lesson 13 transcript + study guide Flashcards
carbohydrates
Quick energy; stored as glycogen in liver and muscle
ex: bread
Lipids
Long-term energy storage; essential fatty acids; insulation
ex: butter
proteins
tissue repair, enzymes, hormones; provides essential amino acids
ex:meat
vitamins
Support metabolism, immunity, bone health, etc.
ex: fruits
- Water-soluble
Not stored; support enzyme function
vitamin C, B
- Lipid-soluble
Stored in fat; support vision, bones, clotting, antioxidants
Vitamin A,D,E,K
Minerals
Bone strength, nerve signals, oxygen transport (iron in hemoglobin)
ex: iron, calcium, sodium
digestion
The mechanical and chemical breakdown of food into absorbable molecules.
mechanical digestion
physical breakdown: chewing, chuning
chemical digestion
enzymatic breakdown: amylase, pepsin
main gi tract in order
Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
accessory organs
liver, gallbladder, pancreas, salivary glands
histology of Gi tract
Mucosa
submucosa
muscularis
serosa
mucosa
secretes mucus, absorbs nutrients
submucosa
Connective tissue with vessels and nerves
muscularis
circular +longitudinal muscle (peristalsis)
serosa
protective outer layer
mouth
mechanical: chewing
chemical: amylase
saliva starts starch digestion
stomach
mechanical: churning
chemical: pepsin
acid denatures proteins, activates enzymes
duodenum
chemical: enzymes
main site of chemical digestion
jejunum/illeum
major site of absorbtion
bird digestive system
crop: stores food
gizzard: grinds food
peristalsis
rhythmic muscle contractions that move food forward
reverse peristalsis
moves food backward
vomiting, rumination
stomach chambers
reticulum
rumen
omasum
abomasum
reticulum
mixes and collects small food particles
rumen
ferments plant material (microbial digestion)
omasum
absorbs water and salts
abomasum
“true” stomach: acidic, enzymatic digestion
surface area adaptions
stomach folds: gastric rugae
small intestine: Villi + microvilli (brush border)
function: maximizes digestion and absorption efficiency
duodenum
bile (from liver/gallbladder)-> emulsifies fats
pancreatic juice-> contains proteases, amylase, lipase
secretes carboxylases-> finish digestion
amino acids
small intestine
absorbed into blood capillaries
monsaccharides
small intestine
absorbed into blood capillaries
fatty acids/lipids
small intestine
enter lacteals as chylomicrons via diffusion
digestive enzymes
salivary amylase
pepsin
brush border enzymes
trypsin and chymotrypsin
pancreatic amylase
lipase
salivary amylase
source-salivary glands
acts on- starch
product-sugar chains
location-mouth
pepsin
source-stomach
acts on-protein
product-polypeptides
location-stomach
brush border enzymes
source-small intestine lining
acts on-sugars, peptides
product-monosaccharides, amino acids
location- small intestine
trypsin and chymotrypsin
source-pancreas
acts on-proteins
product-polypeptides
location- small intestine
pancreatic amylase
source-pancreas
acts on-starch
product-shorter sugar chains
location-small intestine
lipase
source-pancreas
acts on-fats
product-fatty acids, monoglycerides
location-small intestine
non-enzyme digestive
HCl
stomach mucus
bicarbonate
bile salts
HCl
source-stomach (parietal cells)
function-denatures proteins, activates pepsin kills bacteria)
location- stomach
stomach mucus
source-mucus-secreting stomach cells
function-protects stomach lining
location- stomach
bicarbonate
source-pancreas
function-neutralizes acidic chyme
location-duodenum
bile salts
source-liver (stored in gallbladder)
function-emulsify fats
location-duodenum
