Bones

Question 1

What bones form the pelvis?

Answer 1

1. left hip bone
2. right hip bone
3. sacrum
4. coccyx

Question 2

What is the shape of the pelvis?

Answer 2

basin-shaped

Question 3

What is each hip bone formed by?

Answer 3

three fused bones:

1. ilium
2. ischium
3. pubis

Question 4

In anatomical position, how is the pelvis tilted?

Answer 4

• the anterior superior iliac spine and upper margin of the pubic symphysis lie in the same vertical plane
• the tip of the coccyx and the upper margin of the pubic symphysis lie in the same horizontal plane

Question 5

How does the pelvic cavity project from the abdominal cavity?

Answer 5

posteriorly

Question 6

What is the pelvic inlet?

Answer 6

• the superior aperture of the pelvis

- heart, oval, or round-shaped

Question 7

What are the boundaries of the pelvic inlet?

Answer 7

1. sacral promontory
2. sacral alae
3. arcuate line (on ilium)
4. pecten pubis (pectineal line)
5. pubic crest

Question 8

What is the pelvic brim?

Answer 8

• also called the linea terminalis
• continuous border formed by the boundaries of the pelvic inlet
• divides the pelvis into the greater (false) pelvis above and the lesser (true) pelvis below

Question 9

What is the greater pelvis?

Answer 9

• the expanded upper portion of the pelvis

- part of the posterior abdominal wall

Question 10

What are the functions of the greater pelvis?

Answer 10

1. supports abdominal viscera

2. provides muscle attachment for muscles of locomotion

Question 11

What is the lesser pelvis?

Answer 11

• the pelvic cavity proper

- lies between the pelvic inlet above and the pelvic outlet below

Question 12

What does the lesser pelvis contain?

Answer 12

• lower part of the GI tract
• urinary bladder
• lower part of ureter
• internal reproductive organs

Question 13

What is the pelvic outlet?

Answer 13

• the inferior aperture of the pelvis

- diamond shaped

Question 14

What are the boundaries of the pelvic outlet?

Answer 14

1. pubic symphysis (anterior tip)
2. ischiopubic rami (lateral/anterior))
3. ischial tuberosities (lateral points)
4. sacrotuberous ligament (posterior wall)
5. tip of the coccyx (posterior tip)

Question 15

What occupies the pelvic outlet?

Answer 15

structures of the perineum

Question 16

What is the pubic arch?

Answer 16

formed by pubic symphysis, ischiopubic rami, and ischial tuberosities

Question 17

What is an anthropoid pelvis?

Answer 17

• characterized by a long A-P diameter and short transverse diameter
• present in some males and approximately 20% of females

Question 18

What is a platypelloid pelvis?

Answer 18

• characterized by a short A-P diameter and wide transverse diameter
• rare in males, present in 2% of females
• flattened pelvis
• most associated with birth difficulties

Question 19

What is an android pelvis?

Answer 19

• has a heart-shaped inlet

- present in most males and approximately 30% of females

Question 20

What does the term “android” mean?

Answer 20

male-like

Question 21

What is a gynecoid pelvis?

Answer 21

• has an ovoid or round inlet
• present in 50% of females and no males
• this is the ideal pelvis for childbirth
• very spatious: wide A-P and transverse diameters

Question 22

What does the term “gynecoid” mean?

Answer 22

female-like

Question 23

What are the differences between the male and female pelvi?

Answer 23

• male pelvis is generally larger, heavier, and has more pronounced muslce markings than the female pelvis
• male inlet is usually heart-shaped; female inlet is usually oval
• pelvic cavity and pelvic outlet are larger in female
• ilia are more flaring in male
• subpubic angle larger in female
• greater sciatic notch of female is broad and shallow; that of the male is narrow and deep
• female sacrum is shorter and wider than the male sacrum