Week 7: Pelvic Structures

Question 1

The lesser pelvis can also be called

Answer 1

The true pelvis. It is composed of a pelvic inlet and a pelvic outlet.

Question 2

The pelvic inlet is the most superior part of the pelvis. Define its limits.

Answer 2

The pelvic brim. It composes:
1. sacral promontory
2. anterior margin of the ala
3. sacroiliac joint
4. arcuate line of the ilium
5. pectineal line of the pubis
6. pubic crest
7. pubic symphysis
(and the same on the other side)

Question 3

What composes the linea terminalis?

Answer 3

Pubic crest, pecten pubis (pectineal line) and arcuate line.

(some texbooks include it as a whole pelvic rim)

Question 4

What are the bones of the pelvis?

Answer 4

Ileum, Ischium, pubis, sacrum and coccyx

Question 5

Circular (oval) pelvic inlet is likely to be from a

Answer 5

female

Question 6

Heart shaped pelvis is likely to be from a

Answer 6

male

Question 7

Males have a smaller/narrower angle formed by the pubic arch. True or False?

Answer 7

True. The pubic arch is the angle made from the two pubic bones meeting at the pubic symphysis.

Question 8

Narrowest fixed distance (pelvic outlet)

Answer 8

Minimum antero-posterior diameter of lesser pelvis = middle of sacral promontory to posterior-superior margin (closest point) of pubic symphysis.

Question 9

Narrowest part of pelvic canal

Answer 9

Distance between ischial spines (interspinous distance). Not a fixed distance, because it can change due to hormones.

Question 10

What ligaments help to further stabilise the upper pelvis to the lumbar spine?

Answer 10

Little ones. Ileo-lumbar ligament (horizontal), lumbarsacral ligament (vertical).

Question 11

Ligaments of the sacroiliac joint.

Answer 11

The most important ligament and deepest one is the interosseous sacro-iliac ligament. Overlying this ligament we have the anterior and posterior sacroiliac ligaments.

Question 12

Levator ani: function and attachments

Answer 12

• Support pelvic viscera
• Assist with closure of rectum and vagina
• Attach to pubis, ischial spines, thickened fascia of obturator internus (tendinous arch of the levatorani)
• Join in midline

Question 13

What are the 2 classes of fascia observed in the pelvis? How are they different from each other?

Answer 13

The membranous fascia lines both the muscular wall and floor of the pelvis and also the pelvic organs. In contrast, the endopelvic fascia is mostly loose tissue that surrounds the pelvic organs

Question 14

The thickening of membranous parietal fascia is called

Answer 14

Tendinous arch of pelvic fascia

Question 15

In removing a prostate, which fascia should be especially considered?

Answer 15

Rectoprostatic fascia, as it carries innervation that regulates sexual and urinary function, and it is located very close to the prostate.

Question 16

What important landmarks are related to the ureter pathway to the bladder?

Answer 16

Both: the bifurcation of the common iliac into internal and external iliac arteries.

Females: the wrapping of the uterine a. around the ureter

Males: ureters enter the bladder right before crossing its pathway with the vas deferens.

Question 17

What are the ligaments that maintain the bladder in the right spot?

Answer 17

Females: pubovesical ligament (around the bladder neck)

Males: puboprostatic ligament (around the prostate)

Question 18

What are the parts of the male urethra?

Answer 18

Pre-prostatic, prostatic, membranous, and spongy