Anatomy Lecture 28 & 29_The Pelvis & Perineum

Question 1

What are the three bones that make up the pelvis?

Answer 1

The ilium, the ischim, and the pubis

Question 2

Where is the Acetabulum

Answer 2

It is the union of the three bones of the pelvis where the femur inserts

Question 3

Where is the obturator foramen?

Answer 3

It the the foramen formed by the fusion of the ischim and the pubis

Question 4

Where is the greater sciatic

Answer 4

It the the major indentation in the posterior ilium

Question 5

Where is the lesser sciatic notch?

Answer 5

it is the indentation in the posterior ischim

Question 6

What is the easiest way to distinguish a male pelvis from a femal pelvis?

Answer 6

Look at the angle between the pubis bones. In males it will be 90 degrees or less. In females it will be 100 degrees or more.

Question 7

What are the 4 joints of the pelvis?

Answer 7

• Sacro-iliac
• Pubic symphysis
• Lumbosacral
• Sacrococcygeal

Question 8

What are the 4 lumbo-sacral-pelvic ligaments? Where do they attach

Answer 8

• Anterior & Posterior Sacro-iliac
• Iliolumbar
• Sacrotuberous
• Sacrospinous

Question 9

What four points define the perinium?

Answer 9

Pubic symphisis, left and right ischial tuberosities, sacrum

Question 10

Where is the urogenital triangle

Answer 10

it is the triangle of the perinium anterior of the line between ischial tuberosities,

Question 11

Where is the anal triangle

Answer 11

It is the triangle of the perinium posterior of the line between the ischial tuberosities

Question 12

Where is the Perineal Membrane and what does it do?

Answer 12

The perineal membrane is located within the urogenital triangle. It anchors the roots of the external genitalia and acts as a boundary between superficial & deep pouch

Question 13

What are the two layers of Subcutaneous Perineal fascia? What are their analogs in abdominal fascia? What is the deep fascia?

Answer 13

• Superficial Fatty layer (camper’s fascia)
• Deep Membranous layer (Scarpe’s fascia)

The deep fascia is the Deep Perineal fascia (it is an investing fascia

Question 14

Where is the Superficial Fatty Layer of Subcutaneous Fascia in men and women in the urogenital and anal triangles?

Answer 14

In women it is continiouse to the labia majorum within the urogenital triangle, but absent in men.

It is continious within the anal triangle in both sexes

Question 15

Where is the Superficial Membranous Layer of Subcutaneous Fascia (Colle’s) in men and women in the urogenital and anal triangles?

Answer 15

It is present in both men and women in the urogenital triangle. It forms the dartos muscle in men. It is absent from the anal triangle in both men and women because it fuses to the posterior edge of the perineal membrane

Question 16

Which bounderies define the Superficial Perineal Pouch

Answer 16

It is bunded by the perineal fascia (what was scarpe’s fascia in the abdomen) and the perineal membrane.

Question 17

What defines the Deep Perineal Pouch?

Answer 17

Perineal membrane & inferior pelvic diaphragm fascia

Question 18

What are the three superficial perineal muscles and where do they attach?

Answer 18

• Superficial transverse perineal (ischium tuberosity to perineal body)
• Ischiocavernosus (ischial tuberosity to pubic symphisis)
• Bulbospongiosus (pubic symphisis to perineal body)

Question 19

What does the Bulbospongiosus muscle do?

Answer 19

it contracts and inhibits venous return thus causing an erection

Question 20

What is the path of a sperm as it leaves a testi?

Answer 20

1) formed in the Seminiferous tubules
2) Enters the straight tubules
3) goes to the Rete testis (mediastium of the testies)
4) goes to an Efferent ductule
5) goes to the Epididymis

Question 21

What is Hydrocele

Answer 21

serous fluid within cavity of tunica vaginalis &/

or spermatic cord. It leads to a big fluid filed scrotum

Question 22

What is a Hematocele How is it distinguished from a Hydrocele?

Answer 22

It is the accumulation of blood (often from a straddle injury) within the tunica vaginalis. It looks like a hydrocele but can be distinguished with transillumination

Question 23

What is a Varicocele?

Answer 23

It is vericosis of the testicular veins. It typically only occures on the left side because the left testicular vein flows into the left renal vein instead of the IVC (likethe right testicular vein). IT is easier to get increased pressure in on the left side.

Question 24

What are the two structures that run under the superior mesinteric artery and in front of the abdominal aorta?

Answer 24

The duodenum and the left renal vein

Question 25

What is the nutcracker syndrome and what can it cause

Answer 25

nutcracker syndrome is when the left renal vein is pintched between the SMA and the abominal aorta, it can lead to vericocele.

Question 26

What is Superior Mesenteric Artery syndrome?

Answer 26

It is similar to nutcracker syndrome only it is the duodenum that is being compressed instead of the left renal vein

Question 27

What are the 4 sections of the urethra?

Answer 27

• Intramural (preprostatic)
• Prostatic
• Intermediate (membranous)
• Spongy

Question 28

What is the major nerve of the pernium, what are its 3 branches and what nerve level does it arise from?

Answer 28

The pudendal arises from S2-S4. Its three branches are:
• Inferior rectal n.
• Perineal n.
• Dorsal nerve of penis/clitoris

the pudendal enters the plevis through the lesser sciatic foramen

Question 29

What does the inferior rectal nerve innervate

Answer 29

The external anal sphincter

Question 30

What does the Perineal nerve innervate?

Answer 30

The muscles of the perineum and the posterior scrotum/labia

Question 31

What does the Dorsal nerve inervate?

Answer 31

The penis/clitoris