Question

Select the MOST CORRECT answer. At rest, a healthy, normal human...

		has negative intrapleural pressure during both inspiration and expiration.
		contracts the diaphragm during inspiration and generates a negative alveolar pressure.
		contracts internal intercostals and abdominal muscles to expire air.
		Both a) and b) are correct and c) is incorrect.
		a), b) and c) are all correct.

Regarding human reproductive physiology (select the MOST CORRECT statement):

		Both Sertoli cells and Leydig (interstitial) cells are located within seminiferous tubules.
		Sperm cells use their flagella to swim from the seminiferous tubules to the epididymis.
		A spermatogonium can divide by mitosis to give rise to more spermatogonia, or by meiosis to give rise to spermatozoa.
		Both a) and b) are correct and c) is incorrect
		a), b) and c) are all correct

Answer 1

Answer;

1. Both a) and b) are correct and c) is incorrect.

Explanation: Intrapleural pressure:
It is the pressure in the space between lungs and chest wall.
Normally it is negative around - 2.5 mmHg at the start of inspiration. It becomes -6 mmHg at the end of inspiration.

In forced expiration, contracts internal intercostals and abdominal muscles to expire air.

2 C) . A spermatogonium can divide by mitosis to give rise to more spermatogonia, or by meiosis to give rise to spermatozoa.

Explanation: Only Sertoli cell are located within seminiferous tubules. Leydig (interstitial) cells is located outside the seminiferous tubules.

Sperm cells can not use their flagella to swim from the seminiferous tubules to the epididymis because they become motile in the epididymis.