A. Tissue – a grouping of cells that are similar in structure and perform a common or related
function
B. Histology – the study of tissues; requires a microscope
C. 4 basic types
1. Epithelial tissue (epithelium)
2. Connective tissue
3. Nervous tissue
4. Muscle tissue
D. Epithelium
1. Functions
A) Protection
B) Absorption
C) Filtration
D) Excretion
E) Secretion
F) Movement/Propulsion
2. General Categories
A) Lining & covering epithelium
B) Glandular epithelium
3. Characteristics of epithelium
A) Cellularity – almost entirely cells
B) Polarity
1) Apical border
2) Basement membrane
C) Connective tissue support
D) Innervated but avascular
E) Highly reproductive
4. Classification – many types named according to the number of cell layers and the cell’s
shape
A) Number of cell layers
1) Simple
2) Stratified
B) Cell’s shape
1) Squamous
2) Cuboidal
3) Columnar
C) Types of epithelium
1) Simple squamous
a) Lines the systemic capillaries, glomeruli in the kidneys & alveoli in the lungs
b) Filtration, absorption & secretion