Exam 4

organized mass of similar cells with a specific function

• Vertebrates • Cells • Extracellular Matrix (ECM) • Cell Junction

• Epithelium or epithelial tissue • Connective tissue • Nerve tissue • Muscle tissue

Themselves (covered in their turn)

All material outside of cells but materials made by cells and composed of: - Fibers - Ground substance

• Collagen • Elastic FIber

liquidy -> gel -> granular - complex macromolecules - filling in spaces - lubricants and cushions - interstitial fluids: blood plasma, lymph fluid

Specialized structures that connect cells together

• Seal neighboring epithelial cells together tightly enough to prevent liquids from passing between the cells to get to the underlying tissues. • Make the epithelial layer water tight

• adhering junctions: attach cells to each other • desmosomes: attach cells to each other • hemidesmosomes: attach cells to the underlying ECM

• adherins junction: action • desmosomes: keratin in epithelial cells, tonofilaments in other tissues

“tunnel” shaped protein through the plasma membrane of adjacent cells that allows the passage of water, ions, and other small molecules between cells

The tubular protein composed of 6 proteins each called connexin

Covers surfaces - forms a continuous layer that covers most body surfaces and cavities: - classified by cell shape and layering

One cell thick

flat, tile like

about as tall as wide

taller than wide

thin sheet of extracellular proteins-lamina: adhesive fibrous protein and sticky ECM - anchored to the underlying connective tissue

not a “cellular” membrane

Multiple layers

“appearance of multiple layers” but all cells anchored to basal lamina

• Connects, supports, and protects other tissues • The bulk of connective tissue is not composed of cells, but extracellular matrix

3 general unspecialized: 1. Fibroblasts 2. Adipose cells 3. Blood cells