Gastrointestinal Tract

(7 major structures)

1. Oral Cavity
2. Pharynx (3 parts)
3. Esophagus
4. Stomach
5. Small Intestine
6. Large Intestine
7. Rectum

1. Teeth
2. Tounge
3. Salivary Glands
4. Gall Bladder
5. Liver
6. Pancreas

1. Mucosal layer- inner, next to lumen, epithelium, areolar connective tissue, lymph nodules, thing layer smooth muscle
2. Submucosal layer- collagenous fibers, nerves, BVs
3. Muscularis layer- skeletal muscle for swallowing and defication, smooth muscle in between
4. Serosa layer- simple squamous = visceral peritoneum

1) supports intestines, stomach, liver

2) prevents intestinal twisting

3) stores fat

4) pathway for BVs and nerves

anterior: lips = labia = oblicularis oris muscle

lateral: cheeks = buccinator muscle

superior: soft and hard palate

interior: tongue

1) filliform

2) fungiform

3) vallte

32 total teeth

Indisors = 8, for cutting

Canines = 4, for tearing and piercing

Premolars = 8, for grinding and crushing

Molars = 12, for grinding and crushing

20 teeth in a child (no premolars)

sticky matrix on surface of teeth made by bacterial + trapped food aprticles

hardens = tarter

1) cleanse mouth

2) antibacterial

3) start CHO digestion

4) aids in chewing and swallowing

1) parotid

2) submandibular

3) sublingual

largest salivary gland,  inferior and anterior to ears, between skin and maseter muscle

parotid duct = Stensen's duct- connects gland to oral cavity by piercing buccinator muscle

beneath mandible

submandibular duct = Wharton's duct

under the tongue

sublingual duct = Rivinus' duct

funnel-shaped tube that extends from internal nares to esophagus

moves bolus (food) + saliva from mouth to esophagus

pharyngeal stage = peristalsis

circular smooth muscle fibers behind

longitudinal fibers in front

1) cardiac region

2) fundus- air bubble

3) body- greater and lesser curvature

4) phyloric region

outer- longitudinal

middle- circular

inner- oblique

defect in mucosa, hole in wall of organ

cause: HCl, pepsin, helicobacter pylori (bacterial that can live in the acidity of the stomach)

dual therapy =  cut out HCl and antibiotic

1) gentle mixing waves- every 15-20 seconds

2) mixes with 2 quarts/day of gastric juices

3) vigorous waves- travel from body to pyloric

4) intense waves open sphincter and squirt 1-2 teaspoons out/wave

1) parietal cells denature protein and secrete HCl- begin protein digestion

2) cheif cells secrete gastric lipase to break down fats

3) HCl from parietal cells kills microbes in food

4) thick mucous layer protect stomach from being digested

duedenum- digestion

jejunum- absorption

ileum- absorption

makes alkaline mucus to neurtalize chyme

in duodenum

MALT- fight infection

part of lymphatic tissue

in ileum

superior mesenteric vein --> hepatic portal vein

superior mesternic artery

gastroduodenal arter (from hepatic artery)

can surgically cut the peritoneum between the duodenum and the pancreas because there are not BVs

reveals retroperitoneal area

deep folds of mucosa & submucosa to slow down chyme in order for it to be absorbed

in SI

finger-like projections of mucosa

simple columnar epithelium

inc SA for absorption in SA

BVs and LVs (absorb fat)

anchor villi to SI

in most mucosa membranes (respiratory, GI, urogenital)

narrow pouches between villi

secrete water and mucus

contain paneth cells = lysozymes

hair-like projections on the cell membrane of the villi

make up the brush-border

secrete enzymes for protein, sugar, CHO digestion

1) cecum- contains appendix (MALT), part of peritoneum

2) colon

3) rectum

4) anal canal

1) ascending colon, hepatic flexure

2) transverse colon- part of peritoneum, splenic flexure

3) descending colon

4) sigmoid colon- in peritoneum

parasympathetic:

S2, S3, S4

in LI as muscularis externa

3 bands of smooth muscle

produce long, powerful peristalsis to move chyme to rectum

in LI

sac-like poudches

slow segmentation of chyme to mix, and absorb

fat-like bags hanging from serosa

a way the body stores fat

absorb water and vitamins

form feces

1) destroy and store toxins

2) remove foreign debris (old RBC, antibodies, hormones)

3) regulate blood osmolarity: make albumin

hepatocytes- make bile

right lobe

left lobe

cuadate- next to inferior vena cava

quadrate- next to gall bladder

controls the duodenal papillae

(aka hepatopancreatic ampulla)

1) family history

2) female

3) ferricomplectic

4) forty years old

5) how many kids you have

6) fat

7) flatulent

Cholecystokinin

(CCK)

relaxes sphincter of Oddi

allows bile from common bile duct and pancreatic duct to flow into duodenum

enzymes for digestion

amylase- starch digestion

lipase- fat digestion

endopeptidases- protein digestion