BIO1022 Study Guide - Final Guide: Axon Hillock, Motor Neuron, Interneuron
Document Summary
Neurons: cells that conduct information via electrochemical signals. Glia: supporting cells that provide structure, protection and insulation to neurons, and are involved in metabolism. Consists of the brain and the spinal cord. Consists of sensory neurons (ganglia) and motor neurons. Information processing: sensory input, integration, motor output. Highly branched structures attached to cell body. Essential role in transmission and integration of nerve impulses. Releases neurotransmitters to relay signals to other cells. Sensory neuron: cell body located near middle of axon, long neuron. Interneuron: located in the central nervous system, short neuron. Motor neuron: axon myelinated, long neuron. Neurons transfer information as electrical signals (changes in voltage) Every cell has a voltage across its plasma membranes. Stretch-gated ion channels: open when membranes stretch or deform. Chemically-gated ion channels: respond to a chemical stimulus (in synapses) Voltage-gated ion channels: respond to change in membrane potential (in axons) Speed is proportional to axon diameter- significant in invertebrates.
