Lecture 11 (pelvis) Flashcards
List the parts of the pelvis
1) Pelvic girdle
2) Joints and ligaments
3) Paired direct tributaries peritoneum and peritoneal cavity of pelvis
4) Walls and floors of pelvic cavity
5) Pelvic fascia, nerves, vessels, & lymph nodes
6) Pelvic viscera
What are the pelvic viscera?
1) Urinary
2) Reproductive organs
3) Urogenital triangle
4) Anal triangle
5) Female and male urogenital triangle
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
What are the bones, joints and ligaments of the pelvic girdle?
1) Pubic symphysis
2) Paired Sacroiliac
3) Lumbosacral
4) Sacral coccygeal
What are the 3 bones of the bony pelvis?
1) Paired R & L hip (a fusion of 3 bones)
2) Sacrum
1) What 3 bones fuse to make up the left and right hips?
2) What makes up the sacrum?
1) Ilium, pubis, and ischium
2) Fusion of 5 sacral vertebrae
1) What is the acetabulum
2) What is included in it?
1) “Hip joint” with head of femur
2) Components of all 3 bones of hip
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 make up the pelvic diaphragm?
Levator ani and coccygeus muscles
From levator ani to skin of rectum, you can find what?
Perineal compartment
What can occur at the ischo-anal fossa of the perineum?
Abscesses
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 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
1) Where is the Lumbar-sacral-coccygeal nerve plexus?
2) Where is the sacral nerve plexus?
1) L4-5 lumbosacral trunk to sacral plexus
2) Lumbosacral trunk to sacral plexus + S1-S3 (L4-S3)
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 nerve to obturator internus come from?
2) Where does the nerve to piriformis form?
3) Where does the nerve to levator ani and coccygeus m form?
1) L5, S1-2
2) S1-2
3) S3-4
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 inferior gluteal nerve come from, where does it exit, and where does it go?
2) What come from the coccygeus plexus? What 3 things does it supply?
1) L5-S2, exits via greater sciatic foramen to the Gluteus maximus m.
2) Coccygeal nerves; coccygeus m., parts of levator ani, & sacrococcygeal joint
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 make up pelvic autonomic innervation? (3 categories of things)
1) Sacral sympathetic trunk & pelvic splanchnic nerves
2) Hypogastric plexuses & peri-arterial plexuses
3) Parasympathetics via S2-3-4
What are the 3 main parts of pelvic autonomics?
1) Sympathetic
2) Parasympathetic
3) Periarterial plexuses
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 does the peri-arterial plexus of the pelvis do?
Provide post synaptic sympathetic vasomotor to: superior rectal, ovarian, & internal iliac
1) What is the pelvic pain line?
2) How are afferents of the pelvis conducted?
1) Visceral afferents in the pelvis
2) Centrally
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
1) What returns to CNS via parasympathetic S2-3-4?
2) What returns to CNS via sympathetic fibers to T-L cord segment ganglia?
1) Viscera inferior & not in contact with peritoneum + distal sigmoid colon and rectum
2) Visceral superior to and in contact with the peritoneum
1) How does pain above the pelvic pain line travel back? What does this explain?
2) How does pain below the pelvic pain line return, and what organs are included in this?
1) Via the sympathetic fibers (L1, L2, T4-5, whatever, etc). Explains why some uterine pain hurts higher than you think it should; much of the uterus (less of cervix) is covered by peritoneum.
2) Via S2-3-4 parasympathetics; cervix, vagina, distal rectal anus, male internal genitalia, pt of bladder not touched by peritoneum
What are the pelvic viscera?
1) Distal parts of GI (rectum)
2) Distal Urinary tract
3) Reproductive system
Why are the parts of the sigmoid colon and small intestines that extend into the pelvic cavity considered abdominal viscera instead of pelvic?
They are mobile from their abdominal mesenteric attachments
(except the very distal sigmoid colon as it transitions into rectum)
What structures pass through the pelvic diaphragm to reach the perineal compartment? (3)
1) Rectum
2) Vagina
3) Urethra
What are the 3 urinary organs?
1) Ureters
2) Urinary bladder
3) Urethra
