Lecture 3- Mucosal membranes Flashcards
mucosal memerbanes line
most hollow internal organs of the body
mucosal membranes are continues with skin at openings e.g.
lips vagina anus ears nose mouth
mucus membranes secrete mucus which contains
- mucins (proteins)
- electrolyte
- antiseptic enzymes (lysozyme)
- immunoglobulins
mucus membranes function
- Stops pathogens and dirt from entering the body
- Prevent bodily tissues from becoming dehydrated
- Lubricate surface
examples of systems with mucosal membranes
- GI tract
- Urinary tract
- Respiratory tract.
simple structure of mucosal membrane
- epithelium
- lamina propria
+ muscular mucosa (ELM)
basement membrane
- thin acellular layer where epithelial cells are anchored
function of the mucosa
1) absorb substances from the lumen (microvilli)
2) Prevent ingress of pathogens
3) move content and expel waste (peristaltic action)
layers of theGI tract
1) Mucosa (ELM)
2) Submucosa
3) Musculares externa (inner circular and outer longitudinal)
4) serosa
mucosa
epithelial cells
lamina propria
muscularis mucosa
mucosa in gI of
o Epithelial cell lining and supporting mesenchymal layer
muscularis mucosae in the GI
o A thin discontinuous smooth muscle layer
Submucosa
a connective tissue layer that contains artery sand veins
muscularis externa in the GI
o A smooth muscle layer that has muscle fibres going in different directions
An inner circular muscle
Outer longitudinal
the serosa of the GI
o Another connective tissue layer
Contains collagen and elastin fibres with some smaller arteries and veins and some nerve fibre
in the stomach the surface are is increased by invagination called
gastric glands
no villi in
l. intestinal
- has intestinal crypts
order of GI tract
1) Mouth
2) Oesophagus
3) Stomach
4) Liver
5) Gallbladder
6) Pancreas
7) Small intestine
a. Duedenum
b. Jejunum
c. Ileum
8) Large intestine
a. Cecum
b. Ascending colon
c. Transverse colon
d. Descending colon
e. Sigmoid colon
f. Rectum
g. Anal canal
oesophageal structure-function relationship
- Epithelium- stratified squamous non-keratinised (withstands abrasion)
- Submucosa- layer of connective tissue containing mucus-secreting glands
- Muscularis externa- smooth muscle layers
- Inner- circular
- Outer- longitudinal
o Moves bolus of food by peristalsis
stomach layers
M= gastric mucosa secretes acid, digestive enzymes and hormone gastrin (epithelium) MM= muscularis mucosae SM= submucosa (connective tissue) ME= Musucalaris externa (3 layers of s.muscle in stomach- oblique, circular, longitudinal) R= Rugae folds of gastric mucosa forming longitudinal ridges in empty stomach
jejunum layers
M= Jejunal mucosa (simple columnar epithelium (absorbtion) and lamina propria)
MM= Muscularis mucosae
SM= Submucosa (connective)
ME= muscularis externa (2 layers)
Pilcae circulares= circular folds of mucosa and submucosa projecting into gut lumen