Basic tissues Simple epithelia Dr. Károly Altdorfer

Basic tissues

Simple epithelia

Dr. Károly Altdorfer

Basic tissues

Simple epithelia

Dr. Károly Altdorfer

Organs (stomach, eyeball) Tissues (epithelia, …) Cells

Stainings:

Red (acidophil, eosinophil)Blue (basophil)

Most common:

Hematoxylin-eosin (H-E)

Basic tissues

Types of epithelia

1. Covering epithelia2. Glandular epithelia3. Pigment epithelia4. Sensory epithelia5. (Myoepithelium)

Epithelial tissue is composed of tightly packed cells.

Functions of epithelial cells:

-protection of the internal environment (mechanical+biological)-resorption, excretion of materials-secretion

Epithelial tissue

Simple epithelia

Simple squamous epithelium (endothelium, mesothelium, epithelium)

Simple squamous epithelium (mesothelium, AgNO3 impr.)

Simple cuboidal epithelium

Simple columnar epithelium

Pseudostratified columnar epithelium (epididymis)

Apical

Lateral

Basal

cell surfaces

Apical

Lateral

Basal

cell surfaces

Apical surface: microvilli (cuticle – brush border - stereocilia)

Apical

Lateral

Basal

cell surfaces

Apical surface: microvilli, cilia

- Tight junctions (diffusion barrier)

- (mechanical barrier)

or Macula adherens (strong cell junction)

(cell connections: transport)

Lateral surface:

Apical surface

Lateral surface:

Zonula occludens (tight junction)

Desmosome or Macula adherens

Apical

Lateral

Basal

cell surfaces

Basal striation

Basal membrane = basal lamina + fibroreticular lamina

(Light microscope electrone microscope)