MYTUTOR SUBJECT ANSWERS

393 views

Explain how voltage-gated sodium ion channels on the membranes of neurones generate an action potential.

At rest there is a difference in the concentration of sodium ions (Na+) across the membrane of the neurone.

Outside the neurone in the extracellular fluid (ECF) the concentration of Na+ is around 140 mEq/L whereas inside in the intracellular fluid (ICF) it is about 14 mEq/L.

This difference in concentration of Na+ creates a strong concentration gradient across the membrane.

When there is a change in voltage, the voltage-gated Na+ channels open.  This allows the Na+ to flow through the membrane from outside to inside, down the concentration gradient.

Normally the inside of the neurone has a negative charge but, when large amounts of Na+ flood into the neurone when the channels open this makes the inside of the neurone have a positive charge.

This change in charge from negative to positive is knows as depolarisation and this generates an action potential that travels down the neurone (axon). 

Aaron H. Mentoring -Medical School Preparation- tutor, Mentoring -Per...

1 year ago

Answered by Aaron, an A Level Human Biology tutor with MyTutor


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

16 SUBJECT SPECIALISTS

£20 /hr

Seline I.

Degree: Medicine (Bachelors) - Cardiff University

Subjects offered: Human Biology, Maths+ 4 more

Human Biology
Maths
Chemistry
Biology
Art
-Medical School Preparation-

“Who am I? I am a second year medical student at Cardiff University. I have always had a love of science, maths and art and cannot wait to share my passion for these subjects with you. My tutorials will be delivered in an interactive, ...”

£20 /hr

Michal D.

Degree: Medicine (Bachelors) - Newcastle University

Subjects offered: Human Biology, Chemistry+ 4 more

Human Biology
Chemistry
Biology
.UKCAT.
-Personal Statements-
-Medical School Preparation-

“I am a third year Medical Student at Newcastle University, currently undertaking a clinical placement year in hospital. While at Sixth form I was able to gain experience in tuition by helping out other students in their GCSEs and A-Le...”

MyTutor guarantee

£22 /hr

Stephanie K.

Degree: Medicine (Bachelors) - Cardiff University

Subjects offered: Human Biology, -Personal Statements-+ 1 more

Human Biology
-Personal Statements-
-Medical School Preparation-

“Hi, I'm Steph a medical student at Cardiff University with a background in Biomedical Science (Bsc). I tutor Human Biology with a particular interest in Anatomy. Science has always been the core to my love of learning. I hope my passi...”

About the author

Aaron H.

Currently unavailable: for regular students

Degree: Graduate Entry Medicine (MB ChB) (Bachelors) - Bristol University

Subjects offered: Human Biology, -Personal Statements-+ 1 more

Human Biology
-Personal Statements-
-Medical School Preparation-

“A little about me: After graduating with a BSc degree in Physiological Science (how the body works) I applied to study medicine as a graduate and am now studying to be a doctor at the University of Bristol.  I am fascinated by how th...”

You may also like...

Posts by Aaron

Describe the effect of calcium ions on tropomyosin and actin in skeletal muscle.

Describe the roles of DNA and RNA in determining the sequence of amino acids in proteins.

Explain how voltage-gated sodium ion channels on the membranes of neurones generate an action potential.

People with AF often also have narrowing of the valve between the left atrium and the left ventricle. This causes the wall of the left atrium to become thicker. Suggest why.

Other A Level Human Biology questions

People get vitamins mainly from the foods they eat or from vitamin tablets. Give a different way in which people get some vitamin K.

What is the role of a vitamin in the body?

What is a Vitamin?

What is a spinal reflex arc?

View A Level Human 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