The Pelvic Viscera Flashcards
When does the rectum begin (and at which vertebra) and where does it end?
Begins at the 3rd sacral vertebra where the sigmoid colon becomes the rectum
Ends as the rectum pierces the pelvic diaphragm and becomes the anal cavity
What are the four changes as the sigmoid colon becomes the rectum?
- Bowel loses mesentary and becomes closely applied to curvature of sacrum
- Taenia coli broaden out and form complete outer longitudinal layer (in sigmoid colon is three separate bands)
- Haustra disappears
- Epiploic eppndages disappear
What is the lower part of the rectum called where it is dilated?
Rectal ampulla
What artery primarily supplies the rectum?
Superior rectal artery
What part of the rectum does the middle rectal artery supply?
Lower part of rectum; this artery primarily supplies male/female reproductive organs
What is supplied by the inferior rectal artery?
Inferior rectal artery primarily supplies anal cavity rather than rectum
Which muscle of the posterior abdominal wall do the ureters pass over?
The psoas major muscle
In pelvis, the ureter is crossed over by different structures in males and females. What are those structures?
In females, ureters are crossed over by uterine artery
In males, ureters are crossed over by vas defrens
What are the 3 sites of constriction in the ureters?
- At the junction of the ureter and renal pelvis
- Where ureter crosses the pelvic brim
- In passage through the urinary bladder
What spinal cord segments are visceral pain afferents of the ureters relayed?
Segments T11 - L2 (follows sympathetic innervation)
Describe general location of the urinary bladder.
Lies posterior to the pubis, rises into abdomen as it fills. Separated from pubis by the retropubis space. In males the urinary bladder rests on the prostate gland.
What general structure is on top of the urinary bladder on the superior surface of the bladder?
The peritoneum lies on top of the superior surface of the urinary bladder.
What holds the neck of the bladder in position, in males and in females?
Males: puboprostatic ligaments
Females: pubovesical ligaments
What are the 5 main internal features of the urinary bladder?
- Rugae: mucosal folds
- Trigone: no rugae, firmly adhered to muscular coat, near base of bladder
- Uvula (in males): smooth eminence just above urethal orifice
- Detrusser muscles: 3 layers of smooth muscles
- Sphincter vesicae: thickening of circular layer of smooth muscle at neck of bladder
What is the blood supply of the urinary bladder in both males and females?
Males: Superior and inferior vesical arteries
Females: Superior vesical arteries and vaginal branches
Where does the parasympathetic innervation originate from, and where does it innervate/with what actions?
Comes from pelvic splanchnic nerves (S2 - S4)
Provides motor to the detrussor muscle
Is inhibitory to the spinchter vesicae
Where does the sympathetic innervation of the urinary bladder originate from (which spinal cord segments)?
T11 - L2
Where does the pain fibers of the urinary bladder follow back to?
Superior surface of the urinary bladder follow the T11 - L2 (same as sympathetic)
Inferior surface of the urinary bladder follow the pelvic splanchnic nerves S2 - S4 (parasympathetic innervation)
What are the fornices of the vagina?
Vaginal recesses formed at upper end/upper part of vagina. There are anterior, posterior, and lateral fornices that are all really 1 fornix.
What 3 arteries supply the vagina? What artery are they a branch of?
Uterine arteries
Vaginal arteries
Internal pudendal
All 3 are branches of the anterior division of the internal iliac artery
Where does the innervation to the superior and inferior part of the vagina come from?
Superior 3/4 viscerals follow splanchnic nerves S2-S4
Inferior 1/4 somatic pain afferents via pudendal nerve
What 2 structures lie anterior to the vagina?
Bladder above
Urethra below
What 3 structures lie posterior to the vagina?
Upper 1/3: Uterorectal pouch of Douglas
Middle 1/3: Rectal ampulla
Lower 1/3: Perineal body (which separates it from anal canal)
What 3 portions make up the general structure of the uterus?
Fundus: lies above entrance of uterine tubes
Body: lies beneath entrance of uterine tubes
Cervix: narrow inferior portion
The cervical canal communicates with body through the ____ and with the vagina through the ____.
Cervical canal communicates with body through internal os and with vagina through external os.
What is the isthmus of the uterus?
It is the lower portion of the body of the uterus that joins the supravaginal segment of the cervix
What differentiates the supravaginal and intravaginal portions of the cervix?
The cervix protrudes through the uppermost anterior wall of the vagina, demarcating the supravaginal and intravaginal portions of cervix.
What are the two possible orientations of the uterus, and what causes them?
Anteversion, where logitudinal axis of uterus is bent forward 90 degress relative to vagina
- caused by uterosacral ligaments
Anteflexion, where body of uterus is bent forward at junction of internal os and cervical canal
- intrinsic to fibromuscular walls of cervix and body
What are the 4 segments of the uterine tube, starting with the one closest to the body of the uterus?
- Intramural - segment piercing uterine wall
- Isthmus - narrow part close to uterine wall
- Ampulla - widest part where fertilization occurs
- Infundibulum - funnel shaped lateral ends, with fimbriae and ovarian fimbria