pelvis, pelvic diaphragm, and urinary bladder COPY

Question 1

Describe on the hip the ilium, ischium, and pubis regions

Answer 1

* note they all meet in the acetabulum

Question 2

What are the five parts that make up the pelvic inlet?

Answer 2

sacral promontary

Ala

Arcuate line

Pectineal Line

Pubic crest

Question 3

What are the four regions of the pelvic outlet?

Answer 3

ischiopubic ramus

ischial tuberosity

sacrotuberous ligament

coccyx

Question 4

Describe the ‘False pelvis’

Answer 4

superior to pelvic brim/inlet

considered part of the abdominal cavity

Question 5

What is the floor of the true pelvis called?

Answer 5

pelvic diaphragm

Question 6

What is the ‘subfloor’ of the true pelvis?

Answer 6

The perineum - inferior to the pelvic diaphragm

Question 7

Describe the sacro-iliac joint

Answer 7

between the ilium and the sacrum - it is a synovial joint that may potentially ossify. it is strengthened by the sacroiliac ligaments both anteriorly and posteriorly

Question 8

describe the pubic symphysis joint

Answer 8

it is a secondary carilaginous joint that only moves during childbirth

Question 9

How do you distinguish the male pelvis from the female pelvis?

Answer 9

female pelvis = circular pelvic inlet, wider pubic arch (roman) 80-85 degrees, straight ischial spines, and alas flare outwards

male pelvis = heart shaped, gothic pubic arch (50-60 degrees) medially projected ischial spines

Question 10

What purpose do the sacrospious and sacrotuberous ligaments have for the sacrum?

Answer 10

They prevent the upward tilting of the sacrum

Question 11

Name the muscles of the pelvic diaphragm

Answer 11

IschioCoccygeus (AKA coccygeus)

iliococcygeus

pubococcygeus (splits into puborectalis and pubovaginalis or puboprostaticus)

*together the pubococcygeus and the iliococcygeus make up the levator ani muscle*

Question 12

what nerve supplies the pelvic diaphragm?

Answer 12

The pudendal nerve

Question 13

Which part of the pelvic diaphragm maintains the 90 degree angle of the anal canal?

Answer 13

the puborectalis muscle

Question 14

Where does the perineal body sit in the female?

Answer 14

infront of the anus- behind the vaginal opening

Question 15

Describe the branches of the internal iliac artery

Answer 15

internal iliac

Anterior division

• 3x parietal = obturator, inferior gluteal, internal pudendal
• 3x visceral = superior vesical, inferior vesical (vaginal vessel), middle rectal, and uterine artery (only in women)

Posterior division

• 3x parietal= iliolumbar, lateral sacral, superior gluteal

Question 16

What artery runs with the pudental nerve through the alcock’s canal?

Answer 16

The internal pudendal artery. This is the site of the pudendal nerve block

Question 17

Where can we palpate the pudendal nerve?

Answer 17

ischial spine

Question 18

Does the uterine artery cross the ureter superiorly or inferiorly?

Answer 18

superiorly (water under the bridge)

Question 19

What structure is commonly damaged in women who undergo historectomies?

Answer 19

The ureters are commonly mistaken for the uterine artery- uterine artery crosses the ureter superiorly - you can observe the difference in these structures b/c the ureter has peristaltic waves of contractions

Question 20

What are the roots of the sacral plexus?

Answer 20

L4,5 S2,3,4

Question 21

What are the 12 branches of the sacral plexus?

Answer 21

• superior gluteal
• inferior gluteal
• posterior cutaneous femoral
• piriformis
• obturator internus
• quadratus femoris
• sciatic (L4,5 S1,2,3)
  
  • divides into tibial nerve and common fibular nerve
• medial plantar nerve
• lateral plantar nerve
• pudendal (S 2,3,4)
• coccygeal

Question 22

describe the 3 sides of the bladder

Answer 22

Apex = median umbilical ligament to the umbilicus -which is a remnant of the urachus - part of how the bladder forms

superior surface - is covered with peritoneum and triangular in shape

inferolateral surfaces = retropubic fat pad and fascia

levator ani and obturator internus

base = trigone

Question 23

Where does the bladder sit when it is distended vs. when it is empty?

Answer 23

When the bladder is empty it sits in the true pelvis

when it is full it sits in the false pelvis

can hold 150-600 ml urine

Question 24

what muscle makes up the bladder?

Answer 24

The detrusor muscle - 2 longitudinal layers and a circular layer in the middle

Question 25

What sort of surface is the bladder made up of?

Answer 25

transitional epithelium = tight junction with no leaks, but distensible

Question 26

What is the trigone?

Answer 26

triangular area that culminates into urethral opening - functions as a urine funnel

Question 27

Describe the ureteric orifices

Answer 27

This is where the ureters enter the bladder - they are oblique slit like openings to prevent reflux - found at lateral margins of the interureteric crest -

Question 28

Describe the neck of the bladder

Answer 28

most inferior part of the bladder and the origen of the urethra

it is fixed by tough ligaments

female= pubovesical

male = puboprostatic

Question 29

laxity of what ligament contributes to stress incontinence?

Answer 29

laxity of the pubovesical ligament in women

Question 30

Describe the four parts of the male urethra

Answer 30

prostatic urethra (3cm)

membranous urethra (1cm)

bulbous urethra

penile/spogy urethra

Question 31

Approx what length is the female urethra?

Answer 31

4cm - very short, and susceptible to infections

Question 32

describe the blood supply to the bladder

Answer 32

superior/inferior vesical (vaginal in women)

obturator/inferior gluteal branches

+uterine branches in women

Venous drainge is by vesical venous plexus or prostatic/vaginal venous plexus into the internal iliac vein

Question 33

What venous system allows prostate cancer to spread fairly easily?

Answer 33

The valveless veins of bateson -

Question 34

Describe the innervation to the bladder

Answer 34

parasympathetic

• pelvic splanchnic nerves - inhibit internal sphincter and provide motor function to the detrusor

sympathetic

• provide motor to internal sphincter- pain on over distention *clinically this is why we use anticholinergics for symptoms of the detrusor overactivity *

Question 35

Where does the external sphincter sit in the pelvis?

Answer 35

in women- external sphincter is within the deep perineal pouch

in men - external urethral sphincter is also within the deep peroneal pouch!