Nervous Systems

Question 1

Axon Hillock

Answer 1

connection of a neuron to an axon where AP is created

Question 2

Axon

Answer 2

nerve fibers

Question 3

Neurons

Answer 3

generate bioelectric signals to transmit information

Question 4

Glial Cells

Answer 4

“support” cells of the neuron that assist in signaling; produce cerebrospinal fluid

Question 5

Synapse

Answer 5

connection between the axon terminal and effector cells

Question 6

Effector

Answer 6

can be a neuron, muscle cell or any other kind of cell

Question 7

Afferent neurons

Answer 7

receive and carry information to the central nervous system; sensory output

Question 8

Efferent neurons

Answer 8

carry information away from the central nervous system; motor output

Question 9

Potential

Answer 9

difference of electrical charge between regions

Question 10

Current

Answer 10

flow of electrical charge from region to region

Question 11

Membrane Potential

Answer 11

unequal charge distribution across the cell membrane

Question 12

Resting Membrane Potentials

Answer 12

the different concentrations between the inside & outside of the cell membrane; measured when the neuron is inactive

Question 13

Electronic Potentials

Answer 13

move along the surface, can depolarize/hyperpolarize, small changes

Question 14

Action Potentials

Answer 14

-very sudden, large changes happening in the axon
-all or nothing transient
-use voltage gated ions to move
-move through the membrane
-don’t stop once they start

Question 15

Leak Channels

Answer 15

specific types of ion channels in the cell membrane that are always open **they can have their own permeability

Question 16

Polarized cells

Answer 16

Cells that have distinct regions or specialized functions (- inside the cell)

Question 17

Depolarized Cells

Answer 17

inner membrane becomes less negative, Na+ flows into cell (more + inside the cell); membrane potential increases

Question 18

Hyperpolarized Cells

Answer 18

making the membrane potential of a cell more negative inside

Question 19

Repolarization

Answer 19

the inner membrane becomes negative: K+ flows out of the cell; Membrane potential decreases restoring the membrane potential

Question 20

Myelin

Answer 20

a mixture of proteins & lipids that surround nerve fibers, speeding up conduction of impulses and preventing ions from crossing the cell membrane

Question 21

Refraction Period

Answer 21

when a neuron is unable to fire an action potential

Question 22

Spiking Frequency

Answer 22

amount of APs created, carries information

Question 23

Salatory Conduction

Answer 23

jumping from node to node to reach terminals

Question 24

Nodes of Ranvier

Answer 24

allow exchange of ions for speedy electrical transmission

Question 25

Electrical synapses

Answer 25

excitatory signals seen in invertebrates -vital for fight or flight -rapid flow of current -large axon diameter= faster transmission -no neurotransmitters involved -they rely on ion transmission through gap junctions

Question 26

EPSP (excitatory postsynaptic potential)

Answer 26

A small, temporary increase in the membrane potential of a neuron, making the inside of the cell less negative (depolarized); increases chance of firing a signal

Question 27

IPSP (inhibitory postsynaptic potential)

Answer 27

A small, temporary decrease in the membrane potential of a neuron, making the inside of the cell more negative (hyperpolarized); decreases chance of firing a signal

Question 28

Temporal Summation

Answer 28

multiple signals (typically EPSPs or IPSPs) are generated at the same synapse in rapid succession over time

Question 29

Spatial Summation

Answer 29

signals from multiple synapses (different locations on the postsynaptic neuron) are combined

Question 30

EPSP-IPSP Cancellation

Answer 30

(IPSP) and (EPSP) happen at the same time or close in time at a neuron, effectively canceling each other out.

Question 31

Chemical synapses

Answer 31

slower than electrical synapses -no gap junctions -uses neurotransmitters -synaptic cleft

Question 32

synaptic cleft

Answer 32

separates the pre and post synaptic neurons by a gap

Question 33

synaptic vesicles

Answer 33

where neurotransmitters are stored within the presynaptic neuron. When an action potential reaches the synapse, these vesicles fuse with the membrane and release neurotransmitters into the synaptic cleft

Question 34

Integration

Answer 34

sum of hyper and depolarization

Question 35

Neurotransmitter

Answer 35

chemical signals that allow neurons to communicate and control various processes in the body; they bind to a receptor protein in the postsynaptic membrane

Question 36

Mechanoreceptors

Answer 36

-respond to mechanical deformation of the plasma membrane -mechanically gated -located in the dendrites of sensory neurons -make the muscles flex

Question 37

Thermoreceptors

Answer 37

responds to changes in cold & heat

Question 38

Nocioreceptors

Answer 38

respond to pain (tissue damage)

Question 39

Electromagnetic Receptors

Answer 39

respond to electrical & magnetic fields

Question 40

Photoreceptors

Answer 40

respond to light stimuli

Question 41

Chemoreceptors

Answer 41

respond to various chemicals

Question 42

Stretch receptors

Answer 42

non-neuronal, mechanically gated Na+ channels, deformation depolarizes the membrane

Question 43

Hair cells

Answer 43

-non neuronal -found in organs of balance (ears) in many inverts & all verts -mechanically gates K+ channels -in organs of sound -can hyperpolarize and depolarize