sacral plexus

Question 1

what is the spinal root value of the sacral plexus

Answer 1

anterior fibres of S1-S4

Question 2

what nerves originate from the sacral plexus

Answer 2

superior gluteal 
inferior gluteal 
sciatic 
posterior femoral cutaneous 
pudendal nerve

Question 3

what muscle does the sacral plexus sit on

Answer 3

piriformis

Question 4

what foramen do most of the nerves pass through

Answer 4

greater sciatic

Question 5

root value of superior gluteal nerve

Answer 5

L4-S1

Question 6

what muscles does the superior gluteal nerve innervate

Answer 6

gluteus minimus
gluteus medius
tensor fascia lata

Question 7

what is the root value for the inferior gluteal nerve

Answer 7

L5-S2

Question 8

what muscle does the inferior gluteal nerve innervate

Answer 8

gluteus maximus

Question 9

what is the root value for the sciatic nerve

Answer 9

L4-S3

Question 10

what muscles does the sciatic nerve innervate

Answer 10

all muscles in posterior compartment of thigh, leg and sole of foot

Question 11

what areas of skin does the sciatic nerve supply

Answer 11

tibial branch - posterolateral leg, lateral foot, sole of foot
common fibular - lateral leg, dorsum of foot

Question 12

what is the root value of the posterior femoral cutaneous nerve

Answer 12

S1-S3

Question 13

what area of skin does the posterior femoral cutaneous nerve innervate

Answer 13

posterior surface of thigh and leg

perineal branch innervates most skin of perineum

Question 14

root value of pudendal nerve

Answer 14

S2-S4

Question 15

what muscles does the pudendal nerve innervate

Answer 15

skeletal muscles in perineum
external anal sphincter
external urethral sphincter
levator ani

Question 16

what area of skin does the pudendal nerve innervate

Answer 16

penis
clitoris
skin around anus
anal canal

Question 17

what foramina does the pudendal nerve pass through

Answer 17

greater sciatic foramen

lesser sciatic foramen

Question 18

what ligament does the pudendal nerve cross to go from the greater to lesser sciatic foramen

Answer 18

sacrospinous ligament

Question 19

what forms the pudendal canal

Answer 19

the fascia of the obturator internus

Question 20

where is the pudendal canal

Answer 20

inner aspect of ischium
below obturator foramen
moves posterior to anterior

Question 21

what are the contents of the pudendal canal

Answer 21

internal pudendal artery and veins

pudendal nerve

Question 22

what branches does the pudendal nerve give off in the pudendal canal

Answer 22

inferior rectal

perineal nerve

Question 23

what does the pudendal nerve continue as in the pudendal canal

Answer 23

dorsal nerve of penis or clitoris

Question 24

what muscles does the perineal nerve inervate

Answer 24

levator ani muscles
bulbospongiosus
ischiocavernosus

Question 25

what does the dorsal nerve innervate

Answer 25

skin of penis or clitoris

Question 26

what anatomical pathway does the pudendal nerve take

Answer 26

goes through greater sciatic foramen anterior to piriformis | follows ischial spine to enter pelvis again through the lesser sciatic foramen and supplies the perineum

Question 27

describe the anatomical pathway of the superior gluteal nerve

Answer 27

passes through greater sciatic foramen over piriformis to supply gluteus medius and minimus

Question 28

describe the anatomical pathway of the inferior gluteal nerve

Answer 28

passes under piriformis through greater sciatic foramen to supply gluteus maximus

Question 29

describe the anatomical pathway of the obturator nerve

Answer 29

from lumbar plexus runs along lateral wall of pelvis enters obturator canal over the top of psoas major and exists the pelvis to supply the medial thigh

Question 30

obturator nerve route

Answer 30

L2-4

Question 31

superior and inferior gluteal nerve routes

Answer 31

L4-S1 sup | L5-S2 inf

Question 32

where does autonomic innervation of the pelvis come from

Answer 32

sacral and lumbar sympathetic trunks (located medial to spinal nerves)

Question 33

what nerve innervates the skin of the external genitalia

Answer 33

ilioinguinal

Question 34

what effect do parasympathetic nerves have on bladder, rectum and penis

Answer 34

contracts bladder contracts rectum erection

Question 35

what nerves cause ejaculation

Answer 35

sympathetic point and shoot para for erection, symp for ejaculation