Anatomy & Physiology 1 (BIOL 2401) Chapter 4

Group of similar cells that usually have a similar embryological origin and are specialized for a particular function.

1) Eptithelial tissue-covers body surfaces, lines hollow organs, body cavities and ducts; forms glands
2) Connective tissue-binds organs together, stores energy reserves as fat, provides immunity
3) Muscle tissue-movement and generation of force
4) Nervous tissue-initiates and transmits action potentials (nerve impulses)

1) Endoderm (bottom)
2) mesoderm (middle)
3) Ectoderm (top/superficial)

1) Tight junctions-form a watertight seal, cells line GI tract and bladder
2) Adherens junctions-look like long bands, form plaque which is a dense layer of proteins inside cell. Microfilaments extend into cytoplasm, integral membrane proteins connect cells
3) Gap juntions-tiny space between membranes crossed by protein channels called connexons forming fluid tunnels. Cell communication with ions and small molecules. Found in cardiac and smooth muscle.

Where epithelial cells attach to connective tissues. Intracellular intermediate filaments cross cytoplasm. Found in cardiac muscle.

Rather than linking two cells (like desmosomes), hemidesmosomes attach one cell to the extracellular matrix (not connective tissue like desmosomes).

Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial cells are packed tightly together, with almost no intercellular spaces and only a small amount of intercellular substance.

Epithelial tissue, regardless of the type, is usually separated from the underlying tissue by a thin sheet of connective tissue; basement membrane. The basement membrane provides structural support for the epithelium and also binds it to neighboring structures.

Also known as the brush border. Increase surface area exposed to open body cavity such as the small intestine.

Does not have its own blood supply. Gets nutrients from blood vessels below via diffision.

Have contact with nerve fibers.

Replacement via mitosis.

See image.

See image.

See image.