Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Topic 6 - Nervous Coordination > Flashcards

Topic 6 - Nervous Coordination Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

What is the function of the sodium-potassium ion pump

A
  • The sodium potassium ion pump actively transports 2 potassium ions into the axon and 3 sodium ions out of the axon.
  • This results in an overall negative charge inside the axon
  • It also restores resting potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what happens at resting potential

A
  • around -70mV
  • Sodium ions should diffuse back in and potassium ions should diffuse back out through voltage gated ion channels.
  • However the membrane is more permeable to potassium ions.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what happens during depolarisation

A
  • an action potential occurs and some voltage gated sodium ion channels open so sodium ions diffuse into the axon.
  • The chnage in charge causes more sodium ion channels to open so more sodium ions diffuse into the axon.
  • once an action potential occurs the voltage gated sodium ion channels close
  • Voltage gated potassium ions open
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what happens during re polarisation

A

potassium ions diffuse out making the inside of the cell more negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what happens during hyperpolarisation

A
  • there is a slight overshoot in the movement of potassium ions so the inside of the axon is more negative than usual.
  • The voltage gated potassium ion channels close
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens during the refractory period

A
  • short period of time where the axon cannot be excited again.
  • limits number of action potentials a nerve cell can produce
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what happens during repolarisation of the resting potential

A
  • the resting potential is restored by the sodium potassium ion pump.
  • the axon is repolarised
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the stages of polarisation in a neurone

A
  1. resting potential
  2. de polarisation
  3. re polarisation
  4. hyperpolarisation
  5. restoration of resting potential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are dendrites on a nerve cell

A

highly branched fibres that conduct impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are Schwan cells on a nerve cell

A

a cell wrapped around the axon forming the myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the myelin sheath on a nerve cell

A

a thick insulating layer around the axon

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what is the node of Ranvier on a nerve cell

A

gap in the myelin sheath where the axon is exposed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the axon on a nerve cell

A

a long single fibre that carries nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is the all or nothing nature

A
  • action potentials have an all or nothing nature, once the threshold level is reached, an action potential will always fire with the same change in voltage no matter how big the stimulus is.
  • A bigger stimulus wont cause a bigger action potential, but it will cause them to fire more frequently
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what 3 factors affect the speed of conduction of action potentials

A
  • myelination
  • axon diameter
  • temperature
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what does it mean if a neurone is myelinated

A

they have a myelin sheath

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is found at the node of ranvier

A

sodium ion channels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

how does myelination increase the speed of conduction of an action potential

A
  • myelination provides electrical insulation
  • in myelinated neurons depolarisation occurs at nodes and saltatory conduction causes ions to jump from node to node which is fast
  • In non myelinated neurons depolarisation occurs along the whole length of the neurone which is slower.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does axon diameter affect speed of conduction of action potentials

A
  • action potentials are conducted quicker along axons with bigger diameter becauuse there’s less resistance to the flow of ions
  • with less resistance depolarisation reaches other parts of th neurone cell membrane quicker
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

how does temperature affect the speed of conduction of an action potential

A

the speed of conduction increases as the temperature increases because ions are given more kinetic energy so can diffuse faster.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

what is a synapse

A

a junction between a neurone and the next cell/ neurone

22
Q

what is the gap at the synapse called

A

synaptic cleft

23
Q

what is the part of the presynaptic neurone infront of the synpase called

A
  • synaptic knob
  • it contains vesicles filled with neurotransmitters.
  • also has mitochodria
24
Q

how is a nerve impulse transimtted along a cholinergic synapse

A
  1. an action potential arrives at the presynaptic neurone at the synaptic knob.
  2. The action potential stimulates voltage gated calcium ions to open causing calcium ions to diffuse into the synaptic knob.
  3. The calcium ions cause the vesicles containing acetylcholine to move and fuse with the presynaptic membrane, releasing acetylcholine into the synaptic cleft by exocytosis
  4. acetylcholine diffuses across the synaptic cleft and binds to receptors on the postsynaptic membrane.
  5. This causes sodium ion channels to open. The sodium ions into the postsynaptic membrane causes depolarisation. and an action potential is generated if the treshold level is reached
  6. acetylchoine is removed from the synaptic cleft so the action potentials does not keep happening and so that sodiumion channels close it is hyrolysed by acetylcholinesterase and the products are re absorbed by the presynaptic neurone and used to make more acetylcholine.
25
Q

what are exictatory neurotransmitters

A

they depolarise the postsynaptic membrane, making it fire an action potential if the threshold is reached

26
Q

what are inhibitory neurotransmitters

A

they hyperpolarise the postsynaptic membrane (make the potential difference negative) preventing it from firing an action potential.

