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How nerve impulses signal to muscles to contract?

Can someone help me please
Original post by zarahh09
Can someone help me please

GCSE or A-level? Which exam board?
What understanding do you currently have?
Try having a go :smile:
Reply 2
Original post by KA_P
GCSE or A-level? Which exam board?
What understanding do you currently have?
Try having a go :smile:

A level edexcel
I think this is what we are doing as our next topic so far not that much good knowledge about it
Original post by zarahh09
A level edexcel
I think this is what we are doing as our next topic so far not that much good knowledge about it

I suggest you first of all look at your exam board spec for that topic and then annotate it based on what you currently know and what you don't know etc.

Since you haven't started the topic as well, I'd watch a couple of yt vids on it to get a base understanding.

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Original post by KA_P
I suggest you first of all look at your exam board spec for that topic and then annotate it based on what you currently know and what you don't know etc.

Since you haven't started the topic as well, I'd watch a couple of yt vids on it to get a base understanding.

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For this question, what are the keep info needed?
Contraction occurs when nerve impulses are transmitted across neuromuscular junctions to the membrane covering each muscle fibre.
I only go this far, idk what else to say
(edited 2 years ago)
Original post by zuzannasendor18
For this question, what are the keep info needed?
Do u just describe sliding filament theory?

Yes basically but you'd have to include calcium ions as well, I would assume, as well as possibly acetylcholine if I remember correctly.
Original post by KA_P
Yes basically but you'd have to include calcium ions as well, I would assume, as well as possibly acetylcholine if I remember correctly.

I got this far: Contraction occurs when nerve impulses are transmitted across neuromuscular junctions to the membrane covering each muscle fibre.

Idk if it is true or not
I am now stuck
Original post by zuzannasendor18
I got this far: Contraction occurs when nerve impulses are transmitted across neuromuscular junctions to the membrane covering each muscle fibre.

Idk if it is true or not
I am now stuck


Screenshot_2022-01-10-17-47-42-77_e2d5b3f32b79de1d45acd1fad96fbb0f.jpg
This is a screenshot I took from the Edexcel spec for A-Level Edexcel Biology B.
If I'm being honest, I did AQA.
Okay have a read of this
https://www.visiblebody.com/learn/muscular/muscle-contractions
Tbh I would wait until they teach you this since I don't know how in-depth Edexcel is as compared to AQA
(edited 2 years ago)
Original post by zarahh09
Can someone help me please

To understand the transmission of of a nerve impulse, you should be familiar with:

- Stimulation threshold
- Action potential
- Resting Potential
- Refactory period
- Sodium-potassium pump
- Synapses
- Synaptic cleft

They are the key words you should have a closer look on.
.
(edited 2 years ago)
Hi
@zuzannasendor18
@zarahh09

Thank you everyone who has tried to help these two students - unfortunately, all were referring to nerve impulse conduction, [including @Kallisto,

WHEREAS:
the Q posed by OP appears to refer to what happens at the NEUROMUSCULAR JUNCTION. Secondly, I am not a great proponent of students learning ONLY WHAT THE SPEC outlines - there is no harm in learning a little more detail than might be necessary, cos then what you need to know becomes a trrfle! Yummy!! :yum: !

A neurone that supplies a skeletal [=voluntary = striated] muscle fibre has a terminal bouton where it joins the latter. As one member correctly stated, the neurotransmitter here is acetylcholine [ACh].

a] ACh is stored within vesicles in the neuronal bouton and is released on arrival of the impulse therein by exocytosis, [the membrane of the vesicle fuses with the cell membrane of the neurone], which is initiated by release of Ca2+.

b] ACh diffuses across the synapse and acts on nicotinic ACh receptors on the muscle membrane generating an excitatory postsynaptic potential [EPSP], which then triggers a series of steps that culminate in sliding of actin versus myosin filaments [read up on muscle contraction]. This ACh receptor is called "nicotinic" because the first substance that was discovered that acted on it was nicotine [the other type of ACh receptor is called muscarinic after the alkaloid muscarine]. The receptor is made of five chains hence is described as being heteropentameric.

For synoptic Q: there are two types of nicotinic ACh receptors NM [nicotinic muscular] and NG [nicotinic ganglionic cos the neurotransmitter in the ganglia of the autonomic nervous system [both sympathetic + parasympathetic ganglia] is also ACh].

Also look up myasthenia gravis.

Please only read the print in italics
if you are at uni,
OR:
if you are aiming for A*.

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