Term
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Definition
| sensory receptors detect internal and external stimuli and carry information to brain and spinal cord |
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Term
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Definition
| process of sensory information and determining response |
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Term
Motor-responding to infromation
Divisions |
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Definition
Central Nervous System (CNS)
Peripheral nervous system (PNS) |
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Term
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Definition
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Term
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Definition
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Term
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Definition
|
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Term
| • Autonomic nervous system |
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Definition
| - impulses to smooth muscle, cardiac muscle, and glands (involuntary control); sympathetic and parasympathetic divisions |
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Term
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Definition
| impulses to digestive tract |
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Term
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Definition
| connective tissue cells in nervous system organs |
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Term
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Definition
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Term
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Definition
Large, star-shaped
Found at blood-brain barrier
Help in metabolism of neurotransmitters
Maintain balance of K+ for generation of nerve impulses |
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Term
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Definition
| - long unbranched processes; mainly in the white matter |
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Term
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Definition
| short branching processes; found in gray matter |
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Term
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Definition
contain microfilaments giving strength to support neurons
processes wrapped around blood capillaries help create a blood-brain barrier restricting movement of substances between blood and interstitial fluid of CNS
In embryo, secrete chemicals that regulate growth, migration, and interconnection of neurons in brain
Help maintain proper chemical environment for nerve impulse generation
May play role in learning and memory by influencing formation of neural synapses |
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Term
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Definition
– Fewer processes
– Support neurons
– Produce myelin sheath around nerve fibers in brain and cord |
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Term
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Definition
– Small cells
– Enlarge and move about in inflamed brain tissue
– Phagocytic |
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Term
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Definition
– Single layer of epithelial cells with cilia and microvilli
– Line ventricles of brain and central canal
– Form cerebrospinal fluid (CSF) and assist in circulation |
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Term
| • Schwann cells (Neurolemmocytes) |
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Definition
– Produce myelin sheath around PNS neurons
-Each cell myelinates a single axon |
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Term
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Definition
– Support neurons in ganglia of PNS
Surround cell bodies of neurons of PNS ganglia
Regulate exchange of materials between neuronal cell bodies and IF |
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Term
| • Most axons surrounded by |
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Definition
| multilayered lipid and protein covering called myelin sheath |
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Term
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Definition
| insulates axon and increases speed of impulse conduction |
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Term
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Definition
| myelin sheath during fetal development and 1st year of life |
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Term
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Definition
| multiple layers around axon and contain an outer neurolemma (sheath of Schwann) which encloses myelin sheath (neurolemma aids regeneration of injured nerve axon) |
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Term
| • Myelin sheath has gaps at intervals called |
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Definition
| nodes of Ranvier or neurofibral nodes |
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Term
| • Oligodendrocytes deposit myelin sheath without |
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Definition
| forming neurolemma and have fewer neurofibral nodes |
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Term
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Definition
|
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Term
| • Nissl bodies (Chromatophilic substance ) |
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Definition
| layered fragments of RER; synthesize proteins for maintaining and regenerating neuron processes and renewing neurotransmitters |
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Term
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Definition
| fine fibers extending through dendrites, cell bodies, and axons |
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Term
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Definition
| branching process from cell body (are not myelinated) |
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Term
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Definition
| distal ends of dendrites of sensory neurons |
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Term
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Definition
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Term
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Definition
| - single process but may have collateral branches |
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Term
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Definition
– Originates from cell body at axon hillock
– Impulses arise at junction of axon hillock and initial segment called trigger zone
– Axon terminals (telodendria) - fine filaments branching from axon and ending in synaptic end bulbs; contain synaptic vescicles with neurotransmitter substance |
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Term
| – Synapse is junction of two |
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Definition
| neurons or neuron and effector (muscle or gland) |
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Term
| – Neuromuscular junction is |
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Definition
| synapse between neuron and muscle; neuroglandular junction is between neuron and gland |
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Term
| – Neurotropins (proteins) regulate |
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Definition
| normal growth and development of neurons--include nerve growth factor (NGF), brain-derived neurotropic factor, and neurotropins 3, 4, and 5 |
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Term
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Definition
| bundles of myelinated fibers located outside brain and cord |
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Term
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Definition
|
