Lab 12: Perineum and Pelvic Neurovasculature

Question 1

Describe urogenital triangle

Answer 1

apex = pubic symphysis
Line between ischial tuberosity
Lateral border = ischial pubic rami
Roof = pelvic diphragm

Question 2

What is urogenital hiatus

Answer 2

Levator ani opening
Covered by perineal membrane

Question 3

Describe muscle - imrpoatnt

Answer 3

Superficial transverse perineal muscles

Question 4

Describe crura, and bulb of vestibule in afab

Answer 4

2 bulbs next to crura = bulb of vestibule
Muscle covering = bulbospongiosus

Question 5

Describe perineal membrane a

Answer 5

Only covers urogenital triangle

Question 6

Describe deep perineal pouch

Answer 6

Roof = pelvic floor
Floor = perineal membrane
Muscle fibres, sphincters inside, amab bulbourethral gland, external urethral sphincter, deep trasnverse perineal muscle

Question 7

Describe bulb of penis

Answer 7

Corpus spongiosum
Covered by bulbospongiosus

Question 8

Describe crura of penis a

Answer 8

Corpus cavernosum
Covered by ischiocavernosus muscle

Question 9

Describe/compare erectile tissues in afab and amab

Answer 9

Amab = corpus spongiosum
Afab = bulb of vestibule
= both covered by bulbospongiosus muscle
(Crura = same, corpus cav, ischiocavernosus muscle)

Question 10

Describe anogenital triangle

Answer 10

Ischial tub imaginary line
Coccyx = apex
Roof = pelvic diaphragm
Lateral = sacrotuberous ligament

Question 11

Describe ischioanal fossa

Answer 11

Space, adipose tissue
Udner sacrotuberous ligament
Superior = pelvic diaphragm
Lateral = sacrotuberous and ischial tuberosity
Inferior = skin fo anal triangle

Question 12

Describe anterior recess

Answer 12

Between deep perineal pouch and levator ani

Question 13

Describe pudendal nerve

Answer 13

S2,3,4
Coursing around sacrospinous ligament and ischial spine, into pudendal canal to perineal region

Question 14

What does pudendal nerve branch into

Answer 14

Inferior rectal nerves = to anus and external anal sphincter
Perineal branches = to ext genitalia

Question 15

Describe pelvic splanchnic nerves

Answer 15

Psns
S2,3,4
Contribute to inferior hypogastric plexus around bladder and rectum - and vagina in afab

Question 16

Describe sacral splanchnic nerves

Answer 16

Sns
Stem from sacral sympathetic chain to inferior hypogastric plexus

Question 17

Describe blood supply pathway to smaller branches

Answer 17

Abd aorta —> common iliac (bifurcation, on each each side, around sacroiliac joint) —> external iliac (more ant) and internal iliac (more inside) —> INT ILIAC —> anterior trunk and posterior trunk

Question 18

Name divisions of posterior trunk of internal iliac artery

Answer 18

Iliolumbar
Lateral sacral
Superior gluteal

Question 19

Describe iliolumbar artery

Answer 19

Goes up
1st branch
Gives =
Iliac branches to iliacus
Lumbar branches to post abd wall muscles

Question 20

Describe lateral sacral artery

Answer 20

Straight back, can be multiple
Through sacral foramina

Question 21

Describe superior gluteal artery

Answer 21

Leaves through greater sciatic foramen above piriformis
To outside pelvic cavity

Question 22

Describe umbilical artery

Answer 22

Most anterior branch
Remnant fetal dev = turns into medial umbilical ligament
Thick
Usually first branch

Question 23

Describe superior vesical artery

Answer 23

Off umbilical
To distal bladder and ureters

Question 24

Describe obturator artery

Answer 24

Through obturator foramen
Goes to medial thigh
Near obturator internus, obvious where it goes

Question 25

Describe inferior vesical artery

Answer 25

AMAB To base of bladder, seminal vesicles, prostate

Question 26

Describe vaginal and uterine arteries

Answer 26

Uterine = over ureter to cervix Vaginal = more inferior to bladder, vagina and rectum * equivalent to inferior vesical in amab AFAB

Question 27

Describe middle rectal artery

Answer 27

To rectum

Question 28

Describe internal pudendal artery

Answer 28

Leaves via greater sciatic foramen under - inferior to piriformis Loops around ischial spine and comes back in through lesser sciatic foramen —> perineum Closer to ischial spine Gives = inferior rectal (to rectum) and perineal branches (to perineum)

Question 29

Describe inferior gluteal artery

Answer 29

Exit via greater sciatic foramen inferior to piriformis

Question 30

Describe pudendal and pelvic splanchnic

Answer 30

Pudendal = somatic Pelvic splanchnic = psns BUT BOTH COMES FROM S2,3,4 but DIFFFFFFFFF

Question 31

Describe pudendal - somatic innervation

Answer 31

FROM sacral plexus - anterior to piriformis Inside pelvic cavity = to perineum, same pathway as internal pudendal artery = loop

Question 32

Describe pudendal nerve - branches

Answer 32

Inferior rectal nerve Perineal nerve Dorsal nerve of penis/clitoris

Question 33

Describe autonomic

Answer 33

Sns and psns

Question 34

Describe pelvic splanchnic - specifics

Answer 34

GOES UP S2,3,4 Preganglionic parasympathetic Rets an digest To inferior hypogastric plexus Hypogastric nerv from superior hypogastric plexus

Question 35

Describe sacral splanchnic - specifics

Answer 35

GOES DOWN Meets at one ganglia

Question 36

Describe post ganglionic sns

Answer 36

Synapse already in sympathetic trunk —> sacral spinal nerve

Question 37

Describe pre ganglionic sns

Answer 37

Use sacral splanchnic to get to inferior hypogastric plexus