The embryo is directly enclosed in and protected by the amnion.

Gastrulation begins when a groove with raised edges called the ____ appears on the dorsal surface of the embryonic disc. 

Which of the following is not reabsorbed by the PCT?

Sperm mature and are stored in the: 

Normally menstruation occurs when _____.

The function of angiotensin II is to _____.

Blood supply that directly receives substances from the tubular cells. 

Provides nutrients to the developing spermatids. 

The zona pellucida is formed as the follicle becomes a secondary follicle. 

Which of the following is not associated with the renal corpuscle?