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Term
|
Definition
| bundles of myelinated fibers located in CNS |
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Term
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Definition
|
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Term
|
Definition
| neuron cell bodies and unmyelinated fibers |
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Term
| – Sensory or afferent functional classification |
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Definition
|
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Term
| – Motor or efferent functional classification |
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Definition
| carry innrmation away fo SCS |
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Term
| – Association (connecting or internuncial) |
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Definition
| conduct from sensory to motor; located entirely within CNS |
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Term
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Definition
|
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Term
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Definition
| found in retina, inner ear, asnd olfactory area of brain |
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Term
| – Unipolar (pseudounipolar) |
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Definition
| one process comes off neuron cell body but divides almost immediately into one axon and one dendrite |
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Term
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Definition
| pores that may be open or closed in plasma membranes |
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Term
| • Threshold of stimulation |
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Definition
| potential that triggers impulse conduction |
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Term
|
Definition
| - difference in electrical charge or voltage |
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Term
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Definition
| one whose outer and inner surfaces bear different electrical charge |
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Term
|
Definition
| one with zero potential difference across its membrane |
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Term
| • Leakage (nongated) channels |
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Definition
| always open - allow materials to move across membrane primarily by diffusion |
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Term
| • Gated channels open and close in response to |
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Definition
|
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Term
| – Mechanically gated ion channel |
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Definition
| respond to mechanical vibration or pressure such as sound waves or pressure of touch |
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Term
| – Voltage-gated (regulated) ion channel |
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Definition
| opens in response to direct change in membrane potential; gives nerve and muscle plasma membranes property of excitability (irritability) |
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Term
| – Ligand-gated ion channel |
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Definition
| responds to specific chemical stimulus such as neurotransmitters, hormones and ions such as H+ or Ca2+; may operate directly (NT and ions) or via second messenger (hormones and some NTs) |
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Term
| • Chemical and mechanical gated allow for |
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Definition
|
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Term
|
Definition
| responses are larger or smaller depending on how many gated ion channels are opened and for how long |
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Term
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Definition
| potential across nonconducting neurons’ plasma membrane (-70 mV) |
|
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Term
| – Sodium pump transports sodium out of ICF into |
|
Definition
| surrounding ECF and membrane is not very permeable to sodium |
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Term
| – Potassium remains within neuron’s ICF due to |
|
Definition
| potassium equilibrium potential and pull of negative ions |
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Term
| – Cell membrane relatively impermeable to |
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Definition
| intracellular negative ions so number of negative ions diffusing out is less than number of positive ions diffusing out; |
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Term
| minute excess of negative ions inside neuron cell membrane and minute excess of positive ions outside it |
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Definition
| produces resting potential |
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Term
|
Definition
| - potential across membrane of an active (conducting) neuron; also known as nerve impulse; involves depolarization and repolarization |
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Term
| – Graded potential causes membrane to reach threshold (-55 mV) |
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Definition
| opening voltage-gated sodium channels |
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Term
| – Rapid inward diffusion of sodium causes membrane’s inner surface to become |
|
Definition
| positive to outer surface (+30 mV) |
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Term
| – Voltage-gated sodium channels have two gates |
|
Definition
| activation gate and inactivation gate |
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Term
| in resting membrane inactivation gates open but |
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Definition
| activation gates closed; at threshold activation gates open followed shortly by closing of inactivation gates |
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Term
| – Reverse potential causes |
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Definition
| current flow to adjacent region where it acts as stimulus, causing process to be repeated to axon terminals |
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Term
|
Definition
| - replacement of action potential by resting potential |
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Term
| – Threshold opens voltage-gated K+ channels |
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Definition
| but at slower rate than Na+ channels |
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Term
| – Plasma membrane becomes |
|
Definition
| relatively impermeable to sodium (due to gate closure) but highly permeable to potassium (because gates are open) |
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Term
| – More positive potassium ions move out through membrane than move in -- |
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Definition
| restores resting potential |
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Term
| – Gates may stay open long enough to result in |
|
Definition
| hyperpolarization (polarization more negative than resting potential) (-90mV) |
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Term
|
Definition
| • Cell cannot generate another action potential |
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Term
| • Absolute refractory period |
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Definition
|
|
Term
| neuron will not respond to any strength stimulus |
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Definition
| neuron will not respond to any strength stimulus |
|
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Term
| – Large diameter axons absolute refractory period of |
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Definition
| 0.4 msec (2500 impulses/sec) |
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Term
|
