Lab 12: Perineum and Pelvic Neurovasculature Flashcards
Describe urogenital triangle
apex = pubic symphysis
Line between ischial tuberosity
Lateral border = ischial pubic rami
Roof = pelvic diphragm
What is urogenital hiatus
Levator ani opening
Covered by perineal membrane
Describe muscle - imrpoatnt
Superficial transverse perineal muscles
Describe crura, and bulb of vestibule in afab
2 bulbs next to crura = bulb of vestibule
Muscle covering = bulbospongiosus
Describe perineal membrane a
Only covers urogenital triangle
Describe deep perineal pouch
Roof = pelvic floor
Floor = perineal membrane
Muscle fibres, sphincters inside, amab bulbourethral gland, external urethral sphincter, deep trasnverse perineal muscle
Describe bulb of penis
Corpus spongiosum
Covered by bulbospongiosus
Describe crura of penis a
Corpus cavernosum
Covered by ischiocavernosus muscle
Describe/compare erectile tissues in afab and amab
Amab = corpus spongiosum
Afab = bulb of vestibule
= both covered by bulbospongiosus muscle
(Crura = same, corpus cav, ischiocavernosus muscle)
Describe anogenital triangle
Ischial tub imaginary line
Coccyx = apex
Roof = pelvic diaphragm
Lateral = sacrotuberous ligament
Describe ischioanal fossa
Space, adipose tissue
Udner sacrotuberous ligament
Superior = pelvic diaphragm
Lateral = sacrotuberous and ischial tuberosity
Inferior = skin fo anal triangle
Describe anterior recess
Between deep perineal pouch and levator ani
Describe pudendal nerve
S2,3,4
Coursing around sacrospinous ligament and ischial spine, into pudendal canal to perineal region
What does pudendal nerve branch into
Inferior rectal nerves = to anus and external anal sphincter
Perineal branches = to ext genitalia
Describe pelvic splanchnic nerves
Psns
S2,3,4
Contribute to inferior hypogastric plexus around bladder and rectum - and vagina in afab
Describe sacral splanchnic nerves
Sns
Stem from sacral sympathetic chain to inferior hypogastric plexus
Describe blood supply pathway to smaller branches
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
Name divisions of posterior trunk of internal iliac artery
Iliolumbar
Lateral sacral
Superior gluteal
Describe iliolumbar artery
Goes up
1st branch
Gives =
Iliac branches to iliacus
Lumbar branches to post abd wall muscles
Describe lateral sacral artery
Straight back, can be multiple
Through sacral foramina
Describe superior gluteal artery
Leaves through greater sciatic foramen above piriformis
To outside pelvic cavity
Describe umbilical artery
Most anterior branch
Remnant fetal dev = turns into medial umbilical ligament
Thick
Usually first branch
Describe superior vesical artery
Off umbilical
To distal bladder and ureters
Describe obturator artery
Through obturator foramen
Goes to medial thigh
Near obturator internus, obvious where it goes
Describe inferior vesical artery
AMAB
To base of bladder, seminal vesicles, prostate
Describe vaginal and uterine arteries
Uterine = over ureter to cervix
Vaginal = more inferior to bladder, vagina and rectum * equivalent to inferior vesical in amab
AFAB
Describe middle rectal artery
To rectum
Describe internal pudendal artery
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)
Describe inferior gluteal artery
Exit via greater sciatic foramen inferior to piriformis
Describe pudendal and pelvic splanchnic
Pudendal = somatic
Pelvic splanchnic = psns
BUT BOTH COMES FROM S2,3,4 but DIFFFFFFFFF
Describe pudendal - somatic innervation
FROM sacral plexus - anterior to piriformis
Inside pelvic cavity = to perineum, same pathway as internal pudendal artery = loop
Describe pudendal nerve - branches
Inferior rectal nerve
Perineal nerve
Dorsal nerve of penis/clitoris
Describe autonomic
Sns and psns
Describe pelvic splanchnic - specifics
GOES UP
S2,3,4
Preganglionic parasympathetic
Rets an digest
To inferior hypogastric plexus
Hypogastric nerv from superior hypogastric plexus
Describe sacral splanchnic - specifics
GOES DOWN
Meets at one ganglia
Describe post ganglionic sns
Synapse already in sympathetic trunk —> sacral spinal nerve
Describe pre ganglionic sns
Use sacral splanchnic to get to inferior hypogastric plexus
