Pelvis Flashcards
What is the “false pelvis”?
Pelvis Major - the lowermost part of the abdominal cavity lying between the iliac fossae.
What is the “true pelvis”?
Pelvis Minor - inferior to the superior pelvic aperture. Contains the pelvic viscera.
What are the contents of the pelvis?
- Rectum
- Bladder
- Uterus/Vagina in females; prostate gland in males.
What are some main ligaments of the pelvis? (5)
A. Pubic Symphysis: Joins the two pubic bones
B. Sacroiliac Ligaments: From iliac to sacral tuberosities
C. Iliolumbar Ligaments: L5 transverse process to iliac crest
D. Sacrotuberous Ligament: from lateral sacrum and coccyx to the medial side of the ischial tuberosity.
E. Sacrospinous ligament: ischial spine to sacrum
Describe the muscles of the pelvis and their location.
obturator internus- lateral pelvic wall (lateral rotator of thigh)
piriformis -posterior pelvic wall (lateral rotator and abductor of thigh)
pelvic diaphragm- floor of pelvic cavity
urogenital diaphragm- fibers placed inferior to pelvic diaphragm and are oriented in perpendicular direction to pubococcygeus. provides solid support for pelvic viscera
What makes up the pelvic diaphragm?
levator ani, coccygeus, pelvic fascia (continuous with transversalis fascia)
forms floor of pelvic cavity
The pelvic diaphragm separates pelvis from perineum. Structures leave the pelvis and enter the perineum via the greater and lesser ischiadic foramina, respectively.
What artery supplies most blood to pelvis?
internal iliac artery
Describe the anterior division of the internal iliac artery.
umbilical artery (superior vesicle artery)
obturator artery
inferior vesicle artery (vaginal and uterine A in female)
middle rectal artery
inferior gluteal artery
internal pudendal artery
Describe the posterior division of the internal iliac artery.
all are muscular branches
iliolumbar
lateral sacral
superior gluteal
(Pelvic Innervation) Describe the sacral plexus.
(L4 - S5): rests on piriformis muscle, it gives several branches to pelvis and perineum. Represents ventral rami of S1 - S4; and receives L4,L5 contribution from the lumbosacral trunk.
(Pelvic innervation) Describe the sacral plexus branches to pelvis and perineum.
- Branches to pelvis and perineum:
a. N. to piriformis
b. perforating cutaneous (S2, S3)
c. pelvic splanchnics: Autonomics
d. PUDENDAL N. *****
e. perineal branch of S4
(Pelvic innervation) What are the anterior division nerves?
tibial part of sciatic; nerve to quadratus femoris and inferior gemellus; n. to obturator internus and to superior gemellus; medial part of posterior femoral cutaneous n.; PUDENDAL N.
(Pelvic innervation) What are the posterior division nerves?
superior gluteal n.; inferior gluteal n.; common peroneal part of sciatic n.; lateral part of posterior femoral cutaneous n.; n. to piriformis; perforating cutaneous n’s.
Describe the pelvic sympathetic innervation.
sympathetic trunks descend from abdomen along sacrum and converge to form the ganglion impar
Describe the superior hypogastric plexus.
represents the inferior projection of the intermesenteric plexus. It receives contributions from the lumbar splanchnics nerves. The branches of SHP spill over into the pelvis as the R and L HYPOGASTRIC nerves. They mix with the pelvic splanchnics to form the INFERIOR HYPOGASTRIC PLEXUS.
Describe the parasympathetic innervation of the pelvis.
PELVIC SPLANCHNICS (S2-4) combine with the sympathetic branches to form the inferior hypogastric plexus on the walls of the pelvis.
Describe the rectum.
continuous structurally with the colon; it’s called the rectum when the mesentery is lost. Rectum ends at ano-rectal junction which is slung in a loop of the pubo rectalis muscle. Continuous with anal canal inferiorly
What is the rectal ampulla?
terminal dilated part of rectum
has retrovesical pouch
has rectouterine pouch
Describe the arterial supply of the rectum.
superior rectal branch of IMA (upper 2/3)
middle rectal A (from internal iliac A) (lower 1/3 - muscular layer)
inferior rectal A (from internal pudendal A) (anastomoses with superior rectal in anal columns
Describe the venous system of the rectum.
