Pelvis and Perineum

Question 1

Bony Pelvis

Answer 1

A basin-shaped bony ring that attaches the lower limbs to the spine and supports the visceral organs of the pelvis

Question 2

The pelvis is formed by how many bones?

Answer 2

4 bones:
2 Hip bones (os coxae)- Fusion of the ilium, ischium, and pubis during puberty
Sacrum
Coccyx

Question 3

Divisions of the Bony Pelvis

Answer 3

Greater (false) pelvis and a lesser (true pelvis)

Question 4

What separates the Greater and Lesser Pelvis?

Answer 4

The pelvic brim

Question 5

Greater Pelvis

Answer 5

Houses certain abdominal viscera

Question 6

Lesser Pelvis

Answer 6

Accommodates pelvic viscera- bladder and reproductive organs

Question 7

Differences between Male and Female Pelvis

Answer 7

Female Sacrum: Wider; shorter sacral curvature is accentuated
Female Coccyx: More movable; straighter
Female Greater Sciatic Notch: Wide and shallow
Female Pelvic Inlet (brim): Wider; oval from side to side
Female Pelvic Outlet: Wider; ischial tuberosities shorter, farther apart, and everted
Male Sacrum: Narrow; longer; sacral promontory more ventral
Male Coccyx: Less movable; curves ventrally
Male Greater Sciatic Notch: Narrow and deep
Male Pelvic Inlet (brim): Narrow; heart-shaped
Male Outlet: Narrower; ischial tuberosities are longer, sharper, and point more medially

Question 8

Pelvic Ligaments

Answer 8

• Weight of the trunk tends to rotate the sacrum anteriorly
• Pelvic ligaments are arranged to resist this force

Question 9

What hormone releases during pregnancy?

Answer 9

Relaxin

Question 10

Pelvic Diaphragm

Answer 10

• Extends from the pubic symphysis to the coccyx
• Separates pelvic viscera from the perineal structures inferiorly
• Supports the pelvic organs

Question 11

What does the Pelvic Diaphragm Close Off?

Answer 11

Since it is a “funnel” of skeletal muscles, it closes off the pelvic outlet

Question 12

What do the Skeletal Muscles of the Pelvic Diaphragm Help With?

Answer 12

They form a dynamic floor that supports the pelvic viscera inferiorly and helps to raise intra-abdominal pressure; voluntary control of urination, fecal continence, and uterus support

Question 13

Levator ani Muscle consists of three parts according to their fibers:

Answer 13

• Puborectalis
• Pubococcygeus
• Iliococcygeus

Question 14

Levator ani + Coccygeus Muscles + Their Fascias make…

Answer 14

The Pelvic Diaphragm

Question 15

Coccygeus is also known as?

Answer 15

Ischiococcygeus

Question 16

Female pelvic diaphragm permits the passage of what, via what?

Answer 16

Permits the passage of the urethra, vagina, and rectum via the urogenital hiatus

Question 17

Male pelvic diaphragm permits the passage of the what, via what?

Answer 17

Permits the passage of the urethra and rectum via the urogenital hiatus

Question 18

Pelvic Arterial Supply

Answer 18

Paired internal iliac arteries and their branches

Question 19

Pelvic Venous Drainage Parallels the Arterial Blood Supply

Answer 19

Tributaries of the internal iliac veins

Question 20

How many main arteries enter the lesser pelvis in females vs males?

Answer 20

4 main arteries in the lesser pelvis in females, 3 in males

Question 21

These types of arteries deliver the most blood to the lesser pelvis, and they bifurcate into an anterior and a posterior division

Answer 21

Paired Internal Iliac Arteries

Question 22

Pelvic Arteries

Answer 22

• Internal Iliac Arteries
• Paired Ovarian Arteries from the aorta
• Median Sacral Artery
• Superior Rectal Arteries

Question 23

Pelvic Veins

Answer 23

• Internal Iliac Veins and their tributaries
• Superior Rectal Veins (portal venous system)
• Median Sacral Vein
• Gonadal Veins

Question 24

Pelvic structures are innervated mainly by?

Answer 24

The sacral (S1-S4) and coccygeal spinal nerves and pelvic part of the autonomic nervous system

Question 25

Coccygeal Plexus

Answer 25

A small network of nerve fibers formed by the ventral rami of S4 and S5

Question 26

Pudendal Canal

Answer 26

A horizontal passageway within the obturator fascia which covers the medial aspect of obturator interns; transmits the internal pudendal vessels and pudendal nerve: supply the perineum

Question 27

Pudendal Nerve

Answer 27

Somatic innervation (S2-S4) to perineal body wall, muscles, genitalia, external anal sphincter and skin of perineum; also carries sympathetics

Question 28

Perineum

Answer 28

Diamond-shaped pelvic outlet that lies inferior to the inferior pelvic aperture and is bounded by the pubic symphysis anteriorly, ischial tuberosities laterally, coccyx posteriorly

Question 29

The perineum is subdivided into?

Answer 29

A urogenital (UG) triangle and an anal triangle

Question 30

The perineum is bounded superiorly by?

Answer 30

Levator ani (pelvic diaphragm) and laterally by obturator internus

Question 31

Superficial Pouch of the Perineum

Answer 31

Potential space between the membranous layer of subcutaneous tissue and the perineal membrane

Question 32

Deep Pouch of the Perineum

Answer 32

Bounded inferiorly by the perineal membrane and superiorly and laterally by the fascias of the pelvic diaphragm and obturator interns muscles

Question 33

Contents of the Superficial Pouch in Males

Answer 33

- Root (crura and bulb) of the penis and associated muscles - Proximal part of spongy urethra - Superficial transverse perineal muscles - Deep perineal branches of internal pudendal vessels and nerves

Question 34

Contents of the Superficial Pouch in Females

Answer 34

- Clitoris and associated muscles (ischiocavernosus) - Bulvs of the vestibule and surrounding muscles (bulbospongiosus) - Superficial transverse perineal muscles - Greater vestibular gland

Question 35

Contents of the Deep Pouch in Both Sexes

Answer 35

Contains parts of the urethra centrally, the inferior part of the external urethral sphincter muscle, and the anterior extensions of the sischioanal fat pads

Question 36

Contents of the Deep Pouch in Males

Answer 36

- Intermediate part of urethra - Deep transverse perineal muscles - Bulbourethral glands - Dorsal neuromuscular structures of the penis

Question 37

Contents of the Deep Pouch in Females

Answer 37

- Proximal part of urethra - A mass of smooth muscle - Dorsal neurovasculature of the.......

Question 38

Urogenital Diaphragm

Answer 38

The muscles within the deep perineal pouch plus the perineal membrane

Question 39

Ischioanal Fossa

Answer 39

A fat filled, wedge-shaped region surrounding the rectum and anus; located primarily in the anal triangle between the skin of the anal region and the pelvic diaphragm

Question 40

Neurovascular Contents of the Ischioanal Fossa

Answer 40

Inferior anal/rectal vessels and nerves and cutaneous branches of the sacral plexus

Question 41

Disruption of Perineal Body

Answer 41

In women, it provides the final support for the pelvis viscera; if damaged prolapse of the pelvic viscera may occur