GI 1 Flashcards
Primary function of digestive system
Move nutrients, water and electrolytes from the external enviroment into the bodys internal enviroment
Central regulation and integration of metabolic processes throughout the body
Proper functioning necessary for whole body homeostasis
10% of health care costs related to the GI system
GI extends from
Mouth to large intestine
GI tract
A long tube with muscular walls lined by transporting and secretory epithelial. Continuation of External enviroment
Stomach to Anus
Gut
Digestion
Mechanical and chemical breakdown of food primarity occurs in gut
Where does digestion occur
Gut
Accesory gladular organs
Salivary glands, liver, gallbladder and pancreas
Digestion begins with
Mastification in the mouth and the addition of saliva
Functions of salivary glands
- Moisten and lubricate food
- Amylase digests starches
- Dissolve some food molecules (taste)
4, Lysozyme kills bacteria
3 salivary glands
Parotid
Sublingual
Submandibular
Esophagus
Passageway from mouth to stomach
Seperated by upper and lower esophageal sphincter
What is esophagus made of
Skeletal and Smooth muscle
How does food move
Via peristalic waves
3 parts of the stomach
- Fundus
- Body
- Antrum
Majority of digestion happens in the
Small intestine
3 sections of small intestine
- Duodenum
- Jejunum
- Ilem
Where does duodenum gets exocrine secretion from
liver and pancreas
Large intestine
(Colon)
1.5 L of watery chyme pass into here each day
Mostly reabsorbed
Parts of the large intestine
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
In response to metabloic alkalosis the respiratory system will
Decrease the rate / Depth of ventilation
4 layers of GI
inner (mucosa)
Submucosa
muscularis externa
Serosa
Parts of mucosa
Mucous membrane
Lamina propria
Muscularis mucosae
Enteric Nervous System
Submucosal plexus
Myentric plexus
Lipids go into
Lamina Propria
What increases surface area in stomach
Gastric glands (microscopic and small)
Large folding of stomach
Rugae
what increases surface area in small intestine
Villi
Epithelium of Mucosa
has variable functions depending on location,
Has tight functions
Includes transporting epithelial cells, endocrine and exocrine secretory cells
Has a lot of stem cells
Epithelial cells have a
Short life span
Lamina propria
Subepithelial tissue containing nerve fibers, small blood vessels and lymph vessels
Muscularis mucosae
Can alter surface area available for absorbtion
Sub Mucosa Layer
Middle distensible layer containing larger vessels. Has the submucosal plexus. One of the major nerve networks in the enteric nervous system
Muscularis Externa
2 or 3 layers of smooth muscle
Contains myentric plexus
Circular muscle
Decrease diameter
Longitudinal muslce
Shortens the tube
Serosa
Outer covering connective tissue. Holds intestine in place
Secretion
Movement of material from cells into lumen or ECF
and secretion from ECF to lumen
Absorbtion
Movement of material from GI lumen to ECF
Motility
Movment of material through the GI tract as a result of muscle contraction
