Module 10 - Control and Disorders of Gastrointestinal Function Flashcards
Functions of the GI System
Process food substances—dismantle & reassemble food
Produce enzymes and hormones for digestion
Absorb the products of digestion—nutrients, vitamins, minerals, electrolytes, and water
Store and synthesize vitamins
Provide an environment for microorganisms to synthesize nutrients, such as vitamin K
Collect and eliminate wastes
Digestion and absorption requires what two things
an intact and healthy GI epithelial lining that can resist the effects of its own digestive secretions
the presence of enzymes for the digestion and absorption of nutrients
Digestion and Absorption involves…
the movement of materials through the GI tract at a rate that facilitates absorption
Dumping
movement through the GI tract that is too fast to allow digestion and absorption
What are the sections of the digestive system
Upper part
middle portion
lower segment
fourth part - accessory organs
What does the upper part of the digestive system consist of and what does it do?
the mouth, esophagus and stomach
they act as an INTAKE source and receptacle through which food passes and in which INITIAL DIGESTIVE processes take place
What does the middle portion of the digestive system consist of and what does it do?
the small intestine: duodenum, jejunum, ileum
Most digestion and absorption processes occur here in the small intestine
What does the lower segment of the digestive system consist of and what does it do?
The cecum. colon, and rectum
Serves as a storage channel for the efficient elimination of waste and the large intestine allows for some fluid reabsorption
What is the fourth part of the digestive system and what does it do?
It is the accessory organs like the salivary gland, liver, and pancreas
They produce digestive enzymes that help dismantle food and regulate the use and storage of nutrients
What are the important anatomical portions of the mouth
Lips
Cheeks
Palate
Tongue
Teeth (Mastication)
Salivary Glands (Lubrication)
Muscles
Maxillary Bones
Saliva contains the enzyme ___ (___) that aids in digestion of ___
amylase (ptylain); starches
Esophagus
collapsible muscular tube (a transportation tube)
about 10 inches long
carries food from the pharynx to the stomach
What are the sections of the stomach?
the cardia, fundus, body, and pylorus
The Cardia
The portion of the stomach directly connected and closest to the esophagus
contains the cardiac opening
The Pyloris
The area at the bottom of the stomach closest to the duodenum of the small intestine
has the pyloric sphincter
Stomach Body and Fundus
the body is the largest mid portion while the fundus is the top portion above the level of the cardia or on the same level
Cardiac Opening
An opening into the stomach - not really a sphincter since stomach contents can get back out
opens and closes in the cardia
prevents reflux back into the esophagus
What is the pH of the esophagus compared to the stomach
esophagus pH of 8
stomach pH of 1-2
Pyloric Sphincter
sphincter near the end of the stomach leading to the duodenum
regulates the rate of stomach emptying into the small intestine
What does the stomach have that the esophagus does not which allows regeneration and protection from stomach acid
prostaglandins
Barret’s Esophagus
a condition of cellular change in the esophagus from stomach content reflux
What protects the stomach from enzymes and acids?
Gastric Mucosal Protection consisting of water soluble mucus and water insoluble mucus
Water Soluble Mucus
A gastric mucosal protection
It is washed from the mucosal surface and mixes with luminal contents
Its viscid nature makes it a lubricant to prevent MECHANICAL damage to the stomachs mucosal surface
Water Insoluble Mucus
A gastric mucosal protection
forms a thin and stable gel that adheres to the gastric mucosa surface
It gives protection from the proteolytic actions of pepsin
Forms an unstirred layer that traps bicarbonate thus forming an interface between the luminal contents of the stomach and its mucosal surface