Gi Tract Review

Front 1

The functions of the digestive tract

Back 1

-Prehension of food
-Mastication (mechanical grinding and breaking down of food)
-Chemical digestion of food
-absorption of nutrients and water
-elimination of waste

Front 2

Parietal cells

Back 2

located in the body and fundus. Secretes Hydrogen and chloride ions seperately into stomach that combines in the stomach to produce hydrochloric acid. has 3 receptorrs on the blood side of the cell that regulate acid production

-gastrin
-acetylcholine
-histamine

Selectively blocking one off these receptors decreases the production of stomach acid

Front 3

Cheif cells

Back 3

Located in body and fundus of stomach

Release pepsinogen which is the precursor to pepsin.

Hydrochloric acid converts pepsinogen to pepsin enzyme in the stomach. Pepin breaks down proteins into polypeptides and peptides

Front 4

G cells

Back 4

Gastrin cells, secretes gastrin, stimulatingg hydrochloric acid production. Also causes relaxation of the fundus and helps regulate hydrochloric acid in the stomach

Front 5

Goblet cells

Back 5

Located in the respiratory and GI tract and secretes mucus to protect the sstomach and small inbtestines. I think they are the same thing as mucin cells...

Front 6

Cardia

Back 6

Where esophagus and stomach meet. The cardiac sphincter is a weak sphincter of smooth muscle athat acts as a valve to close off the lower end of the esophagus

Front 7

Fundus

Back 7

Distendible bblind pouch of the stomach. Expands as more food is swallowed (has parietal, and cheif and goblet/mucus cells). Acts as a resevoir and relaxes and extends when food is swallowed

Front 8

Body

Back 8

Distendibble middle part off the stomach. Has parietal, goblet, and cheif cells too and contracts to mix foodAlso relaxes when food is swallowed

Front 9

Pyloric antrum

Back 9

Grinds up swallowed food, regulates hydrochloric acid via g cells (secretes gastrin which stimulates HCl pruduction), increases contractions in response to swallowed food, stimulates mixingg, grinding and propulsive conractions that move food to pyloris

Front 10

Pylorus

Back 10

Muscular sphincter that regulates the movement of chyme from the tomach into the duodenum. Prevents backflow of duodenal contents into stomach

Front 11

Reticulum

Back 11

Smallest and most cranial compartment of a ruminant stomach. Separated from the rumen by ruminoreticular folds and has honeycomb arrangements off fold to increase surface area

Front 12

Rumen

Back 12

Large fermentation vat in a ruminant stomach.

Muscular sacs separated by pillars (grooves). Allows cut to be ruminated via ruminoreticular contractions, bult up gases to be eructated, contents converted into VTA by rumen microbes. Carbs and peptides absorbed by microbes and converted into VFA, some peptides converted to ammonia and used by microbes. VTA absorbed into bloodstream and converted to glucose, fat, and milk

Front 13

Omasum

Back 13

Muscular organ w/ muscular folds. Breaks down food particles further and moves ingesta into abomasum. Also absorbs VFA and water not previously absorbed by rumen and removes bicarbonate ions

Front 14

Abomasum

Back 14

Functions as a true stomach in the ruminant stomach

Front 15

Small intestines

Back 15

Duodenum - short segment that leaves the body. Site of fat breakdown, where the bile duct enters and secretes bile

Jejunum - logest portion
-Ileum - Separated ffrom the colon by ileocecal sphincter. Regulates movement of materials from the small intestines into the colon or cecum

Front 16

Segmented contractions

Back 16

Periodic circular muscle contractions that occurr in different adjacent sites. Mixes digestive tract contents and slows their movement through nthe GI tract, allowing forr better absorption

Front 17

Peristallsis

Back 17

Smooth muscle contracts to push food in a forward direction. Alternating contractions of circular and longitudinal muscles move food along the digestive tract.

Coordinated contraction and relaxion of muscle layers, resultingg in movement of bolus of food or ingesta along the GI trac

Front 18

Parotid

Back 18

Salivary gland located just ventrral to the ear canals

Front 19

Mandubular salivary glands

Back 19

Ventral to the parotid glands at the caudal angle of the mandible

Front 20

Sublingual salivary glands

Back 20

Medial to the mandible under the base of the tongue

Front 21

What are the digestive enzymes in saliva?

Back 21

Amylase - Omnivore saliva to break down carbs

-Lipase - in saliva of young animals to break down milk fat

-Sodium bicarbonate- in the saliva of ruminants to neutrilize acids in the rumen

Front 22

Megaesophagus

Back 22

Unknown cause, myathenia gravis can cause it.

Esophagus loses its normal muslce tone and it becomes more of a relaxed bag than a tight muscular tube, and food will accumulate there since it cannot get past the cardia.

-usually seen w/ dogs and they will regurgitate undigested food

--will need to feed liquid dieet at an elevation to prevent aspiration and aspirative pneumonia

Front 23

Parvovirus

Back 23

Affects the lining of the small intestines by invading/destroying the simple columnar tissue, exposing the blood vessels and causing bloody diarrhea

-small intestines become inflammed and the villus do not slow down chyme comming through

-increase in peristaltic activity causes cramps and the propelling of chyme thrrough the small intestines rapidly causes diahrrhea

Front 24

Intussusecption - What is it? Signs Patient has it?

Back 24

Telescoping of the proximal intestine in the distal intestine (usually ileocecal junction)

-Causes hypermotility, enteritis, parasites, or a sudden change in diameter of the small and large intestines

Front 25

Hepatic lipidosis

Back 25

AKA fatty liv disease.

Severe accumulation off fat in the liver that is secondary to a lot of cuases (stress, starvation diabetes mellitus, obesity, etc)

-Complete anorexia in obese cats and you will need to feed the cat to help

Increase in ALP (alkaline Phosphatase), Increase off ALT (Alanine Aminotransferase), and total bilirubin

Front 26

Pancreatic Insufficiency disease, what is it? signs? tests and treatment?

Back 26

Deficiency of pancreatic digestive enzymes (amylase and lipase). More commin in dogs

-marked weight loss and fatty, rancid stool

-Serum test is used for diagnosis and enzyme must be replaced at each meal (VIOKASE powder)

Front 27

mesentary

Back 27

Clear membrane sheet that suspends the intestines from the dorsal wall of the abdomen, preventing intestine entanglement. Brings blood and lymph to and from the intestines and supplies the nerves that supply the GI tract

Front 28

Omentum

Back 28

part of the mesentary

-helps prevent torsion, and is primarliy made of fat.

Attached at the greater curvature of the stomach

Front 29

Digestive function of the liver and gall bladder

Back 29

Liver porduces bile that breaks down fats and cholesterol in the duodenum

Liver is largest gland in the body w/ multiple lobes

Bile secreted into bile ducts > hepatic ducts > gallbladder for storage

Stimulation by the CCK (cholecystokinin) hormone causes gallbladder contractions and forces bile down the common bile duct into duodenum to coat the fat droplets. Lipase goes through the bile coating to break down the fats into fatty acids

The liver removes toxins and infectious agents that enter the wall off the GI

Stores or metabolizes nutrients absorbed by the GI tract

Front 30

Biliary tree

Back 30

Carries bile frrom liver to glalbladder

Front 31

Portal veins

Back 31

Carries blood to the liver

Front 32

Hepatic vein

Back 32

carries filtered blood to the caudal vena cava

Front 33

What are the 4 secretions that the pancrease is responsible for producing that aid in digestion?

Back 33

ALL EXOCRINE!

-Sodium bicarbonate
-trypsin
-amylase
-lipase