Common Pelvic Viscera, Innervation and Vasculature Flashcards
What region is the pelvic cavity?
Region encased within the pelvic girdle, or bony pelvis Basin-shaped ring of bones consisting of R & L “hip bones” (ilium, ischium, pubis) & the sacrum
What is the pelvic cavity continuous with?
With the abdominal cavity superiorly, and occupies the space superior to the pelvic diaphragm (above the perineum)
What does the pelvic cavity contain?
Terminal parts of ureters,urinary bladder, rectum, pelvic genital organs, and part of sigmoid colon and ileum
What is the pelvis divided into?
Greater (false) pelvis and lesser (true) pelvis
The divisions of the pelvis is separated by what?
Oblique plane of pelvic inlet
The bony edge outlining the inlet is formed by what?
Sacral promontory and ala, and the linea terminalis of each hip bone
What does the linea terminalis consists of?
The arcuate line on inner surface of ilium, pectineal line, and the pubic crest of superior border of superior ramus and body of the pubis
What does the greater pelvis contain?
Abdominal contents (ileum and sigmoid colon)
What is the lesser pelvis between?
Pelvic inlet and outlet
What does the lesser pelvis contain?
Pelvic viscera
What is the pelvic outlet bounded by?
Pubic arch anteriorly, ischial tuberosities laterally Sacrotuberous ligament posterolaterally, and tip of coccyx posteriorly
True or False: Peritoneum lies over pelvic structures so they are covered on all sides?
False: Peritoneum lies over pelvic structures so they are NOT covered on all sides
What does the peritoneum serve as?
A conduit for arteries, veins, lymphatic vessels, nerves
What does the peritoneum form?
Folds, fossae (pouches) and ligaments over some structures
How does the peritoneum from the anterior abdominal wall reflect over the bladder? What does this allow?
Loosely over the bladder Allows the bladder to expand when full
Name 2, 3, 5, 6, and 7
- Supravesical fossa
- paravesical fossa(e)
- Ureteric fold
- rectovesical pouch (fossa)
- pararectal fossa(e)
Name 2, 3, 4, 6, and 7
2, supravesical fossa
- paravesical fossa(e)
- vesicouterine pouch (fossa)
- rectouterine pouch (fossa)
- pararectal fossa(e)
What pouch is the pouch of Douglas?
The rectouterine pouch
Collects fluid and is the common site of metastasis of endometriosis
The membranous pelvic fasica is situated between what?
Peritoneum and muscular pelvic walls and floor
Describe the parietal pelvic fascia?
Continuouation of transversalis fascia
Lines muscles of pelvic walls and floor
Describe the visceral pelvic fascia?
Loose connective tissue, compressible
The endopelvic pelvic fascia is situated between what?
Mebranous fascial layers
Describe loose pelvic fasica
Consists of areolar “packing material” that forms a supportive connective tissue matrix for pelvic viscera
Describe condensed pelvic fascia?
Ligamentous
Has a much more fibrous consistency with collagen, eleastic, and smooth muscle fibers
What are the potential spaces?
Prevesical space and retrorectal space
Describe the prevesical space
Retropubic
Potential space between pubic symphysis and bladder
Filled with loose endopelvic fat and connective tissue to allow for bladder expansion
Describe the retrorectal space
Potential space between sacrum and rectum
Filled with loose endopelvic fascia that allows rectal ampulla to fill
What forms ligaments of hypogastric sheath? What are the ligaments?
Condensed endopelvic fasica
Transverse cervical ligament
Sacrouterine ligament
Parietal membranous pelvic fascia condenses to form what?
Pubovesical ligaments in female
Or
Puboprostatic ligaments in male
What separates the rectum from the prostate and the seminal vesicles?
Rectovesical septum (urorectal) which is a condensed endopelvic fascia
What are muscular tubes comprised of smooth muscle and transitional epithelium
Also retroperitoneal?
Ureters
How is urine pushed towards the bladder?
Peristalsis
What are ureters supplied by?
Richly supplied by several sets of blood vessels and nerves
What are the 3 places where urinary calculi catch?
Ureteric junction of renal pelvis
Crossing the external iliac artery and pelvic brin
Vesicoureteric junction
How do the ureters enter the bladder wall?
Obliquely
In females, describe the relationship of the ureter to the uterine artery
The ureter runs medially to the uterine artery and then is crossed by it
Water under the bridge
In males, desribe the relationship of the ureter to the ductus deferens
Crosses posterolaterally to the ductus deferens on its way to the bladder
Water under the bridge
Where is the urinary bladder located?
“in” the retropubic space, inferior to the peritoneum and posterior to the pubic symphysis
What are the parts of the bladder?
Apex
Base (fundus)
Body
Neck
What is the neck of the bladder anchored by?
By lateral ligaments of bladder
Puboprostatic/vesical ligaments(females)
The walls of the bladder are primarily ______ muscle
detrusor
The inside of the bladder is lined by what?
Transitional epithelium that form rugae when empty
Describe trigone
Internal smooth thickened area defined by 2 ureteric orifices and the urethra
Openings of ureters are encircled in ______ muscle that tightens with contraction of the bladder to prevent ____ of urine.
Detrusor
Reflux
What is the blood supply to the superior bladder?
Superior vesical aa from the internal iliac
What is the blood supply to the inferior/posterior bladder?
Inferior vesical aa (male)
vaginal or inferior rectal aa (female)
- intramural part
- prostatic urethra
- membranous urethra
- spongy urethra
What part of the urethra is voluntary?
Sphincter urethrae
Where does the urethra begin in females?
