The pelvis and pelvic floor

Question 1

Anteroposterior diameter of the pelvic brim…

Answer 1

11cm

Question 2

Anteroposterior diameter of the pelvic cavity…

Answer 2

12cm

Question 3

Anteroposterior diameter of the pelvic outlet…

Answer 3

13 cm

Question 4

Transverse diameter of the pelvic cavity

Answer 4

12cm

Question 5

Transverse diameter of the pelvic outlet…

Answer 5

11cm

Question 6

Transverse diameter of the pelvic brim…

Answer 6

13 cm

Question 7

Functions of pelvic floor

Answer 7

Support- organs that are above the pelvic floor
Micturition
Defecation
Sexual intercourse
Pregnancy: vital in supporting the increase in weight of the uterus.
Labour and delivery: rotation and descent of the fetus.

Question 8

What are 3 main muscles of the pelvic floor

Answer 8

Pubococcygeus muscles → extends from the inner pubic bone to the coccyx. Three main bands (first: surrounds the urethra, second: surrounds the vagina and third: loops around the anus) most vital of the deep muscle layer as they support important structures.

Iliococcygeus muscles → extends from the inner aspect of the iliac bone to the midline of the perineum.

Ischiococcygeus muscles → arise from ischial spine and pass to the lower sacrum.

Question 9

What does the pelvic floor consist of …

Answer 9

Muscles, ligaments and connective tissue which includes:
Pelvic peritoneum
Supporting ligaments of the uterus

Question 10

What is an Episiotomy?

Answer 10

Surgical incisions into the perineum before delivery intending to aid the birth of the fetus.
An incision will heal better than a tear.
Episiotomy is carried out during instrumental delivery or fetal distress.
A small incision of the fourchette, the skin of the perineum, the posterior vaginal wall and the superficial muscles of the pelvic floor.
Two types of incision:
Mediolateral
Midline
Informed consent is needed

Question 11

How to assess a perineal trauma?

Answer 11

1st injury to the skin → involves both the forchette and the perineal skin.
no sutures needed

2nd injury to the perineal muscles not involving the anal sphincter. Can involve both the forchette and both muscles of the pelvic floor.

3 classification of the 3rd > due to the different ways of sutures → very serious because it involves the external anal sphincter as well as the structures of a 2nd degree tear

4th degree not only external and internal but also the bowel

Labial and clitoral tears can be left spontaneously to heal is the vulval hygiene is good. It may have to be sutured as they associated with high blood loss.

Question 12

What are the Physiological changes of the pelvic floor through pregnancy?

Answer 12

Pregnancy
Muscles become relaxed due to the effect of hormones → relaxin
Relaxin- produced by the placenta
Pelvic floor exercise- fast and slow fibres → should be done hourly
Perineal massage → massaging the posterior vaginal wall
Stress incontinence
Prolapse

Labour
The muscles of the pelvic floor will aid the expulsion action which pushes the fetus
Maternal position if the woman lies on her left side can reduce perineal trauma

Question 13

What is the Perineal body?

Answer 13

The muscles and connective tissue situated between the vaginal and rectal canals.
Described as being a triangle and each side being 3.5-4 cm long
Helps in the process of birth and defaecation.

Question 14

Role of External anal and urethral sphincter?

Answer 14

Play a role in defecation and micronutrition.

Question 15

What is Superficial muscle layer?

Answer 15

Superficial muscle layer supports the urethral, vaginal and anal sphincter → vitally important in maintaining the overall strength of the pelvic floor.
Ischiocavernosus muscles
Bulbocavernosus muscles
Transverse perineal muscles

Question 16

Blood, nerves and lymph of the pelvic floor?

Answer 16

→ supplied from the pudendal arteries and veins
→ nerve supply is provided by the third and fourth sacral nerves
→ lymph drains into the inguinal and external iliac glands

Question 17

Labour

Answer 17

Rotation of the presenting part decent of the presenting part Maternal position
Perineal massage
Birth
Perineal trauma

Question 18

Postnatal

Answer 18

Pelvic floor exercises
 Analgesia
 Baths
 Oedema
 Bruising
 Midwifery care