Unit 9 - Digestive tract

Alimentary canal

GI tract, a muscular tube that extends from mouth to anus

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

GI tract organs

Rugae

gastric folds that increase the SA of the stomach

Accessory digestive organs

lie external to the GI tract and are connected by ducts

tongue, salivary glands, liver, gallbladder, and pancreas

Accessory digestive organs

Secondary retroperitoneal

partially inside and outside of the peritoneal

duodenum, pancreas, ascending and descending colon, and rectum

Secondary retroperitoneal organs

Mucosa

epithelial lining, connective tissue, lamina propria, muscularis mucosae, lightly folded

Submucosa

connective tissue, major blood vessels, mucosa associated lymphoid tissue

Muscularis

smooth muscle layer, there for motility (adaptive)

Serosa

lubrication of pieces and tunics

MSMS: Mucosa, Submucosa, Muscularis, Serosa

4 Tunics order (deep to superficial)

Superior labial frenulum

connects top lip to gums

Hard palate

forms anterior roof of mouth

Soft palate

forms posterior roof of mouth

Uvula

Lingual frenulum

connects tongue to floor of mouth

Inferior labial frenulum

connect lower lip to gums

Intrinsic salivary glands

exocrine; secretes small continuous amounts of saliva from tongue, palate, lips and cheeks

Extrinsic salivary glands

produces saliva while eating

Parotid salivary glands

Sublingual salivary gland

Submandibular salivary glands

Enamel

Gingiva

epithelial

Dentin

primary mass; much harder than bone

Crown

Neck

Root

Pharynx

inferior two thirds involved in respiration and digestion

Esophagus

muscular tube that joins the pharynx to the stomach; completely collapsible

Superior esophageal sphincter

Esophageal hiatus

passes through diaphragm

Inferior esophageal sphincter

closes lumen to prevent stomach acid from entering esophagus

Cardia

entryway to stomach

Fundus

round top to collect gas

Body

largest portion with alternating muscle layers

Pyloric

funnel-shaped, empties contents to duodenum

Circular muscle

middle muscularis layer

Longitudinal muscle

most superficial muscularis layer

Oblique muscle

deepest muscularis layer

Liver

largest gland in the body with two surfaces

Diaphragmatic

anterior and superior surface of liver

Visceral

posterior and inferior surface of the liver

Right lobe

Left lobe

Porta hepatis

hilum of liver

Bare area

where the liver physically touches the diaphragm

Falciform ligament

divides right and left liver lobes

Caudate lobe

Quadrate lobe

Gallbladder

a muscular sac that lies of the visceral surface of the right lobe of the liver

Common hepatic duct

Cystic duct

Common bile duct

empties into duodenum

Pancreas

both an endocrine and exocrine gland

Main pancreatic duct

joins the bile duct and accessory pancreatic duct to empty into duodenum

Hepatopancreatic ampulla

Duodenum

receives digestive enzymes and bile

Jejunum

superior left part of coiled intestinal mass

Ileum

inferior right part of coiled intestinal mass

Intestinal crypts

filled with stem cells

Large intestine lacks vili, have deeper crypts and have two mucous layers

Differences between small and large intestine

Cecum

a blind pouch that is the beginning of large intestine

Vermiform appendix

contains lymphoid tissue to neutralize pathogens

Colon

divided into distinct segments

Ascending colon

Transverse colon

Descending colon

Sigmoid colon

Rectum

descends along the inferior half of the sacrum

Anal canal

the last subdivision of the large intestine

Ileocecal valve

Haustrum

sacs that help push fecal matter

Transverse mesocolon

Omental appendicies

fat storage

Teniae coli

muscles that ribbons the large intestine

Rectal valve

allows gas to leave separate from fecal matter

Internal anal sphincter

smooth involuntary muscle

External anal sphincter

skeletal voluntary muscle