Lecture 4 part 1 Flashcards
digestion
preparation of food for absorption
absorption
passage of small molecules from GI tract into blood or lymph systems
what makes up digestion
mastication- physical chewing
enzymatic- breaking bonds
chemical- stomach acid
microbial
what is the function of the Gi tract
-preparation of food for absorption
- storage of food
- environment for microbial growth
- location where nutrients absorbed
how long is food stored or takes to digest in nonruminants
24-48 hours
how long is food stored or takes to digest in ruminants
80-100 hours
- much longer because of foods they eat
dysbiosis
wrong community of microbes
- harmful
what are animals classified by diet
based on foods consumed or type of diet
herbivore
- consume plants
- incisors for biting off grass
- molars and premolars for grinding
- most have digestion start in mouth
carnivore
- consume animal tissue
- food easier to digest
- teeth for tearing (sharp canines)
- up and down jaw movement
- no digestion in mouth
omnivore
- consume combination of animal and plant tissue
- incisor adapted for biting off small amounts
- molars for grinding
what type of classification based on anatomy is most efficient in digesting fibers
foregut fermenters
foregut fermenters and ruminants
- variation of 4 chambers
- fermentation happening before true stomach
- feeding microbes first
- most breakdown happening before site of absorption
true non-ruminants
- simple stomach (monogastric)
what are the classifications based on anatomy
- ruminants and foregut fermenters
- true non-ruminants
- hindgut fermenters
hindgut fermenters
- behind the gut
- normal and simple stomach
- larger cecum
- use of microbes different
- lot of absorption in large intestine
examples of hindgut fermenters
- horses
- rabbits
- elephant
non ruminant examples
pigs
poultry
dogs
humans
non ruminant digestion
- monogastric
- single compartment
- utilize fibrous feeds poorly
swine teeth
- prehension
- mastication
swine tongue
- prehension
- mastication and mixing
- taste
swine salivary glands
- 3 paired glands (6 total) that secrete saliva
- saliva contains bicarbonate (buffer), salts, SALIVARY AMYLAS (breaks down starch)
swine esophagus
- hollow, muscular tube that transports ingesta from mouth to stomach
- peristaltic contractions that push food down
swine stomach
- simple
- stores ingested feed
- muscular movements (physical breakdown)
- secretes gastric juices
- 4 regions
what are the 4 regions in a pig’s stomach
- esophageal
- cardiac
- fundic gland
- pyloric gland
esophageal region
nonglandular
- doesn’t secrete anything
cardiac region
cells produce mucin
funic gland region
- active region of stomach
- parietal cells (HCl)
- chief cells (enzymes or enzyme precursors)
pyloric gland region
- mucin and some proteolytic enzymes
- becomes mucus to protect
- located at based where it attaches to stomach
what are the parts of the swine small intestine
- duodenum
- jejunum
- ileum
walls lined with villi
Duodenum
active site of digestion
- closest to stomach
- enzymatic digestion
Jejunum
active in nutrient absorption
- main site of absorption
Ileum
active in nutrient absorption
villi
have own capillary network and lymph system
- provide more surface area
enterocyte
absorptive cell of the SI
- digestive cell
swine large intestine
- cecum
- colon
- rectum
cecum
little significance in pig
- any fermentation happens here
colon
largest portion of large intestine
- up take of minerals and water
function of large intestine
- site of water reabsorption
- secretion of some minerals
- storage reservoir of undigested material
- bacterial fermentation
- limited absorption of nutrients
