Anatomy 1C

Gastro

Stomach

Monogastric

simple stomach

Ruminant

complex stomach: fermentation

Peristalsis

muscular contractions in stomach that mix bolus with enzymes abd stomach acid

Liquefaction

turn food from solid to liquid

Monogastric anatomy

Sphincter at both ends

Cardiac Sphincter

Prevents reflux from stomach into esophagus

Pyloric Sphincter

stops premature release into duodendum

rugue

ridges in stomach that increase surface area

Equine Stomach

Susceptible to ulcers: upper stomach doesn’t produce protective mucus, causing acid to breakdown parts leading to ulcers

Stomach enzymes

primarily for the breakdown and absorbption of proteins and lipids

Zymogen

proenzyme that activates to an enzyme

Pepsinogen

produced by Chief cells

When activated by HCl, pepsin forms(active enzyme)

Rennin

In young ruminants

curdles milk into casin which is then absorbed

HCl with milk

In monogastrics: similar job as rennin

Stomach Acid

HCl

HCl + foodstuffs

Chyme

HCl

Produced by periatle cells

helps breakdown food

activates digestive enzymes (pepsin)

helps absorb material

Gastric juice

produced in fondus and body

HCl+ enzymes

Bicarbonate

base that maintains healthy pH balance in body

Electrolytes

Na, K, Cl, HCl

Mucus

coats stomach to protect it from stomach acid

Intrinsic Factor

protein that helps absorb B12

produced by parietal cells

prevents pernicious anemia

B12

water soluble that aids in Red Blood Cell production

H+:K+ pump

active transport of H+ ions

goes against the gradient: needs ATP

Bicarbonic Anhydrase

Catalyses the H+ reaction

Alkaline tide

after eating a protein rich diet, blood becomes more basic

Vomiting

looses H+ ions quickly so blood becomes more acidic

Mono gastric stomachs

smaller in size so they have to eat more often

can not digest cellulose

Monogastric herbavores

Hind gut fermentation(symbiotic microflora in hind gut)

Horses, Rhinos

ferment in colon

rabbits, some rodents

ferment in cecum