Unit 3- Perineum- Anal Triangle

Question 1

Perineum

Answer 1

Diamond shaped area inferior to the pelvic floor between thighs

Question 2

Bony landparts of the perineum

Answer 2

Anterior: Symphysis pubis

Lateral: Ischial tuberosity

Post: Coccyx

Question 3

Subdivisions of the perineum

Answer 3

Urogenital triangle

Anal triangle

Question 4

Boundaries of the anal triangle

Answer 4

Ant: Imaginary line connecting the Ischial tuberosities

Post: Tip of the coccyx

Lateral: Sacrotuberous ligament overlapped by the gluteus maximus

Question 5

Contents of the anal triangle

Answer 5

Anal canal

Isciorectal fossa

Question 6

Location of the anal canal

Answer 6

From the rectal ampulla to the anal aperture (anus)

-Starts at anorectal junction marked by puborectal sling

Question 7

Upper half of the anal canal epithelium

Answer 7

Columnar - insensitive to cutting

Question 8

Epithelium of lower half of the anal canal

Answer 8

Stratified squamous epithelium

Question 9

Which half of the anal canal has anal columns and valves present?

Answer 9

Upper half

Question 10

Anal valves connect:

They are located:

Answer 10

Lower portion of columns together

Inf border of sinuses

Question 11

Separation of hindgut structures from proctodeum

Answer 11

Pectinate line

Question 12

Nerve supply to upper half of anal canal

Answer 12

Pelvic autonomic plexus (stretch)

Question 13

Nerve supply to lower half of the anal canal

Answer 13

Inf rectal nerve (pain, temp, touch, and pressure)

Question 14

The inferior rectal nerve is a branch of what nerve?

Answer 14

Pudendal

Question 15

Arterial supply of the upper half of the anal canal

Answer 15

Superior rectal art (from the inf mesenteric art)

Question 16

Anterior supply to the lower half of the anal canal

Answer 16

Inf rectral art

From internal pudendal art which is a branch from the internal iliac art

Question 17

Venous drainage for upper half of the anal canal

Answer 17

Superior rectal vein (to the inf mesenteric vein)

Question 18

Venous drainage for the lower half of the anal canal

Answer 18

Inf rectal vein (to the internal pudendal , then to the internal iliac vein)

Question 19

Lymphatic drainage for upper half of the anal canal

Answer 19

Internal iliac nodes

Some to pararectal nodes (to the inf mesenteric nodes)

Question 20

Lymph drainage for the lower half of the anal canal

Answer 20

Superficial inguinal lymph nodes

Question 21

Anal sphincters

Answer 21

Internal and external

Puborectalis part of levator ani

Question 22

Internal sphincter is:
(VOLUNTARY/INVOLUNTARY)

Innervated by:

Located:

Answer 22

Involuntary

Pelvic plexus

At the upper end of the anal canal

Question 23

External Sphincter is:
(VOLUNARY/INVOLUNTARY)

Innervated by:

Parts:

Answer 23

Voluntary

Inf rectal nerve

Subcutaneous, superficial, deep

Question 24

Wedge shaped space on each side of the anal canal

Answer 24

Ischiorectal/Ischioanal fossa

Question 25

Borders of the ischiorectal fossa

Answer 25

Base: Skin

Medial wall:
Levator ani
Anal canal

Lateral wall:
Obturator internus
Covered with pelvic fascia

Question 26

Location of the pudendal canal

Answer 26

On the lateral wall of the ischiorectal fossa

Question 27

The pudendal canal is formed by:

Answer 27

The fascia over obturator internus

Question 28

Contents of the pudendal canal

Answer 28

Pudendal nerve

Internal pudendal vessels

Question 29

Pudendal canal, AKA:

Answer 29

Alcock’s canal