Layers Of The Gut Flashcards
1
Q
List the layers of the gut
A
- mucosa (innermost)
- submucosa
- inner and outer external muscle layers
- serosa (outermost)
2
Q
List the layers of the gut mucosa
A
- epithelial layer
- lamina propria
- musclaris mucosae
3
Q
Outline the epithelial layer of the gutmucosa
A
- selectively permeable barrier
Role: - facilitates transport + digestion of food
- promotes absorption
- produces hormones
- produces mucus
4
Q
Describe the distribution of epithelia in the gut
A
- Stratified squamous in oesophagus + distal anus (start and end)
- Simple columnar in between
5
Q
Outline the lamina propria
A
- lots of lymphoid nodules + macrophages
Role: - produce antibodies (mainly IgA > resistant to proteases)
- protects against bacterial + viral invasions
6
Q
What antibodies are mainly produced by the lamina propria and why?
A
IgA
Resistant to proteases
7
Q
Outline the musclaris mucosae
A
- layers of smooth muscle orientated in different directions
Role: - keeps epithelium in contact with gut contents
- helps keep crypt contents dynamic
8
Q
Describe the submucosa layer of the gut
A
- contains dense connective tissue, blood vessels, glands and lymphoid tissue
- contains submucosal (Meissner’s) plexus
9
Q
Describe the external muscle layers of the gut
A
- Inner circular muscle: constricts to decrease lumen diameter
- Outer longitudinal muscle: constricts to decrease length of the gut
- work in combination for peristalsis
- myenteric (Aleurbach’s) plexus in between outer and inner layer
10
Q
Describe the serosa layer of the gut
A
- contains blood vessels, lymphatic vessels + adipose tissye
- continuous with mesenteries
11
Q
Constriction of the inner circular muscle layer of the gut result in…
A
Decrease in the lumen diameter
12
Q
Constriction of the outer longitudinal muscle layer of the gut results in…
A
Decrease in the length of the gut
13
Q
Constriction of the inner circular muscle and outer longitudinal muscle layer of the gut together helps to aid…
A
Peristalsis
