Answer Happy

Question 2 (1 point) Within the walls of the seminiferous tubules within the testes, Sustentacular cells form a "blood-testes barrier" protecting the developing sperm from .... what? And why? What elements in blood could be harmful to sperm?
Question 3 (1 point) Consider the motor neurons that innervate smooth muscle in the erectile columns of the penis. These motor neurons release acetylcholine (ACh) as the neurotransmitter. Remembering back to our study of the autonomic nervous system, if this motor neuron releases Ach, is it part of the sympathetic nervous system or parasympathetic nervous system? As such, is erection a sympathetic or parasympathetic response? sympathetic O parasympathetic
Question 4 (1 point) Acetylcholine (ACh) binds to a muscarinic cholinergic receptor, which is a G-protein coupled receptor that acts through intracellular signaling molecules to cause smooth muscle relaxation. How can relaxation of smooth muscle cause the penis to become firm? (Hint: think about where smooth muscle is within penile structures. Or, think about what happens at erection: the erectile columns become engorged with blood - What needs to happen to increase the blood flow?)
Question 5 (1 point) Men with erectile dysfunction may take Viagra which maintains relaxation of smooth muscles by blocking the enzymes that would end relaxation of smooth muscle (specifically, it blocks the enzyme that would convert cGMP back to GMP: ending the signal for relaxing smooth muscle "see pic). Why should patients who are also on blood pressure lowering medication, like nitroglycerin or other nitrate-containing drugs, not take Viagra? (Note: Nitrate- containing drugs cause smooth muscle relaxation in blood vessel walls using the nitrate-path (NO is nitric oxide illustrated as triangle in picture).
Question 6 (1 point) ✓ Saved Explain why high-doses of steroids (which mimic testosterone) could lead to infertility.
Question 7 (1 point) Saved Why is hormonal testosterone not an easy solution as a male birth control?
Question 8 (1 point) For what reason is male birth control more difficult than female birth control?
Question 9 (1 point) If the ovaries are removed from a 20-year-old female, what happens to the levels of GnRH, FSH, LH, estrogen and progesterone in her blood? What would be the effects of these hormonal changes on her reproductive organs and her sexual behavior?
Question 10 (1 point) If the ovaries are removed from a post-menopausal woman, what happens to the levels of GnRH, FSH, LH, estrogen and progesterone in her blood? What symptoms would you expect?
Question 11 (1 point) Which hormone(s) could be administered (or otherwise mimicked) to increase the chances of more than one egg being ovulated?
Question 12 (1 point) Many forms of birth control contain progesterone. How does maintaining higher levels of progesterone prevent pregnancy?