MYTUTOR SUBJECT ANSWERS

197 views

Describe the electrical activity of the heart.

The heart is known as myogenic and can beat of its own accord, and this is tightly controlled to ensure the optimum blood flow through the heart to deliver oxygen to the rest of the body. 

Diastole refers to when the heart muscle is relaxed and systole refers to when the heart muscle is contracting. 

The pacemaker of the heart is the Sino-Atrial node (SAN) and this is found in the wall of the right ventricle. As blood pools here from the Vena Cava, depolarisation of the SAN causes contraction of both the atria to push blood into the ventricles. 

The electric signal from the SAN reaches the atrio-ventricular node (AVN) found in the septum between the two atria. This delays the electrical signal spreading across the ventriles to allow time for the ventricles to sufficiently fill with blood. Once ready, the AVN passes the signal down the Bundle of His which are located in the walls of the ventricle to cause coordinated and sequential contraction to expel blood out of the ventricles. 

Extrinsic factors such as the autonomic nervous system and adrenaline can affect the firing of the SAN to increase or decrease heart rate. 

Ben B. A Level Biology tutor, IB Biology tutor, GCSE Biology tutor, I...

4 months ago

Answered by Ben, an IB Biology tutor with MyTutor


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

26 SUBJECT SPECIALISTS

£20 /hr

Wisdom O.

Degree: Medicine, MBBS iBsc (Bachelors) - University College London University

Subjects offered:Biology, Maths+ 5 more

Biology
Maths
German
Chemistry
-Personal Statements-
-Oxbridge Preparation-
-Medical School Preparation-

“ABOUT ME   I'm a first year medical student at University College London. I really enjoy sciences and languages and I work hard to convey my passion and interest in these subjects to those I tutor.  I am very friendly and tutoring my ...”

£20 /hr

Francesco G.

Degree: Conservation Biology and Ecology (Bachelors) - Exeter University

Subjects offered:Biology, Science+ 2 more

Biology
Science
Italian
Human Biology

“I am a conservation biology student at Exeter University. I really enjoy teaching and I have tutored many students in the past. ”

MyTutor guarantee

Oliver W. GCSE Biology tutor, IB Biology tutor, A Level Biology tutor...
£22 /hr

Oliver W.

Degree: Natural Sciences (Bachelors) - Cambridge University

Subjects offered:Biology, Maths+ 4 more

Biology
Maths
Extended Project Qualification
Economics
Chemistry
-Personal Statements-

“I am third year student at the University of Cambridge studying Natural Sciences. I specialise in Neurobiology. However, I have a lot of experience in othersciences and maths, at GCSE and IB level. I studied for 5 years at Sevenoaks Sc...”

About the author

Ben B.

Currently unavailable: for regular students

Degree: Medicine (Bachelors) - Bristol University

Subjects offered:Biology, Science+ 3 more

Biology
Science
Maths
Chemistry
-Medical School Preparation-

“Hi - I'm currently in my 3rd year of studying Medicine at Bristol University and am taking an intercalated year out to conduct my own research into 3D printing applications in Cerebral Palsy. I have a real interest in science with ent...”

MyTutor guarantee

You may also like...

Other IB Biology questions

Describe the three types of fatty acids.

How can I learn all the difficult memory facts if I am not good at memorisation?

Describe why DNA replication is semi-conservative

Explain that female carriers are heterozygous for X-linked recessive alleles.

View IB Biology tutors

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

mtw:mercury1:status:ok