Lecture 18 RH

Question 1

What are the different layersof the pelvic walls?

Answer 1

Bones, Joints, and connecting ligaments

Muscles

Pelvic fascia (parietal layer of peritoneum)(somatic nerves and parietal vessels)

Pelvic viscera

Question 2

Where does piriformis originate and insert?

Answer 2

Piriformis goes from the middle 3 parts of the sacrum and goes through the greater sciatic foramen and attaches to the lower limb.

Question 3

Which muscles are involved in the rotation of the hip?

Answer 3

obturator internis

piriformis

Question 4

Where does the obturator originate and insert?

Answer 4

Starts at the obturator foramen and goes aroung the lesser sciatic foramen between the ischial spine and the iscial tuberosity and also attaches to the lower limb.

Question 5

What covers the surface of obturator internis?

Answer 5

pelvic fascia covers the surface of obturator internis

Question 6

Where does the levator ani get its fascia from?

Answer 6

Obturator internis fascia has an extension from the middle which forms the tendinous arch covering the levator ani.

Question 7

What is the significance of the levator ani’s position?

Answer 7

It separates the pelvic cavity and the perineum

Question 8

What is the perineum?

Answer 8

perineum is the location through which tubular viscera pass. (rectum, vagina, urethra)

Question 9

What are the other names of the levator ani muscles?

Answer 9

pelvic floor or pelvic diaphragm

Question 10

What is found between the levator ani and the obturator internis?

Answer 10

between levator ani and obturator internis is the pudental canal (aka alcox canal)

Question 11

What are the contents of the pudental canal?

Answer 11

Pudental vein

Pudental artery

Pudental nerve

these vessels innervate and supply the pelvic floor and perineum.

Question 12

What kinds of nerves can be found in the pelvis? Where are they found?

Answer 12

posterior pelvic wall contains the sacral plexus and nerves from the lumbar plexus pass through the pelvic cavity.

Question 13

What major artery supplies the pelvis?

Answer 13

internal iliac artery supplies the pelvic cavity

Question 14

What connects the levator ani and the obturator internis?

Answer 14

a raphe is formed where the levator ani meets the obturator internus.

Question 15

What is the result if there is disruption in the levator ani muscles?

Answer 15

incontinence of urine and feces.

Question 16

What are the components of levator ani muscles?

Answer 16

pubococcygeus (puborectalis)

iliococcygeus

(ischio) coccygeus

Under reflex and voluntary control.

Question 17

What is interesting about the puborectalis?

Answer 17

Inferior to the pubococcygeus is the puborectalis. In a child it is under reflex control but then becomes voluntary during adulthood.

Question 18

What is the function of the puborectalis?

Answer 18

puborectalis forms a sling around the rectal canal and is important for fecal continence.

Question 19

What other structures does the levator ani muscles work on?

Answer 19

These muscles act on the anal canal, vagina, and urethra as well and form puboanalis, pubovescialis, and pubourethralis.

levator ani is always under pressure especially after childbirth. In females pelvic outlet is wider.

Question 20

What is the structure of the ischiococcygeus muscle?

Answer 20

ischio coccygeus on the left side is made up of muscle

On the perineal (right) side it is the sacrotuberous ligament

In animals it is called agitator chordae which moves the tail. In humans it is very variable.

Question 21

What is the perineal body?

Answer 21

perineal body is found in both males and females in females it is much larger than it is in males.

Question 22

What is the function of the perineal body?

Answer 22

muscles originate from the perineal body.

Question 23

How does the arrangement of the viscera in the perineum influence where they rest?

Answer 23

urethra and vagina rest against the pubis due to the tilt of the pelvis as a result of the lumbar lordosis

Question 24

How does puborectalis assist the rectum in fecal continence?

Answer 24

puborectalis merges with the external anal sphincter. This is important for fecal continence because it produces a kink in the rectum.

Question 25

How does the pubococcygeus muscle assist in urinary continence?

Answer 25

Prostate has the urethra passing through it (prostatic urethra). Some fibers go to anal canal and bladder and these help maintain continence of the urine.

Question 26

What is the perineal body? What is its function?

Answer 26

In both males and females is a midline fibrous nodule called the perineal body, it is important for the attachments of the muscles (including puborectalis) of the pelvis and its larger in females than in males.

Question 27

What are the functions of the pelvic floor?

Answer 27

Support pelvic viscera

raises pelvic floor (increases intrabdominal pressure)

important for continence

Important for defacation

important for childbirth (rotation and flexion of fetal head).

Question 28

What sacral spinal nerves are responsible for levator ani innervation?

Answer 28

“spinal segments 2, 3, and 4 keep the ass off the floor.”

Question 29

What is the origin of the segmental nerve supply of levator ani from above?

Answer 29

Segmental supply is from S3 and S4 from above.

Question 30

Where does the pudendal nerve originate from?

Answer 30

Pudendal nerve from below from S2 and S3

Question 31

What is the difference in density between the segmental and pudental pelvic floor nerves?

Answer 31

Segmental pelvic floor nerves from above are less dense than the ones from below. Reason for this is that if all nerve supply was from pelvic cavity then they are more susceptible during injury.

Question 32

How does the pudental nerve travel before it reaches the levator ani muscles?

Answer 32

From pelvic cavity to gluteal region with superior gluteal artery and then back through the lesser sciatic foramen into the perineum. This region is typically anaesthatised during childbirth near the ischial spine (landmark)

Question 33

How is the uterus arranged relative to the bladder?

Answer 33

the uterus kinks over the bladder wall from above.

Question 34

What are some problems that can arise if there is weakness in the pelvic floor?

Answer 34

Weakness of pelvic floor may result in prolapse of pelvic viscera through the vagina.

Herniation of the bladder may occur into the urethra or the anterior vaginal wall (cystocoele).

Rectum can herniate into the posterior vaginal wall. (rectocoele)