How will penile function be altered if the blood supply to the corpora cavernosa is impaired?
- (a) The erect penis will be unable to become flaccid.
- (b) Erection will not occur.
- (c) Erection will occur, but ejaculation will not.
- (d) The urethra will be occluded.
The correct answer and explanation is:
Correct Answer: (b) Erection will not occur.
Explanation:
The corpora cavernosa are two sponge-like cylindrical structures running along the length of the penis, playing a crucial role in achieving and maintaining an erection. These structures rely on an adequate blood supply from the penile arteries, primarily the deep arteries of the penis and helicine arteries that dilate during sexual arousal.
When the blood supply to the corpora cavernosa is impaired, it prevents the necessary vascular changes needed for erection. Normally, during sexual stimulation, the parasympathetic nervous system triggers nitric oxide (NO) release, leading to the relaxation of smooth muscle cells in the cavernous sinuses. This relaxation allows increased arterial inflow while simultaneously compressing venous outflow, trapping blood within the corpora cavernosa, thus maintaining erection.
However, if the blood supply is compromised due to conditions like atherosclerosis, vascular damage, diabetes, or trauma, the cavernous sinuses do not fill with blood efficiently, and erection either does not occur or is insufficient for penetration. This condition is a primary cause of vascular erectile dysfunction (ED), which is common in older men and those with cardiovascular diseases.
Other options in the question are incorrect:
- (a) The erect penis will be unable to become flaccid – Incorrect, because blood supply impairment prevents erection, not detumescence issues.
- (c) Erection will occur, but ejaculation will not – Incorrect, as ejaculation is controlled by the sympathetic nervous system, and blood flow impairment primarily affects erection.
- (d) The urethra will be occluded – Incorrect, because the urethra is located within the corpus spongiosum, which has a separate blood supply.
Thus, erection will not occur due to insufficient blood flow to the corpora cavernosa.
Here is a detailed medical illustration showing the male reproductive system with the corpora cavernosa and its blood supply. One half illustrates a healthy blood flow, while the other demonstrates restricted blood supply, highlighting the impact on erectile function. Let me know if you need any modifications!