Definition
| 4 msec absolute refractory period (250 impulses/sec) |
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Term
| • Relative refractory period follows |
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Definition
|
|
Term
| neuron will respond to strong stimulus; |
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Definition
| corresponds to period of increased potassium permeability |
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Term
|
Definition
| – If stimulus generates an action potential, impulse is conducted through entire neuron (propagation) |
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Term
|
Definition
| – Occurs in myelinated fibers; action potential moves from one node of Ranvier to the next instead of point to point |
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Term
| • Speed of impulse conduction |
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Definition
| - related to diameter of axon, myelinization, and temperature(warm would speed up, cold slow down) |
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Term
|
Definition
| largest diameter, myelinated; fastest impulse conduction; touch, pressure, joint position, temp., impulses to skeletal muscles (If converted to mph-it’s be like 200mph-very fast!) |
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Term
|
Definition
| smaller diameter, myelinated; impulses from viscera to CNS and general visceral efferent neurons (Slower than A Fibers) |
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Term
|
Definition
| smallest diameter, unmyelinated, longest absolute refractory period; some impulses for pain, touch, pressure, temperature from skin and pain from viscera and visceral efferent fibers from autonomic ganglia (1-4mph, much slower-the slowest one. It’s good, since it’s for pain) |
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Term
|
Definition
– tiny distensions at presynaptic neuron’s axon terminals
– bulbs contain numerous vescicles with neurotransmitter substance |
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Term
|
Definition
| – space between a synaptic bulb and a postsynaptic neuron’s dendrite or cell body |
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Term
| • Postsynaptic neuron’s plasma membrane |
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Definition
| – protein molecules embedded in membrane function as neurotransmitter receptors and as enzymes (pick up that information from presynaptic neuron) |
|
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Term
|
Definition
| (Are only going to be in a few location) (pg. 473-difference between and chemical and electrical synapse) |
|
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Term
| • Ionic current spreads directly from one cell to |
|
Definition
| another through gap junctions |
|
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Term
| • Each gap junction contains tubular, protein structures called |
|
Definition
| connexons forming tunnels to connect cytosol of two cells (NO SYNAPTIC CLEF! They’re right next to each other so ion can move into other cell very quickly) much faster response, clef causes dely |
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Term
|
Definition
| • Found in visceral smooth muscle, cardiac muscle, and developing embryo |
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Term
| – Advantage of electrical synapse |
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Definition
• Faster communication
• Synchronize activity of group of neurons
• Allow two-way transmission of impulses (With the chemical it’s just with axon, not the dendrite, with electrical because they’re together the cells and stimulate one another due to connections, and chemical is unable to do such.) |
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Term
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Definition
| • Neurons do not touch and neurotransmitter crosses cleft and acts on receptors in postsynaptic neuron (pg 472 table: action potential and greater potential (more up by dendrites)) |
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Term
| – When action potential reaches axon terminals voltage-gated Ca2+ channels |
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Definition
| are opened allowing Ca2+ to enter (Ca into axon terminals) |
|
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Term
| are opened allowing Ca2+ to enter (Ca into axon terminals) |
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Definition
| to be released from synaptic bulb vesicles |
|
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Term
| – Neurotransmitters diffuse across cleft and bind to neurotransmitter receptors in |
|
Definition
| postsynaptic membrane (When you bind to receptor you open whatever channel the receptor is associated with-some excitatory some inhibatory) |
|
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Term
| – Binding of neurotransmitter to receptors |
|
Definition
| opens channels and allows ions to flow across membrane |
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Term
| – Depending on channels opened ionic flow causes |
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Definition
| depolarization or hyperpolarization (less negative-depolarization, causes to move through threshold. Hyperpolarization-move towards more negative.) (pg. 474-summary of this! ) |
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Term
| – If threshold is reached |
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Definition
| action potential is generated |
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Term
| • Excitatory Postsynaptic Potentials (EPSP) |
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Definition
| Depolarizes postsynaptic membrane (If you want to depolarize you would open sodium channels, because it’s what is exchange for action potential. Hyperpolarize opens the potassium channels, because if potassium goes out the inside will be more negative. The other thing to hyperpolarize you can also open the chloride receptor, it’s a negative ion, so chloride would come in. If you depolarize it is easier to generate an impulse. Hyperpolarize is harder to generate an impulse.) |
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Term
| • (Brings membrane closer to threshold) [Excitatory postsynaptic potential-closer threshold=closer to generating an impulse] |
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Definition
|
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Term
| • Opens Na+ channels through which sodium ions diffuse into |
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Definition
| interior of neuron (one neuron opens one neuron. (Towards end of chapter-we’ll hit them in Chp 14) |
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Term
| • Inhibitory Postsynaptic Potentials |
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Definition
| • * Causes hyperpolarization of postsynaptic membrane |
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Term
| • Inhibitory Postsynaptic Potentials |
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Definition
| • (Increases negativity of postsynaptic neuron’s membrane potential above its resting potential); inhibits impulse conduction (more negative, makes it more difficult to generate an impulse, leading it to be inhibitory for the impulse conduction) |
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Term
| • Results from opening of chemically gated Cl- or K+ |
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Definition
| (Chloride to move in, Potassium moves out=inhibitory!!!!) |
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Term
| • Neurotransmitter activity (If it stays in the neuron it may be generating impulses that are |
|
Definition
| not needed-and needs to be terminated) |
|
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Term
| • NT terminated at synapse by |
|
Definition
–Diffuse out of synaptic cleft
–Inactivation by enzymes (ex) Neurotransmitter released-neurotransmitters broken down by enzymes, and sometimes are picked up in order to be reused.)
