Aug30 M3-Pelvis_Anatomy_lecture_2 Flashcards
muscle that lines top of the perineum
levator ani
what’s below the sigmoid colon
rectum
rectum: parts that are intraperitoneal and parts that are retro
top = intraperitoneal
middle and bottom = retroperitoneal
bladder relations in male
bottom = prostate and prostatic urethra post = seminal vesicle anterior = pubis top = peritoneum
seminal vesicles relations in male
top = colon bottom = prostate post = rectum ant = bladder
prostate relations in male
top = bladder bottom = levator ani post = rectum ant = levator ani/pubis
uterus relations in female
top = abdomen, colon, ovaries bottom = cervix, vagina ant = bladder post = rectum
bladder relations in female
ant = pubis post = uterus bottom = urethra top = abdomen, colon
2 layers of muscle in rectum
- inner circular
- outer longitudinal
- continuous with anal sphincter (big blob where levator ani joins
GI landmark of levator ani
anorectal junction or line
anal canal def
what’s below the anorectal line (line where levator ani joins the rectum to form the anal sphincter)
anal canal vs rectum
- rectum smooth + has superior, middle and inferior transverse rectal folds (help for more abso surface + hold feces)
- ampulla of the rectum = between inferior transverse rectal fold and anorectal junction
- anal canal = insinuations
most medial part of levator ani
puborectalis m.
puborectalis m. O and I
O: pubic bone
I: wraps around the rectum and comes back to the pubis
puborectalis fct on rectum
kink to support fecal content
lose kink = incontinence
in the sagittal pelvis, only place where you see puborectalis
posterior to the rectum. (muscle appears cut in X section)
supply to superior rectal canal
superior rectal artery from IMA
supply to middle rectal canal
middle rectal artery from internal iliac a.
supply to inferior rectal canal
inferior rectal a. from internal pudendal a which comes from internal iliac a
location of the internal pudendal a (giving inf rectal a) + how reaches inf rectal canal
near ischial spine. goes out via greater sciatic foramen, then back it via lesser sciatic foramen in the perineum
portal drainage of the rectum is where
superior rectal canal bc have superior rectal vein draining in IMV, which goes to splenic and superior mesenteric
ureters charact
- retroperitoneal
- muscular ducts
- 25-30 cm
ureters relations
- anterior 1 = gonadal vessels (test and ova a and v). over iliacus
- posterior = bifurcation of the common iliac artery to enter the pelvis (to give external and internal iliac. aa), ureters cross over this bifurcation
- anterior 2: vas deferens (in pelvis, near bladder)
3 places where stones can get stuck in the ureter (sites of constriction)
- kidney hilum (junction of ureters to renal pelvis)
- pelvic brim (when ureters cross the pelvic inlet)
- bladder entrance (when ureters pass through the bladder)
shape of bladder
- triangle
- posterior = wall
- anterior = apex (with the median umbilical ligament)
- inferior = neck of bladder with two inferolateral surfaces
urethra landmarks in female (male = prostatic, penile)
proximal and distal urethra
(imp) muscle of bladder
detrusor muscle
(imp) bladder landmarks
- ureteric orifices (on both sides)
- interureteric ridge
- trigone (only area that is smooth mucosa rather than trabeculated transitional cell epith)
- rugae
- uvula (back wall bump over urethral orifice)
- internal urethral orifice
ligament holding bladder at the apex (anterior)
median umbilical ligament
two sphincters for the urethra
- internal urethral sphincter (involuntary = basal CONTRACTED tone)
- external urethral sphincter (voluntary = NOT CONTRACTED all the time except when we contract it voluntarily)
autonomic inn to internal urethral sphincter
- PSS inhibits its tone + contracts the detrusol muscle for micturition
- SS constricts the internal sphincter (all the time) + relaxes bladder wall + prevents semen from entering bladder during ejaculation
when does PSS control of urethral sphincters override SS?
when bladder >300 mL urine AND we override our voluntary reflex of contracting the external urethral sphincter
how semen gets to urethra
EDD, vas deferens (superificla inguinal ring, inguinal canal, deep inguinal ring, wraps around inferior epigastric a), duct of the ampulla, meets the duct of the seminal vesicle to form the ejaculatory duct, ejac duct enters prostatic urethra
ampula of the vas def
widening of the vas when it reaches the back of the bladder
two ducts that meet to form ejac duct
- duct of the ampulla (of the vas)
- duct of the seminal vesicle
vas relations
- ant = bladder
- post = rectum
- medial = nothing (vas is the most medial)
- lateral = seminal vesicles
seminal vesicles fct and location
- principal source of seminal fluid
- back bottom of bladder, between bladder and rectum
on what part of the prostatic urethra does the ejac duct open
in the part that is near the prostatic utricle (part of the prostate that is a tiny vestigial developmental homologue of the uterus)
base vs apex of prostate
is a triangle like bladde rso
- base = top (where the bladder sits)
- bottom = apex of the prostate (crosses through pelvix floor)
prostatic urethra landmarks (5)
- urethral crest (bump in middle of prostatic urethra, vertical)
- prostatic sinus (gutter on each side of urethral crest)
- prostatic ducts opening into the prostatic sinus (20-30 of them)
- prostatic utricle (doughnut like bump in middle of prostatic urethra. hole not going anywhere)
- ejaculatory ducts openings (two at bottom of prostatic utricle)
prostatic utricle is what
male homologue of the female uterus and vagina (remnant of the embryonic uterovaginal canal)
anatomical consequence of prostate tumor
get a bump in the rectum
uvula position with respect to prostatic urethra landmarks
on top of urethral crest (is part of the bladder)
