Pelvis

Question 1

Define the Pelvic Walls of the Pelvic Cavity. What is the basic movement/function of the ligaments?

Answer 1

Pelvic wall The walls of the pelvic cavity consist of the sacrum, the coccyx, the pelvic bones inferior to the linea terminalis, two ligaments, and two muscles. Ligaments of the pelvic wall The sacrospinous and sacrotuberous ligaments are major components of the lateral pelvic walls that help define the apertures between the pelvic cavity and adjacent regions through which structures pass . ■ The smaller of the two, the sacrospinous ligament, is triangular, with its apex attached to the ischial spine and its base attached to the related margins of the sacrum and the coccyx. ■ The sacrotuberous ligament is also triangular and is superficial to the sacrospinous ligament. Its base has a broad attachment that extends from the posterior superior iliac spine of the pelvic bone, along the dorsal aspect and the lateral margin of the sacrum, and onto the dorsolateral surface of the coccyx. - These ligaments stabilize the sacrum on the pelvic bones by resisting the upward tilting of the inferior aspect of the sacrum (Fig. 5.29B). They also convert the greater and lesser sciatic notches of the pelvic bone into foramina (Fig. 5.29A,B). ■ The greater sciatic foramen lies superior to the sacrospinous ligament and the ischial spine. ■ The lesser sciatic foramen lies inferior to the ischial spine and sacrospinous ligament between the sacrospinous and sacrotuberous ligaments. - Two muscles, the obturator internus and the piriformis, contribute to the lateral walls of the pelvic cavity. These muscles originate in the pelvic cavity but attach peripherally to the femur.

Question 2

Sacroilliac Joints

Types, Basic Structure

Answer 2

Anterior and posterior sacroiliac joints

The anterior part of the SI joint has an synovial part (In reality is a continuation of the anterior fibrous capsule)

The Posterior part of the SI joint forms an fibrous syndesmosis joint. The joint is reinforced by strong interosseous sacroiliac ligaments,

the SI ligaments helps to transmit weight from the axial skeleton through the sacroilliac joints

Question 3

The pelvic floor is made of these muscles

Which connects the pubis or pelvic bones to the ____ wall.

Describe their locations and innervations

Answer 3

pelvic wall.

Coccygeus and the Levator Ani Muscles

Levator Ani muscles:

1. Puborectalis
2. Pubococcyxgeus
3. Ilioccygeus

Coccygeus muscle

-sits below the piriformis and is the most posterior of the pelvic floor muscles.

O: ischial spine and sacrospinous ligament

I: sacrum and coccyx

Iliococcygeus muscle

-Nerve to levator ani muscle (S3-S4)

O: ischial spine, obturator internus

I: coccyx

Flex the coccyx

Pubococcygeus

• O: posterior surface of the body of the pubis and into the sacrum & coccyx
• elvate the pelvic floor
• supply by the inferior gluteal artery
• innervate by the nerve to levator ani S3-S4

Puborectalis:

O: pubis, surround the urogenital hiatus and anal hiatus

Action: contract the anal sphincter

Iliococcygeus

Question 4

The lesser pelvis contains a rich network of arteries that mainly arise from the:

1)

This main arterial supply of the pelvis gives rise to the

_____ arteries and supply the _____, ____ thigh, ____ , _____ and female and male ___________ organs.

Answer 4

1) internal iliac artery.

gluteral arteries

buttocks, medial thigh, perineum

Reproductory organs

Question 6

The sympathic supply to the pelvis is

1)

2)

The parasympatheic nerves are:

Answer 6

1) sacral sympathetic turnk
2) superior hypogastric nerves

Splanchnic nerves

Question 7

The urethra is a tube