This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Chapter 48: Nervous System 18/02/2008 18:40:00 ← 1. Name the three stages in the processing of information by the nervous systems. • Sensory input o Sensory neuron-transmit information from sensors that detect external stimuli (light, sounds, touch, heat , smell, and taste) and internal conditions (blood pressure, blood CO2 level, and muscle tension) • Integration o Interneuron-information from sensory neuron is sent to CNS where sensory input is integrated (analyze and interpret) o Takes into account the immediate context as well as what happened in the past • Motor output o Motor neurons- where motor output leaves the CNS which communicates with effector cells (muscle cells or endocrine cells) ← 2. Distinguish among sensory neurons, interneurons, and motor neurons. • Sensory neuron: a nerve cell that receives information from the internal and external environments and transmits the signals to the central nervous system • Interneuron: an association neuron; a nerve cell within the central nervous system that forms synapses with sensory and motor neurons and integrates sensory input and motor output • Motor neuron: a nerve cell that transmit signals from the brain or spinal cord to muscles or glands ← 3. List and describe the major parts of a neuron and explain the function of each. ← • Dendrite: highly branched extensions that receive signals from other neurons; one of usually numerous, short, highly branched processes of a neuron that convey nerve impulses toward the cell body • Axons: a typically long extension, or process from a neuron that carries nerve impulses away from the cell body toward target cells • Axon hillock: the conical region of a neuron’s axon where it joins the cell body; typically the region where nerve signals are generated • Myelin sheath: in a neuron, an insulating coat of cell membrane from Schwann cells that is interrupted by nodes of Ranvier, where salutatory conduction occurs • Synaptic terminal: a bulb at the end of an axon in which neurotransmitter molecules are stored and released • Synapse: the locus where one neuron communicates with another neuron in a neural pathway; a narrow gap between a synaptic terminal of an axon and a signal-receiving portion of another neuron or effector cell • Presynaptic cell: the transmitting cell at a synapse • Postsynaptic cell: the target cell at a synapse • Neurotransmitter: a chemical messenger released from the synaptic terminal of a neuron at a chemical synapse that diffuses across the synaptic cleft and binds to and stimulates the postsynaptic cell ← 4. Describe the function of astrocytes, radial glia, oligodendroctues and Schwann cells. •...
View Full Document
- Winter '08