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49 Cards in this Set
- Front
- Back
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Neurology |
Study of function and disorders of the nervous tissue |
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Neurologist |
Doctor who practices neurology |
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2 divisions of nervous system
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Central Nervous System and Peripheral Nervous System |
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Nervous system characteristics |
Regulates body activities by responding rapidly using nervous impulses Effects are short lived, unless repeated Includes our perceptions, behaviors, memories and initiates all voluntary movements |
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Nerve |
A bundle of hundreds to thousands of axons |
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Brain |
Contains 100 billion neurons |
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Cranial nerves |
Emerge from base of brain. 12 pairs, numbered 1-12. |
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Spinal Cord |
Extends from brain. 100 million neurons. |
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Spinal Nerves |
31 pairs of spinal nerves that emerge from the spinal cord |
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Ganglia |
Contain cell bodies of neurons located outside brain and spinal cord. Closely associated with cranial and spinal nerves. |
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Enteric plexuses |
Extensive networks of neurons located in walls of intestinal tract. Interweaving structures. |
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Sensory receptors |
Dendrites of sensory neurons or separate specialized cells that monitor changes in internal or external environment |
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Sensory function of the nervous system |
Sensory receptors detect many different types of stimuli inside and outside body. Carry sensory info to brain through spinal nerves. Attach at neurons.
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Integrative function of the nervous system |
When nervous system processes sensory info by analyzing and storing some of it and by making decisions for appropriate responses. Many neurons that participate in integration are interneurons. |
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Motor function of the nervous system |
Elicited motor response to stimulus. Involves motor neurons. |
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Central Nervous System (CNS) |
Brain and Spinal Cord |
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Peripheral Nervous System (PNS) |
Cranial nerves and branches; ganglia; spinal nerves; sensory receptors |
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Sensory neurons |
Head, body wall, viscera, limbs, as well as hearing, vision, taste, and smell, conduct info to CNS. |
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Motor neurons |
Transfer info from CNS to muscles |
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Autonomic nervous system |
Sensory organs, sweat, sexual arousal, fight or flight |
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Sympathetic nervous system |
Fight or flight |
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Parasympathetic nervous system |
Rest and digest |
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Enteric nervous system |
Gut brain. Involuntary control of GI tract. Nerves extend most of length of GI tract. |
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Neuron |
Functional unit of nervous system |
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Neuroglial cells |
Function to surround neurons and hold in place. Supply nutrients and oxygen to insulate between neurons, destroy pathogens, and remove dead neurons. |
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Cell body of neuron |
Single nucleus surrounded by cytoplasm and typical organelles including Nissl bodies. |
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Axon |
Axolemma, axoplasm, axon hillock, initial segment, trigger zone, axon collaterals, axon terminals. Transmission part of neuron. Long thing cylindrical projection. Conducts nerve impulses toward another neuron, muscle gland, or cell. |
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Dendrites |
Little tree. Cell processes. Receptors. Input part of neuron. |
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Synapse |
Site where two neurons meet. |
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Synaptic end bulbs |
Large region at end of axon terminal contain synaptic vesicles and synaptic vesicles store nerve transmitters. |
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Multi polar neurons |
Several dendrites; one axon |
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Bipolar neurons |
Only in retina, olfactory part of brain, inner ear |
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Unipolar neurons |
one process that divides into dendrite and axon |
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Myelination |
Axon is covered by a myelin sheath; increases the speed of nerve inpulses. Produced by oligodendrocytes in the CNS and Schwann cells in the PNS |
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Grey matter |
Unmyelinated |
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White matter |
Myelinated |
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Ion Channels |
When ion channels are open, ions move down concentration gradient towards membrane. Cause change in membrane potential. Movement takes place at various gates. |
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Leakage channels |
Always open, Plasma membranes have more K+ gates than Na+ gates. Voltage gated channels open and respond to change in membrane potential. |
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Gated channels |
Ligand gated. Open and close in response to chemical stimulus from neurotransmitters and hormones. |
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Mechanically gated channels |
Open from mechanical stimulus. Vibration, pressure, tissue stretching. |
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Resting membrane potential |
70 milivolts in resting neuron. Electric charge of resting membrane. |
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Action potential |
A sequence of rapidly occurring events that decrease and reverse the membrane potential till it gets back to resting state. |
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Synaptic transmission |
Neurons communicating with other neurons or with effectors by a series of events. Happens at synapses. |
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Steps of synaptic transmission |
1. Nerve impulse arrives at synaptic end bulb of a presynaptic neuron through the axon 2. Impulse opens Ca2+ channels in the synaptic end bulbs 3. Increase in Ca2+ triggers exocytosis of synaptic vesicles, releasing neurotransmitters into the synaptic cleft 4. Neurotransmitters bind to neurotransmitter receptors in the post synaptic neuron's plasma membrane 5. Ion channels open as a result of step 4 6. Voltage of neuron changes; impulse continues or the effect happens |
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Absolute refractory period |
Time in which the neuron can't generate new action potential |
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Relative refractory period |
When suprathreshold stimulus generates action potential |
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Neurapraxia |
Loss of conductivity, but axon stays intact and recovery is complete |
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Axonotmesis |
Degeneration of axon distal to the lesion; connective tissue is intact |
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Neurotmesis |
Same as axonotmesis, but connective tissue is damaged |
