Author Question: The brachial artery branches to form the radial and ________ arteries. A) axillary B) digital C) ... (Read 114 times)

maychende · **on:** Feb 27, 2019

The brachial artery branches to form the radial and ________ arteries.
A) axillary
B) digital
C) ulnar
D) subclavian
E) brachiocephalic

Question 2

The release of FSH and LH from gonadotropes in the adenohypophysis is separately controlled by the same hypothalamic releasing hormone, GnRH. How is it possible to organize their secretion during the menstrual cycle?

Pswine · **Reply #1 on:** Feb 27, 2019

Answer to Question 1

C

Answer to Question 2

In females, the GnRH pulse frequency and amplitude (amount secreted per pulse change throughout the course of the ovarian cycle. Consider changes in pulse frequency, as their effects are both dramatic and reasonably well understood. Changes in GnRH pulse frequency are controlled primarily by circulating levels of estrogens and progestins. Estrogens increase the GnRH pulse frequency, and progestins decrease it. The endocrine cells of the adenohypophysis respond as if each group of endocrine cells is monitoring different frequencies. As a result, each group of cells is sensitive to some GnRH pulse frequencies and insensitive to others. For example, consider the gonadotropes, the cells responsible for FSH and LH production. At one pulse frequency, the gonadotropes respond preferentially and secrete FSH, whereas at another frequency, LH is the primary hormone released. FSH and LH production also occurs in pulses that follow the rhythm of GnRH pulses. If GnRH is absent or is supplied at a constant rate (without pulses), FSH and LH secretion will stop in a matter of hours.