Intro. to Pelvis and Perineum Flashcards
What separates the pelvic cavity and the perineum?
Pelvic diaphragm
What runs through the anterior sacral foramina?
Ventral rami of sacral spinal nerves and blood vessesls
In what portion of the os coxae does the head of the femur articulate?
Acetabulum
What bony feature is between the superior and inferior pubic rami?
Obturator foramen
What runs though the posterior sacral foramina?
Dorsal rami of sacral spinal nerves
In which sex is the infrapubic angle much narrower/smaller?
Males
Which sex has a broader span between the two iliac bones?
Females
What pelvic shape is most common in women?
Gynecoid
What is the anatomical conjugate of the pelvis?
From the top of the pubic symphysis to the promontory of the sacrum
What is the true (obstetric) conjugate?
From the middle portion of the pubic symphysis to promontory at sacrum
What is the shortest fixed distance of the pelvis?
Obstetric conjugate
What is the diagonal conjugate?
From the bottom of the pubic symphysis to the promontory of the sacrum.
What type of joint is the pubic symphysis?
Secondary cartilagenous
What type of joint is between the bodies of L5 and S1?
Secondary cartilaginous
To what structures does the sacrotuberous ligament connect?
Sacrum to ischial tuberosities
To what structures does the sacrospinous ligament connect?
Sacrum to ischial spine
What ligaments form the greater and lesser sciatic foramina?
Sacrospinous and sacrotuberous
To what does the superior pubic ligament attach?
Superior aspects of pubic bodies and interpubic disc,
What does the inferior pubic ligament attach to?
Between the two inferior ischiopubic rami
What forms the apex of the pubic arch on the inferior aspect of the pubic symphysis?
Inferior pubic ligament
What is the proximal attachment of the iliacus m.?
Superior ⅔ of iliac fossa, ala of sacrum, and anterior sacroiliac ligaments
What is the distal attachment of the iliacus m.?
Lesser trochanter of femur and shaft inferior to it, and to psoas major tendon
What innervates the iliacus m.?
Femoral n.
What is the main action of the iliacus?
Flexes thigh and stabilizes hip joint
What is the proximal attachment of the obturator internus?
Pelvic surfaces of ilium and ischium; obturator membrane
What is the distal attachment of the obturator internus m.?
Greater trochanter of the femur
What innervates the obturator internus?
Nerve to obturator internus
What is the main action of the obturator internus?
Rotates the thigh laterally; assists in holding head of femur in acetabulum
What is the proximal attachment of the piriformis m?
Pelvic surface of S2-4 segments; superior margin of greater sciatic notch and sacrotuberous ligament
What is the distal attachment of the piriformis m?
Greater trochanter of the femur
What innervates the piriformis m.?
Branches of S1, S2 spinal nn.
What is the main action of the piriformis m.?
Rotates thigh laterally, adducts thigh; assists in holding head of femur in acetabulum
What m. courses through lesser sciatic foramen?
Obturator internus m.
What muscle courses through the greater sciatic foramen?
Piriformis m.
What is the proxial attachment of the coccygeus m?
Ischial spine
What is the distal attachment of the coccygeus m.?
Inferior end of sacrum and coccyx
What innervates the coccygeus m?
Branches of S4, S5 spinal nerves
What are the muscles that makes up the levator ani m?
Puborectalis, pubococcygeus, iliococcygeus
How many openings are in the female pelvic disphragm? The male?
3, 2
The tendineus arcus is a thickening of what fascial layer?
Obturator internus fascia
What muscle wraps around the rectum and is in a tonic state of contraction?
Puborectalis
What fascia lines muscles forming walls and floor of pelvis?
Parietal
What fascia directly ensheathes the pelvic organs?
Visceral
What fascial layer is between the visceral and parietal fascia?
Endopelvic
The cervical ligaments are formed from thickenings from what fascial layer?
Endopelvic fascia
What ligament extends from the pubis to the cervix?
Pubocervical ligament
What ligament extends from the cervix to the sacrum?
Uterosacral ligament
What ligament extends from the cervix to the pelvic wall?
Transverse cervical ligament?
What are the boundaries of the anal triangle?
Superior- Pelvic Diaphragm; Lateral- Obturator internus m. w/fascia; Medial- External anal sphincter m. and sloping pelvic diaphragm; Anterior- Imaginary line btw ischial tuberosities; Posterior- Sacrotuberous ligament and gluteus maximus m.
What are the boundaries of the urogenital triangle?
Line between the ischial tuberosities are the pubic symphysis
What is contained in Alcock’s canal?
Pudendal n, internal pudendal a. and v.
What forms the roof of the superficial perineal pouch and floor of the deep perineal pouch?
Perineal membrane
What is the path of the pudendal n. to the UG triangle?
Goes out through the greater sciatic foramen, wraps around the sacrospinous ligament, travels back into the pelvis through the lesser sciatic foramen, travels through Alcock’s canal
What part of the bladder is the location of the internal urinary sphincter?
Uvula of bladder
What nerve supplies motor innervation to muscles of both superficial and deep perineal pouches?
Perineal n.
What nerve provides motor innervation to the external anal sphincter m.?
Inferior rectal n
To which lymphnodes do lymphatics drain from above and below the pectinate line?
Above- pararectal lymph nodes–> lumbar nodes; Inferior- superficial inguinal nodes
What is the venous drainage above and below the pectinate line? Of which venous systems are they?
Above- superior rectal v. (portal system); below- inferior rectal v. (systemic)
What is the arterial supply above and below the pectinate line?
Above- superior rectal a.; below- inferior rectal a.
What are the recesses of the anal canal superior to the valves that contain mucous glands?
Anal sinuses
What are the branches of the anterior division of internal iliac a.?
Umbilical- superior vesical, obturator, middle rectal, inferior vesical, internal pudendal, inferior gluteal, (uterine in females)
What is the largest branch of the internal iliac a.?
Superior gluteal a.
What are the contents of the inferior hypogastric plexus (pelvic plexus)?
Hypogastric nn., lower 2 lumbar splanchnics, pelvic splanchnic nn., sacral splanchnic nn.
What are the functions of parasympathetic innervation in the pelvis?
Contraction of detrusor m., erection
What are the functions of synpathetic innervation in the pelvis?
Contract internal urethral sphincter m., contract internal anal sphincter m., ejaculation
What are the branches of the internal pudendal a.?
Inferior rectal, perineal, posterior scrotal branches, a. of the bulb of the penis, urethral a., deep a. of penis, dorsal a. of penis
What vessel courses between the lumbosacral trunk and S1 ventral ramus?
Superior gluteal a.
What are the branches of the posterior division of internal iliac a.?
Iliolumbar, lateral sacral, superior gluteal
What portion of the anal canal is surrounded by the external anal sphincter?
Inferior 2/3
What is the fatty layer of superficial perineal fascia in the UG triangle?
Camper’s fascia
Of which layer of abdominal fascia is Colles’ fascia a continuation?
Scarpa’s