pelvic diaphragm

Pelvic Diaphragm

Introduction

Forms the pelvic floor

Gutter shaped sheet of muscles

They are slung around urethra,vagina, and anal canal

They are

1. Coccygeus muscle (ischiococcygeus)

2. Iliococcygeus muscle

3. Pubococcygeus

(2 + 3 = Levator ani)

Origin and insertion

1. Arises from the ischial spine; inserts into the side of the coccyx

2 & 3 Arise from the white line ( arcus tendineus )which is stretched between the ischial spine and the body of the pubis across the obturator fascia and insert into the side of the coccyx and the ano-coccygeal raphe. ( the raphe is formed by the interdigitations of the right and left muscle fibres and extends from the tip of the coccyx to the junction of the rectum and anal canal.

The medial most fibres of the puborectalis form a U shaped sling around the junction of the rectum and anal canal : called puborectalis.

Blood supply

Artery : Occipital artery and the superior thyroid artery

Nerve supply

Inferior rectal nerve

Perineal nerve

Action

Increasing the intraabdominal pressure and maintaining the continence of bladder and rectum

They act and help delivery during childbirth.