– Uptake by presynaptic neuron by neurotransmitter transporters (The neuron might have more than one impulses coming towards it, and it has to respond to all the impulses. Summation next point) |
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Term
| • Adding together of effects of excitatory and inhibitory NTs |
|
Definition
| released from various knobs that synapse with a single postsynaptic neuron (spatial summation pg 478-both 477) |
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Term
| • Buildup of neurotransmitter released by |
|
Definition
| by a single presynaptic end-bulb firing 2 or more times in rapid succession (temporal summation pg 477) |
|
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Term
| • Facilitation (subthreshold EPSP) |
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Definition
| – Decrease in negativity of postsynaptic neuron’s potential to level below its resting potential but above its threshold of stimulation ( |
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Term
| Effect of NTs may be either |
|
Definition
| facilitation, impulse conduction, or inhibition of postsynaptic neuron |
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Term
|
Definition
| – Grouping of nerve cell bodies outside CNS |
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Term
|
Definition
| – Bundle of fibers(axons or dendrites) within CNS |
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Term
|
Definition
| – Sensory impulses sent up cord to brain |
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Term
|
Definition
| – Motor tracts carrying impulses down cord |
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Term
|
Definition
| – Mass of unmyelinated nerve cell bodies and dendrites within CNS (analysis to the ganglia-Nucleus in CNS) |
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Term
|
Definition
| – Major areas of gray matter within spinal cord |
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Term
|
Definition
| white fibrous tissue outer layer |
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Term
|
Definition
| cobwebby, delicate middle layer |
|
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Term
|
Definition
| transparent, fibrous membrane; adheres to outer surface of cord and brain; contains blood vessels (nutritive layer) |
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Term
|
Definition
| between dura mater and vertebral canal |
|
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Term
|
Definition
| - between dura mater and arachnoid--contains serous (watery) fluid |
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Term
|
Definition
| between arachnoid and pia mater -- contains cerebrospinal fluid |
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Term
|
Definition
| thickenings of pia mater in spinal cord; project laterally and fuse with dura mater between ventral and dorsal nerve roots of spinal nerves (pg494-495) |
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Term
|
Definition
about 45 cm long
– Two enlargements: cervical and lumbar |
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Term
| – Below lumbar enlargement |
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Definition
| spinal cord tapers to conical portion (conus medullaris) between 1st and 2nd lumbar |
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Term
| – Filum terminale arises from |
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Definition
| conus medullaris (extension of pia mater |
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Term
|
Definition
| - tail-like collection of roots of spinal nerves at inferior end of cord (pg 495) |
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Term
| – Two deep grooves, anterior median fissure and posterior median sulcus, |
|
Definition
| incompletely divide cord into right and left symmetrical halves |
|
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Term
| • Anterior median fissure deeper |
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Definition
| and wider than posterior groove |
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Term
|
Definition
|
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Term
|
Definition
| cross bar of H, contains central canal (joining piece\connecting piece) |
|
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Term
| • Anterior gray horns, posterior gray horns, and lateral gray horns make up |
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Definition
|
|
Term
| – White matter (myelinated fibers) |
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Definition
| • Present in columns--anterior, lateral, and posterior |
|
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Term
| • Each column divided into tracts |
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Definition
| (fasciculi) which are ascending and descending (Different locations for each track) |
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Term
|
Definition
– Sensory tracts conduct to brain from peripheral nerves; motor tracts conduct from brain to peripheral nerves
– Synapses and association neurons in gray matter function as reflex centers for spinal reflexes
– Sensory information carried over spinothalamic and posterior column tracts |
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Term
| • Spinothalamic tracts carry impulses for |
|
Definition
| pain, temperature, crude touch, and deep pressure |
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Term
| • Posterior column tracts (fasciculus gracilis and fasciculus cuneatus) carry impulses for |
|
Definition
| proprioception, discriminating touch, two-point discrimination, pressure and vibrations |
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Term
| – Motor information carried via |
|
Definition
| pyramidal and extrapyramidal tracts |
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Term
| • Pyramidal tracts (corticospinal and corticobulbar) convey |
|
Definition
| impulses for precise voluntary movements of skeletal muscles |
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Term
| • Extrapyramidal tracts (rubrospinal, tectospinal, and vestibulospinal) carry impulses for |
|
Definition
| automatic movements, tone and posture, equilibrium, coordinate body movements with visual stimuli |