27
Q

what are the 2 types of summation

A

spatial
temporal

28
Q

what is spatial summation

A
  • sometimes many pre synaptic neurones connect to one postsynaptic neurone.
  • The small amount of neurotransmitter released from each of these neurones can be enough all together to reach the threshold level in the post synaptic neurone to trigger an action potential.
29
Q

what is temporal summation

A
  • two or more nerve impulses arrive in quick frequency from the same presynaptic neurone.
  • this makes an action potential more likely because more neurotransmitter is released into the synaptic cleft
30
Q

what is a neuromuscular junction

A

a synapse between a motor neurone and a muscle cell

31
Q

what neurotransmitter does a neuromuscular junction use

A

acetylcholine

32
Q

what are the 3 differences of a neuromuscular junction compared to a cholinergic synapse

A
  1. the posysynaptic membrane has lots of folds that form clefts. they store acetylcholinesterase enzymes
  2. the postsynaptic membrane has more receptors than other synapses
  3. always excitatory at a neuromuscular junction. A cholenergic synapse can be inhibitory or excitatory
33
Q

what are the affect of different drugs in synaptic transmissions

A
  • same shape - bind to receptors so they are constantly activated
  • block receptors - so they cant be activated.
  • inhibit enzymes - inhibit the enzyme that breaks neurotransmitters down so there is more in the synaptic cleft to bind to receptors for longer.
  • stimulate neurotransmitters - drugs can stimulate the release of a neurotransmitter from the presynaptic neurone so more receptors are activated
  • inhibit neurotransmitters - fewer receptors are activated.
34
Q

what are tendons

A

attach bones to muscles

35
Q

what are ligaments

A

attach bones to bones

36
Q

what are antagonistic pairs of muscles

A
  • antagonist - relaxing
  • agonist - contracting
  • they contract to move bones at a joint
37
Q

what is the structure of skeletal muscle

A
  • skeletal muscle is made up of large bundles of long cells called muscle fibers
  • In a muscle fiber the cells fuse to form a fibre
  • each fibre contains myofibrils
  • the pattern on the myofibrils is made by sarcomeres which are arranged end to end
  • sarcomeres are made of protein filaments called myofibrils.
  • myofirbrils are made of myofilaments
38
Q

how does muscle contraction occur by sliding filament theory

A
  • the I band, H zone and distance between the Z lines decrease
  • while the A band stays the same size.
  • This is because the actin are pulled closer to the M line causing the think and thin filaments to overlap more.
39
Q

in a sarcomere, what is the A band, I band and H zone ?

A
  • A band - dark band, both
  • H zone - myosin (thick)
  • I band - light band, actin (thin)
40
Q

what are the binding sites on myosin

A
  • myosin filaments have globular heads that are hinged so they can move back and forth.
  • Each myosin head has a binding site for actin, and a binding site for ATP.
41
Q

what are the binding sites on actin

A

actin filaments have binding sites for myosin heads, called actin myosin binding sites.

42
Q

what happens at rest before a muscle contraction

A

in a resting muscle the actin myosin binding site is blocked by tropomyosin so myofilaments cant slide past each other because the myosin heads cant bind to actin myosin binding site on actin

43
Q

what happens during muscle contraction

A
  • when an action potential from a motor neurone stimulates a muscle cell, it depolarises the sarcolema. depolarisation spreads down the T-tubules to the sarcoplasmic reticulum.
  • This causes the sarcoplasmuc reticulum to release stored calcium ions into the sarcoplasm.
  • At high concentrations the calcium ions bind to troponin on the actin filament . This caises the tropomyosin to moce exposing the actin binding sites.
  • The activated myosin heads can now bind to the actin filament - actinmyosin bridge - this causes tension in the muscle.
  • Binding to the actin causes myosin head to change angle (powerstroke) . This causes the entire myosin filamet to pull along the actin. ADP can now be released from the myosin head.
  • ATP can now bind to the myosin head. This breaks the actinmyosin bridge.This is broken down to produce ADP and Pi and energy. The energy allows the myosin head to return to its original state.
  • The cycle can now repeat, dragging the myosin filament further along the actin, the sarcomere will continue to contract if there is a supply of ATP.
44
Q

how do calcium ions leave the sarcolema after contraction

A
  • calcium ions are actively transported back into the sarcoplasmic reticulum.
  • This causes the tropomyosin molecules to move back so they block the actin myosin binding site again.
  • actin filaments slide back to their relaxed position which lengthens the sarcomere.
45
Q

what type of exercise is aerobic and anaerobic respiration good for

A
  • aerobic - long periods of low intesnity exercise because it only works when there is oxygen.e.g. marathon running
  • anaerobic - short periods of high intensity exrercise, e.g. sprinting
46
Q

What is the ATP-phosphocreatine system

A
  • ATP is made by phosphorylating ADP adding a phosphate taken from phosphocreatine.
  • Phosphocreatine is stored inside cells and the system generates ATP very quickly
  • phosphocreatine runs out very quickly so it is used during short bursts of exercise.
  • the system is anaerobix and doesn’t form lactate.
47
Q

what are the 2 types of muscle fibres

A

slow twitch
fast twitch

48
Q

what are the properties of slow twitch fibers

A
  • contract slowly
  • generates ATP slow
  • muscles for posture, e.g. back muscles
  • endurance activities
  • long time without tiring
  • energy is released slowly through aerobic respiration
  • lots of mitochondria
  • red colour due to myoglobin protein that stores oxygen
49
Q

what are the properties of fast twitch fibers

A
  • contract quickly
  • generates ATP fast
  • fast movement, e.g. eyes and legs
  • short bursts of speed and power, e.g. sprint
  • get tired quickly
  • energy is released quickly through anaerobic respiration using glycogen
  • few mitochondria
  • white colour because not much myoglobin (cannot store much oxygen)
50
Q

what is the function of ATP in muscle contraction

A
  • binds to the myosin head
  • broken down by ATP hydrolase to form ADP and Pi
  • energy from this allows the myosin head to return to it’s orgininal state
  • breaks the actin myosin bridge
  • allows for active transport of calcium ions after contraction

Biology (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions