Structural Organisation In Animals Question 226
Question: Assertion : Mast cells in the human body release excessive amounts of inflammatory chemicals which cause allergic reactions. Reason : Allergens in the environment on reaching human body stimulate mast cells in certain individuals. [AIIMS 2003]
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: A
Solution:
The symptoms of an allergic reaction develop in response to histamine.
Mast cells release a large amount of histamine into the blood stream and it also act as initiator of the inflammatory response which aids the arival of leucocytes at a site of infection.
Histamine stimulates capillary dilation, increased capillary permeability, and closure of bronchial tubes, mucus secretion, pain and swelling.
BETA
