Pressure gradient between the lungs and atmosphere is maintained by
(1)diaphragm

(2)external intercostal muscles

(3)internal intercostal muscles

(4)All of these

The volume of air involved in breathing movements can be estimated by using
1. ECG
2. Sphygmomanometer
3. spirometer
4. Barometer

Which of the following events happen when air enters lungs
1. Ribs and sternum raised
2. volume of thorax increased
3. Diaphragm contracted
4. All of the above

Which of the following events happen when air expelled from lungs
1. Ribs and sternum returned to original position
2. volume of thorax decreased
3. Diaphragm relaxed and arched upwards
4. All of the above

On an average, a healthy human breathes ______times/minute.
1. 70-72
2. 20-25
3. 12-16
4. 120-80

On an average, a human child breathes ______times/minute.
(1)70-72

(2)24-27

(3)12-16

(4)120-80

The breathing rate of human embryo ______times/minute.
(1)70-72

(2)20-25

(3)12-16

(4)None of these

Which of the following is true regarding breathing rate
(1)It’s minimum in Whale/Elephant

(2)It’s is maximum in shrew

(3)more in child than an adult

(4)All of these

Which of the following factors will increase the breathing rate
(1)Acidity

(2)decrease in pH

(3)Blood pressure

(4)All of the above

Which one is odd out regarding breathing rate
(1)heart beat rate

(2)B.M.R

(3)CO₂ concentration

(4)Body size