the blood.

Multiple choice

The pulmonary veins carry ________.

  1. impure blood from body organs to the heart

  2. impure blood from lungs to the heart

  3. pure blood from the heart to body organs

  4. pure blood from lungs to the heart
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is the function of the pulmonary veins.

Multiple choice

Which of the following statements is true of the fetal circulation?

  1. 100% of the cardiac output goes to the lungs via the pulmonary artery.

  2. The arterial duct (ductus arteriosus) helps send oxygenated blood to the brain.

  3. Blood shunts across the duct ‘left to right’ (from the aorta to the pulmonary artery).

  4. The foramen ovale typically closes by 36 weeks' gestation.

  5. The umbilical vein carries well-oxygenated blood.
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Unusually for a vein, the umbilical vein carries oxygenated blood from the placenta to the IVC via the ductus venosus. Umbilical cord pH is usually higher in the vein than in the artery.

Multiple choice

Inside the veins blood appears

  1. blue

  2. bright red

  3. dark red

  4. dark pink
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is dark red in its deoxygenated form (i.e., returning to the lungs), when hemoglobin is bound to carbon dioxide to form carboxyhemoglobin i.e. inside the veins.

Multiple choice

Which of the following carries oxygenated blood?

  1. Pulmonary artery

  2. Pulmonary veins

  3. Hepatic portal vein

  4. All of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Veins are vessels that bring blood to the heart. Pulmonary veins carry oxygenated blood from the lungs, to the left atrium. There are four pulmonary veins, which extend from the left atrium to the lungs. They are the right superior, right inferior, left superior and left inferior pulmonary veins.

Multiple choice

Which of the following carries deoxyegenated blood?

  1. Coronary artery

  2. Hepatic artery

  3. Renal artery

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

The pulmonary arteries carry deoxygenated blood, from the heart to the lungs. They are the only arteries (other than umbilical arteries in the fetus) that carry deoxygenated blood.

Multiple choice

Oxygenated blood flows in

  1. pulmonary artery

  2. renal veins

  3. hepatic vein

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

All of the above mentioned blood vessels carry deoxygenated blood.

Multiple choice

Which of the following carries blood away from the heart?

  1. Hepatic vein

  2. Pulmonary vein

  3. Renal veins

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

Arteries are blood vessels that carry blood away from the heart. This blood is normally oxygenated, exceptions made for the pulmonary and umbilical arteries. The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries (other than umbilical arteries in the fetus) that carry deoxygenated blood.

Multiple choice

Thick muscular walls are present in

  1. Arteriole

  2. Artery

  3. Capillary

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

An artery is an elastic blood vessel that transports blood away from the heart. There are two main types of arteries: pulmonary arteries and systemic arteries. It has got a thick wall which has three layers.