Pelvis and Perineum Flashcards
What is the pelvis comprised of?
2 pelvic bones - right and left os coxae and the terminal vertebral column (sacrum and coccyx)
What is the perienum?
Inferior floor of pelvic cavity, contains external genitalia and external openings for UG and GI systems
What makes up the false pelvis?
ilium, lower lumbar vertebrae, part of abdomen, sigmoid colon, cecum
What makes up the true pelvis>
pubis ischium and sacrum, bounded by inlet and outlet, urinary and reproductive organs
What are the borders of the pelvis INlet?
-posterior - sacral promontory and ala
-lateral- arcuate line on inner surface of ilium, pectenial line on superior pubic rems
-anterior - pubic symphysis
What does the pelvic inlet contain?
colon, rectum, bladder and some of the reproductive organs
What are the borders of the pelvis OUTlet?
– posterior- tip of coccyx
– lateral- ischial tuberosities, inferior margin of the sacrotuberous ligament
– anterior- pubic arch
What does the pelvis OUTlet contain?
terminal parts of vagina, urinary and GI tracts
What are some differences in male and female pelvises?
male has higher iliac crest, heart shaped pelvic inlet and a smaller pubic arch angle (50-60 degreees)
women have a larger pubic arch angle, a shorter pelvis in general, and a more circular pelvic cavity
What structures exit the greater sciatic foramen?
piriformis
superior gluteal n
sciatic n
inferior gluteal n
pudendal n
What structures exit the lesser sciatic foramen?
obturator intenus muscle
What structures enter the lesser sciatic foramen?
pudendal n, a, v
The sacrospinous ligament attaches to the sacrum and what other structure?
Ischial spine
what is the action of the piriformis muscle?
lateral rotation of thigh and aBduct thigh at hip
what is the action of the Obturator Internus muscle?
lateral rotation of thigh at hip
what is the action of the coccygeus muscle?
form pelvic floor, support pelvic viscera, pull coccyx forward after defication
Which of the following make up the pelvic diaphragm?
Piriformis
Obturator internus
Obturator externus
Gluteal minimus
Coccygeus
Coccygeus
What makes up the levator ani muscle?
puborectalis m., pubococcygeus m., illiococcygeus m.
What makes up the pelvic diaphragm?
Levator ani and coccygeus muscle (ishiococcygeus)
What innervates the pelvic floor?
pudendal nerve (S2-S4)
What is the perineum?
diamond-shaped region inferior to pelvic diaphragm
What are the functions of the perineum?
contain and support pelvic viscera (bladder, rectum, anal canal, reproductive organs), anchor the roots of the external genitalia
Where is the perineal body?
Between the UG and anal triangles, center point of perineum
What are the UG diaphragm muscles?
Superficial perineal space
*Superficial transverse perineal
*Bulbospongiosus
Deep perineal space
*External urethral sphincter m.
*Deep transverse perineal mm.
External anal sphincter
Fibers of levator ani
What does the anal triangle contain?
anal aperture, external anal sphincter, ischio-anal fossae
What is the anal lined by?
simple columnar epithelium
Is internal anal sphincter voluntary or involuntary control?
involuntary
Is external anal sphincter voluntary or involuntary control?
volunary
What is a hemorrhoid?
dialated and inflamed venous plexuses within the anorectal canal
External hemorrhoids are ___________ to the pectineal line
inferior
Why are external hemorrhoids painful?
somatic sensory nerve innervation, detect pain
Where are Internal hemorrhoids?
Superior to pectineal line
Which type of hemorrhoids are usually not painful?
Internal, visceral sensory nerves lack pain receptors
What is rectal prolapse?
When rectum drops out of normal place, pushes out of anal opening
What is in the urogenital triangle?
