Gastrointestinal system 1 Flashcards
What is the primary function of the GI system
Bring nutrients into the internal environment
Where is stratified squamous in the GI tract
Mouth/oral cavity
Esophagus
Where is simple columnar in the GI tract
Stomach
Small and large intestine
Where is stratified squamous in the GI tract
Anal canal
Describe goblet cells (unicellular glands)
In columnar epithelium
Goblet shape
Apical mucous granules
Basal nucleus
What are the types of multicellular glands
When epithelium invaginates to form glands
Simple: Single duct
Compound: 2 or more ducts
What are the four layers of the gut tube
Mucosa
Submucosa
Muscularis
Adventitia
Describe what the mucosa consists of
Epithelium
Lamina propria (FCT)
Muscularis Mucosa
(sometimes glands)
Describe the submucosa
Contains glands and blood vessels - connective tissue
Secretion regulated by submucosal nerve plexus (enteric nervous system)
Describe the muscularis
Consists of smooth muscle
Inner circular - controls diameter
Outer longitudinal - shortens tube
What is the myenteric plexus
Part of ENS
In between muscle layer
Regulates motility
Describe the adventitia
Outermost layer. FCT
Describe the peritoneum
Serous membrane Parietal layer - Lines body wall Visceral layer - Lines organs Fluid between layers (retroperitoneal)
What is the mesentery
Double layer of visceral peritoneum - connects organ to body wall
Describe the Omenta
Double layer of visceral peritoneum - connects organ to another organ
What happens in the mouth and oral cavity
Digestion begins - enzymes
Lubrication
What are the 3 salivary glands
Parotid - Serous fluid with amylase
Sublingual - Mucous
Submandibular - mix
1L per day
What is an acinus
Cells in cluster
What do acinar cells secrete
Enzymes (amylase)
What do duct cells secrete
Bicarbonate (buffering)
Where is the esophagus located
Posterior to trachea - extends from pharynx to stomach
What does the epiglottis do
Stops food from entering the trachea
How is the esophagus modified
Highly folded submucosa and mucosa - expand
How does the esophagus change as it goes down
First 1/3 - skeletal muscle
Middle 1/3 - mixture
Last 1/3 - Smooth muscle
How does the esophagus produce mucous
Glands with ducts to surface
no goblet cells
