Stomach and Duodenum

Question 1

L and R Gastric Veins

Answer 1

Lesser curve.
-both drain into the portal vein that drains into liver before returning to the systemic circulation

Question 2

Splenic Vein

Answer 2

drains from spleen and superior/posterior pancreas

Question 3

Inferior mesenteric vein

Answer 3

Drains the hindgut (inferior colon) into the splenic vein

Question 4

Superior mesenteric vein

Answer 4

Drains the midgut (small intestine) and joints splenic vein

Question 5

Hepatic portal vein

Answer 5

formed from gastric veins, splenic vein (IMV) and superior mesenteric vein

Question 6

Mechanical Digestion in Stomach

Answer 6

Gentle mixing waves
- every 15-25 s, mixes bolus w 2 quarts/day of gastric juice to turn it into chyme
More vigorous waves
- travel from body of stomach to pyloric region
Intense waves near pylorus
- open and squirt out 1-2 teaspoons full w each wave

Question 7

Chemical Digestion in Stomach

Answer 7

Protein digestion begins
- HCL denatures protein molecules
- HCL transforms pepsinogen into pepsin that breaks peptide bonds between certain amino acids
Fat digestion continues
- Gastric lipase splits the triglycerides in milk fat (most effect at pH 5-6 aka infant stomach)
HCL kills microbes in food (protective)
Mucous cells project stomach walls from being digested with 1-3mm thick layer of mucous

Question 8

Celiac Phase

Answer 8

“Stomach getting ready”
Cerebral Cortex: sight, smell, taste, thought
- stimulates parasympathetic nervous system
Vagus Nerve: parasympathetic
- increases stomach muscle and glandular activity

Question 9

Sympathetics

Answer 9

DESCENDING. T5/T10 (preganglionic) via greater thoracic splanchnic nerve. Synapses in celiac ganglia via splanchnic nerve. Postganglionic through celiac plexus to organ

Question 10

Parasympathetics

Answer 10

Vagus N (preganglionic) passes through the celiac ganglia but doesn’t synapse there, instead synapses in the ganglia of target organ (postganglionic)
- travels with alimentary canal and sends off branches to serve organs regionally, also sends branches through specific ganglia to travel with sympathetics

Question 11

Absorption of nutrients by the stomach

Answer 11

• water (especially cold)
• electrolytes
• Some drugs (aspirin) and alcohol

Question 12

Absorption of alcohol in stomach

Answer 12

Fat content in the stomach slows the passage of alcohol to the intestine where absorption is more rapid.
Gastric mucosal cells contain Alcohol Dehydrogenase that converts some alcohol to acetaldehyde
- more acetaldehyde in males than females, because females have less total body fluid and do not degrade alcohol as quickly

Question 13

Vomiting (emesis)

Answer 13

Forceful expulsion of contents of stomach and duodenum through mouth.
CAUSE: irritation or digestion of stomach, unpleasant sights, general anesthesia, dizziness, drugs
-Sensory input from medulla causes stomach contraction and complete sphincter relaxation
-contents of stomach squeezed by abdominal muscles and diaphragm and forced through open mouth
-can cause loss of acidic gastric juice and can lead to alkalosis

Question 14

Duodenum

Answer 14

First part of small intestine (10 in long)
3 accessory organs associated
- pancreas (pancreatic duct), gallbladder(cystic D.), liver (hepatic D.)
Brunner’s Glands- make alkaline mucous to neutralize chyme

Question 15

Small intestine

Answer 15

Convoluted tube (length varies in muscular tone, shorter in live person)
Longest part of GI tract
Extends from pyloric sphincter to ileocaval valve
3 regions
- duodenum
-jejunum
- ileum

Question 16

Parts of the duodenum

Answer 16

Superior part: ampulla/duodenal cap, has no circular folds
Descending part: receives contents from accessory digestive organs via major and minor duodenal papilla
Horizontal part
Ascending part

Question 17

Where do the pancreas, gallbladder, and liver empty their contents

Answer 17

second part of duodenum aka descending part

Question 18

Falciform ligament

Answer 18

specialized mesentery on anterior body wall from the umbilical vein in development
- supplies oxygenated blood to baby
-inferior aspect contains round ligament of liver

Question 19

Which lobe of the liver is greater

Answer 19

Right lobe is larger than left

Question 20

Ligamentum Venosum

Answer 20

Where falciform and round ligaments carry destroyed umbilical vein thru fissure

Question 21

Liver

Answer 21

Largest internal organ
2 major lobes: right and left anchored by falciform ligament
- quadrate and caudate associated with underside of left
Digestion:
- bile production (alkaline yellow-green fluid) breakdown production of heme
-bile salts (cholesterol derivative) emulsify large fat globules for enzyme attack
Other functions:
- destroys or stores toxins
- removes antibodies, foreign debris, or old RBC’s, hormones in circulation
-plasma protein synthesis

Question 22

Portal Triad

Answer 22

Hepatic portal vein, hepatic artery proper, and common hepatic duct
- where things enter and exit the liver

Question 23

Gallbladder

Answer 23

• Muscular greenish sac attached to liver (ventral side)
• Stores and concentrates bile (released thru cystic duct)
• Common bile duct + pancreatis duct= hepatopancreatic ampulla -> duodenal papilla. Opening is controlled by hepatopancreatic sphincter (sphincter of oddi)
• Cholecystokinin (CCK)= contraction of bladder and relaxes sphincter of oddi
  -Gallstones

Question 24

What does the sphincter of oddi do

Answer 24

releases bile and pancreatic juices to duodenum when relaxes

Question 25

Gallstones (Cholelithiasis)

Answer 25

concentrated bile can form crystals (stones) (gallbladder associated)

Question 26

Pancreas

Answer 26

-tadpole-shaped gland
-retroperitoneal
-Endocrine gland= insulin, glucagon, somatostatin: inhibits gastrin (islet cells)
-Exocrine Gland= Pancreatic Juice (acini cells)
- Juices delivered to duodenum by merger of pancreatic duct w/ common bile duct= Duodenal Pappilla

Question 27

Pancreatic Exocrine Gland

Answer 27

Pancreatic Juice (acini cells)
- water
-HCO3-
-Amylase (starch digestion)
-Lipase (fat digestion)
-Endopeptidase (protein digestion)
- chymotrypsin cleared from chymotrypsinogen= zymogen