Home
Class 12
BIOLOGY
Read the following statements (A) Rel...

Read the following statements
(A) Relaxation of diaphragm and inter costal muscles (B) Increase in the volume of thoracic chamber
(C) Lisfts up the sternum
(D) Intra pulmonary pressure in higher than atmospheric pressure
(E) Increase the pulmonary volume
How many statement are correct about Expiration ?

A

Two

B

Three

C

Four

D

One

Text Solution

AI Generated Solution

The correct Answer is:
To determine how many statements are correct about expiration, let's analyze each statement step by step: 1. **Statement A: Relaxation of diaphragm and intercostal muscles** - During expiration, the diaphragm and intercostal muscles relax. This is true as their relaxation allows the thoracic cavity to decrease in volume, which is essential for expiration. - **Conclusion**: This statement is correct. 2. **Statement B: Increase in the volume of thoracic chamber** - During expiration, the volume of the thoracic chamber decreases as the diaphragm and intercostal muscles relax. This decrease in volume leads to an increase in intrapulmonary pressure, facilitating the expulsion of air from the lungs. - **Conclusion**: This statement is incorrect. 3. **Statement C: Lifts up the sternum** - Lifting the sternum occurs during inspiration when the external intercostal muscles contract, increasing the thoracic volume. During expiration, the sternum does not lift; instead, it returns to its original position, contributing to a decrease in thoracic volume. - **Conclusion**: This statement is incorrect. 4. **Statement D: Intrapulmonary pressure is higher than atmospheric pressure** - During expiration, the intrapulmonary pressure indeed becomes higher than atmospheric pressure, which is what drives air out of the lungs. - **Conclusion**: This statement is correct. 5. **Statement E: Increase the pulmonary volume** - An increase in pulmonary volume occurs during inspiration, not expiration. During expiration, the pulmonary volume decreases as air is expelled from the lungs. - **Conclusion**: This statement is incorrect. **Final Count of Correct Statements**: - The correct statements are A (Relaxation of diaphragm and intercostal muscles) and D (Intrapulmonary pressure is higher than atmospheric pressure). Therefore, there are **2 correct statements** about expiration. ### Summary of Correct Statements: - A: Correct - B: Incorrect - C: Incorrect - D: Correct - E: Incorrect ### Total Correct Statements: 2
Promotional Banner

Similar Questions

Explore conceptually related problems

Select the correct events that occur during inspration. (a) Contraction of diaphragm (b) Contraction of external inter-costal muscles (c) Pulmonary volume decreases (d) Intra pulmonary pressure increases

Read the following statements A) In E .coli transcription and translation takes place in cytoplasm. (B) In humans,exons are interrupted by introns. (C) Introns are segment of DNA. (D) The principle of complementarity does not govern the process of transcription How many statements are incorrect?

Read the following statement (A - D). (A) The movement of air into and out of the lungs is carried out by creating a pressure gradient between the lungs and atmosphere. (B) Inspiration can occur if the pressure within the lungs is more than the atmospheric pressure. (C) Expiration takes place when the intrapulmonary pressure is lesser than the atmospheric pressure. (D) The diaphragm and a specialized set of intercostal muscles in between the ribs help in the generation of such pressure gradients for breathing. How many of the following statements are correct?

Which of the following sequenes is correct to intite inspiration ? (i) the contraction of external intercostal muscles raises the ribs and sternum (ii) Volume of thorax increases in the dorso-ventral axis (iii) intrapulmonary pressure decreases (iv) Diaphragm contraction (v) Air rushes into lungs (vi) Volume of thorax increases in the anterior-posterior axis

Assertion :- Inspiration can occur if intra pulmonary pressure is less than the atmospheric pressure. Reason :- Inspiration is initiated by the relaxation of diaphragm and external intercostal muscle.

Read the following steps of inspiration (A) Increases horacic volume (B) Air move into lungs (C) Contraction in diaphragm and EICM (D) Increases pulmonary volume (E) Lungs expand (F) Decreases the intra pulmonary pressure Find out the correct sequence of these steps

Read the following statements (A - D). A - Solidification of faeces in the rectum, reduces the urge for defaecation. B - Vomiting is a reflex action C - Electrolytes like Cl - are absorbed in the gut by simple diffusion D - Micelles are formed in gut lumen How many of the above statements are correct?

Read the following (A-D) statements: (A) Plasma without the clotting factor is called lymph. (B) The spleen is the graveyard of RBCs. (C) Eosinophils resist infections and are also associated with allergic reactions. (D) The universal donor blood group is O+ve . How many of the above statements are correct?