The nervous system7-test1.txt

_________ form myelin sheath around peripheral axons in the PNS

___________ support sensory and autonomic ganglia ( ganglia=PNS)

________ form myelin sheath around CNS axons

________ help regulate the external environment of neurons (CNS)

________ line the ventricles in the brain and the spinal cord (CNS)

________ travel the CNS and "eat" foreign and degenerated materials

some axons in the CNS and PNS are surrounded by ________, which is a fatty layer of insulation

Successive wrapping of Schwann cells around axons in the ____ produces myelin sheath.

exposed gaps of myelin sheath used to produce nerve impulses are named nodes of __________

Oligodendrocytes use octopus-like extentions to create _________ around multiple axons in the _____. (AKA white matter)

The ________ is defined by its tight junction selective molecule diffusion, requiring specific transport methods through the capillaries into the brain.

The _____________ is significant in preventing drug treatment of degenerative disorders (i.e. Parkinson's). Certain chemicals do not diffuse into the brain properly.

pseudounipolar neurons have one process that splits ('T' shaped). They are _________ neurons

sensory neurons are ________polar neurons

Bipolar neurons have (2) processes, such as in the retina and cochlea (bow-tie shaped). They are ________ neurons

neurons with (2) processes are ________polar neurons

Multipolar neurons have many dendrites but one axon. They are 1: _______ 2: __________ neurons

Schwann cells "eat" cut(damaged) axons, form a tube, and then a new axon tip grows to fill it out. This is ________, and it occurs in the ___.

myelination = ________ color; non-myelinated axons = ________ color

L-Dopa is permeable to the ____________ but dopamine is not (Parkinson's).

Step (1) of action potential: ___+ gates open and the __+ diffuses into the cell (starting depolarization)

Step (2) of action potential: ___+ gates open and the __+ diffuses out of the cell (while continuing to depolarize)

resting potential is __ mV

Threshold (potential) is at __ mV

action potential is at __ mV

Hyperpolarization is at __ mV

Na+ gates are deactived at _______ potential

depolarization is caused by _____________ into the axon

repolarization is caused by _____________ out of the axon

conduction in _________ axons: every surface of axon membrane can produce an action potential

saltatory ("leaping") conduction happens in _________ axons

myelination increases OR decreases action potential conduction?

a stimulus causes positive charges to flow into a cell; this is called __________

a return to resting membrane potential is called _________

Axon resting potential: Permiability ratio of Na+ (out) to K+ (in) is __:__

Na and K gating allows for action potentials because each gate opens at a different _________

once an axon is depolarized to threshold, it will fire. this is the _________________ law

increased stimulus strength = __________ action potential frequency

the manditory minimum interval between action potentials is called a _______________ (regulates frequency)

gap junctions are found in ____________ synapses

__________ synapses are when pre and postsynaptic neurons are separated by a synaptic cleft

cardiac muscle is an example of ___________ synapses (gap junctions)

Na+ or Ca+ entering a (post-synaptic) neuron causing graded depolarization for it to become less negative is ___________

Cl- entering a (post-synaptic) neuron causes graded polarization, making it more negative is ___________

______ junctions are joined in areas of contact with low electrical resistance. this allows for uniform action potentials in the ____ muscles

______________ are little bubbles of neurotransmitters in the axon terminal that dock with SNARE and released by exocytosis (into the cleft)

action potentials stimulate the entry of __+ into the axon terminal of the pre-synaptic neuron, prompting vesicles to undergo exocytosis into the cleft

NT release: 1-action potential, 2- ___+ channels open, 3- __+ binds (to protein) 4- __+ protein complex stimulates fusion and exocytosis

_________ gated/regulated ion channels require input from something like Ca+ (found in post-synaptic membrane)

_________ gated/regulated ion channels require input from something like a +30 mV charge (found in axon)

While NT binding receptors are specific, certain "toxins" may also activate these receptors. ACh's stimulatory effects (muscle contractions) may be activated by __________

ACh binds to muscarinic receptors in the heart cells, causing ___-protein to open K+ outward diffusion, which means ____ heart rate (K+ out = polarization/inhibition)

The enzyme ___________ deactivates free ACh at the post-synaptic cell membrane after it "does its job" to prevent further activations (No deactivation = spastic paralysis in muscle; principle of nerve gas)

Alzheimer's disease is associated with the loss of ___________ neurons, which use ACh as a NT (Tx = AChE inhibitors)

_________ are regulatory molecules derived from amino acids. They are also NT's ( i.e. dopamine, norepinephrine, epinephrine).

monoamine NT's at the synapse are stopped by (1):_________ from the cleft into the presynaptic Neuron, then (2): __________ of the monoamine by an enzyme MAO (monoamine oxidase)

two pathways of dopamine NT use in the brain are 1: ______ control, & 2: __________

MAO inhibitors prevent reuptake of monoamines, which plays a role in treatment for __________

cocaine ___________ reuptake of dopamine

SSRI's prevent reuptake of __________

_________ are inhibitory motor NT's: they hyperpolarize the post-synaptic neuron rather than depolarizing (Opens Cl- channels rather than Ca+)

Huntington's disease is defined as a loss of motor control. This is because of a deficiency in inhibitory motor NT _____.

Example categories of _________: Amines, amino acids, lipids, gases (Nitric oxide etc) Purines(ATP)

___________ is the major excitatory NT in the brain (80% of all)

NMDA receptors are involved in ____________ storage

Benzodiazepines are _________ agonists, regulating anxiety.

"runner's high" may be influenced by exogenous ________

_________ acts as a blood vessel dialator. involved in Viagra

____________ summation is the result of many pre-synaptic neurons converging on the dendrites of a neuron

__________ summation is successive NT release, resulting in the summation of EPSPs in the post-synaptic neuron.

Synaptic potential OR action potential: which does NOT have a refractory period?

the improved ability of a presynaptic neuron that has been stimulated at a high frequency to then stimulate the post-synaptic neuron over a long period of time is __________ (method of neural learning?)

a process where endocannabinoids suppress the release of NT from pre-synaptic neurons. this happens over a long period and inhibits functioning for some time _________

_______________ inhibition: the amount of NT released at the end of the pre-synaptic neuron is decreased by a second neuron's signal

_______________ inhibition: induces hyperpolarization in a post-synaptic neuron