GI System - Lecture 1 Flashcards
what is the two parts of the Digestive system
alimentary Tracts and GI tract
what are the accessory organs
liver, pancreas, salivary glands and gallbladder
what are the 4 functions of the GI tract
absorption, digestion, secretion and motility
what are the two ways food is digested
mechanically and chemically
why is food converted into macromolecules
due to the osmolarity of the cell
what is osmolarity dependant on
the amount of molecules
what are the two types of digestive absorption
diffusion (passive) and active transport
what are lymphatic vessels
tube like structures that carry blood away from the tissues and back into the bloods’ circulation
what is motility
the ability of an organism to move independently, using metabolic energy
what type of gland is the liver
exocrine gland
what is the main function of the liver
to store and concentrate bile
what are the 4 main layers of the GI tract
mucosa, submucosa, muscularis externa and serosa/adventitia
what are the 3 sub-layers of the mucosa
epithelium, lamina propria and muscularis mucosae
what is the purpose of the submucosa
to act as a thick, connective tissue that supports the mucosa
what does the submucosa contain
large blood vessels, that supply the muscularis externa and serosa, lymphatic vessels and nerves
what is the purpose of the muscularis externa
controls the contractility of the GI tract
what are the two types of muscle in the muscularis externa
circular and longitudinal
what a are the two types of GI tract motility
peristalsis and segmentation
what is the purpose of the adventitia/serosa
connective tissue that links the GI tract to the peritoneal cavity
what is the function of the mucosa epithelium
to absorb nutrients and water from the lumen, and secretion happens
what is the lamina propria
thin, loose connective tissue and also supplys blood to the epithelium
what is the purpose of the muscularis mucosae
thin, smooth muscle that controls contractility of the GI tract
what does stratified mean
more than one layer
why does the stomach, small and large intestine have simple cells and not stratified
to allow maximum and faster absorption of nutrients
what is the submucosal plexus
a network of neurons between the submucosa and muscularis externa
what is the network of neurons called that is between the muscularis externa and serosa/adventitia
myenteric plexus
what is the enteric NS (ENS)
the two network of neurons within the GI tract
