Ch. 35 Nervous System Sec 1 = Human Body Systems Key Concepts: Describe how the human body is organized. Explain homeostasis. Recall levels of organization: cellstissuesorgansorgan systems

The 11 systems work together to maintain homeostasis (maintaining internal conditions despite external environment.) Nervous Integumentary Respiratory Digestive Excretory Skeletal Muscular Circulatory Endocrine Reproductive Lymphatic / Immune

4 Types of Tissue Epithelial = cover interior & exterior body surfaces Connective = provides support Muscle = enables movement Nervous = transmits nerve impulses

Sec 2 The Nervous System Controls & coordinates functions throughout body Responds to internal and external stimuli Specialized cells carry impulses = neurons (sensory, motor, interneurons)

The Nerve Impulse A neuron is stimulated by another neuron or by the environment Impulse travels rapidly down the axon away from cell body toward axon terminals Na+ and K+ ions allow for action potential

Sec 3 Divisions of Nervous System CNS = relays messages, processes info, analyses info PNS = receives info from environment, relays commands from CNS to organs & glands

5 categories of sensory receptors: Sec 4 The Senses 5 categories of sensory receptors: pain thermo mechano chemo photo