Internal Rectal Plexus: just deep to the epithelium, it drains to the SUPERIOR RECTAL V.
External Rectal Plexus: external to the muscular wall, the superior part drains to the SUPERIOR RECTAL V., the inferior part drains to the INTERNAL PUDENDAL V’s.
Describe the nerve supply of the rectum (sympathetic and parasympathetic)
sympathetics- from hypogastric plexus directly and via fibers accompanying the superior rectal A
parasympathetics- from Pelvic splanchnics S2-S4
Describe the bladder. muscle? ligaments? interior? blood supply? nerve supply?
has the detrusor muscle
ligaments from levator ani and pubic bone to bladder (condensation of subserious fascia)
pubovesical lig- female
puboprostatic lig- male
interior: trigone, interureteric fold
blood supply: superior vesical a and inferior vesical a.
nerve supply:
sympathetics- pelvic plexus
parasympathetics- pelvic splanchnics =motor to detrusor m.
Describe the Urethra.
female
male
innervation
in female: 1.5 in long, runs from neck of bladder to end in vestibule of vagina
in male: 3 parts (prostatic, membranous, spongy)
parasympathetic innervation: pelvic splanchnics
Describe the prostate.
lies between the bladder and pelvic floor
perforated by the urethra
Describe the pathway of vas deferens.
Enters the abdomen through the deep inguinal ring. It turns medially, crosses the pelvic brim and passes anterior to iliac vessels. It runs downward and backward along the lateral pelvic wall. It crosses the umblicial a. the obturator n. and vessels, the ureter and vessels to the bladder. Continues toward the neck of the bladder, medial to the seminal vesicles, joins the duct of the seminal vesicles and becomes the ejaculatory duct on the back of the bladder
Describe the seminal vesicle.
branched tube which joins the distal end of the vas deferens to form the ejaculatory duct. Located superior to prostate and lateral to vas deferens
What does sympathetic innervation cause?
contraction of smooth muscle
Describe the uterus:
cervix: body: fundus: postion: peritoneal reflections:
pear shaped hollow organ which lies between the rectum (posteriorly) and bladder (anteriorly) of the female. The lumen of uterus is continous with the lumen of uterine tubes
cervix: inferior 1/3
body: superior 2/3
fundus: rounded superior part of the body of the uterus
position: anteversion and anteflexion
peritoneal reflections: vesicouterine pouch, rectouterine pouch
Describe the uterine ligaments
BROAD ligament- fold of peritoneum which surrounds uterine tube (extends from sides of uterus to lateral wall of pelvis), laterally it is prolonged over ovarian vessels as SUSPENSORY LIGAMENT of OVARY
round ligament
transverse cervical ligaments
uterosacral ligaments
Describe the uterine vessels. Where does the uterine artery pass above?*
uterine artery - passes above ureter in base of broad ligament (Water under the bridge!)
tubal branch of ovarian artery
Describe the nerve supply of uterus.
sympathetic- T12-L1 via hypogastric plexus
parasympathetic- pelvic nerve from S1-4
Describe the uterine tubes.
approx 4 inches long
attached to fundus of uterus
lumen of tube continuous with lumen of uterus
tube forms direct connection between peritoneal cavity and uterine cavity.
carries ovum to uterine cavity
What are the 4 parts of the uterine tubes?
Where does it lie?
isthmus, ampulla, infundibulum, fimbriae
lies in upper border of BROAD LIGAMENT
Describe the ovary.
located on lateral pelvic wall. attached to the posterior leaf of the broad ligament by the mesovarium
Describe... ligament of the ovary: Round ligament: suspensory ligament: blood supply:
ligament of ovary: slings ovary to uterus (deriv. of gubernaculum) runs in the mesovarium of the broad ligament
Round ligament
Suspensory ligament: suspends ovary laterally to pelvic wall. Is a condensation of fascia surrounding blood vessels to ovary
Blood supply: ovarian artery
Where would blood in the superficial perineal pouch go?
Blood or urine in the superficial perineal pouch can enter the scrotum and ascend the anterior abdominal wall.
