Question
The diagram shows part of a blood vessel.
Which evidence in the diagram shows that it is a vein and not an artery?
A There is a valve inside the blood vessel.
B Blood is flowing in an upwards direction.
C The blood vessel has a relatively small lumen.
D The blood vessel has a relatively thick wall.
▶️Answer/Explanation
Ans: A
The correct answer is A, because :
The main differentiating feature between artery and vein is presence of valves in the veins.
Valves are helpful in passing blood in one direction.
Whereas,
• Artery will have small lumen.
• Artery will have thick wall.
• Blood flow can’t be taken as evidence as it can be flown upward in both arteries and veins based on location.
Question
The diagram shows blood vessels entering and leaving some organs in the human body.
Which row identifies the pulmonary artery and the renal vein?
▶️Answer/Explanation
Ans: A
The correct answer is A, because :
Image indicates the double circulation.
Pulmonary artery carries blood from heart to lungs and Renal vein carries blood from kidney to the heart.
As per the image shown, option 1, 3 is correct.
Question
During a long race, an athlete’s skin temperature rises.
What causes this?
A increased sweating
B opening of the pores in the skin
C vasoconstriction of the blood vessels in the skin
D vasodilation of the blood vessels in the skin
Answer/Explanation
Ans: D
The correct answer is D, because :
An athlete during race, he needs a lot of energy and its need to be supplied to muscles for continuous running and it demands more blood flow.
In compensation, blood vessels become vasodilated and it causes increase blood flow and meets the demand.
Whereas,
• Increased sweating, opening of pores cools the body
• vasoconstriction reduces the blood flow and causes cramps
Question
Which statement describes the circulation of blood in the human body?
A Blood is pumped away from the heart by the atria.
B Blood is pumped away from the heart through arteries.
C Blood is pumped away from the heart through veins.
D Blood is pumped to the heart through capillaries.
▶️Answer/Explanation
Ans B
The correct answer is B, because :
Blood is carried to heart by veins.
Blood is carried away from heart by arteries.