Bony Pelvis and Pelvic Wall

Question 1

What are pelvic girdle ligaments?

Answer 1

Sacroiliac Ligaments (Anterior and Posterior)
Sacrotuberous Ligament (STL)
Sacrospinous Ligament (SSL)

Question 2

What are the major functions of STL and SSL?

Answer 2

Prevent rotation of sacrum

Together with the hip bone create greater and lesser sciatic foramina

Question 3

Anterioposterior compression of pelvis (car accidents) produces fractures in ______ _____ .

Answer 3

Pelvic rami (pubic rami and ischial rami)

Question 4

Lateral forces squeeze _________ and ilia together breaking both.

Answer 4

Acetabulum

Question 5

What are the weak areas of pelvis?

Answer 5

Pubic rami
Acetabulum
SI joints
Ala

Question 6

At what level are greater pelvis and lesser (true) pelvis separated?

Answer 6

L5/S1

Question 7

Boundaries of lesser (true) pelvis

Answer 7

Superiorly: pelvic brim (pelvic inlet)

Inferiorly: Pelvic diaphragm

Laterally and Anteriorly: lower 1/2 of the hip bones

Posteriorly: sacrum and coccyx

Question 8

Which lines demarcate pelvic brim (pelvic inlet)?

Answer 8

Arcuate and pectineal lines.

Question 9

Greater (false) pelvis is superior to ____ ______, occupied by ________ _________.

Answer 9

pelvic brim; abdominal viscera

Question 10

Which bone predominantly bears abdominal weight?

Answer 10

Pubic bone

Question 11

Male vs Female pelves (android vs gynecoid)

1. Pelvic outlet
2. Pubic arch and subpubic angle
3. Obturator foramen
4. Greater sciatic notch

Answer 11

1. Small; large
2. Narrow (<70degrees); wide (>70degrees)
3. Round; oval
4. Narrow; almost 90 degrees

Question 12

What are the major pelvic wall muscles?

Answer 12

Obturator Internus

Piriformis

Coccygeus

Question 13

Obturator Internus

Answer 13

Origin: ilium/ischium surface, obturator membrane
Insertion: greater trochanter
Innervation: obturator n

Question 14

Piriformis

Answer 14

Origin: S2-4 surface; superior margin of greater sciatic notch; STL
Insertion: greater trochanter
Innervation: S1–S2

Question 15

Coccygeus

Answer 15

Origin: ischial spine
Insertion: inferior end of sacrum and coccyx
Innervation: S4–S5

Question 16

What muscle supports pelvic viscera and flexes coccyx?

Answer 16

Coccygeus

Question 17

Four muscles that make up the pelvic diaphragm? What are the origins?

Answer 17

1. (ischio)coccygeus m (ischial spine)
2. Iliococcygeus m (tendinous arch)
3. Pubococcygeus m (pubis)
4. Puborectalis m (pubis)

Question 18

What three muscles of pelvic diaphragm elevate the anus and are together called levator ani?

Answer 18

Iliococcygeus
Pubococcygeus
Puborectalis

Question 19

Thickening of obturator fascia between ischial spine and body of pubis

Answer 19

Tendinous arch of levator ani.

Question 20

Which muscle loops around the anorectal angle?

Answer 20

Puborectalis m

Question 21

T/F: Puborectalis m is distinct from internal and external anal sphincters.

Answer 21

True

Question 22

Passageway for utethra and rectum, and in females also the vagina

Answer 22

Unogenital (levanor) hiatus

Question 23

What are the most medial muscles forming the urogenital hiatus that are the closest to the vagina and are most likely to get torn during childbirth?

Answer 23

Pubococcygeus m

Puborectalis m

Question 24

Dimond shaped space inferior to pelvic floor (diaphragm) filled with primarily fat

Answer 24

Ischiorectal fossae

Question 25

Ischiorectal fossae can be divided into two triangles, what are those?

Answer 25

Urogenital triangle | Anal triangle

Question 26

What is the role of ischiorectal fossa?

Answer 26

Allows movement of pelvic diaphragm and expansion of the anal canal Contains neurovasculature to the anal canal (and some to perineum)

Question 27

Where is ischiorectal fossae in relation to the perineal membrane?

Answer 27

Extends anteriorly above the perineal membrane.

Question 28

Where does the anal canal begin?

Answer 28

At the level where rectum 'perforates' levator ani.

Question 29

What structures does the anal canal consist of?

Answer 29

Anal columns Anal valves Anal sinuses

Question 30

At what level is rectosigmoid juncton?

Answer 30

S3

Question 31

What type of muscle is the internal anal sphincter?

Answer 31

Smooth circular muscle (involuntary)

Question 32

What type of muscle is the external anal sphincter?

Answer 32

Skeletal muscle (voluntary)

Question 33

Internal anal sphincter is responsible for what percent of the resting anal tone?

Answer 33

55-85%

Question 34

What parts does the external anal sphincter consist of?

Answer 34

Subcutaneous Superficial Deep

Question 35

Essentially enlarged and collapsed version (varicosity) of normal venous anatomy?

Answer 35

Hemorrhoids

Question 36

Hemorrhoids are a major clinical consequence of what?

Answer 36

Portal hypertension

Question 37

T/F External hemorrhoids are not painful

Answer 37

False, internal hemorrhoids are not painful

Question 38

What nerves innervate the anus above pectinate line?

Answer 38

Inferior hypogastric plexus (autonomic)

Question 39

What nerves innervate the anus bellow the pectinate line?

Answer 39

Inferior rectal nerves (somatic)

Question 40

What veins drain blood from anus above the pectinate line?

Answer 40

Superior rectal vein (portal)

Question 41

What veins drain blood from anus bellow the pectinate line?

Answer 41

Inferior rectal vein (systemic)

Question 42

What types of hemorrhages are found in anus above the pectinate line?

Answer 42

Internal hemorrhages (not painful)

Question 43

What types of hemorrhages are found in anus bellow the pectinate line?

Answer 43

External hemorrhages (painful)

Question 44

What is the destination of lymph vessels above the pectinate line?

Answer 44

Internal iliac lymph nodes, inferior mesenteric

Question 45

What is the destination of lymph vessels bellow the pectinate line?

Answer 45

Superficial lymph nodes

Question 46

What is the embryological epithelial origin of anus above the pectinate line?

Answer 46

endoderm

Question 47

What is the embryological epithelial origin of the anus bellow the pectinate line?

Answer 47

ectoderm