Bio 03 Tissue Notes

The Tissue Level of Organization
 Tissues- collections of cells that perform a specific function and work
together to form tissues
- There are 4 types of tissues:
1. Neural tissue
2. Muscle tissue
3. Connective tissue
4. Epithelial tissue

1. Neural Tissue
 Neurons are specialized to carry electric impulses
 They consist of a nerve cell body, the axon, and the dendrite

2. Muscle Tissue
 Muscle cells are specialized to contract and relax using actin and myosin
protein fibers. In hard working cells, there are so many actin and myosin
fibers that they appear as stripes called striations
- Skeletal or striated muscle
- Smooth muscle
- Cardiac muscle

 Skeletal Muscle Tissue
- Locations: combined with connective tissues and nervous tissue in
skeletal muscles, organs such as the skeletal muscles of the limbs
- Functions: moves or stabilizes the position of the skeleton; guards
entrances and exits to the digestive, respiratory, and urinary tracts;
generates heat, protects internal organs

 Cardiac Muscle Tissue
- Location: heart
- Functions: circulates blood; maintains blood (hydrostatic) pressure

 Smooth Muscle Tissue
- Locations: encircles blood vessels; found in the walls of digestive,
respiratory, urinary, and reproductive organs