Anatomy: Neural Supply of the Pelvic Cavity

Question 1

__ provides somatic (voluntary) innervations that originate at the spinal cord to the pelvic viscera

Answer 1

the pudendal nerve

Question 2

__ provides parasympathetic innervation that contracts the detruser muscle and relaxes the internal urethral sphincter

Answer 2

the pelvic nerve

Question 3

explain the sympathetic nerves that innervate the pelvic viscera

Answer 3

sympathetic innervation originates in the thoracolumbar region from caudal L1 to L4 until they reach the caudal mesenteric ganglion (these are pre-ganglionic fibers) and then become the hypogastric nerve (post-ganglionic) which enter the pelvic plexus to innervate the urinary bladder

Question 4

the sympathetic nerves cause the detruser m to __ while the parasympathetic cause it to __

Answer 4

relax, contract

Question 5

T/F: the hypogastric nerves are the only source of sympathetic fibers to the pelvic plexus and therefore to the pelvic organs

Answer 5

T

Question 6

the internal urethral sphincter contracts under __ control

Answer 6

sympathetic

Question 7

inside the pelvic region the pudendal nerve innervates the __ and __

Answer 7

external sphincter of the urinary bladder and the striated muscle wall of pelvic urethra

Question 8

outside the pelvic region what does the pudendal nerve become and innervate?

Answer 8

1. caudal rectal n: external anal sphincter
2. perineal nerves: superficial- sensory to skin of the perineum and scrotum
   deep- motor to skeletal muscles of F/M repro tract and ext anal sphincter
3. dorsal nerve of the penis/clitoris -> sensory

Question 9

during sx if the the caudal rectal nerves are damaged bilaterally __ can result while unilateral damage may be tolerated without __

Answer 9

fecal incontinence, fecal incontinence

Question 10

what reflex can be used to test integrity of the sacral and coccygeal components of the spinal cord?

Answer 10

perineal reflex

Question 11

The genitofemoral nerve is formed from the ventral branches of L3 and L4 and courses retroperitoneally leaving the abdominal cavity through the __ and plays a role in the descent of the __

Answer 11

inguinal canal, testes

Question 12

t/f: the cremaster muscle, although a skeletal muscle is not under voluntary control

Answer 12

T

Question 13

t/f: the cat has a cremaster m

Answer 13

F

Question 14

the genitofemoral carries GSA fibers in but no GSE fibers in the __ while it contains both in the __

Answer 14

female, male

Question 15

genitofemoral n GSA fibers

Answer 15

sensory to parts of the external genitalia and medial surface of the thigh

Question 16

genitofemoral n GSE fibers

Answer 16

motor fibers to cremaster m in DOG no motor branch in the bitch