Colle’s fascia and perineal membrane, forms floor of deep perineal pouch and roof of superficial perineal pouch
What muscles are in the superficial perineal space/pouch?
ischiocavernosus, bulbospongiosus
What erectile tissues and glands are in the superficial perineal pouch?
crus of clitoris (or penis), bulb or vestibule / clitoris (penis), greater vestibular gland (females only), perineal membrane
What muscles are in the deep perineal pouch?
deep transverse perineal muscle, external urethral sphincter
What erective tissues/glands are in the deep perineal pouch?
bulbourethral/ Cowper’s gland
neurovasculatur (pudendal nerve/ internal pudendal artery and vein branches)
What is the significance of the deep perineal space clinically?
external urethral sphincter muscle important for urinary continence
All of these are levator ani muscles EXCEPT
Piriformis
Puborectalis
Pubococcygeus
Iliococcygeus
Piriformis
Which of these would be found within the superficial space?
Deep transverse perineal muscle
Greater vestibular glands
Bulbourethral glands
Sphincter urethrae muscle
Greater vestibular glands
Name the nerves and roots in the sacral plexus
ventral rami of L4-S4
Superior gluteal (L4-S1)
Inferior gluteal (L5-S2)
Sciatic (L4-S3)
Posterior femoral cutaneous (S1-S3)
Nerves to obturator internus (L5-S2) and quadratus femoris (L4-S1)
Pudendal (S2-S4)
What is the course of the pudendal nerve?
exit greater sciatic foramen, hooks around ischial spine and sacrospinous ligament, enter perineum via lesser sciatic foramen
What is the motor innervation of the pudendal nerve?
external urethral sphincter, external anal sphincter, perineal muscles
What is the cutaneous innervation of the pudendal nerve?
innervation to perineum and clitoris/penis
What are the nerve roots of the pudendal nerve?
S2, S3, S4
Where is the pudendal canal?
within the fascia of the obturator internus muscle
What does the pudendal canal contain?
pudendal nerve, internal pudendal artery and vein
Inferior rectal pudendal nerve branches:
Motor->external anal sphincter
Sensory->skin around anus
Perineal pudendal nerve branches
motor- all superficial and deep space muscles
sensory- perineum
Is dorsal nerve of penis/clitoris sensory or motor?
sensory
anal wink causes what to contract?
external anal sphincter due to bulbocavernosus/bulbospongiosus reflex
What nerve is blocked during childbirth?
Pudendal nerve
What are landmarks to locate the pudendal nerve?
ischial spine and sacrospinous ligament
What are the sympathetic pelvic nerves?
sacral splanchnics and hypogastric nerves
What do the sympathetic pelvic nerves do?
vasoconstriction, contract internal urethral and anal sphincters, ejaculation
What is the parasympathetic innervation of the pelvis?
Pelvis splanchnics (S2-S4)
What does the parasympathetic innervation of the pelvis do?
vasodilation, stimulate bladder contraction for urination, stimulate defecation, stimulate erection
Which of these nerves would innervate the perineum?
Obturator
Inferior gluteal
Superior gluteal
Femoral
Pudendal
Pudendal
Internal iliac artery divides into what anterior to the SI joint?
anterior and posterior trunks
What does the anterior trunk of the internal iliac artery do?
Supply pelvic viscera, perineum, gluteal region, adductor region
What does the posterior trunk of the internal iliac artery do?
Supply posterior pelvic wall, lower posterior abdominal wall, gluteal region
Which of these arise from the anterior trunk of the internal iliac artery?
Inferior gluteal
Lateral sacral
Superior gluteal
Ovarian
Iliolumbar
Superior gluteal
Where does the vaginal artery come from?
The vaginal artery is said to come from either the internal iliac artery or the uterine artery.
What do the internal iliac arteries do?
Supply pelvic organs
What do the internal pudendal arteries do?
Supply viscera located in the perineum
Where is the superior gluteal artery in relation to the spinal column?
Between lumbosacral trunk and S1
Where is the inferior gluteal artery in relation to the spinal column?
Between S1 and S2
Is internal pudendal artery posterior or anterior to coccygeus
posterior
What is the male equivalent to the vaginal artery?
Inferior vesicle artery
