Session 5a : Reproduction - Pelvic Floor & Perineum

Question 1

What are the ideal features for child birth (of the pelvis) ?

Answer 1

Round inlet 
Ischial spines not to prominent 
Sacral pomontry not to prominent 
Su- pubic arch of greater than 90º 
Well rounded greater sciatic notch 
Straight sided walls

Question 2

What is measured when clinically assessing the pelvis?

Answer 2

Pelvic inlet - anterior posterior Diameter
Mid pelvis- bispinous diameter (distance between ischial spines) and the straight side walls
Pelvic outlet - transverse diameter of the region check between the ischial tuberosities (fist should sit here) & the infrapubic angle

Question 3

How do you measure the anterior posterior diameter in females ?

Answer 3

You can check the different conjugates :
Anatomical : from the sacral pomontry to the superior border of the pubic symphysis
Obstetric : from the sacral pomontry to the midpoint of the pubic symphysis
Diagonal : from the sacral Pomontry to the inferior border of the pubic symphysis.

Question 4

What are the features of a male pelvis?

Answer 4

Heart shaped inlet 
Narrow infapubic angle (50-60º) 
Medially prominent ischial spines 
Prominent sacral promontory 
Narrow and sharp ended greater sciatic notch 
Tip of coccyx faces more inward

Question 5

What are the boundaries of the pelvic outlet?

Answer 5

Posteriorly : coccyx
Anteriorly : pubic symphysis
Posterolaterally : sacrotuberous ligaments
Anteriolaterally : ischiopubic rami

Question 6

What are the boundaries of the pelvic inlet ?

Answer 6

Posteriorly : sacroiliac joints, sacral promontory
Anteriorly : pubic symphysis and the pubic crests
Laterally : arcuate line , ileopectineal line

Question 7

What is the difference between the True and fake pelvis?

Answer 7

The pelvic inlet/ brim Seperates the pelvis into true (below it) and false (above it).
The false pelvis is a continuation of the posterior abdominal wall which contains no pelvic organs, its mainly made up of the iliac fossa.
The true pelvis is below the brim and contains the pelvic and reproductive organs.

Question 8

Which two ligaments are important in the formation of the different foramen in the pelvis?

Answer 8

Sacrotuberous - triangle ligament the base of which is attached to the sacrum and coccyx and will run to the ischial tuberosity.
Sacrospinous - runs from the sacrum to the ischial spines.

These will help form the greater and lesser sciatic foramen.

Question 9

Where are the greater and lesser sciatic notch found?

Answer 9

In lateral view :
The greater notch runs from the posterior inferior iliac spine to the ischial spine.
The lesser notch runs from the ischial spine to the ischial tuberosity.

Question 10

Where is the perineal region located?

Answer 10

This is located below the pelvic outlet.

Question 11

What is the perineal body?

Answer 11

This is a connective tissue mass located in the centre of the perineum , between the ischial tuberosities.

It is a condensation of the superficial perineal muscles, the fibres of the external anal sphincter, levator ani and the fascia of the rectum and vagina .

Question 12

What are the layers of enodervical fascia which support the vagina ? And the pelvic organs ?

Answer 12

1. The uterosacral ligament which attaches the uterus to the sacrum holding it up and in position .
2. The fascia surrounding the vagina posterior and Anteriorly , this will help place the vagina laterally against the lateral pelvic wall. This means that normally the vagina is flattened laterally. This can be felt upon examination (lateral sulcus)
3. The perineal region and superficial muscles

Question 13

What are the key functions of the pelvic floor?

Answer 13

Helps stabilise the trunk - truncal stability
Aids in childbirth
Supports the pelvic viscera from rises in the interabdominal pressure
Prevents incontinence both urinary and foecal

Question 14

How does the pelvic floor prevent foecal incontinence ?

Answer 14

The muscles of the levator ani - the puborectalis will hold the anorectal junction at a 90 degree flexure and Anteriorly , this will close the anal canal until the muscle tone relaxes and the canal can become open to defecate.

Question 15

How does the pelvic floor relate to the urinary incontinence?

Answer 15

It will help position the urethra Anteriorly
The levator ani and the superficial muscles and ligaments will then absorb the rise in the abdominal pressure so that the bladder pressure will remain lower than external sphincter pressure, to prevent the bladder from emptying.

Question 16

How does the pelvic floor aid in childbirth ?

Answer 16

The shape of the pelvic floor is the shape of a bowl which will push the baby’s head (rotate it) toward the urogenital hiatus.

Question 17

How does the pelvic floor aid in truncal stability?

Answer 17

It will support the abodminal cavity inferiorly.

Note : when the abdomen contracts so does the pelvic floor.

Question 18

What is an episiotomy ?

Answer 18

Episiotomy - is when you deliberately cut the perineum in either a midline plane (toward the anal sphincter) or in a mediolateral plane.
This is done then to limit the damage that can occur with tearing.

Question 19

What is the function of the perineal body ?

Answer 19

Anchors the perineal muscle 
Anchors the vagina and the rectum 
Central fulcrum of pelvic support 
Acts as a tear resistance in the region 
Anchors the posterior wall of the vagina

Question 20

Where is the perineum located?

Answer 20

Located most inferior point of the pelvic outlet

Inferior to the levator ani and above the skin of the vulva.

Question 21

Which space is the perineal space continous with ?

Answer 21

The ischiorectal fossa

Question 22

What is the ischiorectal fossa ?

Answer 22

This region is laterally placed to the anal canal in the deep perineal pouch, it is bordered by the obturator internus and the levator ani muscles.
It is continous with the space below the levator ani and the gluteal muscle fat, in the buttocks.

Question 23

What is in the ischiorectal fossa?

Answer 23

Fat - this allows the distension of the anal canal

Pudendal canal - the pudenal nerve and vessels run through here.

Question 24

What is the subperitoneal space in the perineum?

Answer 24

This is the region above the levator ani which has the uterine artery , relative lymphatics and the ureter.

Question 25

What muscles make up the pelvic floor?

Answer 25

The lateral wall of the pelvic floor : obturator internus and piriformis (and coccygeal)
Floor : the muscles of the levator ani , puborectalis, pubococcygeus and illiococcygeus

Question 26

What are the borders of the perineum ?

Answer 26

Diamond shaped region on the inferior side of pelvic outlet :

Posterior : coccyx 
Anterior : pubic symphysis 
Laterally : ischiooubic rami and the sacrotuberous ligaments 
Roof : levator ani muscles 
Floor : skin

Question 27

How can the regions of the perineum be separated ?

Answer 27

They can be separated by a theoretical line drawn between the ischial tuberosities, this will separate the region into a :
Urogenital triangle Anteriorly - urethra & (vagina)
Anorectal triangle posteriorly - anus

Question 28

If the urethra is pierced below the perineal membrane where is the urine collected ?

Answer 28

In the superficial perineal pouch