This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Ch. 2: Biological Foundations of Psych 29/09/2008 19:18:00 Neurons, The Building Blocks of The Nervous System Neuron a specialized cell that transmits neural impulses or messages to other neurons, glands and muscles Dendrites receive neural impulses from adjacent neurons Axon a slender tube that extends from the soma and transmits these messages to other neurons (or to muscles and glands). Synaptic Terminals the ends of axons that divide into a number of tiny branches. The ends of these branches have tiny swellings called the synaptic terminals Synapse a slight gap between the terminal button and the cell body or dendrites of the receiving neuron. The gap is called the synaptic gap . Neuro-transmitter a chemical that diffuses across the synaptic gap and stimulates the next neuron Sensory Neurons transmit impulses received by receptors to the central nervous system Motor neurons carry outgoing signals from the brain or spinal cord to muscles and glands Interneurons receive the signals from the sensory neurons and send impulses to other interneurons or to motor neurons. Found only in the brain, eyes and spinal cord Nerve a bundle of elongated axons belonging to hundreds or thousands of neurons Nucleus in the brain and spinal cord, a group of cell bodies of neurons Ganglion a group of neuronal cell bodies found outside the brain and spinal cord Glial Cells the nervous system has a large number of nonneural cells. Outnumber neurons 9:1 and take up more than half the volume of the brain. Greek work for glue. Holds neurons together. Action Potentials Action Potential an electro-chemical impulse that travels from the cell body down to the end of the axon Ions electrically charged neurons that cause action potential by moving Semipermeable some ions can pass through the cell membrane easily and others are not allowed to pass through except when special passageways in the membrane open. Ion Channels donut shaped protein molecules that form pores across the cell membrane. These pores allow ions to pass thru. Resting Neuron a neuron that is not generating action potential Ion Pumps found in resting neurons. Help maintain the uneven distribution of ions across the cell membrane by pumping them into or out of the cell. Resting membrane potential the electrical potential of a neuron at rest Depolarization when a neuron is excited and electricity is released...
View Full Document
- Spring '08