Exam 1 (Intro + Neuroendocrine) Flashcards
Animals require what 2 things?
- energy
- basic chemical constituents (amino acids)
What is the purpose of basic chemical constituents like animo acids?
growth + repair
What is the drive to eat?
satisfy energy needs
What is assimilation?
taking nutrients into body
What two processes occur with assimilation?
digestion
absorption
Definition of digestion
ingested food changes to suitable form for absorption
Digestion occurs (inside/outside) the body tissues.
outside
3 examples of mechanical component to digestion
chewing
kneading (peristalsis)
ventriculus (gizzard) + grit - bird
What 4 things are GI exocrine secretions?
water
electrolytes
enzymes
mucus
What is the purpose of electrolytes in GI exocrine secretions?
nutrient absorption
What is the purpose of water + electrolytes in GI exocrine secretions?
provide volume
dissolution (dissolving)
control acid/base environment
Enzymes are powerful in which locations?
saliva
pancreas
intestines
microbe
Function of hydrolytic enzymes
use water to break bonds
Functions (2) of mucus GI secretions
lubricate dry matter to prevent injury
bacterial barrier
Digestion barrier functions to keep the body safe from what 3 things?
autodigestion
bacterial invasion
physical damage
What 3 things are part of the digestion barrier?
epithelium
mucus
proenzymes
What type of epithelium is present from the mouth to the cardia of the stomach?
stratified squamous
What type of epithelium is present in the stomach to the intestines?
simple columnar
What type of epithelium is present in the anus?
stratified squamous
Proenzymes are produced (active/inactive) and active in the _____.
inactive (no cell interference)
GI lumen
Carnivores have a (simple/complex) GI tract and the small intestine is ____x the body length.
simple
4x
Carnivores have a (short/long) transit time.
short
Omnivores have a (simple/complex) GI tract and the small intestine is ___x the body length.
complex
10-15
______ is retained for microbial digestion in omnivores.
plant matter
Which species dietary type has compartmentalized large intestines?
omnivore
What are the 2 strategies herbivores use to get nutrients?
hind-gut fermenters
foregut fermenters
(Hindgut/Foregut) Fermenters are considered monogastric.
hindgut
Hind-gut Fermenters have a compartmentalized large intestine that generates _______.
volatile fatty acids (VFA) or short chain FA
Hind-gut Fermenters have a small intestine that is ____x their body length.
6
Example of a hind-gut fermenter vs. foregut fermenter
hind-gut: horse
foregut: sheep
Foregut fermenters have a large, complex forestomach before their _____ stomach.
true
_____ can occur before the “true” stomach in foregut fermenters.
microbial digestion
Are hind-gut or foregut fermenters more efficient?
foregut
The ingested form of proteins have a (loose/tight) 3D molecular structure.
tight
What process is used to digest proteins?
hydrolysis (enzymatic digestion)
What is the absorbable form of proteins?
amino acids, dipeptides/tripeptides
Protein digestion pathway
epithelium –> blood –> portal vein –> liver
Ingested form of carbohydrates
complex polysaccharides
Ingested form of soluble carbohydrates vs. insoluble
Soluble: starches
Insoluble: cellulose
How are starches digested?
hydrolysis of 1-4 glycosidic link by mammal enzymes
How is cellulose digested?
hydrolysis of beta 1-4 glycosidic link by bacterial enzymes
Absorbable form of starches vs. cellulose
starches: monosaccharides
cellulose: volatile fatty acids
Starch (carb) digestion process
starch –> monosaccharide –> blood –> portal V –> liver
Cellulose (carb) digestion process
cellulose –> VFA across epithelium –> blood –> portal V –> liver
Ingested form of fat
triglycerides (hydrophobic)
What process does fat undergo by bile salts?
emulsification
What do triglycerides break into after emulsification?
micelles for better enzyme access
What process is fat digested by?
hydrolysis
Micelles release _____, _____, and _____.
glycerol
monoglycerides
free fatty acids
Micelles are re-esterified into triglycerides and exported in ______.
chylomicra
Chylomicra
glycoprotein triglycerides packaged to make them water soluble
Digested fat enters ______.
lymph
Why does digested fat enter lymph? (2)
too large for capillary pores
limited liver availability
Process by which digested foods enter blood or lymph
absorption
What 2 processes can occur during absorption?
active transport
passive transport
(T/F) Active transport is only paracellular.
False - only transcellular
What transporters are on the luminal side?
Nutrient transporters
Na/H exchanger
Cl/HCO3 exchanger