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Flashcards in List #7 Deck (46)
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1

myelin

-lipid material that forms a sheath like covering around some axons

2

axonal transport

- movement occurs in both directions between the cell body and the ends of the axon.
-enzymes required for neurotransmitter synthesis are produced in the cell body and transported to the axon terminals.

3

membrane potential

- The potential difference across the cell membrane(measured in millivolts)

4

resting membrane potential

- one that is not sending impulses or responding to other neurons(-70 millivolts)

5

action potential

- a rapid change in the membrane potential, first in a positive direction, then in a negative direction, returning to the resting potential
- all or nothing
-regenerative

6

depolarization

- if the membrane becomes more positive than the resting potential
-can be caused by Sodium entering
- means the threshold is lowered for an action potential

7

hyperpolarization

- if the membrane potential becomes more negative than the resting potential
-the threshold is raised

8

refractory period

- During the absolute refractory period which lasts about 1/1,000 of a second, the axon's voltage-gated sodium channels are temporarily not responsive at all, and the axon cannot be stimulated.
-Then the relative refractory period follows, as the membrane reestablishes its resting potential.

9

saltatory conduction

-Action potentials appear to jump form node to node
- conduction on myelinated axons is many times faster than conduction on unmyelinated axons

10

synaptic potentials

- enable one neuron the affect another
-EPSP/IPSP
-graded
-non-regenerative

11

EPSP

- A neuro transmitter binds to a post-synaptic receptor and opens sodium ion channels, the ions diffuse inward, depolarizing the membrane possibly triggering an action potential.
- lasts for about 15 milliseconds
-Depolarizing
-Glumate

12

IPSP

-A different neurotransmitter binds other receptors and increases membrane permeability to potassium ions, these ions diffuse outward hyperpolarizing the membrane
-Hyperpolarizing
-GABA

13

monoamines

- modified amino acids

14

neuropeptides

- These peptides act as neurotransmitters or a neuromodulators, which are substances that alter a neurons response to a neurotransmitter or block the release of a neurotransmitter.
-enkephalins and endorphins

15

enkephalins

-Generally inhibitory; reduce pain by inhibiting substance P release (CNS)

16

glutamic acid (glutamate)

-Generally excitatory (CNS)

17

monoamine oxidase

- Inactivates the monoamine neurotransmitters epinephrine and norepinephrine after reuptake
- It is found in the mitochondria in the synaptic knob

18

serotonin

-Primarily inhibitory; leads to sleepiness; action is blocked by LSD, enhanced by selective serotonin reuptake inhibitor antidepressant drugs (CNS)

19

tryptophan

- Neurotransmitter affected: Serotonin
-Mechanism of Action: Stimulates neurotransmitter synthesis
-Effect: sleepiness

20

dopamine

- Creates a sense of well-being; deficiency in some brain areas associated with Parkinson disease (CNS)

21

GABA

- Generally inhibitory (CNS)

22

endorphins

-Any group of neuropeptides synthesized in the pituitary gland and hypothalamus that suppress pain

23

meninges

-located between the bone and the soft tissues of the nervous system
-They have three layers the dura mater, arachnoid mater, and the pia mater

24

spinal nerves

-Nerves that arise from the spinal cord

25

reflex arc

- Components of a reflex, consisting of a sensory receptor, sensory neuron, interneuron, motor neuron, and effector
-protection

26

patellar knee jerk reflex

- example of a simple monosynaptic reflex, so-called because it uses only two neurons- a sensory neuron communicating directly to a motor neuron.

27

ascending and descending tracts of the spinal cord

-ascending tracts of the spinal cord are afferent information dealing with sensory neurons
-descending tracts of the spinal cord deal with efferent information and motor neurons

28

central nervous system

-Consists of the brain and spinal cord.

29

peripheral nervous system

-Consists of cranial and spinal nerves

30

sensory receptors

-The ends of neurons in the peripheral nervous system provide the sensory function of the nervous system.
-These receptors gather information by detecting changes inside and outside of the body.