Question

Describe the pathway of the parasympathetic fibers to the rectum.

a) Pelvic splanchnic nerves (S2-S4) → inferior hypogastric plexus → rectal plexus
b) Vagus nerve → pelvic plexus → rectal plexus
c) Sacral spinal nerves → superior hypogastric plexus → rectal plexus
d) Celiac ganglia → inferior mesenteric plexus → rectal plexus

Answer 1

The pathway of the parasympathetic fibers to the rectum is from the pelvic splanchnic nerves (S2-S4) to the inferior hypogastric plexus, then to the rectal plexus.

Step-by-step explanation:

The pathway of the parasympathetic fibers to the rectum follows a specific route. These fibers originate in the sacral region of the spinal cord, specifically from the sacral segments S2 to S4. From there, they travel through the pelvic splanchnic nerves and make their way to the inferior hypogastric plexus. Upon reaching this plexus, the fibers then continue to the rectal plexus, which directly supplies the rectum.

The correct pathway for the parasympathetic fibers to the rectum is: Pelvic splanchnic nerves (S2-S4) → inferior hypogastric plexus → rectal plexus. It's also important to understand that the preganglionic parasympathetic fibers are generally longer because they travel to terminal ganglia located near or within the target effector organs, whereas the postganglionic fibers are shorter as they project the short distance to the target tissues within the organ.