Layers Of Gut Flashcards
Is the gut an interior or exterior surface?
Exterior surface
What type of cells line the gut?
Epithelial cells
How many layers are in the gut tube?
Mucosa, submucosa, external muscle layers/muscularis and serosa
What part of the body is the gut continous with?
The skin
What are the 3 layers to mucosa?
Epithelial layer
Lamina propria
Muscularis mucosa
What is the function of the epithelial layer?
Selectively permeable
Facilitates transport and food digestion
Promotes absorption
Produces hormones and mucus
What is the function of lamina propria ?
Important innate immunity (protects from infection)
Contains lymphoid nodules, macrophages and produces antibodies (IgA) to protect against infection
Why is IgA the antibody mainly produced by the lamina propria?
Resistant to proteases
Describe the distribution of epithelia across the gut:
Stratified squamous in oesophagus and distal anus (abrasion areas)
Highly specialised simple columnar cells in between
What is the function of muscularis mucosa?
Is smooth muscle orientated in different directions so when it contracts helps keep the dynamics of the crypts
Helps with absorption
What is the function of the submucosa?
Contains dens connective tissue, blood vessels, glands, lymphoid tissue and part of the enteric nervous system (submucosal plexus)
What are the 2 layers of muscle in the external Muscularis layer?
Inner circular uscle
Outer longitudinal muscle
What is the action of the inner circular muscle of the external muscle layer when it contracts?
Constricts lumen
What is the action of the outer longitudinal muscle of the external muscle layer when it contracts?
Changes length of gut
Where is the Myenteric plexus located?
Between the circular nad longitudinal muscle of the external muscle
