Lecture 25: Bony Pelvis and Pelvic Wall

Question 1

Pelvic girdle refers to…
Parts of the hip bone
Bony pelvis refers to…

Answer 1

• 2 hipbones fuse anteriorly at the pubic symphysis and attached posteriorly with sacrum via SI joints (S1-S3)
• ileum, ischium, pubis
• hipbones + sacrum + coccyx

Question 2

Be able to label the parts of the sacrum, os coxae and label pelvis major and minor in the image

Answer 2

Ok

Question 3

Describe the organization of the sacrum and coccyx

Answer 3

Sacrum: 5 vertebrae fused together
Coccyx: 3-5 vertebrae
Sacrococcygeal joint (fibrocartilaginous disc) connects both

Question 4

Where is the pelvis major (false) and pelvis minor (true)?

Answer 4

above and below the pelvic brim

Question 5

Be able to label the boundaries of the pelvic inlet on the image

Answer 5

Ok

Question 6

What are the ligaments of the lumbosacral joint?

What are the ligaments of the pubic symphysis?

Be able to label these on the image

Answer 6

Anteriorly: Iliolumbar (prevents L5 from sliding forward), anterior longitudinal
Posteriorly: Supraspinous, intertransverse

Superior pubic ligament, arcuate pubic ligament

Question 7

What are the ligaments of the sacrococcygeal joint?

What are the ligaments of the SI joint?

Answer 7

Anterior: anterior sacrococcygeal ligament
Posterior: Deep and superficial dorsal sacrococcygeal ligament

Anterior: Anterior sacroiliac ligaments
Posterior: Interosseous sacroiliac ligament, dorsal sacroiliac ligament, posterior sacroiliac ligament

Question 8

What forms the lateral pelvic wall?

Be able to to label the parts of the lateral pelvic wall in the image

Answer 8

Hip bone parts below pelvic inlet
Obturator internus + fascia + obturator fascia
Sacrotuberous and sacrospinous ligaments

Question 9

What are the major muscles of the pelvis

Be able to label these muscles on the blocked images (anterior and posterior views)

Answer 9

Obturator internus muscle (covered with fascia)
Pelvic diaphragm (Levator anii muscle  + Coccygeus muscle)
Urogenital diaphragm 
Piriformis
Superior gemellus
Inferior gemellus
Obturator internus
Obturator externus
Quadratus femoris

Question 10

What is the tendinous arch?

Answer 10

Dense part of the obturator fascia that serves as the attachment point of the obturator internus muscle and levator anii

Question 11

What are the 3 layers of the pelvic fascia?

Be able to label these on the image

Answer 11

Parietal pelvic fascia
Diaphragmatic pelvic fascia
Visceral pelvic fascia

Question 12

Describe the three types of urinary continence?
Overflow
Stress
Urge/overactive

Answer 12

• urethral blockage so bladder cannot empty properly, (BPH - large glands constricting urethra)
• relaxed/weakened pelvic floor muscles/sphincter and increased abdominal pressure, pushing urine out of the urethra
• oversensitive from infection or neuro issues, increase contraction of the bladder wall muscles

Question 13

Describe the three types of urinary continence?
Overflow
Stress
Urge

Answer 13

• urethral blockage so bladder cannot empty properly,
• relaxed/weakened pelvic floor and increased abdominal pressure, pushing urine out of the urethra
• oversensitive from infection or neuro issues, increase contraction of the bladder wall muscles

Question 14

What are some causes of stress urinary incontinence?

Answer 14

Pregnancy/childbirth
age
obesity
chronic cough (increased abdominal/pelvic pressure)
genetics

Question 15

What muscle can be damaged during normal vaginal delivery and what are the effects?

Answer 15

Puboccocygeus. Injury can cause damage to pelvic floor and cause urinary incontinence

Question 16

OINA:

External anal sphincter

Answer 16

N: Inferior anal (rectal) nerve and pudendal nerve
A: constrict anal canal during peristalsis to prevent defecation, support perineal body and pelvic floor

Question 17

OINA:

Bulbospongiosus

Answer 17

N: perineal nerve and pudendal nerve
A: support pelvic/perineal floor, compress bulb of the penis/act as vaginal sphincter, assists erection of penis/clitoris

Question 18

OINA:

Ischiocavernosus

Answer 18

N: perineal nerve and pudendal nerve
A: maintains penis and clitoris erection,

Question 19

Action of Superficial and deep transverse perineal muscles

Answer 19

Supports and fixes perineal body/pelvic floor to support abdominopelvic viscera and resist increased intra-abdominal pressure

Question 20

OINA:

External urethral sphincter

Answer 20

N: dorsal nerve of the penis and clitoris
A: Compresses urethra to maintain urinary continence