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Term
|
Definition
| reflex is fast response to changes (stimuli) in internal or external environment allowing the body to maintain homeostasis |
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Term
|
Definition
| result in contraction of skeletal muscle |
|
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Term
| • Visceral (autonomic) reflexes |
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Definition
| - cause contraction of smooth or cardiac muscle |
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Term
|
Definition
| carried out by spinal cord alone |
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Term
|
Definition
| involve brain and cranial nerves |
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Term
|
Definition
| two or more neurons that conduct impulses from periphery to spinal cord or brain stem and back to periphery |
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Term
|
Definition
| receptors and ends in effectors |
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Term
|
Definition
| distal ends of sensory neurons |
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Term
|
Definition
| muscle or glandular cells |
|
|
Term
| • Two-neuron or monosynaptic reflex arc |
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Definition
|
|
Term
| – One sensory neuron and one motor neuron |
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Definition
|
|
Term
| – Initiated when muscle is stretched stimulating muscle spindles which |
|
Definition
| which send impulse into spinal cord |
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Term
| – Sensory neuron synapses with |
|
Definition
| motor neuron which sends impulse to skeletal muscle causing contraction |
|
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Term
| • Polysynaptic reflex arc |
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Definition
– At least one sensory neuron, synapse, association neuron, synapse, and motor neuron (ex. Withdrawal reflex)
– May involve intersegmental reflex arc due to activation of several association neurons to stimulate more than one effector |
|
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Term
| • Contralateral reflex arcs exist |
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Definition
| such as crossed extensor reflex |
|
|
Term
| • Reflexes of significance |
|
Definition
• Patellar reflex
• Achilles reflex
• Babinski sign
• Abdominal reflex
• Spinal Nerves |
|
|
Term
| • Number of spinal nerves |
|
Definition
|
|
Term
| • Originate by anterior and posterior roots from cord |
|
Definition
| emerge through intervertebral foramina; spinal ganglion on each posterior root |
|
|
Term
| • Spinal nerves are mixed |
|
Definition
| both sensory and motor fibers |
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Term
|
Definition
| connective tissue covering individual fibers |
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Term
|
Definition
| groups (bundles) of fibers |
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|
Term
| groups (bundles) of fibers |
|
Definition
| covering of fascicles (bundles) |
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Term
|
Definition
| outermost covering which fuses with meninges |
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Term
|
Definition
| branches distributed to skin, mucosa, skeletal muscles |
|
|
Term
| • After passing through intervertebral foramen spinal nerve divides |
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Definition
|
|
Term
|
Definition
| - serves deep muscles and skin of dorsal surface of trunk |
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Term
|
Definition
| serves muscles and structures of upper and lower extremities and lateral and ventral trunk |
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Term
|
Definition
| reenters spinal canal and supplies vertebrae, vertebral ligaments, blood vessels of cord and meninges |
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Term
|
Definition
| - involved with autonomic nervous system |
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Term
|
Definition
|
|
Term
|
Definition
| ventral rami of first 4 cervical nerves (contributions from C5) and supply skin and muscles of head, neck, and upper part of shoulders (phrenic) |
|
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Term
|
Definition
| ventral rami of spinal nerves C5-C8 and T1; nerve supply for upper extremities and shoulder region (median, ulnar, radial) |
|
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Term
|
Definition
| ventral rami of spinal nerves L1-L4; supplies anterolateral abdominal wall, external genitalia, and part of lower extremity (femoral, obturator) |
|
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Term
|
Definition
| - ventral rami of spinal nerves L4-L5 and S1-S4; supplies buttocks, perineum, and lower extremities (sciatic) |
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Term
|
Definition
| skin segment supplied by dorsal root of a spinal nerve |
|
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Term
|
Definition
• Conduct impulses both to cord from periphery and from cord to periphery
• Nerves need to know: phrenic, musculocutaneous, median, ulnar, radial, axillary, femoral, obturator, sciatic, tibial, common peroneal |
|
|
Term
| • Glutamic (glutamate) and aspartic acids (aspartate) are most common |
|
Definition
| excitatory transmitters at brain synapses |
|
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Term
|
Definition
| inhibitory transmitter in brain (opens chloride channels) (Valium enhances action of GABA) |
|
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Term
|
Definition
| inhibitory transmitter in cord (opens chloride channels) |
|
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Term
|
Definition
| - inhibitory; involved in emotional responses, addictive behaviors, and pleasurable experiences; and subconscious movements of skeletal muscles (Parkinson’s muscular stiffness due to degeneration of neurons releasing dopamine) |
|
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Term
|
Definition
