notes_ four types of animal tissue.pdf

Four Types of Animal Tissues Types of Epithelial Tissue Epithelial Tissue (Covering) Tightly-joined closely-packed cells. One side of epithelium exposed to air or internal fluid, other side attached to a basement membrane, a dense mat of extrac...

Four Types of Animal Tissues Types of Epithelial Tissue Epithelial Tissue (Covering) Tightly-joined closely-packed cells. One side of epithelium exposed to air or internal fluid, other side attached to a basement membrane, a dense mat of extracellular matrix (connective tissue). Made of cells that cover and protect the surface. One side is exposed outside. Other side is stuck to a basement membrane (a sticky mat that holds everything in place). Covers the outside of the body and lines (thin barrier/protect) the internal organs and cavities. Barrier against mechanical injury, invasive microorganisms, and fluid loss. Provides surface for absorption, excretion and transport of molecules. Cell Shape Squamous Cuboidal Columnar Number of cell layers Simple Pseudostratified Columnar Relate structure to function! Connective Tissue (Framework) Main function: binding and supporting other tissues. Large amount of extra-cellular matrix with fewer cells. It has fewer cells, but a lot of space around those cells filled with a material called extracellular matrix. Connective tissue cells secrete the extra-cellular matrix (a gel or web of fibers that helps hold everything together and provide structure), Extracellular matrix consists of a network of fibers in liquid, jelly-like or solid matrix. Muscle Tissue (Movement) Composed of long cells called muscle fibers. Contraction movement. Muscle tissue is the part of your body that makes movement happen by contracting. Nervous Tissue (Control) Has a central part called the cell body, which acts like the "control center" of the cell. Dendrites: These are the extensions that bring signals toward the cell body. Axon: These are long extensions that carry signals away from the cell body to another cell or to an effector (a muscle or gland). Senses stimuli and transmits signals called nerve impulses from one part of an animal to another. Consists of a cell body and long extensions called dendrites (towards the cell body) and axons (towards another cell or an effector).