Tissue Basics

What are the four primary tissue types?

Epithelial, connective, muscle, and nervous.

What is histology?

The microscopic study of tissues.

What is a biopsy?

Removal of tissue for diagnostic purposes.

What is an autopsy?

Examination of a body after death to determine the cause of death.

What are the three embryonic germ layers?

Endoderm, mesoderm, and ectoderm.

What does the endoderm form?

The lining of the digestive tract and its derivatives.

What does the mesoderm form?

Muscles, bones, blood vessels, and most connective tissues.

What does the ectoderm form?

Skin and the nervous system.

What is epithelial tissue mainly composed of?

Cells with very little extracellular matrix.

What are the main functions of epithelial tissue?

Protection, barrier formation, absorption, secretion, and allowing substances to pass.

Is epithelial tissue vascular or avascular?

Avascular.

How does epithelial tissue receive nutrients?

By diffusion from the underlying connective tissue.

What is the basement membrane?

A layer that anchors epithelial tissue to the underlying connective tissue.

What are the two layers of the basement membrane?

Basal lamina and reticular lamina.

What are the three surfaces of epithelial cells?

Apical, lateral, and basal.

What is the apical surface?

The free surface exposed to a body cavity or the outside.

What is the basal surface?

The surface attached to the basement membrane.

What is the lateral surface?

The side of the cell that contacts neighboring cells.

What does "simple" mean in epithelial tissue?

One layer of cells.

What does "stratified" mean in epithelial tissue?

Two or more layers of cells.

What does "pseudostratified" mean?

Looks multilayered, but every cell touches the basement membrane.

What is transitional epithelium?

A stratified epithelium that changes shape when stretched.

What does squamous mean?

Flat, thin cells.

What does cuboidal mean?

Cube-shaped cells that are about as tall as they are wide.

What does columnar mean?

Tall cells that are taller than they are wide