Perineum I (pre-study)

Question 1

What forms the pelvic girdle?

Answer 1

Fusion of the two os coxae and sacrum

Question 2

What is the anterior fusion of the os coxae?

Answer 2

pubic symphysis

Question 3

What is the posterior fusion of the os coxae?

Answer 3

sacroiliac joints

Question 4

What is the superior pelvic aperture and what does it consist of?

Answer 4

• Linea Terminalis
• A line circumscribing the sacral promontory (S1 vertebrae), arcuate line of ilium, pectineal line of pubis, and pubic symphysis

Question 5

What is the Inferior pelvic aperature and what does is consist of?

Answer 5

• Pelvic Outlet

- Inferior margin of the pubic symphysis, inferior pubic rami, sacrotuberous ligaments, tip of coccyx

Question 6

How does the pelvis communicate with the lower limb and gluteal region?

Answer 6

• greater sciatic foramen

- obturator canal

Question 7

How does the pelvis communicate with the perineum?

Answer 7

• Gap in perineal membrane just posterior to the pubic symphysis

Question 8

What two areas are able to communicate via the lesser sciatic foramen?

Answer 8

• gluteal region into and out of perineum

Question 9

Describe the course of most of the neurovasculature that supplies the perineum.

Answer 9

• Through Greater sciatic foramen into gluteal region

- Then thought lesser sciatic foramen to reach the perineum

Question 10

Define the boundaries of the Perineum.

Answer 10

• Anterior - symphysis pubis
• Anterolateral - Ischiopubic rami (pubic arch)
• Lateral - Ischial tuberosity
• Posterolateral - Sacrotuberous ligaments and the overlying glut. maximus fibers
• Posterior - coccyx
• Floor - skin and fascia
• Roof - Pelvic diaphragm

Question 11

What line divides the perineum into the anal triangle and urogenital triangle?

Answer 11

A line drawn between the two ischial tuberosities

Question 12

What forms the pelvic diaphragm and what spaces does it divide?

Answer 12

• Levator ani and Coccygeus (and their deep fascia)

- Divides Pelvis and Perineum (floor of pelvis, roof of perineum)

Question 13

How do the vagina and anal canal get through the pelvic cavity into the peritoneum?

Answer 13

• Urogenital hiatus and anal hiatus

Question 14

What bisects obturator internus?

• where does this happen?
• What is the consequence?

Answer 14

• Bisected by the attachment of the pelvic diaphragm to the lateral pelvic walls (aka ischial tuberosity)
• Means obturator internus is in BOTH the perinuem and pelvic cavities

Question 15

T or F: Periformis has fibers that extend into the perinem?

Answer 15

False

Question 16

What musculofascial diaphragm is located entirely within the perineal space?
- what two structures does it span?

Answer 16

• Urogenital Diaphragm

- stretches between the isciopubic rami

Question 17

What structures pierce the UG diaphragm?

Answer 17

• Urethra (male and female)

- Vaginal Canal (female)

Question 18

T or F: the UG diaphragm serves as a foundation for the attachment of the external genitalia and contributes to support of the pelvic viscera

Answer 18

True

Question 19

T or F: superior communication between the perineum and pelvis.

Answer 19

True

Question 20

What lines the UG diaphragm on superior and inferior surfaces and what difference exists between the two?

Answer 20

• superiorly = superior fascia of the UG diaphragm
• Inferioly = inferior fascia of the UG diaphragm
• The inferior fascia is more fibrous and dense

Question 21

What node extends from the free posterior magin of the UG diaphragm?

Answer 21

Perineal Body

Question 22

What is the significance of the perineal body?

Answer 22

• Provides additional support for pelvic visceral, especially important in females

Question 23

T or F: the Urogenital and anal triangles lie in the same horizontal plane.

Answer 23

FALSE- They are located at roughly 90º to each other with the UG triangle running horizontal and parallel to the floor.

Question 24

What part of the the perineum is deepest?

Answer 24

• Lateral part = deepest because of the bowl shape of the Pelvic diaphragm