Chapter 3

Question 1

Neurophysiology

Answer 1

Studying the specialized life processes that allow neurons to use chemical and electrical processes to sum up vast amounts of information and pass it on to other neurons.

Question 2

Ions/Anions/Cations

Answer 2

Ions-electrically charged molecules
anions-negatively charged
cations-positively charged

Question 3

Microelectrode

Answer 3

Inserted into the interior of a neuron to place an electrode into a neuron

Question 4

Resting Potential

Answer 4

Between -50 to -80 millivolts (mV)

Question 5

Ion Chanel

Answer 5

tubelike pore that allows ions of a specific type to pass through it.

Question 6

Potassium ions (K+) and Sodium Ions (Na+)

Answer 6

Two ions that are important with the action potential/firing of a cell

Question 7

Selective permeability

Answer 7

allowing some things to pass but not others. Cell membrane of a neuron is this way.

Question 8

Electrostatic Pressure/Diffusion

Answer 8

Both part of creating an action potential/rebalancing cells charge
Electrostatic Pressure - charged particles exerting electrical forces on one another. Like charges repel and opposites attract
Diffusion - force that causes molecules of a substance to spread from regions of high concentration to regions of low concentration

Question 9

Sodium-Potassium pumps

Answer 9

Pump three Na+ ions out for every two K+ ions pumped in.

Question 10

Equilibrium Potential

Answer 10

The electrical charge that exactly balances the concentration of the gradient (around -60 mV) Also the resting potential of cells ^

Question 11

Hyperpolarization/Depolarization

Answer 11

Hyper - increase in membrane potential, neuron is even more negative.
Depol - decrease in membrane potential, neuron is closer to zero.

Question 12

Local Potentials

Answer 12

Ripples that spread across the membrane after the action potential and get smaller as they spread from the point of stimulation.

Question 13

Threshold/Action Potential

Answer 13

Threshold= -40 mV
Action potential - sudden and brief response to reaching threshold lasting .5-2.0 milliseconds. A rapid reversal of the membrane potential that momentarily makes the inside of the membrane positive with respect to the outside. Follows the all-or-none property.
After potentials are small potential changes immediately after the spike

Question 14

Voltage-gated Na+ channel

Answer 14

Tubular, membrane-spanning protein, the central Na+ selected pore is gated. Electrically stimulated to open and allow Na+ ions through for a short period.

Question 15

Refractory

Answer 15

(Temporarily unresponsive or inactivated) After one action potential, the axonal membrane is unable to respond to a second stimulus and be _____.

Question 16

Absoute Refractory/Relative Refractory

Answer 16

Absolute - Brief period immediately following the production of an action potential in which no amount of stimulation can induce another action potential
Relative - Only a strong stimulation well beyond threshold can produce another action potential.

Question 17

Conduction Velocity

Answer 17

varies with diameter of axon, it is the speed of action potentials along axons.

Question 18

Saltatory Conduction

Answer 18

When the action potential “jumps” across Nodes of Ranvier between myelinated axon chunks.
Multiple Sclerosis is a disease which myelin is compromised.

Question 19

Excitatory Postsynaptic Potential (EPSP) and Inhibitory Postsynaptic Potential (IPSP)

Answer 19

EPSP-Na+ channels open to let in more positive ions, thus pushing the charge closer to the threshold.
IPSP-becomes more polarized/further away from threshold. Usually caused by channels permitting Chloride ions (Cl-).

Question 20

Spatial and Temporal Summation

Answer 20

Spatial - action potentials have different physical origins along cell body
Summation - action potentials come from a single location after one another.

Question 21

Calcium Ions (Ca2+)

Answer 21

Ions which come into the axon terminal from the extracellular through Ca2+ channels which open at the arrival of the action potential. This causes synaptic vesicles to bind to the cell membrane and release the neurotransmitter.

Question 22

Synaptic Delay

Answer 22

Time needed for Ca2+ to enter the terminal and for transmitter to diffuse across the cleft and interact with the receptors on the postsynaptic cell.

Question 23

Ligand

Answer 23

substance that binds to receptor molecules, such as neurotransmitter or drugs that bind with postsynaptic receptors.

Question 24

Acetylcholine (ACh)

Answer 24

Neurotransmitter that is produced and released by parasympathetic postganglionic neurons, by motoneurons and neurons throughout the brain. Fits into ligand binding sites. Neuromuscular PNS junctions/basic movement and learning and CNS memory/arousal/award process.

Question 25

Neurotransmitter receptor

Answer 25

“receptor” a specialized protein, often embedded in the cell membrane that selectively senses and reacts to molecules of a corresponding neurotransmitter or hormone.

Question 26

Curare/Bungarotoxin

Answer 26

Neurotoxin that causes paralysis by blocking acetylcholine receptors in muscle. Bungarotoxin is isolated from the venom or the “many-branded krait” that selectively blocks acetylcholine receptors.

Question 27

Agonists and Antagonists

Answer 27

Agonists-substance that mimics or potentiates that actions of a transmitter or other signaling molecule
Antagonists-substance that blocks or attenuates the actions of a transmitter or other signaling molecule.

Question 28

Cholinergic

Answer 28

Cells that use acetylcholine as their synaptic transmitter

Question 29

Degradation and Acetylcholinesterase (AChE)

Answer 29

Chemical breakdown of a neurotransmitter into inactive metabolites. Ace….is the enzyme that inactivates the transmitter acetylcholine.

Question 30

Reuptake

Answer 30

process which released synaptic transmitter molecules are taken up and reused by the presynaptic neuron, thus stopping synaptic activity. Transporters used.

Question 31

Transporter

Answer 31

Specialized membrane component that returns transmitter molecules to the presynaptic neuron for reuse. Process of reuptake.

Question 32

Axo-dentritic

Answer 32

Synapse which a presynaptic axon terminal, synapses to a dendrite of the postsynaptic neuron either via a dendritic spine or directly onto the dendrite itself.

Question 33

Axo-somatic

Answer 33

Synapse where a presynaptic axon terminal synapses onto the cell body (soma) of the postsynaptic neuron.

Question 34

Axo-axonic

Answer 34

Synapse where a presynaptic axon terminal synapses onto the axon terminal of another neuron.

Question 35

Dendro-dendritic

Answer 35

Synapse where a synaptic connection forms between the dendrites of two neurons.

Question 36

Electroencephalograms (EEGs)

Answer 36

Record the gross electrical activity of the brain via large electrodes placed on the scalp.

Question 37

Event-related potentials (ERPs)

Answer 37

“evoked potential” averaged EEG recordings which measure brain responses to specific stimuli.

Question 38

Epilepsy/Seizure

Answer 38

Brain disorder marked by sudden changes in the electrophysiological state of the brain which are called seizures. Grand mal are the biggest followed by petit mal. Complex partial seizures don’t involve the entire brain and produce a wide variety of symptoms preceded by an unusual sensation, or aura.