Neurons & Synapses

Question 1

Neurons

Answer 1

cells specialized for conducting nerve impulses

Question 2

Central Nervous System

Answer 2

nervous system that consists of brain and spinal cord

Question 3

Peripheral Nervous System

Answer 3

nervous system that links CNS with receptors and effectors

Question 4

Autonomic Nervous System

Answer 4

nervous system responsible for automatic processes, contains sympathetic and parasympathetic NS

Question 5

Somatic Nervous System

Answer 5

nervous system that deals with sensory input and motor output

Question 6

Neuron Cell Body

Answer 6

part of neuron that contains nucleus, ribosomes, and cytoplasm

Question 7

Dendrites

Answer 7

part of neuron that receives messages

Question 8

Axon Button

Answer 8

part of neuron that sends messages via neurotransmitter

Question 9

Myelin Sheath

Answer 9

part of neuron that helps speeds up and boost action potential down the axon

Question 10

Schwon Cell

Answer 10

cell type that makes up the myelin sheath

Question 11

Sensory/afferent neuron

Answer 11

neuron that conducts nerve impulses from receptors to CNS

Question 12

Interneuron/relay neurons

Answer 12

neurons that conduct nerve impulses within CNS (aka brain cells)

Question 13

Motor/efferent neurons

Answer 13

neurons that conduct nerve impulses from CNS to effectors

Question 14

Excitatory neurotransmitter

Answer 14

type of neurotransmitter that makes the cell more positive by letting in sodium to the cell and opening ligand-gated sodium channels, allowing for depolarization (ex. dopamine, noradrenaline)

Question 15

Inhibitory neurotransmitter

Answer 15

type of neurotransmitter that makes the cell more negative by bringing potassium out of cell, creating hyperpolarization (ex. GABA)

Question 16

Summation

Answer 16

where excitatory and inhibitory neurotransmitters compete to make the cell more positive and negative, it is the result of the total effect all neurotransmitters have on the voltage in the cell

Question 17

Vitamin A

Answer 17

vitamin useful for eyes

Question 18

Vitamin B

Answer 18

vitamin useful for iron absorption

Question 19

Vitamin C

Answer 19

vitamin where deficiency causes scurvy

Question 20

Vitamin D

Answer 20

vitamin responsible for serotonin

Question 21

Vitamin K

Answer 21

vitamin responsible for blood clotting

Question 22

Folic Acid

Answer 22

vitamin useful for preventing spina bifida in childbirth

Question 23

Synapse/synaptic cleft

Answer 23

junction between the axon and the dendrite

Question 24

Reuptake

Answer 24

where excess neurotransmitter in the synapse is taken back up by the signaling cell, rather than docking to receptors in the receiving cell

Question 25

Process of Releasing a Neurotransmitter

Answer 25

1. Action potential reaches terminal
2. Ca2+ channels open
3. Increased Ca2+ causes vesicles to release neurotransmitter
4. Neurotransmitter crosses synapse through exocytosis
5. Neurotransmitter either binds to receptors or excess is reuptaked, and ligand gated ion channels are opened
6. Signal opens sodium or potassium channels in the cell and action potential may or may not occur, depending on the neurotransmitter

Question 26

Resting Potential

Answer 26

the charge difference across the neural membrane when a neuron is not firing (-70mV) and is maintained by the sodium potassium pump

Question 27

How many Na+ and K+ are pumped by ATPase?

Answer 27

3Na+ out of cell, 2K+ into cell

Question 28

Depolarization

Answer 28

the opening of sodium channels and the process of a neuron becoming more positive

Question 29

Action potential

Answer 29

charge difference when neuron is firing (30mV)

Question 30

Threshold Level

Answer 30

charge that must be reached inside of cell to trigger action potential (-55mV)

Question 31

Efflux

Answer 31

out of cell

Question 32

Influx

Answer 32

into cell

Question 33

Repolarization

Answer 33

the refractory period of a neuron’s firing, where the charge inside the neuron must move back to negative by opening the K+ channel

Question 34

Axon hillock

Answer 34

part of neuron where summation occurs, and all the electrical pulses from dendrites combine and potentially send an action potential

Question 35

Saltatory Conduction

Answer 35

describes the way that impulses jump from node to node down the axon, rather than moving continuously, as a result of the myelin sheath

Question 36

Nodes of Ranvier

Answer 36

part of the neuron that provides stopping points in the myelin sheath, gap in the myelin sheath needed for saltatory conduction

Question 37

Antiport mechanism

Answer 37

name of the mechanism of the ATPase ion pump, where Na+ and K+ are moved opposite ways through the cell membrane, instead of the same way

Question 38

Why is the refractory period important?

Answer 38

makes sure that signals only travel in one direction down the axon

Question 39

Batrachotoxin (BTX)

Answer 39

toxin produced by poison dart frog that covalently binds to Na+ ion channels, forcing them to stay open and preventing repolarization and relaxation of muscles (leads to paralysis)

Question 40

Curare

Answer 40

plant derivative that acts as a competitive inhibitor and inhibits nAChR (nicotinic actylcholine receptor) so it cannot fire (inhibits muscle contraction, so used as a muscle relaxant)

Question 41

Neonicotinoids

Answer 41

substance that leads to overstimulation of nAChR receptor because it covalently bonds to acetylcholinesterase (AChE), which is an enzyme used to get rid of excess acetylcholine, so it can no longer break down acetylcholine, used as a pesticide to create paralysis in bugs