| found in sensory nerves, spinal cord pathways, and parts of brain associated with pain; enhances perception of pain |
|
|
Term
| • Enkephalins and endorphin are transmitters |
|
Definition
| that serve as pain-killers – suppress release of substance P |
|
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Term
|
Definition
| excitatory neurotransmitter at neuromuscular junctions; may be inhibitory at some synapses (opens potassium channels in heart); Neurotransmitter of parasympathetic system (Helps to slow the heart rate down) |
|
|
Term
|
Definition
| excitatory neurotransmitter outside CNS; Neurotransmitter of sympathetic system; within brain may be related to arousal, dreaming, and regulation of mood |
|
|
Term
|
Definition
| excitatory in brain; may be involved in inducing sleep, sensory perception, temperature regulation, and control of mood, appetite, and induction of sleep |
|
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Term
|
Definition
• Medulla
• Pons
• Midbrain |
|
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Term
|
Definition
| separates two hemispheres of cerebrum |
|
|
Term
|
Definition
| separate two hemispheres of cerebellum |
|
|
Term
|
Definition
| separates cerebrum from cerebellum |
|
|
Term
| • Ventricles and cerebral aqueduct inside brain |
|
Definition
|
|
Term
| • 1st and 2nd (lateral) ventricles |
|
Definition
| large cavities one in each cerebral hemisphere; connected to 3rd ventricle by Foramen of Monro (interventricular foramen) |
|
|
Term
|
Definition
| - vertical slit in cerebrum beneath corpus callosum and longitudinal fissure |
|
|
Term
|
Definition
• diamond-shaped space between cerebellum and medulla and pons
• expansion of central canal of cord
• connected to 3rd ventricle by cerebral aqueduct
• 3 openings (median aperture of Magendie and 2 lateral apertures of Luschka) lead from 4th ventricle to subarachnoid space |
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Term
• Cerebrospinal fluid
• Formation |
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Definition
| • Formed by plasma filtering from network of capillaries (choroid plexus) in each ventricle; pass through ependymal layer which with choroid plexus forms blood-brain barrier; allows for selective passage of materials into interior of brain |
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Term
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Definition
| • Circulates from lateral ventricles → 3rd ventricle → cerebral aqueduct → 4th ventricle (& central canal) → median and lateral apertures → subarachnid space of cord and brain → arachnoid villi → venous sinuses (especially superior sagittal sinus) |
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Term
• Cerebrospinal fluid
• Composition of CSF - |
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Definition
| glucose, proteins, lactic acid, urea, cations and anions, some wbc |
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Term
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Definition
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Term
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Definition
| - provides optimum chemical environment for neuronal signaling |
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Term
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Definition
| - provides nourishment and removes wastes |
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Term
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Definition
| • Enlargement of cord as it enters cranial cavity through foramen magnum |
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Term
| • Consists of white matter (ascending and descending tracts) and |
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Definition
| mixture of gray and white matter (reticular formation) |
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Term
| • Motor tracts of pyramids undergo |
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Definition
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Term
| • Contains nucleus gracilis and nucleus cuneatus and |
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Definition
| vestibular nucleus complex and nuclei of cranial nerves VIII-XII |
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Term
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Definition
• Lies above medulla
• Ascending and descending tracts make up white matter
• Contains reticular formation (functions in consciousness and arousal from sleep)
• Nuclei include pneumotaxic area and apneustic area and nuclei of cranial nerves V- VIII |
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Term
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Definition
• Lies above pons, below diencephalon and cerebrum
• Contains ascending/descending tracts and reticular formation
• Cerebral peduncles connect pons to cerebrum (tracts) |
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Term
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Definition
| 2 superior and 2 inferior colliculi - rounded eminences on dorsal surface of midbrain |
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Term
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Definition
• Red nucleus and substantia nigra are prominent nuclei
• Cerebral aqueduct is fluid space in midbrain
• Medial lemniscus extends through medulla, pons, and midbrain |
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Term
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Definition
| Two-way conduction between cord and brain |
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Term
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Definition
• Cardiac, vasomotor, and respiratory centers in medulla vital in control of heartbeat, blood pressure, and respiration
• Centers for reflexes of swallowing, vomiting, coughing, sneezing, and hiccuping
• Important for maintaining equilibrium
• Centers for cranial nerves VIII-XII |
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Term
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Definition
• Centers for cranial nerves V-VIII
• Contain pneumotaxic and apneustic centers for respiration
• Has transverse fibers connecting opposite sides of cerebellum and longitudinal fibers connecting medulla with other parts of brain |
