Circulatory System — Set 5
Biology · परिसंचरण तंत्र · Questions 41–50 of 50
Which of the following is the liquid part of the blood without the clotting factors?
Correct Answer: D. Serum
Serum is obtained after blood has clotted and the cells and fibrin have been removed. It is used in various diagnostic tests and for determining blood types. It contains electrolytes, antibodies, and hormones but no fibrinogen.
Which blood vessel has the thinnest walls in the human body?
Correct Answer: A. Capillary
The correct answer is 'Capillary'. Capillaries have walls that are only one cell thick to facilitate diffusion. This thinness allows oxygen and nutrients to move easily into the tissues. They are so narrow that red blood cells often pass through them in single file.
The protein fibrinogen is converted into which substance during blood clotting?
Correct Answer: C. Fibrin
Fibrin forms a mesh-like structure that traps blood cells to create a solid clot. This transformation is the final step in the coagulation process. Fibrin is insoluble, which makes the clot stable enough to seal a wound.
Which part of the heart is separated by the tricuspid valve?
Correct Answer: C. Right atrium and Right ventricle
The tricuspid valve is located on the right side of the heart. It prevents blood from flowing back into the right atrium during ventricular contraction. It gets its name because it consists of three triangular flaps.
Which of the following carries oxygen-rich blood away from the heart to the rest of the body?
Correct Answer: B. Arteries
Arteries are strong, elastic vessels designed to handle high-pressure blood flow. Except for the pulmonary artery, all arteries carry oxygenated blood. They branch into smaller vessels called arterioles as they reach the tissues.
What happens to the heart rate during vigorous exercise?
Correct Answer: B. It increases
The heart rate increases to supply more oxygen and nutrients to the active muscles. The brain signals the SA node to speed up the electrical impulses. This response also helps in the faster removal of carbon dioxide from the body.
Which of the following is the largest vein in the human body?
Correct Answer: C. Vena cava
The vena cava consists of the superior and inferior branches that return deoxygenated blood to the heart. The inferior vena cava is the largest individual vein in the human body. It carries blood from the lower half of the body.
Rh factor in blood is named after which animal?
Correct Answer: A. Rhesus monkey
The Rh factor was first discovered in the blood of Rhesus monkeys in 1937. It is an inherited protein found on the surface of red blood cells. People who have this protein are Rh positive, while those without it are Rh negative.
Which of the following prevents the mixing of oxygenated and deoxygenated blood in the heart?
Correct Answer: D. Septum
The septum is a thick muscular wall that divides the heart into left and right halves. This division is essential for the efficiency of the double circulation system. It ensures that only oxygen-rich blood is sent to the body's tissues.
What is the primary function of the coronary arteries?
Correct Answer: A. Supply blood to the heart muscle
Coronary arteries provide the heart muscle with the oxygenated blood it needs to function. They branch off from the aorta near the base of the heart. Keeping these arteries clear is essential for preventing cardiovascular disease.