lesson 13 Flashcards
human nutrition
-source of energy and raw materials
-calories and Calories (kilocalories)
-basal metabolic rate (BMR)
-proteins -essential amino acid
-carbohydrates
-fats
-vitamins
-minerals
-water
human digestive system
tubular gastrointestinal (GI) tract
accessory organs
-oral cavity
-salivary glands
-pharynx
-esophagus
-stomach
-liver
-gallbladder
-small intestine
-large intestine
anus
tissues of the digestive tract
-mucosa-epithelial
-submucosa-connective
-muscularis-smooth
-serosa-epithelial
the mouth and teeth
-many vertebrates have teeth used for mastication
-birds: lack teeth- break up food in 2 chambered stomach
beginning of chemical digestion
mouth
-ingestion
salivation
-3 pairs of salivary glands secrete saliva
parotid gland
:water (99.55%), musicus, salivary amylase, antibacterial compounds
submandibular gland
sublingual gland
the mechanics of swallowing
bolus
initiated voluntarily, continued under involuntary control/reflex
esophagus
muscular tube connecting the pharynx to the stomach
-peristalsis
-swallowing center in brain stimulates successive one-directional waves of contraction
the stomach
convoluted surface allows expansion
-mixes food with gastric juice
-mucus
hydrochloric acid (HCL)
-pepsin (pepsinogen is inactive form)
the small intestine
location of the most digestion and absorption
consists of duodenum, jejunum, ileum
small intestine folded epithelium with villi and microvilli
microvilli participate in digestion and absorption
brush border enzymes
accessory organs-pancreas
pancreatic juice:
-trypsin
-chymotrypsin
-pancreatic amylase
-lipase
-bicarbonate
accessory organs-liver and gallbladder
liver:
-detoxification
-protein synthesis
-glycogen storage
-bile secretion
-bile: bile pigments and bile salts
junction of small and large intestines
colon
-water absorption
-electrolyte absorption
-vitamin K absorption
-compact feces
excretion of feces
-Rectum
:2 sphincter muscles
-Anus
-Feces
:water, electrolytes, mucus, bacteria, bile pigments, bacterial compounds
Hormonal control of the gastrointestinal tract
Gastrin
Cholecystokinin (CCK)
Gastric inhibitory Peptide
Secretin
Gastrin
-response to protein
-targets chief and parietal cells
cholecystokinin (CCK)
-response to fatty chyme
-targets the gallbladder and pancreas
Gastric inhibitory peptide (GIP)
-response to fatty chyme
-targets stomach
secretin
-response to acid
-targets pancreas
