Muscle & Nervous Tissue OBJECTIVES: Differentiate between the 3 types of muscle tissue. Be able to identify muscle tissues by sight. Anatomy of a neuron Different method of tissue repair

Muscle Tissue Highly specialized to contract/shorten to produce movement. 3 Types: Skeletal Cardiac Smooth

1. Skeletal Muscle Attached to the skeleton Can be controlled voluntarily Causes gross body movements Cells of muscle tissue are long, cylindrical, have many nuclei, and are striated (striped).

2. Cardiac Muscle Found only in the heart. Is striated Cells fit tight together at junctions called intercalated disks. Intercalated disks contain gap junctions that allow impulses to travel. Involuntary control.

3. Smooth Muscle No visible striations. Cells have a single nucleus and are spindle shaped. Found in walls of hollow organs (stomach, bladder, uterus) Can contract (making organ smaller) or enlarge (making organ dilate) to move substances along. Peristalsis: moving food through the esophagus.

Nervous Tissue Found in the brain, spinal cord, & nerves Specialized to react to stimuli and conduct impulses. Made up of cells called neurons.

Tissue Repair Tissues repair themselves in 2 major ways. Regeneration: the replacement of destroyed tissue by the same kind of cells. Fibrosis: involves repair by dense connective tissue forming scar tissue. The type of repair chosen depends on the type of tissue damaged and the severity of the injury. Clean cuts heal much more easily and quickly than rips or tears.