Bones and Joints of Pelvis

Question 1

What are the 3 surfaces of the ilium?

Answer 1

iliac fossa, gluteal surface, sacral surface

Question 2

What are the features of the pubis?

Answer 2

body, pubic crest, pubic tubercle, superior and inferior pubic ramus, pectineal line on superior ramus

Question 3

What are the features of the ischium?

Answer 3

body, ischial ramus, ischial tuberosity, ischial spine

Question 4

What differentiates the greater and lesser sciatic notches?

Answer 4

the ischial spine

Question 5

What bounds the obturator foramen?

Answer 5

the superior and inferior pubic rami and the ischial ramus

Question 6

How many vertebrae are fused to make the sacrum?

Answer 6

5

Question 7

What is the lateral mass of the sacrum?

Answer 7

the fused transverse processes

Question 8

What is the sacral promontory?

Answer 8

the prominent anterior margin at the superior surface of the sacrum

Question 9

What is the alar?

Answer 9

the superior surface of the lateral masses of the sacrum

Question 10

Where does the sacrum articulate?

Answer 10

with L5, with the coccyx, and with the hip bone on either side

Question 11

What is the false or greater pelvis?

Answer 11

the pelvis above the iliopectineal line - the iliac fossae and iliac crests

Question 12

What is the true or lesser pelvis?

Answer 12

the pelvis between the pelvic inlet and pelvic outlet

Question 13

What defines the pelvic inlet?

Answer 13

superior margin of pubic symphysis, pubic crest, pectineal line of pubis, arcuate line of ilium, sacroiliac joint

Question 14

What is the gynaecoid type of pelvis?

Answer 14

where the pelvic inlet is wider transversely

Question 15

What is the android and anthropoid type of pelvis?

Answer 15

where the pelvic inlet is wider in the PA direction

Question 16

What are the differences between the male and female pelvis?

Answer 16

males is thick and heavy where female is thin and light
males have a heart shaped inlet where females have a transverse oval
the greater sciatic notch in males is a narrow inverted v where as its almost 90 degrees in females
the subpubic arch is an acute angle in males and an obtuse angle in females
the acetabulum is large in males and small in females
the obturator foramen is round in males and oval in females

Question 17

What is the shape of the pelvic outlet?

Answer 17

diamond

Question 18

What are the boundaries of the pelvic outlet?

Answer 18

inferior margin or pubic symphysis, tip of coccyx and ischial tuberosities

Question 19

What is the plane of least dimensions?

Answer 19

from S4 through the ischial spine to the base of the pubic symphysis

Question 20

What is the articular surface of the sacroiliac joint called?

Answer 20

the auricular surface

Question 21

What are the 3 sacroiliac ligaments?

Answer 21

anterior, posterior and the interosseus sacroiliac

Question 22

What is the role of the interosseus sacroiliac ligament?

Answer 22

tightens as sacrum rotates forward to limit mobility

Question 23

What are the accessory ligaments of the sacroiliac joint?

Answer 23

iliolumbar, sacrotuberous and sacrospinous

Question 24

What is the role of the accessory ligaments of the sacroiliac joint?

Answer 24

resist nutation and counternutation

Question 25

What is nutation and counternutation?

Answer 25

movements of the sacrum- nutation closes the pelvic inlet and opens the outlet - counternutation opens the inlet and closes the outlet

Question 26

What type of joint is the pubic symphysis?

Answer 26

a cartilaginous joint

Question 27

What are the ligaments of the pubic symphysis?

Answer 27

the superior pubic ligament above, the inferior arcuate ligament below

Question 28

What reinforces the pubic symphysis?

Answer 28

fibres from oblique abdominal muscles, rectus sheath and adductor longus