At internal urethral orifice of the bladder, there is no internal urethral sphincter
Describe the urethra pathway in females?
Passes through pelvic diaphragm, external urethral sphincter and perineal membrane
What is the urethral sphincter (females) innervated by?
Deep perineal nerve from pudendal nerve
The urethra is shorter in males or females?
Females (4cm)
Short length allows for bacteria from the external environment to be introduced into the bladder, which can lead to UTI
Where does the rectum run from and to?
From rectosigmoid junction to anorectal junction
The rectum is S-shaped from lateral view due to what?
Sacral flexure and anorectal flexures
What are the three transverse rectal folds (lateral flexures)?
Superior
Intermediate
Inferior
Describe the rectal ampulla?
Dialated terminal part of rectum
Superior to anorectal line: line joins the tops of the anal columns
What is the rectum innervated by?
Lumbar splanchnic nerves (sympathetic)
Hypogastric plexuses
Pelvic splanchnic nerves (parasympathetic)
What is the anorectal flexure?
Sharp posteroinferior angle at tip of coccyx bone where gut perforates pelvic diaphragm (leavtor ani muscles)
What is the anorectal flexure created by?
Puborectalis muscle as it forms a “sling” at the anorectal junction
What is the significance of the anorectal flexure?
Important mechanism for fecal continence due to tonus of puborectalis muscle during resting state, or its active contraction during peristaltic conctraction if defecations is not to occur
80 degree angle
What does the pectinate line divide?
Upper 2/3 (endoderm) from lower 1/3 (ectoderm) of anal canal
Describe the neurovascular supply to the superior 2/3 of anal canal (endoderm)
Superior rectal artery (br of inferior mesenteric a)
Internal venous plexus drains superiorly
Lymph drains to internal iliac nodes
Visceral nn.; pain fibers travel with parasympathetics to S2, S3, S4
Describe the neurovascular supply to the 1/3 (ectoderm)
Inferior rectal artery (br of internal pudendal a)
Internal venous plexus drains into inferior rectal veins
Lymph drains to superficial inguinal lymph nodes
Somatic nn. - canal is sensitive to pain, touch and temperature
What are the divisions of the internal iliac artery?
Posterior and anterior
The posterior division of the internal iliac artery gives off what arteries?
Superior gluteal artery
Illiolumbar artery
Lateral sacral artery
Where does the superior gluteal artery usually exits the pelvis?
Between the lumbosacral trunck (L4/L5) and S1
Where does the illiolumbar artery run?
Superolaterally towards iliac fossa
Where does the lateral sacral artery supply?
Pass medially and anterior to supply rami of sacral plexus
What are the parts of the external anal sphincter?
Deep, superficial and subcutaneous part.
How much of the population have an “abnormal” or accessory obturator artery?
20%
What artery is a branch of the inferior epigastric, crosses over the pelvic brin along the pubic ramus, and is endangered during hernia surgeries?
Obturator artery
What artery in the pelvic cavity is obliterated?
umbilical artery
What are the branches of the anterior divison of the internal illiac artery?
Obturator artery
Ubilical artery
Internal pudendal artery
Superior vesical arteries
Uterine artery
Vaginal artery
Middle rectal artery
Inferior gluteal artery
What arteries are from patent part of umbilical a. and supplies the superior bladder?
Superior vesical arteries
What artery usually leaves the pelvis between S2 and S3 of the sacral plexus? But is extremely variable?
Inferior gluteal artery
What artery almost always exits the pelvis near the ischial spine?
Internal pudendal artery
What is the attachment point of coccygeus muscle?
Ischial spine
The vaginal artery takes the place of what artery that is found in males?
Inferior vesical a.
Males do not have a uterine artery, what may replace this artery in males?
Ductus deferand a.
What is the blood supply for the superior bladder?
Superior vesical aa from the internal iliac artery
What is the blood supply to the inferior/posterior bladder?
Inferior vesical aa (male)
Vaginal or inferior rectal aa (female)
What arteries arise from the aorta
cross anterior to the ureter, over bifurcation of common iliac arteries and
run in the suspensory ligament (infundibulopelvic) created by peritoneum?
Ovarian arteries
What artery arises from posterior aorta at bifurcation into common iliac aa.?
Median sacral a.
What aa. anastomose with the deep circumflex iliac aa. off of external iliac aa.?
Iliolumbar aa
The superior rectal artery arises from what?
inferior mesenteric
The pelvic plexus of veins is made up of what?
Rectal plexus (internal and external)
Vesical plexus
Prostatic plexus (m)
Uterine plexus (f)
Vaginal plexus (f)
What do the veins of the pelvis drain into?
internal iliac veins
What do the superior rectal vv empty into?
The inferior mesenteric vein, which in turn empties into the portal vein
What do the middle rectal vv empty into?
Internal iliac vv which empties into the inferior vena cava
What do the inferior rectal vv drain into?
The internal pudendal veins which eventually drains to the internal iliac
Hemorrhoids may or may not be related to _____ or high blood pressure, but the anatomical ____ contributes to them
cirrhosis
overlap
What hemorrhoid is a prolapsed rectal mucosa containing veins of the internal rectal plexus?
Internal: internal rectal veins that prolapse into the anal canal and often strangulate -> painless (visceral nerves)
What hemorrhoid is clots in veins of the external rectal venous plexus (fed by branches of the inferior rectal vein)?
External:
Clotted blood in the external rectal veins. usually caused by increased abdominal pressure or straining -> painful (somatic nerves)
What are the pudendal nerve branches (M)?
Inferior rectal nerve
Perineal nerve: superficial (posterior scrotal n.) and deep
Dorsal nerve of penis