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Term
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Definition
• Centers for cranial nerves III and IV (pupillary reflexes and eye movements)
• Centers for movements of head and trunk in response to auditory stimuli (corpora quadrigemina)
• Helps coordinate muscular movements |
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Term
| • Netlike arrangement of small areas of gray matter among white matter of brainstem |
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Definition
| and extending into spinal cord and diencephalon |
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Term
| • Reticular activating system |
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Definition
| (part of reticular formation with fibers projecting to cerebral cortex) responsible for maintaining consciousness and awakening from sleep |
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Term
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Definition
• Center section (vermis) lies between two hemispheres
• Surface is grooved with sulci and has slightly raised, slender convolutions
• Internal white matter in leaflike pattern (arbor vitae)
• Attached to brain stem by 3 tracts (cerebellar peduncles) - inferior, middle, and superior |
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Term
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Definition
• Synergic control of skeletal muscles
• Mediates postural and equilibrium reflexes |
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Term
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Definition
• Large rounded mass of gray matter, one in each hemisphere of cerebrum, lateral to 3rd ventricle
• Includes medial geniculate, lateral geniculate, and ventral posterior nuclei |
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Term
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Definition
• Includes gray matter around optic chiasma, pituitary stalk, posterior lobe of pituitary gland, mammillary bodies and adjacent regions
• Prominent nuclei are supraoptic and paraventricular
• Tracts connect diencephalon with cerebral cortex, basal ganglia, brain stem and cord |
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Term
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Definition
• Relays sensory impulses from cord to cerebral cortex
• Registers crude sensations of pain, temperature, and touch
• Emotions of pleasantness or unpleasantness associated with sensations
• Part of pathway for arousal or alerting and for complex reflex movements |
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Term
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Definition
| major regulator of homeostasis |
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Term
| • Higher center for both sympathetic and parasympathetic divisions of autonomic system, |
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Definition
| regulating and coordinating them and thus integrating responses by visceral effectors |
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Term
| • Link between psyche and soma (mind-over-body) by |
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Definition
| relaying impulses from cerebral cortex to autonomic centers |
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Term
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Definition
• Supraoptic and paraventricular nuclei synthesize posterior pituitary hormones
• Synthesize and secrete releasing hormones that regulate secretion by anterior pituitary gland
• Part of pathways for arousal and alerting (rage and aggression) and for regulating appetite, temperature, and thirst
• One of centers that maintains waking state and sleep patterns |
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Term
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Definition
| • Longitudinal fissure divides cerebrum into 2 hemispheres, connected only by corpus callosum; each cerebral hemisphere divided by fissures into 5 lobes--frontal, parietal, temporal, occipital, and insula (island of Reil) |
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Term
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Definition
| - outer gray matter arranged in ridges called convolutions or gyri |
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Term
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Definition
| bundles of axons compose white matter in interior of cerebrum |
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Term
| • Commissural tracts transmit from one hemisphere to other |
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Definition
| (includes corpus callosum, anterior and posterior commissure) |
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Term
| • Association tracts transmit from one convolution (gyri) |
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Definition
| to another in same hemisphere |
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Term
| • Basal ganglia (cerebral nuclei) |
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Definition
• Masses of gray matter embedded deep inside white matter in interior of cerebrum
• Largest is corpus striatum which consists of caudate nucleus and lentiform nucleus
• Lentiform nucleus is subdivided into putamen and globus pallidus |
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Term
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Definition
• On inner border of cerebrum and floor of diencephalon
• Made up of limbic lobe (with hippocampus, parahippocampal and cingulate gyri), dentate gyrus, septal neuclei, amygdaloid body, mammillary bodies, anterior nucleus of thalamus, olfactory bulbs, and axons |
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Term
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Definition
| sensory areas of cortex compare, evaluate, and integrate sensations to form total perceptions |
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Term
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Definition
| - control voluntary (skeletal muscle) movements |
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Term
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Definition
| • Consciousness, Memory, and Emotions |
