Chapter 2 Outline
The Biological Perspective
A specialized cell transmitting nerve impulses; a nerve cell
Dendrites are treelike extensions at the beginning of a neuron that help increase the surface area of the cell body and are covered with synapses
The soma is the cell body of a neuron.
The Axon of a neuron is a singular fiber that carries information away from the soma to the synaptic sites of other neurons (dendrites and somas), muscles,
Glial cells are non-neural cells that perform "housekeeper" functions such as clearing out debris and excess materials. Glial cells support neurons by providing support and nutrition. There are several different types of glial cells: astrocytes, oligodendrocytes, microglia, ependymal cells, radial glial, satellite cells and schwann cells. It is estimated that there are 10 to 50 times more glial cells than there are neurons in the brain.
A material that forms a layer, the myelin sheath, usually around only the axon of a neuron
Axon terminal (synaptic knobs)
distal terminations of the branches of an axon. An axon nerve fiber is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses (called "action potentials") away from the neuron's cell body, or soma, in order to transmit those impulses to other neurons.
The all-or-none law is a principle that states that the strength of a response of a nerve cell or muscle fiber is not dependent upon the strength of the stimulus. If a stimulus is above a certain threshold, a nerve or muscle fiber will fire. Essentially, there will either be a full response or there will be no response at all.
How do neurons use neurotransmitters to communicate with each other? The neurotransmitter molecules fit into receptor sites on the next cell, stimulating or inhibiting that cell’s firing.
What do Agonists and Antagonists do?An agonist is a chemical substance that mimic or enhances the effects of a neurotransmitter on the receptor sites of the next cell, increasing or decreasing the activity of that cell. Antagonists are chemical substances that block or reduce cell's reponse to the action of other chemicals or neurotransmitters.
Acetylcholine Excitatory or inhibitory: involved in memory and controls muscle contractions
Serotonin Excitatory or inhibitory: involved in mood, sleep,and appetite.
GABA Major inhibitory neurotransmitter: involved in sleep and inhibits movement.
Glutamate Major excitatory neurotransmitter; involved in learning, memory formation, and nervous system development.
Norepinephrine Mainly excitatory; involved in arousal and mood.
Dopamine Excitatory and inhibitory; involved in control of movement and the sensations of pleasure.
Endorphins Inhibitory neural regulators; involved in pain relief.
Central Nervous System
The central nervous system (CNS) is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except radially symmetric animals such as sponges and jellyfish. It contains the majority of the nervous system and consists of the brain and the spinal cord.
The brain is the center of the nervous system in all vertebrate and most invertebrate animals
The spinal cord is a long, thin, tubular bundle of nervous tissue and support cells that extends from the brain (the medulla oblongata specifically).
Peripheral Nervous System
The peripheral nervous system (PNS, or occasionally PeNS) consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the central nervous system (CNS) to the limbs and organs.
Somatic Nervous System Division of the PNS consisting of nerves that carry information from the...
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