(GI!) Panic Deck

Question 1

Describe the structures of the foregut

Answer 1

esophagus –> first half of duodenum, including accessory organs

Question 2

Describe structures of midgut

Answer 2

second half of duodenum –> first 2/3 of transverse colon

Question 3

Describe structures of hindgut

Answer 3

Last 1/3 of transverse colon –> upper anal canal

Question 4

Describe arterial supply to the fore-, mid-, and hindgut

Answer 4

Fore = Celiac a
Mid = Superior mesenteric a
Hind = Inferior mesenteric a

Question 5

Where are the sympathetic preganglionic cell bodies for the fore-, mid-, and hindgut located?

Answer 5

Fore = T5-T9
Mid = T19-T12
Hind = T12 - L2

Question 6

What are the sympathetic splanchinc nerves for fore-, mid-, hindgut?

Answer 6

Fore = Greater
Mid = Lesser
Hind = Least

Question 7

What are the preaortic ganglions for sympathetic innervation to the fore-, mid- and hindgut?

Answer 7

Fore = Celiac
Mid = Superior mesenteric
Hind = Aortico-renal***

Question 8

What paths do sympathetic axons to the fore-, mid-, and hind-gut follow?

Answer 8

Fore = Celiac artery
Mid = Superior mesenteric a
Hind = Infeior mesenteric a

Question 9

Describe the location of the preganglionic cell bodies, the nerve, and the ganglia location for parasympathetic innervation to the fore, mid, and hindgut

Answer 9

Fore and Midgut share PNS innervation patterns:
Preganglionic cell bodies in the brainstem; CN X; ganglia in organ walls

Hindgut is slightly different:
Preganglionic cell bodies in S2-S4; pelvic splanchnic n.; ganglia in organ walls

Question 10

What is the cellular change that occurs in Barrett’s esophagus?

Answer 10

Cells change from stratified squamous epi –> simple columnar, producing mucous to try to protect from acid

Question 11

What are the portal-caval anastamoses that occur in esophageal varices?

Answer 11

L gastric (branch of portal) + azygos (branch of SVC)

Question 12

What are the portal-caval anastamoses that are present in Caput Medusae?

Answer 12

Paraumbilical vv + throacoepigastric + superior epigastric (branch of portal) and inferior epigastric (branch of IVC)

Question 13

What is the deficient enzyme in non-classical galactosemia?

Answer 13

Galactokinase

Question 14

What product accumulates in non-classical galactosemia?

Answer 14

Galactose

Question 15

What is the deficient enzyme in classical galactosemia?

Answer 15

Galactose-1-phosphatase

Question 16

What product accumulates in classical galactosemia?

Answer 16

Hepatotoxic galactose-1-phosphate

Question 17

What is the route intermediates that accumulate in non/classical galactosemia take?

Answer 17

Polyol pathway –> cataracts, kidney damage

Question 18

What is the deficient enzyme in fructose intolerance?

Answer 18

Aldolase B

Question 19

What product accumulates in fructose intolerance?

Answer 19

Fructose-1-phosphate (hepatotoxic)

Question 20

What is responsible for the unpleasant effects of drinking alcohol?

Answer 20

Acetaldehyde

Question 21

What systems are responsible for the metabolism of alcohol?

Answer 21

Alcohol dehydrogenase and, in heavy drinking, MEOS

Question 22

What is the intermediate produced by the metabolism of alcohol?

Answer 22

Alcohol –> acetaldehyde via alcohol dehydrogenase and/or MEOS

Question 23

How is acetaldehyde metabolized?

Answer 23

Aldehyde dehydrogenase –> acetate

Question 24

What ratio is disrupted in alcohol metabolism, and what effects does this have?

Answer 24

Low NAD+ (consumed during metabolism with no regulation)
High NADH

Alters hepatic metabolism:

• B-oxidation of fatty acids is inhibited (steatosis, hyperlipidemia)
• TCA cycle is inhibited (ketoacidosis)
• Lactate can’t be converted to pyruvate in liver (lactic acidoses, hypoglycemia, hyperuriecmia)

Question 25

What enzyme is deficient in Maple Syrup Urine Disease?

Answer 25

Alpha-keto acid dehydrogenase (accumulation of alpha-keto acids)

Question 26

What is the deficiency in PKU?

Answer 26

Phenylalanine hydroxylase or its cofactor, tetrahydrobioterin