Recap lectures 11-12 (pelvis + perineum) Flashcards
Pelvis + perineum (134 cards)
What are the two main parts of the pelvic cavity? What marks where each begins?
1) Greater; Supracristal plane
2) Lesser; pelvic brim
What are the two main parts of the lesser pelvic cavity? What structures are located at each?
1) Pelvic inlet: Superior pubis to sacral promontory
2) Pelvic outlet: Inferior rami of pubis and Ischial tuberosities anterolaterally; tip of coccyx posterior
1) What do the Sacrospinous and sacrotuberous ligaments prevent?
2) What can they be responsible for?
1) Excessive lumbar lordosis during weight bearing
2) “Back pain”
1) What form the anterior inferior wall of the pelvis?
2) What form the lateral wall?
1) Body and rami of pubic bone; pubic symphysis
2) Boney hips, obturator foramen, membrane, muscle, vessels and nerves
1) Compare the pubic arches of male and female pelvises
2) Compare the thickness and heaviness of bones of male and female pelvises
1) Males have a narrower pubic arch < 70 degrees; females have a wide pubic arch > 80 degrees
2) Male pelvises have thick and heavy bones; females have thin and light boney structure
1) Compare the deepness of male and female greater pelvises
2) Compare the deepness of male and female lesser pelvises
1) Males’ greater pelvis is deep, females’ is shallow
2) Males’ lesser pelvis is narrow and deep; females’ is wide and shallow
1) Compare the inlet shapes of male and female pelvises
2) Compare the outlet shapes of male and female pelvises
1) Males’ inlet is heart-shaped; female inlet oval or rounded
2) Males’ outlet is smaller, female outlet larger
What is the pelvic floor also called?
Pelvic diaphragm
What 3 things cover the pelvic diaphragm?
Levator ani + coccygeus muscles + fascia
1) What forms the tendinous arch of levator ani? Where?
2) What are the two primary muscles that make up the levator ani?
1) Obturator fascia (thickened); ~ L5-S4
2) Pubococcygeus and iliococcygeus
What provide the blood and innervation to the perineal compartment? Where does the blood flow come from?
Pudendal vessels (come off anterior internal iliac) and pudendal nerves (lumbo-sacral nerves)
List the 4 main muscles of the pelvic walls.
Which of these makes up the lateral wall? What about the posterior wall?
1) Levator ani
2) Coccygeus m.
3) Obturator internus – lateral wall
4) Piriformis – posterior wall
What two main nerves are formed by the sacral plexus? What does each innervate?
1) Sciatic n.– posterior thigh and leg below knee
2) Pudendal n. – nerve to perineum
Besides the two main nerves of the sacral plexus, what else does it form? What does each innervate?
1) Superior gluteal n. – glut min, medius, TFL
2) Inferior gluteal n.– glut max
Where is the coccygeal plexus?
S4-5, Co1 to pelvic floor
1) Where does the sciatic nerve come from and where does it exit?
2) Where does the superior gluteal n come from and exit? What 3 muscles does it innervate?
1) L4 -S3, exits thru greater sciatic foramen, inferior to pyriformis m.
2) L4-S1, exits via greater sciatic foramen, supplies 3 muscles in glut region: gluteus Medius and Minimus mm., & TFL
1) Where does the pudendal nerve come from? What is the it main nerves of?
2) Where does it enter?
1) S2-S4, main nerve to the perineum and chief sensory nerve of the external genitalia
2) Enters perineum via lesser sciatic foramen
1) Where does the obturator nerve come from?
2) Where does it pass through?
3) What is it the primary nerve to?
1) L2-L4
2) Passes thru the pelvis BUT is not a pelvic nerve
3) Medial (adductor group) thigh
1) What do structures do at the greater sciatic foramen?
2) What muscle is located here?
3) What 4 nerves are here?
4) What else is located here?
1) Exit pelvis
2) Piriformis m. to femur
3) Sciatic nerve, pudendal nerve, superior/inferior gluteal n.
4) Vessels
1) What do structures do at the lesser sciatic foramen?
2) What muscle is located here?
3) What nerve is here?
1) Exit pelvis and re-enter perineal compartment
2) Obturator internus m.
3) Pudendal nerve
What does sympathetic innervation of the pelvis do? (3 things)
1) Vasomotion
2) Inhibit peristalsis of rectum
3) Stimulates contraction of genital organs during orgasm (ejaculation in males)
What does parasympathetic innervation of the pelvis do? (2 things)
1) Stimulate contraction of bladder and rectum
2) Supply erectile bodies of genitalia resulting in erection
What are the 3 main parts of pelvic autonomics?
1) Sympathetic
2) Parasympathetic
3) Periarterial plexuses
1) Reflex visceral afferents (not aware consciously) of the pelvis are conducted how? Where to?
2) How do pain visceral afferents (aware consciously) differ?
1) Via parasympathetic to spinal ganglia S2-3-4
2) Diff. based on “pelvic pain line” that corresponds to the inferior limit of the peritoneum