Chapter 14- Digestive System Flashcards
4 Accessory Organs
1) Salivary Glands
2) Liver
3) Gallbladder
4) Pancreas
Hollow tube
GI Tract
Space within a tube
lumen
8 Parts of GI Tract
1) mouth
2) pharynx
3) esophagus
4) stomach
5) small intestine
6) large intestine
7) rectum
8) anus
Four layers of GI tract walls (inner to outer)
1) mucosa
2) submucosa
3) muscularis
4) serosa
Layer of GI Tract, innermost, mucous membrane in contact with the lumen
Mucosa
Layer of GI Tract, connective tissue containing the blood vessels, lymph vessels, and nerves
Submucosa
Layer of GI Tract, two or three layers of smooth muscles, responsible for movement an motility
Muscularis
Layer of GI Tract, outermost, protects and anchors digestive tract
Serosa
Thick muscular rings that separate some organs
Sphincters
5 Processes for digestion
1) Mechanical processing and movement
2) Secretion of fluid, enzymes, hormones, bile, ph, mucous
3) Digestion
4) Absorption
5) Elimination
2 Types of motility aid digestion
1) perastalsis
2) segmentation
Type of motility aid digestion, propels food foreward
Perastalsis
Type of motility aid digestion, mixes food and chops it up
Segmentation
Where does motility aid digestion occur
Muscularis layer
Composition of saliva (4)
1) mucin
2) salivary amylase
3) bicarbonate
4) lysozyme
Component of saliva, antibacterial
lysozyme
Component of saliva, maintains ph of 6.5-7.5 for optimal amylase activity
bicarbonate
Component of saliva, can help prevent formation of biofilms
Mucin
Component of saliva, begins digestion of starch
salivary amylase
Which parts deliver food to the stomach (2)
1) Pharynx
2) Esophagus
Salivary glands (3)
1) Parotid (cheek jaw)
2) Sublingual (under tongue)
3) Submandibular (lower jaw)
Voluntary phase of swallowing
tongue pushes bolus of food into pharynx (throat)
Involuntary phase of swallowing
swallowing reflex, trachea closes, esophagus opens
Throat, common passageway for air and food
Pharynx
Closes airway temporarily so food will not enter the trachea
Epiglottus
Food passes through to stomach by way of
peristaltic contractions thru esophagus, and lower esophageal sphincter
Functions of stomach (3)
1) food storage 2) digestion of proteins 3) regulates delivery of partially digested food into small intestine
In stomach, breaks down proteins
Gastric Juice
Gastric juice is made up of (4)
1) hydrochloric acid
2) Intrinsic factor
3) Mucus
4) Pepsinogen
Part of Gastric Juice, pH of 2, breaks down large bits of food
Hydrochloric acid
Part of Gastric Juice, needed to absorb vitamin b12
Intrinsic factor
Part of Gastric Juice, protects stomach lining from acid
Mucus
If mucus is damaged, can cause
peptic ulcur
Part of Gastric Juice, converted to pepsin by acid, begins protein breakdown
pepsinogen
watery mixture of partially digested food and gastric juice that is delivered to the small intesting
chyme
sphincter between esophagus and stomach
esophagael sphincter
sphincter between stomach and small intestine
pyloric sphincter
how long does it take for stomach to empty
2-6 hrs
does stomach absorb nutrients
no, but alchohola and aspirin are
Organ that digests food and absorbs nutrients and water
Small intestine
Digestion in the small intestine (3)
1) nutralizes acid from stomach
2) breaks down protreins carbs and lipids into monomers
3) adds digestive enzymes and bile
Regions of absorption in the small intestine (3)
1) duodenum
2) jejunum
3) ileum
in small intestine, increase surface area to facilitate absorption
mucosa adaptations
in small intestine, microscopic projections containing blood and lacteal capillaries
villi
in small intestine, cytoplasmic projections of epithelial cells of villi
microvilli
in small intestine, region of absorption that the most digestion occurs in
duodenum
Organ that has exocrine functions, secretes digestive enzymes and sodium bicarbonate to neutralize somach acid
pancreas
Digestive enzymes of pancreas (3)
1) proteases
2) pancreatic amylase
3) Lipase
Digestive enzyme of pancreas, digests starch
pancreatic amylase
Digestive enzyme of pancreas, digests protein
proteases
Proteases (3)
1) trypsin
2) chymotrypsin
3) carboxypeptidase
Digestive enzyme of pancreas, digests fats (lipids)
lipase
Organ that produces bile
Liver
Organ that concentrates and stores bile
Galbladder
Functions of the liver
metabolic: storage, synthesis, chemical processsing
drains blood from the digestive tract to the liver
Hepatic portal system
organ that absorbs nutrients and water and eliminates waste
large intestine
parts of large intestine
cecum, appendix, colon, rectum, a nus
regulation of digestion depends on
volume and content of food
stretch receptors in stomach, increase paristealsis and secretion of gastric juice
nervous system
Hormones (3)
1) Gastrin
2) Secretin
3) CCK
Hormone released by stomach, causes release of gastric juice
Gastrin
Hormone triggered by stretching of stomach and presence of protein
Gastrin
Hormone released by duodenum, stimulates pancreas to secrete water and bicarbonate
Secretin
Hormone released by duodenum, signals pancreas to secrete digestive enzymes and gallbladder to release bile
CCK
Hormone that responds to filling stomach
gastrin
Hormone that responds to acid
secretin
Hormone triggered by presence of acid in chyme
secretin
Hormone triggered by fat and protein in chyme
CCK (choleccytstokinin)