Parasympathetics Part 3 (Sacral)

Question 1

What cord levels contribute to the sacral parasympathetic pathways?

Answer 1

S2, 3, and 4

Question 2

T/F: Sacral parasym fibers arise in the dorsal horns of S2-S4 cord levels.

Answer 2

False; lateral horns

Question 3

T/F: sacral parasym fibers are carried inferior in the cauda equina.

Answer 3

True

Question 4

T/F: Sacral parasym fibers exit the posterior sacral foramina and are carried in the pelvic splanchnic nerve.

Answer 4

False; exit anterior sacral foramina, but are carried in pelvic splanchnic nerves

Question 5

What plexus do pelvic splanchnic nerves travel to before being distributed to pelvic organs?

Answer 5

inferior hypogastric (pelvic) plexus

Question 6

What network of ganglia and nerves covers the rectum, internal genitalia and base of the urinary bladder and contains both parasympathetic and sympathetic fibers?

Answer 6

Inferior hypogastric (pelvic) plexus

Question 7

After traveling through the inferior hypogastric plexus, fibers reach the distal part of the digestive tract and what other plexuses?

Answer 7

superior hypogastric and inferior mesenteric plexuses

Question 8

T/F: Preganglionic parasympathetic fibers travel through the inferior hypogastric plexus to reach the superior hypogastric and inferior mesenteric plexuses by way of the “hypogastric nerve.”

Answer 8

True

Question 9

Postganglionic parasympathetic fibers reach the distal colon from what plexus?

Answer 9

inferior mesenteric plexus

Question 10

Preganglionic parasympathetic fibers to the rectum and anus travel to which plexus before reaching the target structures?

Answer 10

inferior hypogastric plexus

Question 11

What is the principal target of postganglionic parasympathetic fibers that travel from the inferior hypogastric plexus in route to urinary bladder?

Answer 11

detrusor muscle

Question 12

What is the result of parasympathetic stimulation on the bladder?

Answer 12

emptying the bladder

Question 13

T/F: Somatic supply to the external urethral sphincter follows the same pathway as the parasympathetic supply to the bladder and these neurons are inhibited as the bladder empties.

Answer 13

True

Question 14

T/F: Preganglionic fibers reach the prostatic plexus via the superior hypogastric plexus.

Answer 14

False; via inferior hypogastric plexus

Question 15

What do postganglionic fibers from the prostatic plexus reach/supply?

Answer 15

smooth muscles of the prostatic urethra and seminal vesicle

Question 16

T/F: Preganglionic fibers to the uterus travel to the inferior hypogastric plexus and then postganglionic fibers are distributed throughout the myometrium of the uterus.

Answer 16

True

Question 17

T/F: Parasympathetic stimulation probably stimulates the myometrium muscles, but hormonal factors may play a larger role, especially during pregnancy.

Answer 17

False; parasym probably inhibits these muscles, but hormones may play a larger role, especially during pregnancy

Question 18

Where do preganglionic fibers of the pathway to the vagina synapse after traveling through the inferior hypogastric plexus?

Answer 18

vaginal plexus

Question 19

What is the result of parasympathetic stimulation of the vagina?

Answer 19

vasodilation and increased secretory activity

Question 20

What nerve might be used for fibers reaching the inferior part of the vagina?

Answer 20

pudendal nerve

Question 21

In the pathway to the penis or clitoris, preganglionic fibers travel to which plexus via the inferior hypogastric plexus? What is the result of parasympathetic stimulation to these targets?

Answer 21

cavernous plexus;

vasodilation and filling of the sinuses of erectile tissue