Pelvis & Perineum Flashcards
What is the only type of innervation found in the pelvic diaphragm?
Somatic ONLY (no visceral)
What does SI joint stand for and what type of joint is this (2)?
Sacroiliac joint (SI) is a synovial joint anteriorly and a syndesmosis joint posteriorly
What are the five joints of the pelvic joint and what are their functions? (hint: 2 grouped together and other 3 grouped together)
- Iliolumbar joint (stabilize joint)
- Anterior SI joint (stabilize joint)
- Posterior SI joint (stabilize joint)
- Sacrospinous (prevent flexion)
- Sacrotuberous (prevent flexion)
What three subunits make up the levator ani muscle?
- Pubococcygeus
- Iliococcygeus
- Puborectalis
What is the urogenital hiatus (where is it located)? What structures pass through it?
Urogenital hiatus is an opening in the levator ani muscles that allows for the passage of the urethra in males and females, as well as the vagina in females
During defecation, what is the role of each of the levator ani muscles?
- Pubococcygeus and Iliococcygeus contract to resist increased abdominal pressure when the abdominal muscles contract
- Puborectalis relaxes to straight then anorectal junction
What are the three branches of the posterior division of the Internal Iliac a.?
- Iliolumbar a.
- Lateral sacral a.
- Superior rectal a.
What are the eight branches of the anterior division of the Internal Iliac a.?
- Umbilical a.
- Obturator a.
- Middle rectal a.
- Internal pudendal a.
- Inferior gluteal a.
- Superior vesical a.
- Uterine a./Inferior vesical a.
- Vaginal branches/prostatic branches
What are the two arteries/branches found in the anterior division of the Internal Iliac a. that are analogous in females versus males?
- Uterine a. and Inferior vesical a.
- Vaginal branches and prostatic branches
What levels of the vertebral column provide somatic innervation to the pelvic diaphragm?
- Lumbosacral trunk (L4-5 anterior rami)
- Sacral plexus (S1-4 anterior rami)
What are the ten branches from the sacral plexus that pass through the pelvis?
- Sciatic n.
- Superior gluteal n.
- Inferior gluteal n.
- Pudendal n.
- Posterior femoral cutaneous n.
- Nerve of piriformis
- Nerve of obturator internus
- Nerve of quadrates femoris
- Nerve of levator ani
- Nerve of coccygeus
What is the one nerve that branches from the lumbar plexus and passes through the pelvis?
Obturator n.
What plexus provides innervation to the pelvis? What are the sympathetic (visceral motor) innervations and the parasympathetic (visceral motor) innervations?
Superior hypogastric plexus
- Sympathetics: lower lumbar splanchnic nn. and upper sacral splanchnic nn.
- Parasympathetics: Pelvis splanchnic nn. (S2-4)
Where do the hypogastric nerves originate from and what plexus do they form? What type of ganglions are found in this plexus?
Hypogastric nerves come from the Superior hypogastric plexus and converge to form the Inferior hypogastric plexus
- Postganglionic sympathetics (synapse in plexus)
- Preganglionic parasympathetics (wait and synapse at target organs)
What is the one pouch found in the peritoneum of males?
Rectovesical pouch (between rectum and bladder)
What are the two pouches found in the peritoneum of females? Which is more anterior?
- Vesicouterine pouch (between bladder and uterus) - more anterior of the two
- Rectouterine pouch (between rectum and uterus)
Where is the pelvic pain line located? What are the rules for visceral pain and non-pain sensation above/below the PPL?
Pelvic pain line (PPL): inferior extent of peritoneum across the midpoint of the sigmoid colon
Above PPL
- Non pain: parasympathetics in reverse
- Pain: sympathetics in reverse
Below PPL:
- Non pain: parasympathetics in reverse
- Pain: parasympathetics in reverse
What type of muscle makes up the internal urethral sphincter? What type of muscle makes up the external urethral sphincter?
- Internal urethral sphincter: smooth muscle
- External urethral sphincter: striated muscle