Digestion Flashcards
The physical, chemical and enzymatic means the body uses to render a feed/food ready for absorption
Digestion
What controls appetite and food intake?
Hypothalamus (hunger and satiety)
Blood glucose levels
Physical capacity
Environmental temperature
What are the three types of digestive processes with examples
Physical/ mechanical (chewing/muscular action of digestive tract)
Chemical (hydrocloric acid denatures proteins/ secretory)
Enzymatic
- proteases, amylase, lipase
- catalyze chemical reactions with proteins
- hydrolysis
What are the two types of stomachs?
What digestion does the complex one do?
Monogastrics
Ruminants
Microbial digestion
What do the following eat
Carnivore
Omnivore
Herbivore
Eat animal flesh mostly (produce more lysosomes)
Consume plants and animals
Depend on plants for food
How animals bring food into their mouth
Prehension
This is known as chewing or regurgitating or chewing cud
Poultry rely on grinding action in gizzard for this
Mastication
What is the purpose of mastication
To break down smaller particles which increases surface area which makes it more assessable to digestion
This is the secretion and mixing of saliva with food
Salivation (salivary glands)
What does saliva do
- lubricates
Dissolves
Cleanses
Buffers stomach/rumen acid
What is the act of swallowing
Deglutition
Food passes down the _______ to the stomach
Esophagus
What is the true stomach but also called proventriculus in birds
Abomasum
In the glandular stomach also known as _______________, what type of digestion begins and which one is there more of
Abomasum
Enzymatic and chemical digestion
More chemical
In ruminants, ______________ occurs first in rumen/reticulum
Fermentation
_________________ acid is secreted into the stomach
Hydrochloric
What are the three parts of the small intestine?
What does each do
Duodenum- digestion via pancreatic (mostly) and liver secretions
Jejunum- longest portion and major site of ABSORPTION (some digestion)
Ileum: absorption and connects to the large intestine
What is the act of expelling fecal matter via rectum or cloaca
Defecation
What is urination, components include nitrogenous compounds, minerals and water and is regulated by the kidney
Micturition
In micturition, what are the nitrogenous compounds in mammals
Birds
Urea mammals
Uric acid
What can monogastrics not use as a source of nutrients
Fiber or
High fiber feed stuff
What is the one exception in monogastrics that allow some to digest fiber
Functional cecum
What are the roles the stomach plays
Acid secretion
Enzyme production
Food storage
Release of chyme to small intestine
Go through the order of the monogastrics stomach
Mouth- esophagus- abomasum- duodenum- jejunem- ileum- cecum- colon- rectum
What would a carnivores by more adept at absorbing?
Amino acids in the jejunem
What are the specialized parts of a chicken turkey and duck
What do they do
Crop: feed softening and storage
Proventriculus: glandular stomach, acid and enzymes
Gizzard: grinding aided by grit important since birds have no teeth
What % of ruminants at birth is rumen, reticulum, omasum?
Abomasum?
30%
70%
When is a calf rumen functional and what does it do
7 weeks
Fermentation
Decline in blood glucose
Production of vfas
In a mature ruminant what % is the following
Rumen
Reticulum
Omasum
Abomasum
Rumen 80%
Reticulum 5%
Omasum 7%
Abomasum 8%
What part of a ruminant is the fermentation vat, microbes synthesize amino acids, b vitamins, microbes become food
How much digestion occurs here
Rumen
60-90%
Looks like a honeycomb
Mixes
Pacemaker for rumen contracts
Reticulum
Many plies (book)
Absorbs water, Electrolytes and some VFAs
Omasum
This is the true stomach it has acid and enzymes
Abomasum
What accounts for 60% of energy animals absorb
Vfa’s
Between what two parts of ruminants is there a free flow of digestion
Rumen and reticulum
Where is the microvilli located (brush border)
What does it do
Small intestine jejunem
Increase surface area
What covers the villi and micro villi
Epithelial cells
Where does carbohydrate digestion begin?
For humans monkeys and pigs the mouth because of salivary amylase
For ruminants (no salivary amylase) it begins in the small intestine where pancreatic amylase is secreted into duodenum
What does amylase hydrolyze starch into
Maltose maltotriose and a limit dextrins
Where does completion of carb digestion happen
Small intestine mainly first two little in the ileum
In the small intestine during carb digestion pancreatic ________ is secreted into the ___________ after that additional _________ border enzymes are secreted into small intestine. These include _____________ , sucrase, and _____________ and lactase
amylase
Brush
Maltase
Isomaltase
In brush border enzymes, what does each break down and into what
Maltase
Sucrase
Isomaltase
Lactase
Maltase breaks down maltose to g and g
Sucrase breaks down sucrose to g and f
Isomaltase breaks down dextrins to produce maltose
Lactase breaks down lactose to g and galactose
What are absorbed in the small intestine during carb digestion?
Protein digestion?
Fats?
Simple sugars / monosaccharides
Amino acids (arginine lysine
Fatty acids
To digest cellulose what is required?
What produces cellulase to break cellulose to glucose
Micro organisms
Bacteria
__________ in the rumen use glucose to produce vfa’s which are ________ ______ _______
Bacteria
Acetate propionate butyrate
What provide 50-70% if animals energy requirement
Vfa’s
What fingerlike projections increase surface area
Papillae
In carbs each complex sugar for ruminants becomes what?
They get concerted into _______ ______ ______ or lactic acid
And the majority of carbs in rumens are going to do this
Glucose
Vfa’s
Digesting proteins is equivalent to
Degradation or breakdown
Where does protein digestion begin
___________ acid supplies the proper _____ for enzymes pepsin and __________ to begin hydrolysis of proteins
Begins abomasum
Hydrochloric
PH
Rennin
What does pepsin do?
What does rennin do
Digests proteins into peptones and dippeptides (generic digest a lot of dif proteins)
Hydrolyzes Casein which coagulates into paracaseunate which pepsin digests
What pancreatic enzymes are secreted into the duodenum during protein digestion
Trypsin
Chymotrypsin
Carboxypeptidase
______________ peptidases are also present at the brush border of the intestinal epithelial cells
Intestinal
What is the end product of protein digestion and where absorbed
Amino acids
Jejenum
(Dipeptides and tripeptises are also absorbed and digested to amino acids in epithelial cells)
Where does fat digestion begin and with what enzyme
True stomach.
Gastric lipase
FAT DIGESTION
Bile __________ Lipids in the duedenum and increases _______________ __________ of lipid mixture 10,000x
Before this ______ salts are produced by the ________ and sores in the gall bladder
Emulsifies
Surface area
Bile
Liver
FAT DIGESTION
What is enzyme is added after increase of surface area and converts triglycerides to fatty acids and monoglycerides and it is primarily absorbed where
Pancreatic lipase
Jejunum
LIPID DIGESTION RUMINANTS
Rumen microorganisms ___________ dietary triglycerides to yield _______ _____ _______ and glycerol
Hydrolyze
Free fatty acids
T or F with non ruminants the fatty acids reaching the duodenum of ruminants are less saturated than dietary FA
False they are more highly saturated
R VS M DIGESTION
what type of DIGESTION does each do
Mono- chemical and enzymatic
R- microbial fermentation
In __________ fiber DIGESTION is limited but fiber is _______
Monogastrics
Necessary
What are 3 things that have fictional cecum
Where are the VFA produced and absorbed
Horses rats and rabbits
Large intestine
When rabbits eat soft fecal material fermented in cecum- contains what?
Cecotrophy
Contains proteins, B vitamins, V K all can by utilized
This is the act of eating feces the nutrients are digested and absorbed by upper GI tract
Coprophagy
