4.1 Types of Tissues

Tissue

A group of similar cells that perform a common or related function.

Histology

The study of the structure and function of tissues.

What are the four basic types of tissues?

Epithelial, connective, muscle, and nervous tissue.

What are the two basic components of tissues?

Related cells and the ECM

Extracellular Matrix (ECM)

The substances found in a liquid, thick gel, or solid that surrounds cells of a tissue. Made of ground substance and protein fibers.

Ground substance

Made of cell-adhesion molecules (CAMs) and protein fibers.

Cell-adhesion molecules (CAMs)

Made of glycoproteins, adheres cell to cell, cell to surroundings, and holds everything in place within the ECM.

Protein fibers

Ropelike, long molecules made of many fibrous subunits, is embedded in ground substance, has enormous tensile strength.

What protein fibers are found in the ECM?

Collagen, elastic, and reticular fibers.

Collagen

White fibrous protein, is resistant to pulling, stretching, and pressure.

Elastic

Made of elastin surrounded by glycoprotein, is elastic and recoils.

Reticular fibers

Thin, short collagen fibers, form a meshwork that supports cells and GM. Also forms web-like trap (spleen).

Connective tissue membrane

Solely made of CT, encapsulates organs and lines our movable joints.

Synovial membrane

A type of CT membrane that lines the cavity of a freely movable joint.

Hyaluronan

Released by fibroblasts, hyaluronan traps water to form synovial fluid which is a lubricant.

Epithelial membrane

A layer of epithelium attached to a layer of connective tissue (Skin).

Mucous membrane

Composite of connective and epithelial tissues. Line body cavities and hollow passageways that open to the external environment. Mucus is produced by the epithelial exocrine glands.

Lamina propria

Underlying connective tissue, supports the fragile epithelial layer.

Serous membrane

Line coelomic cavities (cavities that do not open to the outside), and cover the organs in those cavities. A membranous bag that secretes serous fluid.

Cutaneous membrane

Skin, a stratified squamous epithelial membrane resting on top of connective tissue.

Totipotent

Having the ability to divide, differentiate, and develop into a new organism.

Ectoderm

Outer, gives rise to epidermis, neurons, and pigment cells.

Mesoderm

Middle, gives rise to muscles, connective tissue proper, and membranes

Endoderm

Lining of the airways, digestive tract, and glands.