Pelvis

Question 1

What is the “false pelvis”?

Answer 1

Pelvis Major - the lowermost part of the abdominal cavity lying between the iliac fossae.

Question 2

What is the “true pelvis”?

Answer 2

Pelvis Minor - inferior to the superior pelvic aperture. Contains the pelvic viscera.

Question 3

What are the contents of the pelvis?

Answer 3

1. Rectum
2. Bladder
3. Uterus/Vagina in females; prostate gland in males.

Question 4

What are some main ligaments of the pelvis? (5)

Answer 4

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

Question 5

Describe the muscles of the pelvis and their location.

Answer 5

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

Question 6

What makes up the pelvic diaphragm?

Answer 6

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.

Question 7

What artery supplies most blood to pelvis?

Answer 7

internal iliac artery

Question 8

Describe the anterior division of the internal iliac artery.

Answer 8

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

Question 9

Describe the posterior division of the internal iliac artery.

Answer 9

all are muscular branches

iliolumbar
lateral sacral
superior gluteal

Question 10

(Pelvic Innervation) Describe the sacral plexus.

Answer 10

(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.

Question 11

(Pelvic innervation) Describe the sacral plexus branches to pelvis and perineum.

Answer 11

1. 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

Question 12

(Pelvic innervation) What are the anterior division nerves?

Answer 12

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.

Question 13

(Pelvic innervation) What are the posterior division nerves?

Answer 13

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.

Question 14

Describe the pelvic sympathetic innervation.

Answer 14

sympathetic trunks descend from abdomen along sacrum and converge to form the ganglion impar

Question 15

Describe the superior hypogastric plexus.

Answer 15

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.

Question 16

Describe the parasympathetic innervation of the pelvis.

Answer 16

PELVIC SPLANCHNICS (S2-4) combine with the sympathetic branches to form the inferior hypogastric plexus on the walls of the pelvis.

Question 17

Describe the rectum.

Answer 17

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

Question 18

What is the rectal ampulla?

Answer 18

terminal dilated part of rectum

has retrovesical pouch
has rectouterine pouch

Question 19

Describe the arterial supply of the rectum.

Answer 19

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

Question 20

Describe the venous system of the rectum.

Answer 20

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.

Question 21

Describe the nerve supply of the rectum (sympathetic and parasympathetic)

Answer 21

sympathetics- from hypogastric plexus directly and via fibers accompanying the superior rectal A

parasympathetics- from Pelvic splanchnics S2-S4

Question 22

Describe the bladder.
muscle?
ligaments?
interior?
blood supply?
nerve supply?

Answer 22

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.

Question 23

Describe the Urethra.
female
male
innervation

Answer 23

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

Question 24

Describe the prostate.

Answer 24

lies between the bladder and pelvic floor

perforated by the urethra

Question 25

Describe the pathway of vas deferens.

Answer 25

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

Question 26

Describe the seminal vesicle.

Answer 26

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

Question 27

What does sympathetic innervation cause?

Answer 27

contraction of smooth muscle

Question 28

Describe the uterus:

cervix:
body:
fundus:
postion:
peritoneal reflections:

Answer 28

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

Question 29

Describe the uterine ligaments

Answer 29

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

Question 30

Describe the uterine vessels. Where does the uterine artery pass above?*

Answer 30

uterine artery - passes above ureter in base of broad ligament (Water under the bridge!)
tubal branch of ovarian artery

Question 31

Describe the nerve supply of uterus.

Answer 31

sympathetic- T12-L1 via hypogastric plexus

parasympathetic- pelvic nerve from S1-4

Question 32

Describe the uterine tubes.

Answer 32

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

Question 33

What are the 4 parts of the uterine tubes?

Where does it lie?

Answer 33

isthmus, ampulla, infundibulum, fimbriae

lies in upper border of BROAD LIGAMENT

Question 34

Describe the ovary.

Answer 34

located on lateral pelvic wall. attached to the posterior leaf of the broad ligament by the mesovarium

Question 35

Describe...
ligament of the ovary:
Round ligament:
suspensory ligament:
blood supply:

Answer 35

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

Question 36

Where would blood in the superficial perineal pouch go?

Answer 36

Blood or urine in the superficial perineal pouch can enter the scrotum and ascend the anterior abdominal wall.