Hormones released into the interstitial fluid by the anterior pituitary enter the circulation easily because
A)the adjacent capillaries are fenestrated to permit passage of large molecules into the circulation.
B)a strong countercurrent mechanism maintains a concentration gradient that draws them in.
C)they pass easily through the infundibulum.
D)they are brought through the choroid plexus by active transport.
E)None of the answers are correct.

Question

Quizplus · Accepted Answer

Fenestrations are small holes in the capillary walls that allow larger molecules, such as hormones released by the anterior pituitary, to pass through easily into the circulation. This allows for efficient distribution of hormones throughout the body. The other options are not correct, as there is no countercurrent mechanism involved, hormones do not pass through the infundibulum to enter the circulation, and the choroid plexus is not involved in the release of hormones from the anterior pituitary.

Hormones Released into the Interstitial Fluid by the Anterior Pituitary