Lectures 16-18

Question 1

What is the all or none law?

Answer 1

an action potential fires or it doesn’t

Question 2

What are two mechanisms used in the all or nothing law? (angry neurons)

Answer 2

1) high frequent communications by sending lots of action potentials
2) Number of neurons sending the same message

Question 3

Why is there an all or none law?

Answer 3

To describe that an action potential either fires or it doesn’t at all, always maintains same size and stops around same point.

Question 4

what is a refractory period? (speed)

Answer 4

Limit on how fast neuron can fire

Question 5

What is the absolute refractory period and in what stage (1-3) of an action potential does it occur?

Answer 5

Period during an action potential when another action potential cannot fire, during rising and peak phase

Question 6

What’s the relative refractory period and what makes it more difficult?

Answer 6

State where it is harder than normal to fire an action potential, due to needing many more milivolts due to its state.

Question 7

what are the nodes of ronvier?

Answer 7

spaces in between myelin segments

Question 8

What is saltatory conduction and it’s two benefits to the neuron? (sautè)

Answer 8

Action potentials being conducted at myelinated axons, jump from node to node.

1) faster action potentials
2) reduced energy

Question 9

what’s a sodium potassium pump and it’s function? (take 2, release 3)

Answer 9

Pulls in 2 Potassium to release 3 Sodium ions, helps use less energy during saltatory conduction

Question 10

Why’s saltatory conduction faster than normal conduction? (think team of tug o war, how will you win the fastest)

Answer 10

Only needs voltage gated channels in nodes of ronvier, makes density easier and faster to get through as its more concentrated instead of spread throughout

Question 11

whys myelin important?

Answer 11

Several human disorders are linked with impaired myelin

Question 12

What is the nature of connection between neurons?

Answer 12

Kajal was right, neurons aren’t connected

Question 13

What are the 3 components of a synaptic structure and their functions? intro middle cliffhanger

Answer 13

1) pre synaptic component -send and receive mssgs
2) post synaptic component-receive mssgs
3) Synaptic cleft-space between pre and post synaptic component

Question 14

What are the 3 types of synapses
(the axos…)

Answer 14

1) axodendritic synapse
2) axosematic synapse
3)axoaxomic synapse

Question 15

functions of the 3 synapses:
(axos..)

Answer 15

Axodendritic- majority of synapses
Axosematic: synapses between brain and body
Axoaxomic: synapses between one axon to another

Question 16

What did sherrington find in their expirement?
(the dog toe pincher)
speed as a hint

Answer 16

Synapse Speed was lower than expected, whatever happens in it must be slower than an action potential

Question 17

What did Elliot find in Elliot and Loewis frog heart expirements?

Answer 17

Accelerator nerves mimick same effect as adrenaline

Question 18

What did Loewi find in Elliot and Loewis frog heart expirements?

Answer 18

Fluid transferred from one heart beaker to another, could increase/decrease the other heart rates beats

Question 19

What does synaptic transmission involve and release?

Answer 19

Involves release of neurotransmitters

Question 20

What are neurotransmitters?

Answer 20

Internal chemicals that transmit signals from neuron to target cell across the synapse

Question 21

What are the 4 Chemical structures of neuro transmitters ? (BANO)

Answer 21

Biogenic amines
amino acids
neuropeptides
other

Question 22

What is an amine, and how many amines do bio amines and mono amines have in them biologically?

Answer 22

An amine is a type of chemical grouping

Bio amines have 1 or more amine in them biologically

Mono amines have only 1 amine in them biologically

Question 23

What type neurotransmitters fall under the biogenic amine group ? and name all 5…
happy.. cliff jumping…turkey meat has..

NEADS

Answer 23

The catecholomines and mono amines sub grouping

Norepinephrine
Epinephrine
Acetylcholine
Dopamine
Serotonin

Question 24

What are the functions of serotonin and dopamine?
(zzz, haha!) (hmm, how do i deal with this?)

Answer 24

Serotonin aids in sleep and mood
Dopamine helps process info in the brain and regulates movement

Question 25

What are the functions of norepinephrine and epinephrine and what else can they be known as to the average person?

Answer 25

Roles in arousal and mood
Norepinephrine : nor adrenaline
epinephrine: adrenaline

Question 26

What are the two neurotransmitters that fall under the Amino acids chemical structure and what are their functions ? (opposites, double G’s, highs and lows)

Answer 26

Glutamate: main excitatory neurotransmitter
GABA: main inhibitory neurotransmitter(decrease activity)

Question 27

What are neuropeptides and what two neurotransmitters fall under this chemical structure ? (pain and blocking, the only cool name for a neurotransmitter)

Answer 27

def: shorter chains of amino acids
1) Substance p
2) endorphins

Question 28

What are the functions of substance P (1) and endorphins(2)?
(What did michaels cousin do when he broke his leg … what could this be known as?)

Answer 28

substance P: process pain messages
Endorphins: block pain messages, regulate breathing

Question 29

What does it mean by “others” in Chemical structure 4? And what neurotransmitter (1) falls under this category?

Answer 29

Don’t fit it neatly with others, weird things
1) nitric oxide

Question 30

What are the 5 steps in neurotransmission? think about it as baking a cake, 1) you get your ingredients ready, 2) prep everything for the bake,3) put it in the oven 4) beep beep on the oven 5) it’s done! everyone eats

Answer 30

1) synthesis: making neurotransmitter
2) Preparation for release
3) Release
4) Signalling
5) Termination of actions

Question 31

Where(2) and what does the synthesis stage do and involve(2 things it involves) ( in the 5 steps of making neurotransmitters )

Answer 31

Can be made in pre synaptic terminal or cell body

Makes the neurotransmitter using precursors and synthetic enzymes

Question 32

What happens during the preparation for release phase (2 steps)? Think about it like going on a boat, what are the three steps to it… boarding…. what’s the next two?

Answer 32

Synaptic vesicles fill with neurotransmitters
1) Loading neurotransmitters
2) Transporting and docking neurotransmitters to active zone

Question 33

What is a quanta and quantal release? (goes in 2 step cycle) (quant-quantity)

Answer 33

Quanta: amount of neurotransmitters in a synaptic vesicle
Quantal release : Synaptic vesicles release as a group of neurotransmitters

Question 34

What causes neurotransmitters to move into the synaptic cleft? (queues of arrival)

Answer 34

The arrival of an action potential is the queue for neurotransmitters to move into the synaptic cleft.

Question 35

What is a snare complex and in what step of neurotransmission does it occur? Like creating a monkey bridge, to form soemthing…)

Answer 35

Occurs in the release step(3rd)
It’s proteins holding vesicles in place to form a protein complex in the active zones

Question 36

What occurs chemically in the release step (number 3, in five steps of neurotransmission) (3 steps, who comes, changes, fuses and then is pushed into somewhere)

Answer 36

Calcium comes,

protein changes shape and pulls synaptic vesicles into synaptic membrane,

Synaptic vesicle then fuses with synaptic membrane and gets pushed into synaptic cleft

Question 37

Why was the first (old) dales law incorrect and how did we change it? (wrong numbers dale)

Answer 37

Stated each neuron can only synthesize and release one type of neurotransmitter when they can really synthesize and release 1-3.