Pelvis and Perineum – osteology and boundaries

Question 1

How many vertebrae is sacrum made up of?

Answer 1

5

Question 2

How many vertebrae is coccyx made up of?

Answer 2

4

Question 3

List bones of the pelvis

Answer 3

• Sacrum
• ilium
• coccyx
• coxal bone
• ischium
• pubis

Question 4

What is the Lumbosacral joint?

Answer 4

joint between lumbar vertebra and the first sacral segment of the vertebral column.

Question 5

What is Sacroiliac joint?

Answer 5

Joint between ilium and sacrum

Question 6

What is Pubic symphysis?

Answer 6

cartilaginous joint between R + L pubic bones

Question 7

What is Sacrococcygeus joint?

Answer 7

Joint between sacrum and coccyx

Question 8

What is bi-spinous diameter?

Answer 8

• Diameter between ischial spines
• narrowest transverse diameter
  – also used to determine birth

Question 9

What is sig of triradiate cartilage?

Answer 9

Eventually fuses and forms one hip bone in adult – why its div into 3 parts

Question 10

What is true pelvis?

Answer 10

Space between pelvic inlet and outlet

Question 11

What is false pelvis?

Answer 11

Inlet to top of iliac crest

Question 12

Why is there No diaphragm sep true and false pelvis?

Answer 12

allow room for uterus and bladder and rectum to expand

Question 13

What is function of pelvic diaphragm?

Answer 13

pelvic organs stay in place and don’t collapse when abdom pressure inc
separates pelvis from perineum.

Question 14

What is diff between male and female pelvis?

Answer 14

• Sub-pubic angle = 80 degrees in males and 120 degrees in females – wider for childbirth
• females have deeper greater sciatic arch

Question 15

What is Antero-posterior diameter of pelvic inlet?

Answer 15

50-60 degrees

Question 16

What is diagonal conjugate diameter?

Answer 16

• Should be 10.5-11 cm – narrowest diameter for birth

– 8/9cm or less – can’t deliver vaginally

Question 17

What is obstetric conjugate diameter?

Answer 17

Diagonal conjugate minus 1.5cm

Question 18

Antero-posterior diameter of pelvic outlet?

Answer 18

10-15 degrees

Question 19

Where is the rectovesical/perineal pouch?

Answer 19

in male between rectum and bladder

Question 20

Where is uterovesical pouch located?

Answer 20

• in female between uterus and bladder

Question 21

What is function of pelvic floor?

Answer 21

supports the pelvic organs and separates pelvic cavity from perineum

Question 22

What would happpen if pelvic floor is incompetent?

Answer 22

• Incontinence = can’t control bladder/rectum,

- prolapse = organs leaking out e.g. vaginal walls of women who’ve had more than 1 child = multi-parous women

Question 23

What are the 2 muscles of pelvic diaphragm?

Answer 23

• Levator ani

- Coccygeous

Question 24

What are 3 parts of levator ani?

Answer 24

puborectalis, pubococcygeus and iliococcygeous

Question 25

What is genito-urethral opening?

Answer 25

opening in males – sperm and urine from same opening

Question 26

What is Perineum divided into?

Answer 26

• Urogenital and Anal triangles

Question 27

Name 3 points of urogenital triangle

Answer 27

• pubic symphysis

- R + L ischial tuberosities

Question 28

Name 3 points of anal triangle

Answer 28

• coccyx

- R + L ischial tuberosities

Question 29

List 4 muscles of the perineum

Answer 29

• Ischiocavernosus
• Bulbospongiosus
• Transverse perineal
• All converge to form perineal boody

Question 30

What is perineal mem?

Answer 30

• Mem between perineal diaphragm and perineal muscles

- attached to ischial tuberosities and ischiopubic ramus

Question 31

What is deep perineal pouch?

Answer 31

Between lower pelvic diaphragm/floor and peri mem

Question 32

What is superficial perineal pouch?

Answer 32

• Everything between skin and perineal mem

– all muscles in triangle contained within it

Question 33

List features of male perineum

Answer 33

• deep peri pouch
• peri mem
• sup peri pouch
• deep peri fascia
• corpus cavernosum
• urethra
• ext. urethral sphincter

Question 34

What happens if shatter pubic symphysis?

Answer 34

blood pool in deep pouch and go up as limited by peri mem

Question 35

What can cause urethral injuries?

Answer 35

• pelvic trauma

- complications of urinary catheterization

Question 36

What does peri mem cause if damage to urethra?

Answer 36

working as limiting mem – if damage to urethra outside/from the bottom – pooling of blood outside = extraversation injuries

Question 37

How do ishcial foss comm with each other?

Answer 37

Posteriorly