a&p final ch24

activities of digestive process

ingestion, propulsion, mechanical digestion, chemical digestion, absorption, defecation

GI tract path

mouth, pharynx, esophagus, stomach, small intestine, large intestine, anus

length of GI tract

30 ft

mucosa

epithelium(strat. squam. in mouth, esophagus, anus; simple column. elsewhere), lamina propria(areolar connective tissue), muscularis mucosae(smooth muscle)

submucosa

dense connective tissue, blood vessels, glands

muscularis externa

circular and longitudinal smooth muscle

serosa/adventitia

esophagus/retroperitoneal organs

stratified squamous cells are found in

mouth, pharynx, esophagus, anus (protects against friction)

simple columnar cells are found in

stomach to rectum (secretion and absorption)

bolus

soft mass of chewed food ready for swallowing

peritoneum layers

parietal, visceral, peritoneal cavity

retroperitoneal organs

behind peritoneum; kidneys, pancreas, parts of colon and duodenum

peritoneal folds

greater omentum, lesser omenum, mesentery, mesocolon, falciform ligament

buccal cavity

tongue, teeth, hard and soft palate, salivary glands

lingual frenulum

tissue that anchors the tongue to the floor of the mouth

lingual lipase

enzyme from tongue; digests lipids in the stomach

saliva

99.5% water, enzymes, mucus, antibodies; begins carbohydrate digestion

salivary glands

parotid, submandibular, sublingual

deciduous teeth

baby teeth; 20 total

permanent dentition

32 adult teeth

pharynx parts

nasopharynx, oropharynx, laryngopharynx

esophagus

no digestion; moves bolus via peristalsis

esophageal hiatus

opening in diaphragm where esophagus passes

sphincters

upper and lower (cardiac/gastroesophageal)

deglutition

swallowing

stomach parts

cardia, fundus, body, pylorus

pyloric sphincter

controls passage of chyme into small intestine

mucus in stomach

protects stomach lining from acid

chyme

partially digested food and gastric juice

how long does food spend in the stomach

2-4 hours

rugae

folds in stomach allowing expansion

parts of pancreas

head,body,tail

endocrine function of pancreas

islets of langerhans (insulin and glucagon)

exocrine function of pancreas

acinar cells and enzymes (amylase, lipase, proteases)

falficorm ligament

connects liver to anterior wall

round ligament

remnant of fetal umbilical vein

bile

emulsifies fat; made in liver, stored in gallbladder

hepatocytes functions

bile production, metabolism of nutrients, detoxification, storage of glycogen and vitamins

small intestine segments

duodenum, jejunum, ileum

folds, villi, and microvilli increase

surface area

villus contains

capillaries, lacteals, absorptive cells

enterocytes

absorb nutrients

goblet cells

secrete mucus

paneth cells

antimicrobial

enteroendocrine cells

hormomes

peyer’s patch

lymphoid tissue in ileum for immune protection

parasympathetic influence

stimulates digestion

sympathetic influence

inhibits digestion

micelles

carry lipids to cells for absorption

chylomicrons

transport lipids via lymph

how long is chyme in the small intestine

3-6 hours

large intestine divisions

cecum, ascending, transverse, descending, sigmoid, rectum, anal canal

appendix

lymphoid tissue, hangs off cecum

rectum

final storage of feces

haustra

pouches

teniae coli

longitudinal muscle bands

bacteria in colon

produce vitamins, ferment carbs, aid immunity

internal anal sphincters

involuntary/smooth muscle

external anal sphincter

voluntary/skeletal muscle