Intro to GI tract Flashcards
Definition of ingestion
intake of food
Definition of digestion
breakdown of food bit by bit into molecules small enough to be absorbed by cells
Definition of absorption
transportation of productions into the blood
Definition of assimilation
making food part of the cell
Definition of elimination
removing unused food
What valve is responsible for opening into the stomach and controlling regurgitation?
Cardiac sphincter
Definition of mechanical digestion
physical breakdown
Definition of chemical digestion
chemical breakdown due to enzymes
What is the first part of the small intestine?
duodenum
What is the second part of the small intestine?
jejunum
What is the third part of the small intestine?
illeum
Which colon goes up?
ascending colon
Which colon goes over?
transverse colon
Which colon goes down?
descending colon
What is the liver’s job in digestion?
Make bile, which aids in digestion and absorption of fat
What is the pancreas’ job in digestion?
release bicarbonate to neutralize intestinal contents, produce enzymes that digest carbs, protein, and fat
What is the gallbladder’s job in digestion?
store bile and release it in to the small intestine when signaled
What is the mouth’s job in digestion?
chew food ad mix with saliva
What is the salivary gland’s job in digestion?
produce saliva, which contains amylase
What is the pharynx’s job in digestion?
swallows chewed food mixed with saliva (bolus)
What is the esophagus’ job in digestion?
move food bolus to stomach
What is the small intestine’s job in digestion?
digests food and absorbs nutrients into blood or lymph
What is the large intestine’s job in digestion?
absorb water/vitamins/minerals, hoe to intestinal bacteria, passes waste material
What is the anus’ job in digestion?
opens to allow waste to leave the body
What is peristalsis?
a wave-like movement that moves food down the esophagus and throughout the gi tract (involuntary muscle contractions)
T/F dogs have salivary amylase but cats don’t
False, they both do not produce salivary amylase
______ helps in bolus formation and softening of feed as well as antibacterial action
saliva
What is a normal pH of a nonruminant?
1-3
What valve controls the amount of food that leaves the stomach and goes into the small intestine to not overload it?
pyloric sphincter
What does protease break down?
proteins
What does lipase break down?
fats
What does amylase break down?
amylase
Why is the stomach so acidic?
destroy bacteria and hydrolyze some proteins and disaccharides, activates the proenzyme pepsinogen to pepsin
What is pepsinogen?
secreted by gastric glands and low stomach pH converts to pepsin
What is pepsin?
pepsin helps digest protein and is probably more important for animal than plant protein digestion
Where is lipase most active?
long-chain fatty acids
The ____ is the largest gland and is a central organ in nutrient digestion and assimilation
liver
_____ produced by the liver is important for _____ digestion and absorption
bile;lipid
most bile acids are conjugated with _____
taurine
What are the functions of the gallbladder?
storage of bile, releasing bile, regulating bile flow, bile pH regulation, absorption of certain vitamins in our body
When chyme moves from the stomach to the duodenum, the ______ is stimulated to secrete digestive enzymes
pancreas
Where does most enzymatic digestion occur?
small intestine
What is intestinal mucosa?
It releases the hormones secretin and cholecystokinin (CCK) which regulate the output of pancreatic juice
What does secretin increase?
bicarbonate secretion
What does CCK increase?
pancreatic enzyme production
T/F: CCK and pancreatic enzymes have a direct relationship
true
T/F: The small intestine is highly coiled to fit in the body and acts as an immune organ
true
The main increase in surface area of the small intestine is from ______
villi and microvilli
What is the function of villi and microvilli?
enhance surface area and absoprtive capability
Absorption of electrolytes/water and fermentation of some nutrients is the primary role of ______
the large intestine
How long does undigested food stay in the large intestine of dogs and cats?
12 hours
What are the end products of colonic fermentation?
short-chain fatty acids, lactate, carbon dioxide, and hydrogen gas
T/F: : Long-chain fatty acids provide energy for colonocytes in the large intestine
False, short-chain fatty acids (butyrate) do
What are the three parts of the large intestine?
cecum, colon, rectum
What does a large cecum signify in an animal?
long gi tract and herbivore
T/F: there is no chemical digestion in the colon
false, the bacteria partake in chemical digestion
What kind of mechanical/chemical digestion takes place in the stomach?
mechanical: peristaltic mixing propulsion
chemical: proteins and fats
absorption: lipid-soluble substances (alcohol and aspirin)
What kind of mechanical/chemical digestion takes place in the small intestine?
mechanical: mixing and propulsion
chemical: carbs, fats, polypeptides, nucleic acids
absorption: peptides, amino acids, glucose, fructose, fats, water, minerals, vitamins
What kind of mechanical/chemical digestion takes place in the large intestine?
mechanical: segmental mixing and propulsion
chemical: only by bacteria
absorption: ions, water, minerals, vitamins, organic molecules
What kind of mechanical/chemical digestion takes place in the mouth?
mechanical: mastication
chemical: salivary amylase to break down carbs
no absoprtion
