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 humans, the pulmonary artery originates from:

  1. fossa ovalis

  2. limbus of the fossa ovalis

  3. crista terminalis

  4. conus arteriosus

  5. septomarginal trabecula
Reveal answer Fill a bubble to check yourself
D 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

The oxygenated haemolymph entering the heart is isolated by:

  1. coronary sulcus

  2. pericardial sinus

  3. sternocostal surface

  4. fibrous pericardium

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

It refers to the wall at the back of the pericardial sac. It acts as a collection reservoir to isolate oxygenated haemolymph entering the heart.

Multiple choice biology organization of life

Choose the correct answer from the alternatives givens.
When a human being is cold, the superficial blood vessels

  1. dilate, and the sweat glands are inactive

  2. dilate, and the sweat glands are active

  3. constrict, and the sweat glands are inactive

  4. constrict, and the sweat glands are active
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Vasoconstriction occurs in superficial blood vessels of warm-blood vessels of warm-blooded animals when their ambient environment is cold, this process diverts the flow of heated blood to the center of the animal, preventing the loss of heat

So, the correct answer is 'constricted, and the sweat glands are inactive'

Multiple choice biology organization of life

Circulatory system also performs the function of homeostasis.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Homeostasis is a phenomenon of maintaining an equilibrium of internal environment despite constantly changing external environment. Various body systems are involved in performing the function of homeostasis. Circulatory system maintains homeostasis by continuous and controlled movement of blood that reaches every cell in the body. Nutrients pass from capillary blood into fluids surrounding the cells and waste products are removed.

Thus, the correct answer is option A.

Multiple choice

What is the body system involving your heart and blood?

  1. Respiration system

  2. Cardiovascular system

  3. Heart system

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

The cardiovascular system consists of the heart, blood vessels, and blood, and is responsible for transporting nutrients and oxygen throughout the body.

Multiple choice

Blood can't flow backward through your veins due to

  1. negative pressure

  2. constant pressure supplied by the heart

  3. valves in the heart

  4. valves in the veins
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Veins contain one-way valves that prevent blood from flowing backward due to gravity or low pressure. These valves ensure that blood moves toward the heart.

Multiple choice hepatic portal system components of the circulatory system transport in animals the circulatory system biology

Which of the following vessel in rabbit starts with capillaries and ends in capillaries?

  1. Pulmonary artery

  2. Renal vein

  3. Hepatic portal vein

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

The hepatic portal system includes the veins that drain blood from capillaries in the spleen, stomach, pancreas, and intestine. Instead of emptying their blood directly into the inferior vena cava, they deliver it by way of the hepatic portal vein to the liver. Upon entering the liver, the portal vein divides and sub-divides into ever smaller branches. Eventually, the portal blood flows into a vast network of sinus like vessels called sinusoids. These are enlarged capillaries that serve as blood channels within the tissues of the liver, spleen, thyroid gland, and other structures. After leaving the sinusoids, blood is finally collected by the hepatic veins, which empty into the inferior vena cava. 

So, the correct answer is option C.

Multiple choice hepatic portal system components of the circulatory system transport in animals the circulatory system biology

The veins starting from the stomach and intestines do not directly convert the blood to the posterior vena cava. Instead, they first enter the ........... as a combined hepatic portal vein.

  1. Kidney

  2. Pancreas

  3. Spleen

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

The hepatic portal vein carries blood from the spleen and intestines into the liver. The veins from the spleen and intestines break into capillaries before entering the liver as the hepatic portal vein. 

So, the correct answer is option C.

Multiple choice hepatic portal system components of the circulatory system transport in animals the circulatory system biology

Which of the following is an example of portal vein?

  1. Renal portal vein

  2. Hepatic portal vein

  3. Both A and B

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

The hepatic portal vein carries blood from the spleen and intestines into the liver. The veins from the spleen and intestines break into capillaries before entering the liver as the hepatic portal vein.

The renal portal vein is involved in the movement of the blood from the renal glomeruli to the peritubular plexus that surround the proximal and distal convoluted tubules.
So, the correct answer is option C.

Multiple choice hepatic portal system components of the circulatory system transport in animals the circulatory system biology

A portal system is one in which

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

  2. A vein starts from an organ and ends up in another organ.

  3. A vein starts from heart and ends up in lungs.

  4. None of the above.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
There are two types of portal systems they are Hepatic portal systems and renal portal system. In Hepatic (liver) portal system a vein collects blood from the intestine and passes it to the liver and in renal (kidney) portal system a vein collects blood from renal glomeruli and passes it to peritubular plexus (the blood capillaries that surrounds the proximal and distal convoluted tubules). Both hepatic and renal portal systems are found in fishes, amphibians, and reptiles. In mammals only hepatic portal system is present. Hence A portal system is one in which A vein starts from an organ and ends up in another organ.
So, the correct answer is 'A vein starts from an organ and ends up in another organ'.
Multiple choice hepatic portal system components of the circulatory system transport in animals the circulatory system biology


The hepatic portal vein is located between the:-

  1. hepatic vein and the vena cava

  2. small intestine and the liver

  3. mouth and the stomach

  4. pancreas and the small intestine
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Measuring approximately 8 cm (3 inches) in adults, the portal vein is located in the right upper quadrant of the abdomen, originating behind the neck of the pancreas. In most individuals, the portal vein is formed by the union of the superior mesenteric vein and the splenic vein

So, the correct answer is 'small intestine and the liver'

Multiple choice hepatic portal system components of the circulatory system transport in animals the circulatory system biology

The circulatory system of a rabbit differs from that of a frog in that there 

  1. Renal portal system in rabbit

  2. Hepatic portal system in rabbit

  3. Posterior vena cava in rabbit

  4. Dorsal aorta in rabbit
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
  • The renal portal system is absent in the rabbit. The hepatic portal system is present in rabbit and it consists of a hepatic portal vein ventral to the post caval vein. It enters into the liver, divides into a number of branches to supply to various lobes of the liver.
  • In the rabbit, the blood from different organs of the body is collected by two superior vena cavae and a posterior vena cava which open separately into the right auricle.
  • In Frog, the blood from different organs of the body is collected by two precavals and one post caval which unite together to form a sinus venosus that in turn opens into the right auricle.

So, the correct answer is 'Posterior vena cava in rabbit'.