Chapter 42 - Animal Digestive Systems Flashcards
Essential nutrients
1) 7~8 amino acids
2) unsaturated fatty acid
3) vitamins
4 stages of food processing
1) Ingestion
2) Digestion
3) Absorption
4) Elimination
Linoleic acid
-used to make steroid hormones
Essential nutrients
1) 7~8 amino acids
2) unsaturated fatty acid
3) vitamins
4) mineral ions
Vitamin B3
Niacin
-makes Nicotinamide Adenine Dinucleotide (NAD+), electron carrier
Vitamin B5
Pantothenic acid
-component of coenzyme A in TCA cycle
Vitamin B9
Folic acid
-involved in embryonic development of nervous system
Vitamin B12
Cobalamin
-involved in absorption of minerals and production of nucleic acids
Vitamin C
used in:
- connective tissue production
- antioxidant
-deficiency: causes scurvy (degeneration of skin and teeth)
Vitamin A
retinol
retinol-retinal-rhodopsin (pigment of rod cell)
deficiency syndrome: night blindness
Vitamin D
steroid hormone
- needed for Ca2+ absorption
- deficiency syndrome: rickets (bone deformities)
Vitamin E
Tocopherol
-antioxidants - removes oxygen from free radical
Vitamin K
Phylloquinone
-important in blood clotting
Mouth
- ingestion
- mechanical digestion
- amylase (carbohydrate degradation enzyme)
- stratified squamous epithelium (으로 싸여있음)
Digestive system
- organ system for food processing
- mouth, esophagus, stomach, small intestine, large intestine, rectum, anus.
- breakdown of food into smaller components (polymers to monomers) to be absorbed and assimilated
Gastrin
A hormone released from stomach.
stimulate all 3 cells ‘chief cell, parietal cell, mocous cell’
chief cell : secretes pepsinogen
parietal cell : secretes H+ & Cl- ,these will activate pepsinogen to pepsin
mucous cell : secretes mucous
stomach (structure, enzymes)
- has two sphincters (upper part and lower part), = muscular valve
- low pH = kill bacteria
- gastrin hormone release -> stimulates 3 cells in stomach
chief cell -> secretes pepsinogen
parietal cell -> secretes H+ & Cl- -> activate pepsinogen to pepsin
mucous cell -> secretes mucous (protects inner lining of stomach)
-pepsin
: active form of pepsinogen, digestive enzyme for protein.
small intestine
- release disaccharidase, peptidase, nucleosidase.
- most water absorption occur (not the rate)
3 parts (duodenum, jejunum, ileum)
-Duodenum : first part of small intestine, most enzymatic hydrolysis occurs
(connected to stomach, gallbladder, and pancreas)
-jejunum & ileum : most absorption occurs
pancreas
- both exocrine & endocrine (beta cell = insulin, alpha cell = glucagon)
- chymotrypsinogen, trypsinogen, amylase, lipase, nulease
gall bladder
-bile storage and secret to duodenum
bile : emulsifiers for lipid (not a digestive enzyme), synthesized from liver (amphipathic steroid molecule)
nutrient absorption in small intestine
- mainly occurs at jejunum and ileum
- micro villi makes the absorption surface larger
- H2O soluble nutrient : capillary- hepatic portal vein
- H2O insoluble nutrient (lipid) : lacteal - subclavian vein
5 function of liver
- synthesize bile
- old RBC (Red Blood Cell) sorting
- glycogen storage (from glucose) = regulation of blood glucose lvl
- detoxification (SER)
- steroid synthesis (SER)
: goes to steroid consuming cell with LDL
consuming cell to liver (with HDL form)
erythropoietin
hormone, secreted from kidney
bone marrow is target cell (for RBC synthesis)
hormone regulation of small intestine
if the chyme reaches the duodenum
2 hormones are released (CCK & Secretin)
: cholecystokinin (CCK) hormone is released ->
-> stimulate pancreas (for digestive enzymes) & gall bladder (bile)
: Secretin, stimulate pancreas -> release bicarbonate ion (pH buffer)
