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
Objectives
Principle Parts of Nervous System
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)
Motor Division: 2 parts
Sympathetic – flight or fight Parasympathetic – conserves energy,
promotes nonemergency functions
Autonomic divisions: 2 parts
Cells of the Nervous System Communicators/messengers
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
Sensory neurons - INPUT
Of CNS transmit impulses between components of CNS
Receives information from sensory neurons, Integrates/interprets information and Influences the functioning of other neurons
Interneurons - INTERGRATION
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
Neuron Structure
Sensory neural axons originate from a dendrite
Interneurons and motor neurons axons originate from axon hillock (cone shaped area of soma)
Neuron adaptations