Flashcards in Sacral And Coccygeal Plexuses Deck (115)
Through which opening do the posterior primary rami of S1-S4 travel through?
The four posterior sacral foramina
Through which opening does the S5 posterior ramus travel through?
In which direction do the sacral posterior rami decrease in size?
From superior to inferior
Which of the sacral posterior primary rami divide into medial and lateral branches?
What do the medial branches of S1-S3 posterior primary rami supply?
What do the lateral branches of the posterior primary rami of S1-S3 supply?
Skin over the buttocks (combined with branches from L5 and S4)
What is the supply of the posterior primary rami of S4 and S5 and their union with the coccygeal posterior rami?
Skin over the coccyx
What travels through the anterior sacral foramina?
Anterior primary rami of S1-S4
Which sacral anterior primary ramus travels through the sacral hiatus?
There are usually how many sacral sympathetic ganglia that form the communication with the sympathetic trunk?
Three or four
The anterior primary ramus of each sacral nerve will receive what kind of information via a gray ramus communicans?
Postganglionic sympathetic fibers
What forms the sacral plexus?
Anterior primary rami of L4, L5, S1-S3, part of S4
What forms the lumbosacral trunk?
L4 and L5
The sacral plexus forms on the anterior surface of what muscle?
When do the nerve roots of the sacral plexus divide into anterior and posterior divisions?
Shortly after exiting their IVF/sacral foramen
What fibers are contained in the nerve to the quadratus femoris and gemellus inferior?
L4, L5, and S1
The nerve to the quadratus femoris and gemellus inferior leaves the pelvis through what opening?
Greater sciatic foramen
The muscles supplied by the nerve to the quadratus femoris and gemellus inferior share what common action?
Lateral rotation and adduction of the thigh
What fibers are contained in the nerve to the obturator internus and gemellus superior?
L5, S1, S2
The nerve to the obturator internus and gemellus superior leaves the pelvis through what opening?
Greater sciatic foramen
The nerve to the obturator internus and gemellus superior re-enters the pelvis through what opening to supply what muscle?
Lesser sciatic foramen, obturator internus
The muscles that are supplied by the nerve to the obturator internus and gemellus superior share what common action?
Lateral rotation and abduction of the thigh
What fibers are contained in the pudendal nerve?
S2, S3, and S4
What is the course of the pudendal nerve?
Leaves pelvic cavity through greater sciatic foramen, arches around the ischial spine and into the perineum via lesser sciatic foramen
Then, through the pudendal canal inferior to the pubic symphysis to reach dorsal side of penis or clitoris
What branches of the pudendal nerve come off within the pudendal canal?
Inferior rectal nerves, perineal nerve, dorsal nerve of penis/clitoris
The superior and inferior gluteal nerves are named in reference to what muscle?
The inferior rectal nerves carry sensory information from what locations?
Skin around the anus and the inferior 2/3 of the anal canal
What is the motor supply of the inferior rectal nerves?
External anal sphincter
Which branch of the perineal nerve has motor supply? Which has sensory supply?
Motor - deep branch
Sensory - superficial branch