Gastrointestinal: Clinical anatomy of Faecal Continence - the Distal GI tract

Question 1

where are faeces stored?

Answer 1

rectum

Question 2

where is the rectum located?

Answer 2

lies between the pelvic inlet and pelvic floor

Question 3

when does the sigmoid colon become the rectum?

Answer 3

anterior to s3

- the rectosigmoid junction

Question 4

when does the rectum become the anal canal?

Answer 4

tip of the coccyx

Question 5

what lies immediately superior to the elevator ani muscle?

Answer 5

rectum ampulla

Question 6

what formed most of the pelvic diaphragm?

Answer 6

Levator Ani Muscle

Question 7

what type of muscle is the Levator Ani Muscle made out of?

Answer 7

skeletal

Question 8

what is the function of the Levator Ani Muscle?

Answer 8

provides support for the pelvic organs - tonically contracted most of the time

THIS MUST BE RELAXED TO ALLOW DEFECATION

Question 9

what supplies the Levator Ani Muscle?

Answer 9

nerve to levator ani (branch of the sacral plexus)

Pudendal (S2,3,4)

Question 10

what happens when the puborectalis contracts?

Answer 10

decreases the anorectal angle

Question 11

how many sphincters does the anal canal have?

Answer 11

2 [internal and external]

Question 12

what type of muscle is the internal anal sphincter?

Answer 12

smooth muscle

Question 13

what stimulates the contraction of the internal anal sphincter?

Answer 13

sympathetic nerves [sphincter is closed]

T12-L2

Question 14

what type of muscle is the external anal sphincter?

Answer 14

skeletal muscle

Question 15

what stimulates the contraction of the external anal sphincter?

Answer 15

pudendal nerve

Question 16

what marks the junction between the part of the embryo which formed the GI tract (endoderm) and the part that formed the skin (ectoderm)?

Answer 16

Pectinate line

Question 17

what is the arterial supply above the pectinate line?

Answer 17

inferior mesenteric artery

Question 18

what is the venous drainage above the pectinate line?

Answer 18

portal venous system

Question 19

what is the lymphatic drainage above the pectinate line?

Answer 19

inferior mesenteric nodes (internal iliac nodes)

Question 20

what is the arterial supply below the pectinate line?

Answer 20

internal iliac artery

Question 21

what is the venous drainage below the pectinate line?

Answer 21

to systemic venous system (internal iliac)

Question 22

what is the lymphatic drainage below the pectinate line?

Answer 22

superficial inguinal nodes

Question 23

what drains inferior pelvic structures? (lymph)

Answer 23

internal iliac

Question 24

what drains lower limb, and more superior pelvic structures? (lymph)

Answer 24

external iliac

Question 25

what drains lymph from the external and internal iliac?

Answer 25

common iliac

Question 26

where does lymph from the common iliac drain to?

Answer 26

lumbar nodes

Question 27

what supplies (arterial) the hind gut organs?

Answer 27

inferior mesenteric artery

Question 28

what causes rectal varices?

Answer 28

portal hypertension

Question 29

what lies on the right and left of the anal canal?

Answer 29

ischioanal fossae