MYTUTOR SUBJECT ANSWERS

334 views

How does an action potential cause contraction in skeletal muscle?

The point at which a motor neurone synapses with a muscle fibre is called the neuromuscular junction. The unmyelinated nerve fibre stops around 30 nanometers before the muscle fibre, leaving a gap called the synaptic cleft, with the nerve ending being referred to as the pre synaptic membrane, and the muscle fibre end called the post synaptic membrane.

When an action potential reaches the nerve ending, the sudden depolarisation causes an influx of calcium ions through voltage gated channels. These ions bind to specific receptors on vesicles within the motor neuron, causing them to move towards and fuse with the presynaptic membrane and release neurotransmitter into the synaptic cleft. The neurotransmitter diffuses across the cleft and binds to its specific receptors on te post synaptic membrane. The binding of the neurotransmitter causes the opening of ligand gated ion channels. The influx of negatively charged ions causes depolarisation of the muscle fibre, setting off the mechanisms that lead to muscle contraction.

Orla  M. A Level Biology tutor, GCSE Biology tutor, Mentoring Biology...

2 years ago

Answered by Orla , an A Level Biology tutor with MyTutor

Still stuck? Get one-to-one help from a personally interviewed subject specialist

131 SUBJECT SPECIALISTS

£20 /hr

Victoria S.

Degree: Physiology (Bachelors) - Liverpool University

Subjects offered: Biology, Maths

Biology
Maths

“About me:Hey! My name is Tory and I am in my second year studying Physiology in the School of Life Sciences at The University of Liverpool. After completing my current degree, I hope undertake a Graduate-entry Medicine course to furt...”

£20 /hr

Carlamarita H.

Degree: Biological Science (Masters) - Durham University

Subjects offered: Biology, Chemistry

Biology
Chemistry

“About me! I am a Biological Sciences student at Durham University and my hobbies are playing the guitar and karate! I have previous tutoring experience where I worked with my secondary school to tutor GCSE students to help them reach ...”

MyTutor guarantee

£20 /hr

Steven A.

Degree: Bioscience (Masters) - Durham University

Subjects offered: Biology, Science+ 5 more

Biology
Science
Maths
Human Biology
English
Chemistry
-Personal Statements-

“Hey! I'm Steven, 18 years old and I'm studying Biochemistry at Durham University. I love tutoring people, to put it simply. At my college i was a tutor to a student in the year below me for chemistry and growing up with a younger sist...”

About the author

£20 /hr

Orla M.

Degree: Biomedical Sciences (Bachelors) - Durham University

Subjects offered: Biology, Physics+ 2 more

Biology
Physics
Maths
Chemistry

“Top tutor from the renowned Russell university group, ready to help you improve your grades.”

MyTutor guarantee

You may also like...

Other A Level Biology questions

How to write an essay which will get me top marks in my exam

What is the difference between natural selection and evolution?

Describe the main differences between the innate and adaptive immune response?

Explain why an enzyme catalyses only one reaction.

View A Level Biology tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok