Question

For erection to occur

A) there must be sufficient blood hydrostatic pressure.
B) nitric oxide must be present.
C) the sacral spinal cord must be intact.
D) all of the above
E) A and B only

Answer 1

To achieve an erection, there must be sufficient blood hydrostatic pressure, nitric oxide presence, and an intact sacral spinal cord; hence, all of the stated factors are necessary.

Step-by-step explanation:

For erection to occur, all of the following factors are necessary:

1. There must be sufficient blood hydrostatic pressure to create the engorgement of penile tissues.
2. Nitric oxide (NO) must be present, which is released during sexual arousal, causing relaxation of smooth muscles around the penile arteries and leading to vasodilation.
3. The sacral spinal cord must be intact to facilitate the nervous control required for sexual arousal and penile engorgement.

Therefore, the answer to the question is D) all of the above.