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Term
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Definition
| state of awareness of one’s self, one’s environment and other beings; depends on excitation of cortical neurons by impulses from reticular activating system; normal variations in degree of level of consciousness (waking, REM sleep, deep sleep); also several kinds of altered states of consciousness (ASC) (anesthesia, coma, and yoga) |
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Term
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Definition
| several parts of cortex (temporal, parietal, occipital lobes) store memories and limbic system (“emotional brain”) and protein synthesis play key roles in memory; protein synthesis crucial for long-term memory |
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Term
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Definition
| both subjective experience and objective expression of emotions involve limbic system |
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Term
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Definition
| depends on widespread integrated cortical processes; regions called speech centers in several lobes serve as focal points for integration of speech processes; speech defects (aphasias) of different kinds result from lesions of different speech centers |
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Term
| • Generalizations about cerebral functions |
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Definition
| • Cerebral activity goes on as long as life itself; EEGs are records of cerebrum’s electrical activity (brain waves) |
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Term
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Definition
| moderately fast, moderately high-voltage waves - dominate in relaxed nonattentive state |
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Term
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Definition
| - fast, low-voltage waves - dominate in attentive waking state |
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Term
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Definition
| - very slow, high-voltage waves characteristic of deep sleep; normal in awake infant, indicate brain damage in awake adult |
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Term
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Definition
| moderately slow, low-voltage waves that appear as drowsiness descends; occur in children and in adults experiencing emotional stress |
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Term
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Definition
| specializes in language functions and in control of skilled movements and gesturing movements of right hand |
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Term
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Definition
| specializes in perception of nonspeech sounds and in locating objects in space; may also function better in tactual perception and in visualizing spatial relationships |
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Term
| • Functional areas of cerebral cortex |
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Definition
• Sensory areas
• Primary somatic sensory area - crucial for experiencing general sensations (heat, cold, touch, proprioception, and pain)
• Primary visual area - crucial for vision
• Primary auditory area - crucial for auditory sensations
• Primary gustatory area - important for taste
• Primary olfactory area - crucial for smell |
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Term
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Definition
• Primary somatic motor area - dominates control of somatic effectors (skeletal muscles)
• Language areas (motor speech area or Broca’s area) - control muscles of larynx, pharynx, and mouth; involves coordination with other areas |
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Term
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Definition
| connect motor and sensory areas and large parts of cortex |
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Term
| • Somatosensory association area |
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Definition
| integrate and interpret sensations; store memories of past sensory experiences |
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Term
| • Visual association area |
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Definition
| relates present to past visual experiences with recognition and evaluation of what is seen |
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Term
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Definition
| voluntary scanning movements of eyes |
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Term
| • Auditory association area |
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Definition
| determines if sound is speech, music, or noise |
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Term
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Definition
| interprets meaning of speech by recognizing spoken words |
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Term
| • Gnostic area (common integrative area) - |
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Definition
| integrates sensory inputs from other association areas so common thought can be formed |
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Term
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Definition
| causes specific group of muscles to contract in specific sequence; memory bank for learned skilled movements |
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Term
| • Early development (of Nectoderm) |
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Definition
by 4th week
• Prosencephalon - forebrain
• Mesencephalon - midbrain
• Rhombencephalon - hindbrain |
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Term
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Definition
• Later - after 5th week
• Telencephalon - cerebrum
• Diencephalon - thalamus an hypothalamus
• Mesencephalon
• Metencephalon - cerebellum
• Myelencephalon - medulla oblongata |
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