Term
| Central Nervous System (CNS) |
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Definition
| Consists of the brain and spinal cord, which are enclosed and protected by the cranium and vertebral column |
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Term
| Peripheral Nervous System (PNS) |
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Definition
| comprises all the nervous system other than the brain and spinal column; composed of nerves and ganglia- divided into sensory and motor division |
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Definition
| a bundle of nerve fibers wrapped in fibrous connective tissue |
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Definition
| a knotlike swelling in a nerve where the cell bodies of neurons are concentrated |
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Term
| sensory (afferent) division |
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Definition
| part of PNS; carries sensory signals by way of afferent nerve fibers from sensory receptors to the CNS |
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Term
| visceral sensory division |
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Definition
| carries signals mainly from the viscera of the thoracic and abdominal cavities such as the heart, lungs, stomach, and urinary bladder |
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Definition
| carries signals from receptors in the skin, muscles, bones, and joints |
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Term
| motor (efferent) division |
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Definition
| carries motor signals by way of efferent nerve fibers from the CNS to effectors (cells and organs that carry out the body's responses; mainly gland and muscle cells) |
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Term
| visceral motor devision (autonomic nervous system) |
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Definition
| carries signals to glands, cardiac muscle, and smooth muscle; usually involuntary and the system operates on an unconscious level; the responses of this system and its effectors are visceral relfexes |
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Term
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Definition
| "fight or flight" accelerating the heartbeat and incresing respiratory airflow and inhibiting digestion |
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Term
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Definition
| adapt the body to a state of rest, reducing the heart rate and respiratory airflow, but stimulating digestion |
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Definition
| carries signals to the skeletal muscles; this output produces muscular contractions that are under voluntary control as well as involvuntary muscles contractions called somatic reflexes |
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Term
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Definition
| the functional unit of the nervous system; neurons carry out the system's communicative role |
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Term
| 3 physiological properties of neurons |
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Definition
| excitability (irritability), conductivity, secretion |
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Term
| sensory (afferent) neurons |
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Definition
| specialized to detect stimuli such as light, heat, pressure, and chemicals, and to transmit information about them to the CNS; neurons can begin anywhere, but end in the brain or spinal cord |
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Term
| interneurons (association neurons) |
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Definition
| lie entirely within the CNS; they receive signals from many other neurons and carry out the integrative function of the nervous system; process store and retrieve information and "make decisions" about how the body responds to stimuli |
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Term
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Definition
| send signals predominantly to muscle and gland cells, the effectors that carry otu the body's responses to stimuli; called motor because most of them lead to muscle cells |
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Term
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Definition
| soma=body the control center of the neuron; has a single centrally located nucleus with a large nucleolus |
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Term
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Definition
| the cytoskeleton of a neuron made of dense microtubules |
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Definition
| thick processes that radiate from soma; primary site for receiving signals from other neurons |
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Term
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Definition
| part of the soma to which the axon attaches |
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Definition
| specialized nerve fiber for rapid conduction of the nerve signals to points remote from the soma |
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Definition
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Definition
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Definition
| an extensive network of fine braches at the distal end of the axon |
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Term
| synaptic knob (terminal button) |
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Definition
| a swelling that forms a junction (synapse) with a muscle cell, gland cell, or another neuron |
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Definition
| have one axon and tow or more usually many dendrites; most common type of neuron |
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Term
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Definition
| protect the neurons and aid in their function; bind neurons together; |
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Definition
| CNS resemble an octopus; form myelin in brain and spinal cord |
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Definition
| CNS cover brain surface and nonsynaptic regions of neurons; stimulate formation of blood-brain barrier; remove neurotransmitters and K+ from extracellular fluid (ECF) of brain and spinal cord; help to regulate composition of ECF; form supportive framework in CNS; form scar tissue to replace damaged nervous tissue |
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Definition
| CNS line cavities of brain and spinal cord; secrete and circulate cerebrospinal fluid |
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Definition
| CNS phagocytize and destroy microorganisms, foreign matter, and dead nervous tissue |
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Definition
| PNS form neurilemma around all PNS nerve fibers and myelin around most of them; aid in regeneration of damaged never fibers |
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Definition
| PNS surround somas of neurons in the ganglia; function uncertain |
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Term
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Definition
| an insulating layer around a nerve fiber, formed by oligodendrocytes in the CNS and Schwann cells in the PNS; consists of plasma membranes of glial cells |
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Definition
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Definition
| gaps btw the myelin sheath segments |
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Term
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Definition
| the myelin-covered segments of neurons |
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Term
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Definition
| a rapid voltage change in which a plasma membrane briefly reverses electrical polarity; has a self-propagating effect that produces a traveling wave of excitation in nerve and muscle cells |
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Definition
| a wave of action potentials traveling down the axon |
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Definition
| meeting btw a neuron and any other cell |
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Term
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Definition
| a junction at which the presynaptic neuron releases a neurotransmitter to stimulate the postsynaptic cell |
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Term
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Definition
| synaptic knob ->synaptic cleft ->synaptic vesicles |
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Term
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Definition
| adjacent cells are joined by gap junctions that allow ions to diffuse directly from one cell into the next ex: cardiac muscle cells |
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