Anatomy Of The Pelvis Flashcards
Renal arteries are at the level of?
L1-L2
Visceral pain afferents return to the spinal cord from the kidneys at what level? What are the referred cutaneous areas?
T12 to L2
Pain is referred to the cutaneous areas supplied by T12 to L2. - posterior and lateral abdominal wall below the ribs and above the iliac crest into the scrotum and labia majora and proximal anterior thigh.
Psoas major is innervated by?
L1 to L3
The psoas joins the iliacus at what level? What’s the innervation?
Joins illiacus L2-L4 - femoral nerve to become the iliopsoas
Quadratus lumborum is innervated by?
T 12 to L4
Supine the kidneys are approximately at what level? Is the right or left one lower?
Supine -Around T12 to L3 vertebrae,
Ribs 11-12 to L3-4 - When erect they are slightly lower
The right is lower than the left.
The right kidney is close to what structures?
Descending duodenum, posterior liver, hepatic flexure of the colon.
The left kidney is close to what structures?
Kidney is close to the the stomach, spleen, pancreas, and splenic flexure.
What muscle is medial to the kidneys?
Psoas
The kidneys are surrounded by what? Are they retroperitoneal or intra?
The kidneys are retroperitoneal and they are surrounded by renal fascia
The fascia is a perinephric (perineal) fat.
The True (lesser) and false (greater) pelvis are separated by what?
Separated by the pelvic inlet
The dermatomal sacral segments of the pelvis are what?
S3 to S5
The skeletal muscle in the perineum and pelvic floor including urethra and anal sphincters are innervated by what?
Innervated by S2-S4
Much of the somatic motor and sensory innervation of the pelvis is innervated by what nerve?
Pudendal nerve - s2-s4
Where do you numb the pelvis in a female?
Go through the vagina and go to the ischial tuberosity and then inject. This will numb the pudendal nerve.
What nerve plexus innervates the pelvis area?
Inferior hypogastric (pelvic) plexus - has SNS, PSNS, and visceral afferent components
What blood vessel does the pelvis get its blood from?
Basically from the internal iliac artery, anterior and posterior branches.
Deep pelvic structures drain into what lymph chains?
Deep pelvic structures drain into the internal and external iliac chains.
Deep perineal structures drain into what chain?
Deep perineal structures drain into the internal iliac chain.
Superficial structures like the penis, scrotum, clitoris, labia majora drain into what?
Drain into the superficial inguinal nodes.
Other superficial perineal structures - like the glans penis, glans clitoris, labia minors, and the inferior end of the vagina drain into what?
Drain into the deep inguinal nodes and the external iliac chain.
The ovaries and related uterine structures and the testes (the lymphatic accompany the gonadal arteries) drain into what NODES?
Drain into the lateral and pre-aortic nodes.
Gluteal nodes drain into what?
Drain into the internal iliac chain
Drainage from the lower extremities drains into what nodes?
Superficial and deep inguinal nodes.
Lower abdominal wall, gluteal and superficial areas of the lower limb drain into what?
The superficial inguinal nodes
What nodes receive drainage from the femoral lymphatic and the perineal areas?
Deep inguinal nodes.
The key to lymph drainage is that the deep parts of the perineum are drained by the?
Internal pudendal chain —> internal iliac nodes —> aortic nodes.
The key part to the drainage of the superficial perineum and external genitalia are drained by what nodes?
Superficial inguinal nodes —> deep inguinal nodes —> external iliac nodes
Extending across the ischiopubic arch is a thick triangular fascia structure that has transverse muscles within is called the?
Urogenital diaphragm/perineal membrane and the deep perineal pouch.
What are the perforations in the urogenital diaphragm?
Male - the urethra
Female - the urethra and the vagina
What are the boundaries of the perineum? innervation and blood supply?
Includes the urogenital triangle (anterior) and the anal triangle (posterior)
Innervation is the pudendal n and artery is the internal pudendal artery.
The perineal membrane is composed of what?
Composed of a thick fibrous sheet with a free posterior border.
The deep perineal pouch consists of?
Contains muscles and neuro-vascular structures within the perineal membrane.
The pelvic diaphragm is composed of what muscles?
Levator Ani and the Coccygeus muscle
Levator Ani - composed of iliococcygeus muscle, pubococcygeus muscle, and puborectalis muscle.
The levator Ani is called the levator sling. It arises from the walls of what?
It arises from the walls of the true pelvis, from the posterior pubic bone, from a ligament on the Obturator internist muscle, from the ischial tuberosity.
The coccygeus arises from what? Where does it insert?
From the ischial spine and sarcospinous ligament and inserts on the sacrum and the coccyx.
What are the three muscles that the levator Ani is composed of?
Pubococcygeus muscle
Puborectalis muscle - pulls anorectal junction forward to help keep the GI system closed at rectal area (called perineal flexure), helping the anal sphincter muscles. “Muscle of civilization”
Iliococcygeus muscle - which arises from the ilium and the tendonous arch on the obturator internus muscle.
What places in the perineal space can abscess form?
The ischiorectal (ischialanal) fossa - is called the deep perineal space - abscesses can form here.
What two structures come together at the perineal body?
The Levator Ani and Perineal Membrane come together at the perineal body.
If you have a tear through the perineal body and through the anal sphincter you get what?
You get a “cloaca” - a common cavity at the end of the digestive tract for the release of both excretory and genital products in vertebrates
The perianal area, - smooth muscle of the internal anal sphincter - is innervated by?
Autonomic nervous system (contracts) and PSNS (relaxes).
The perianal area - the external anal sphincter - skeletal muscle - is innervated by?
Three components - innervated by the inferior rectal branches of the pudendal nerve - a somatic nerve.
The transition zone between the rectal mucosa and nonkeratinized squamous epithelium is called what?
The anal pecten. Then the anocutaneous line (true skin)
The external hemorrhoidal veins go to what?
The systemic circulation
The internal hemorrhoidal veins go to what?
The portal system.
As the bladder begins to fill, it lifts what?
Lifts the peritoneum up and away from the abdominal wall.
What 3 structures support the uterus?
Pelvic diaphragm (pelvic floor) - levator ani, coccygeus muscle, and associated fascia
Urogenital diaphragm/perineal membrane
Perineal body
Note: the broad ligament, round ligament, and suspensory ligament of the ovary, and the perineal folds associated with the uterus are not considered to be true uterine support structures. - Just folds of peritoneum, not true support structures.
What are the 3 “ligamentous supporting” structures of the uterus?
Cardinal ligament - (transverse cervical, Mackenrodt) - fibromuscular fascia from either side of the cervix
Uterosacral ligaments - from the posterior cervix to the sacrum — comprised of the recto-uterine folds - comprised of fibrous tissues and muscular fibers attached to the front of the sacrum.
Anterior pubocervical ligament - from the uterus to the pubic symphysis.
T/F the peritoneal folds associated with the uterus are supporting structures?
False, - broad ligament, mesovarium, mesosalpinx, round ligament are not true support structures.
What are the 3 pouches are associated with folds of the peritoneum in the perineum.
Urachus, umbilical folds
Vesicouterine pouch
Rectouterine pouch (douglas)
What pouch is a deep pouch posterior to the uterus and anterior to the rectum.
Pouch of Douglas. Rectouterine or rectovaginal pouch
