Transcript Digestion and Absorption - Killingly Public Schools

Digestion and Absorption
Continued…
Mouth to Stomach
• food pushes into the esophagus (muscular
tube connecting the mouth to the stomach)
• food carried via peristalsis
• lower esophageal sphincter controls the
passage of food and liquid between the
esophagus and stomach
• as food approaches the closed sphincter,
the muscle relaxes and lets food pass
through to the stomach
Stomach
• stores swallowed food
and liquid
• mixes food and liquid with
digestive enzymes and
acid it produces (chyme)
• Acidic due to HCl (pH 13)
– Why doesn’t the
stomach get damaged
with such a low pH?
Gastric Enzymes
• Pepsin: breaks protein into amino acids
• Gastric Lipase: breaks apart lipids
Small Intestine
• muscles mix food with
digestive enzymes from the
pancreas, liver, and intestine
and push the mixture forward
(via persistalsis) to the large
intestine
• walls absorb the digested
nutrients (via vili) into the
bloodstream
• pH 8
Major Pancreatic Enzymes
• Trypsinogen:
protease
• Lipase: breaks apart
lipids into glycerol and
fatty acids
• Amylase: breaks
starch down into
glucose
Liver and Gallblader
• gallbladder is located
under the liver and on the
right side of the abdomen
– primary function is to store
and concentrate bile
(yellow-brown liquid
produced by the liver)
• bile aids in the digestion
of fats and neutralizing
the chyme leaving the
stomach
Large Intestine
• waste products of the digestive process include undigested parts of
food and older cells from the GI tract lining
• absorbs water and any remaining nutrients and changes the waste
from liquid into stool
• rectum stores stool
Gastric Parasites
• Coccidiosis: acute invasion and
destruction of intestinal mucosa by
protozoa
• Clinical signs: diarrhea, fever, decreased
appetite, weight loss, & emaciation
• Potential to be fatal
Coccidiosis
• Pathogenesis: ingestion
of oocysts via feces
• Diagnostic: clinical signs
and fecal sample
• Treatment:
Sulfadimethoxine
• Canine or feline coccidia
are not considered
zoonotic agents
Gastric Parasites
• Giardia: intestinal infection
caused by a protozoan
parasite (“beaver fever”)
• Clinical signs: acute foulsmelling diarrhea, greenish
tinge or bloody diarrhea,
excess mucus in the feces,
and vomiting gradual weight
loss may become apparent
• Potential to be fatal
Giardia
• Pathogenesis: transmitted by
eating or sniffing the cysts from
contaminated ground, or by
drinking contaminated water
• Diagnostics: clinical signs and
fecal test
• Treatment: Metronidazole
• Zoonotic