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Tissues -Lecture 4 Cheat Sheet (DRAFT) by

Lecture 3

This is a draft cheat sheet. It is a work in progress and is not finished yet.

General Defini­tions

A group of cells that have similar structure and function plus extrac­ellular substance (matrix)
Study of the tissues of the body and how tissues are arranged to constitute organs
Extrac­ellular Matrix
Glue that holds the cells together in tissues
Basic types of tissues
- Epithelial
- Connective
- Muscle
- Nervous

Epithelial Tissues

- Covers internal and external surfaces of the body
- ex: Skin, linings of the digestive and respir­atory tracts, blood vessels, body caviti­es...
- Cells close (packed) together (very little extrac­ellular matrix)
- Form most glands
- Have a free (apical) surface
- Have a Basal surface which attaches epithelial cells to underlying tissue
Places Found
Surface of skin
Lining of digestive tract
Lining of respir­atory tract
Lining of Secretory glands

Classi­fic­ations of Epithelia

1. Simple Squamous - Single layer of flat cells
eg. lining blood vessels, aveoli of the lungs, kidney tubules, serous membra­nes...
Advantage: easier for substances to diffuse or be filtered across
Good for gas exchange
2. Stratified squamous, kerati­nized - several layers of cells
eg. skin
3. Stratified squamous, non-ke­rat­inized moist
eg. lining esophagus
4. Simple cuboidal
eg. kidney tubule
5. Simple columnar
eg. intestine
6. Pseudo­str­ati­fied
eg. upper respir­atory tract
7. Stratified Cuboidal
8. Stratified Columnar
9. Transi­tio­nal
eg. urinary bladder

Funtions of Epithelia

1. Permit the passage of substaces
2. Protect underlying structures
3. Barrier
4. Absorption
5. Secretion