Pelvis 01: Overview Flashcards
Pelvic cavity
The true pelvis, just below the abdomen
What are the superior and inferior borders of the pelvic cavity?
Superior: pelvic inlet
Inferior: pelvic diaphragm
Perineum
A region underneath the pelvic cavity that houses the external genitalia
What is the relationship of the peritoneal sac with the pelvic cavity?
The peritoneal sac extends down into the pelvis and drapes over the top of pelvic organs
Endopelvic fascia
A fascia found in the pelvis that is the continuation of the abdominal preperitoneal and retroperitoneal fasciae
Intraperitoneal
Mostly surrounded by peritoneum
Subperitoneal
Below the peritoneum (and thus mostly not related to it)
What are the female pelvic intraperitoneal structures?
Ovaries, uterine tubes, fundus and much of the body of the uterus
What are the female pelvic subperitoneal structures?
Bladder, lower uterus, cervix, vagina
Is the bladder at all related to the peritoneal?
The superior surface is related; however, the bladder is not intraperitoneal
Vesicouterine pouch
A small pouch found in the female pelvis between the uterus and the bladder
Rectouterine pouch of Douglas
A small pouch found in the female pelvis between the uterus and the rectum
What is the lowest point of the peritoneal sac?
Rectouterine pouch of Douglas
Broad Ligament
A ligament of peritoneum found in the pelvic cavity between the lateral sides of the uterus and the lateral pelvic walls
Uterosacral ligament
A ligament that runs between the uterus and the sacral bones; it suspends the uterus
Pararectal fossa
A hollow pouch on each side of the rectum
Suspensory ligament of ovary
A ligament that contains the ovarian vessels and the peritoneal fold
Pubocervical ligament
A ligament that runs between the pubis and the cervix
How does the endopelvic fascia support female reproductive structures?
It condenses into various ligaments that hold organs in place
Rectovesical pouch
A pouch that is found only in the male pelvis between the bladder and rectum. It is continuous with the pararectal and paravesical fossae
Paravesicle fossa
Fossa found only in the male pelvix between the blade and the vessels of the lateral pelvic wall
Pubic symphysis
The bony ligament that connects anteriorally the two sides of the pelvic bone
Sacrum
The fusion of the five sacral vertebral bodies that form the posterior spine of the pelvic bones
Pelvic outlet
The central hole in the pelvic bones
Ischiopubic ramus
A bone of the pelvis that runs between the pubis and the ischium
Ischial tuberosity
The bony part of the ischium of the spine that is the attachment site of the sacrotuberous ligament
Sacrotuberous ligament
A ligament that runs from the sacrum to the ischial tuberosity
Pelvic diaphragm
A group of muscles that form the floor of the pelvic cavity and separates it from the perineum
What are the hiatuses of the male pelvis?
Urogenital hiatus and anal hiatus
What are the four palpable structures of the pelvis?
Public symphysis, right and left ischial tuberosity, and tip of coccyx
What are the hiatuses of the female pelvis?
Urogenital hiatus and anal hiatus. The urogential hiatus will contain the urethra and the vagina
What are the superior and inferior boundaries of the perineum?
Pelvic diaphragm is the roof; skin is the floor
Using anatomical terms, how is the perineum positioned relative to the pelvic diaphragm in the body?
The perineum is superficial and inferior to the pelvic diaphragm
Lithotomy position
Position of patient on their back and opening their legs to reveal the perineum
What are the two triangles formed by the palpable structures of the pelvis?
Urogenital triangle and anal triangle
What are the three points that define the urogenital triangle?
Public symphysis and left and right ischial tuberosities
What are the three points that define the anal triangle?
Tip of coccyx and right and left ischial tuberosities
What membrane is found at the anal triangle?
There is none!
Urogenital diaphragm
The perineal membrane, found in the front half of the perineum
How does the urogenital diaphragm differ in male and female pelvices?
In the female pelvis, the urogenital diaphragm takes up the whole space of the urogenital triangle. In the male pelvis, it is slightly smaller than the triangle
In the female pelvis, what are the two openings found in the urogenital hiatus? Which one is more ventral?
Urethra and vagina; urethra is more ventral
Ischio-anal fossae
A fossa found between the ischium and the anus, superficial to the pelvic diaphragm and deep to the deep perinal pouch and perineal membrane
From superficial to deep, what are the layers found in the urogenital triangle?
