PNB 2264 Lab 1 (Histology)

Skeletal muscle tissue characteristics

striations, muscle fibers = muscle cells (not branches, cylindrical), multiple peripheral nuclei

Cardiac muscle tissue Characteristics

striations, intercalated discs, muscle fibers, single centrally located nucleus

Smooth muscle tissue characteristics

Not striated, muscle fibers, single centrally located nucleus

Four basic types of tissue in the body

1. Epithelial

2. Connective

3. Nervous

4,. Muscular

Common features of the epithelia

1. Avascular

2. Little intercellular material

3. Surface specializations

4. Junctional complexes

5. Basal lamina

What does the epithelial tissue rest on

on a condensation of extracellular matrix elaborated both by the epithelial cell as well as underlying connective tissue called the basement membrane (basal lamina)

Two parts of the basal lamina

1. A layer of collagen (type IV) and amorphous ground substance secreted by the epithelial tissue

2. Reticular fibers which extend into the ground substance from the underlying connective tissue

Function of epithelial cells

1. absorption (gastrointestinal tract)

2. secretion (in a sweat gland)

3. transportation and excretion (as in urine formation in the kidney)

4. sensation (taste buds or olfactory cells)

5. protection

Squamous epithelial cells

flat

Cuboidal epithelial cells

shaped like a cube

Simple (1 layer) squamous

Stratified (multiple layers) squamous

Simple cuboidal

stratified cuboidal

simple columnar epithelium

where can simple squamous epithelium found

they are composed of flattened polygonal cells and they line the heart and blood and the lymph vessels as well as the body organs (alveoli and bowman's capsule)

where can simple cuboidal epithelium be found

it lines the ducts of many glands, kidney tubules and follicles of the thyroid gland

where can the simple columnar epithelium be found

it lies much of the gastrointestinal tract such as the stomach, intestines, gallbladder and the major ducts of he digestive glands