Identify the principle parts of the nervous system Describe the cells that make up the nervous system Describe what starts and stops a nerve impulse (action potential) The role of neurotransmitters Compare the functions of the CNS & PNS Identify the principle parts of the brain
Central nervous system (CNS): “command central” ◦ Components: brain and spinal cord ◦ Functions: receives, processes, and transfers information Peripheral nervous system (PNS): “messengers” ◦ Components: nerves outside CNS ◦ Sensory neurons: carry information toward the CNS ◦ Motor neurons: carry information away from CNS
1. Somatic - under conscious control (movement of skeletal muscles) 2. Autonomic – unconscious control (smooth muscle, cardiac, glands)
Sympathetic – flight or fight Parasympathetic – conserves energy, promotes nonemergency functions
Neurons: specialized cells for communication: ◦ Cell adaptations: cell body, axon, dendrites ◦ Types: sensory, interneurons, motor neurons
Of PNS transmit impulses to the CNS Specialized to respond to specific stimuli like light or pressure Impulses are electrical –as they travel they cause depolarization and repolarization of membrane potential = measurable difference in voltage across a cell membrane
Of CNS transmit impulses between components of CNS Receives information from sensory neurons, Integrates/interprets information and Influences the functioning of other neurons
Of PNS transmit electrical impulses away from the CNS to muscles and glands
Cell body – BATTERY - nucleus, DNA, mitochondria, etc Dendrites – SENSORS - extension of cell body (soma) = info receivers/receptors Axon – WIRING – long, slender tube of cell membrane specialized to conduct electric impulses Axon terminals & axon bulbs (plugs & lights) – connections to tissues or other neurons
Sensory neural axons originate from a dendrite Interneurons and motor neurons axons originate from axon hillock (cone shaped area of soma)