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

Blood vessels are lined with

  1. Mesothelium

  2. Endothelium

  3. Pericardium

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

The endothelium is the thin layer of cells that lines the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. These cells are called endothelial cells.

Multiple choice

The valves present at the base of both the pulmonary trunks are called as

  1. Bicuspid valve

  2. Tricuspid valve

  3. Aortic valve

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

These are located at the base of both the pulmonary trunk (pulmonary artery) and the aorta, the two arteries taking blood out of the ventricles. These valves permit blood to be forced into the arteries, but prevent backflow of blood from the arteries into the ventricles. These valves do not have chordae tendineae.

Multiple choice

The four pulmonary veins become malpositioned in

  1. Shone's syndrome

  2. Pentalogy of cantrell

  3. Tetralogy of fallot

  4. Total anomalous pulmonary venous connection (TAPVC)
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Total anomalous pulmonary venous connection (TAPVC), is a rare cyanotic congenital heart defect (CHD) in which all four pulmonary veins are malpositioned and make anomalous connections to the systemic venous circulation.

Multiple choice

Which of the following is characterized by anomalous venous return from the right lung?

  1. Partial anomalous pulmonary venous connection

  2. Scimitar syndrome

  3. Patent ductus arteriosus

  4. Interrupted aortic arch
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Scimitar syndrome, or pulmonary venolobar syndrome, is a rare congenital heart defect characterized by anomalous venous return from the right lung. This anomalous pulmonary venous return can be either partial (PAPVR) or total (TAPVR).

Multiple choice

The defect involving the abnormal spatial arrangement of any primary blood vessels is

  1. Pulmonic stenosis

  2. Transposition of the great vessels

  3. Tricuspid atresia

  4. A ventricular septal defect
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Transposition of the great vessels (TGV) is a group of congenital heart defects (CHDs) involving an abnormal spatial arrangement of any of the primary blood vessels: superior and/or inferior vena cavae (SVC, IVC), pulmonary artery, pulmonary veins, and aorta.

Multiple choice

The truncus arteriosus does not properly divide into the pulmonary artery and aorta in

  1. Persistent truncus arteriosus

  2. Ventricular septal defect

  3. Coarctation of the aorta

  4. Levo-transposition of the great arteries
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Persistent truncus arteriosus is a rare form of congenital heart disease that presents at birth. In this condition, the embryological structure known as the truncus arteriosus never properly divides into the pulmonary artery and aorta.

Multiple choice

The smallest blood vessel of the body is

  1. Arteries

  2. Arteriole

  3. Capillaries

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

Capillaries are the smallest of a body's blood vessels and are parts of the microcirculation. They are only 1 cell thick. These microvessels, measuring 5-10 μm in diameter, connect arterioles and venules, and enable the exchange of water, oxygen, carbon dioxide, and many other nutrient and waste chemical substances between blood and surrounding tissues.

Multiple choice

The oxygenated blood is supplied to the head and neck through

  1. Carotid artery

  2. Subclavian arteries

  3. Renal arteries

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

The common carotid artery is an artery that supplies the  oxygenated blood to head and neck .It divides in the neck to form the external and internal carotid arteries.

Multiple choice

The outermost layer of a blood vessel is known as

  1. The tunica intima

  2. The tunica media

  3. The tunica externa

  4. The pericardium
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The tunica externa, also known as the tunica adventitia (or adventitia), is the outermost layer of a blood vessel, surrounding the tunica media. It is mainly composed of collagen and is supported by external elastic lamina.

Multiple choice

Which of the following statements is wrong regarding the tunica media? 

  1. The middle coat is composed of a thin layer of connective tissue with elastic fibres.

  2. In the smaller arteries, it consists principally of plain muscle fibres in fine bundles, arranged in lamellو and disposed circularly around the vessel.

  3. In the larger arteries, as the iliac, femoral, and carotid, elastic fibres unite to form lamellو which alternate with the layers of muscular fibres.

  4. In the largest arteries, as the aorta and brachiocephalic, the amount of elastic tissue is very considerable.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The middle coat is composed of a thick layer of connective tissue with elastic fibres, intermixed, in some veins, with a transverse layer of muscular tissue.

Multiple choice

Oxygenated blood is found in the ______________.

  1. superior venacava

  2. right ventricle

  3. inferior venacava

  4. pulmonary vein

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

The pulmonary vein carries oxygenated blood from the lungs and opens into the left atrium. This oxygenated blood is then supplied to the entire body through the aorta.