Skin -> fatty layer of superficial perineal fascia -> Colle’s fascia -> Perineal cleft -> Superficial perineal pouch -> Perineal membrane -> Deep perineal pouch -> ischioanal fossa -> pelvic diaphragm -> Endopelvic fascia -> Peritoneum -> pertioneal cavity
From superficial to deep, what are the layers found in the anal triangle?
Skin -> fatty layer of superficial perineal fascia -> Colle’s fascia -> Perineal cleft -> Superficial perineal pouch -> ischioanal fossa -> pelvic diaphragm -> Endopelvic fascia -> Peritoneum -> pertioneal cavity
There is no peritoneal membrane or deep perineal pouch
Deep perineal pouch
A pelvic pouch found above and deep to the perineal membrane
Superficial perineal pouch
A pelvic pouch found superficial to perinal membrane and deep to the deep perineal fascia; it contains erectile tissue and associated skeletal muscles
What is the difference between the male and female pelvis with regards to the superficial perineal pouch?
Male: trilobar. Female: quadrilobar
Perineal cleft
A pelvic cleft found deep to Colle’s fascia and superficial to the deep perineal fascia; also known as the subcutaneous perineal pouch
Levator ani
The group of muscles that make up the pelvic diaphragm, they lift up the anus
What are the muscles that make up the levator ani?
Iliococcygeus, pubococcygeus, puborectalis
What are the three bones that make up the pelvic bone?
Ilium, ischium, pubis
Ischial spine
A spiny part of the ischium that is the attachment site of the sacrospinous ligament
Greater Sciatic foramen
A foramen that is above the ischial spine
Lesser Scieatic forament
A forament that is below the ischial spine
Sacrospinous ligament
A ligament that runs from the sacrum to the sichial spine
Sacrotuberous ligament
A ligament that runs from the sacrum to the ischial tuberosity
Obtuator canal
A small canal that runs through the obturator membrane in the pelvic
Piriformis
A muscle that runs from the pelvic brim to the sacrum
Obturator internus
A muscle that spans the obturator foramen of the pelvis
What nerve innervates the piriformis? What spinal cord segments does it originate from?
“Nerve to piriformis”; L5, S1, S2
What nerve innervates the obturator internus? What spinal cord segments does it originate from?
“Nerve to obturator internus”; L5 and S1
Pudendal nerve
The nerve that innervates the pelvic diaphragm
What spinal cord segments does the pudendal nerve originate from?
S2, S3, S4
Puborectalis
A muscle that originates from the pubis and wraps around the rectum; it is one of the pelvic diaphragm muscles
What nerves innervate the pelvic diaphragm?
Pudendal nerve; S4 directly
How do visceral nerves get past the pelvic diaphragm?
They run through the urogenital hiatus
How do somatic nerves get past the pevlic diaphragm?
They go around it
What nerves and vessels leave the pelvic cavity from above the piriformis?
Superior gluteal
What nerves and vessels leave the pelvic cavity from below the piriformis?
Sciatic nerve; post femoral cutaneous nerve; nerve to quadratus femoris; inferior gluteal nerve and vessels; pudendal nerve; nerve to obturator internus
Sciatic nerve
The largest nerve in the body; it leaves the pelvic cavity beneath the piriformis
What nerves and vessels leave the pelvic cavity from the obturator canal?
Obturator nerve and vessels
What nerves and vessels leave the pelvic cavity from under the inguinal ligament?
Femoral nerve and vessels
What nerves and vessels enter the perineum from the lesser sciatic foramen?
Pudendal nerve, nerve to obturator internus, internal pudendal vessels
Pudendal canal
A canal found through the lesser sciatic foramen where the pudendal nerve and internal pudendal artery runs through. It runs along the surface of the obtuator internus muscle
External anal spinchter
A sphincter of skeletal muscle that controls the opening and closing of the anus
What spinal cord segments control the external anal sphincter?
S2, S3, S4
Gluteus maximus
The most superficial muscle of the back of the pelvis
Gluteus medius
A muscle that is just deep of the gluteus maximus but the most superior of the back pelvic muscles
Os coxae
The name of the fused bones that make up the pelvic bone
