Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
39 Cards in this Set
- Front
- Back
|
Central Nervous System (CNS) |
Is integrating and control center of nervous system, interprets sensory input and dictates motor output based on reflexes, current conditions, and past experience |
|
|
Peripheral Nervous System (PNS) |
Serve as communication lines that link all the parts of the body to the CNS |
|
|
CNS location |
Brain and spinal cord, dorsal body cavity |
|
|
PNS location |
Nervous system outside the CNS, consists mainly of nerves that extend from brain, spinal cord, and ganglia |
|
|
Afferent division (PNS) |
Sensory division, convey impulses TO the CNS from sensory receptors located throughout the body Keeps CNS constantly informed of events going on both inside and outside the body |
|
|
Efferent division (PNS) |
Motor division, transmits impulses FROM CNS to effector organs Impulses activate muscles to contract and glands to secrete |
|
|
Efferent division- subdivisions |
Somatic- skeletal muscles; voluntary nervous system Autonomic- visceral organs; involuntary nervous system |
|
|
Astrocytes (CNS) |
Support and brace the neurons and anchor them to nutrient supply lines, help determine capillary permeability, control chemical enviro. around neurons |
|
|
Microglial (CNS) |
Monitor health of neurons, protect neurons from invading microorganisms |
|
|
Ependymal (CNS) |
Form a permeable barrier, help to circulate cerebrospinal fluid that cushions the brain and spinal cord |
|
|
Oligodendrocytes (CNS) |
Wrap their processes tightly around the fibers and produce an insulating covering (myelin sheath) |
|
|
Satellite cells (PNS) |
Have same function as astrocytes do in CNS |
|
|
Schwann cells (PNS) |
Vital to regeneration of damaged peripheral nerve fibers, also act in same way oligodendrocytes do in CNS |
|
|
Dendrites |
Main receptive or input regions Provide enormous surface areas for receiving signals from other neurons Convey incoming messages toward the cell body |
|
|
Multi-polar neurons (structural classes of neurons) |
Have three or more processes, one axon, and the rest dendrites Most common Major neuron type of CNS |
|
|
Bipolar neurons (structural classes of neurons) |
Have two processes, an axon, and a dendrite Found in retina of eye and olfactory mucosa |
|
|
Uni-polar neuron (structural classes of neurons) |
A short single process that emerges from cell body Found in ganglia in PNS |
|
|
Sensory/Afferent neurons (functional classes of neurons) |
Transmit impulses from sensory receptors in skin or internal organs toward or into the CNS Unipolar neurons Found in special sense organs |
|
|
Motor/Efferent neurons (functional classes of neurons) |
Carry impulses away from the CNS to the effector organs Multipolar neurons Found in muscles and glands |
|
|
Interneurons/Association neurons (functional classes of neurons) |
Shuttle signals through CNS pathways where integration occurs Multipolar neurons Found between motor and sensory neurons in neural pathways |
|
|
Nerves |
Bundles of neuron processes found in PNS |
|
|
Tracts |
Bundles of neuron processes found in CNS |
|
|
Axodendritic synapse |
Between axon ending and dendrites |
|
|
Axosomatic synapse |
Between axon ending and soma |
|
|
Axoaxonal synapse |
Between axons |
|
|
Dendrodendritic synapse |
Between dendrites |
|
|
Somatodendritic synapse |
Between soma and dendrites |
|
|
Neurotransmitter |
Released from chemical synapse, receptor region |
|
|
Speed of action potential |
Myelinated- saltatory conduction, fast Unmyelinated- continuous conduction, slower |
|
|
Acetylcholine |
Excitatory, direct action (CNS), indirect action (PNS) ACh levels decrease in certain brain areas in Alzheimer's disease Ach receptors destroyed in myasthenia gravis |
|
|
Norepinephrine |
Excitatory or inhibitory, indirect action Feel good neurotransmitter Enhanced by amphetamines (antidepressants, cocaine) |
|
|
Dopamine |
Excitatory or inhibitory, indirect action Feel good neurotransmitter Deficient in Parkinson's disease Increases in schizophrenia |
|
|
Histamine |
Excitatory or inhibitory, indirect action Involved in wakefulness, appetite control, and learning and memory |
|
|
Serotonin |
Mainly inhibitory, indirect action Plays role in sleep, appetite, nausea, migraine headaches, and regulating mood Drugs that block its uptake relieve depression and anxiety Activity blocked by LSD and enhanced by ecstasy |
|
|
Resting membrane potential |
When the resting potential across the membrane is electrically neutral Value varies from -40mV to -90mV |
|
|
Absolute refractory period |
Period from the opening of Na+ channels until Na+ channels begin to reset to their original resting state |
|
|
Relative refractory period |
Follows the absolute refractory period Most Na+ channels have returned to resting state, some K+ channels are still open, and repolarization is occuring |
|
|
Depolarization |
Decrease in membrane potential Inside of membrane becomes less negative Na+ channels open |
|
|
Repolarization |
Restores the internal negativity of resting neuron Abrupt decline in Na+ permeability and increased permeability of K+ contribute to repolarization |
