THE NERVOUS SYSTEM I pp. 1003-1015 Warm-up 4/9: What are the 4 main types of tissues. Describe each. THE NERVOUS SYSTEM I pp. 1003-1015

FUNCTION network of cells (neurons) that communicate and control the body through electrical impulses Includes neurons (cells that carry messages), brain and spinal cord

CENTRAL NERVOUS SYSTEM CNS Brain – control center with different sections controlling different parts of the body Spinal cord – column of nerve tissue that acts as a communication link between brain and Peripheral NS.

PERIPHERAL NERVOUS SYSTEM PNS carries impulses to and from the CNS. Motor division (reacts to sensory input) 1. somatic nervous system (voluntary): transmits impulses to and from skeletal muscle

2. Autonomic nervous system (involuntary) – controls glands, internal organs, and other smooth muscle tissue.

NEURONS

1. Axons: extension of cell body 2. Axon terminal: end of the axon 3. Dendrites: receive action potentials (electrical impulse/message) from other neurons 4. Synapse: gap between neurons 5. Myelin sheath: lipid layer around axon (insulator) 6. Schwann cells: produce myelin sheath

TYPES OF NEURONS sensory – sense organs/receptors to CNS. motor – CNS to muscles/glands. interneurons – connect sensory and motor and carry impulses between them.

homework Cover Page Physio Read pp. 1003-1015 P 1015 # 1-6, 8