Question
Write the events that occur during the process of breathing in humans.
✓
Answer
Breathing in humans is divided into 2 steps:
- Inhalation: In the process of inspiration, there would be a contraction of muscles attached to the ribs on the outer side which pulls out the ribs and results in the expansion of the chest cavity. Later, the diaphragm, contracts, moves downwards and expands the chest cavity resulting in the contraction of the abdominal muscles. The expansion of the chest cavity produces a partial vacuum which sucks air into the lungs and fills the expanded alveoli.
- Exhalation: The expiration process is considered once after the gaseous exchange occurs in the lungs and the air is expelled out. This expulsion of air is called expiration. During this process, muscles attached to the ribs contract, the muscles of the diaphragm and the abdomen relax which leads to a decrease in the volume of the chest cavity and increases the pressure of the lungs, causing the air in the lungs to be pushed out through the nose.
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Similar questions
Analyse the following observation table showing variation of image distance (v) with object distance (u) in case of a convex lens and answer the questions that follow, without doing any calculations:
|
S. No.
|
Object distance u (cm)
|
Image distance v (cm)
|
|
1
|
-90
|
+18
|
|
2
|
-60
|
+20
|
|
3
|
-30
|
+30
|
|
4
|
-20
|
+60
|
|
5
|
-18
|
+90
|
|
6
|
-10
|
+100
|
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i. How pituitary gland regulates the growth of the body?
ii. Which hormone is responsible for the carbohydrate, protein, and fat metabolism in the body?
iii. Which pair of glands prepare the body to deal with emergency situations?
iv. Which gland secretes insulin and what does it do in the body?
v. What is the function of endocrine glands?
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