# Applied Science AQA/The Heart
## Topic Title
### Setting Applied context

Those working in cardiac sciences diagnose and monitor diseases that affect the structure and function of the heart, carry out exercise stress testing to determine whether the blood vessels supplying the heart are working properly, and programme pacemaker devices to ensure that they function correctly.
* Syllabus Content
* •    key structures of the heart, including bicuspid valve, tricuspid valve, mitral valves, sinoatrial node (SAN), atrioventricular node (AVN), Purkinje fibres, bundle of His
* •    myogenic stimulation of the heart
* •    the role of the SAN, AVN, Purkinje fibres and bundle of His in cardiac stimulation
* •    the role of carbon dioxide chemoreceptors and baroreceptors in controlling heart rate
* •    artificial pacemakers as treatment for arrhythmia (abnormal heart rate), and how they work to re-establish normal heart rate
* •    the advantages and disadvantages of different types of artificial pacemakers.

### Exploration of key ideas (must be original text, not C&P) – level checked by AQA

In general, point students towards the approach to take, as opposed to just giving them information.
Structures of the heart:
Bicuspid valve: this is a form of heart disease where parts of the aortic valve fuse in the womb to form a 2 leaflet valve instead of a 3 leaflet valve.
Tricuspid valve: this is also known as the right atrioventricular valve and is function is to stop the back flow of blood into the right atrium.
mitral valve: this valve controls the flow of blood from the left atrium to the left ventricle.
sinoatrial node: this is the part of the heart which controls the hearts pace. It does this by generating electrical impulses.
atrioventricular node: this is the part of the heart which controls its rate. It does this by controlling the electrical impulses generated by the SA node. It slows down these impulses so that there is a delay between the ventricles and the atrium. It does this to make sure that the ventricles have enough time to fully contract to make sure that all of the blood can be pumped out of the heart.
purkinje fibers: these fibers conduct the signals sent by the AV node and send them across both ventricles simultaneously causing them to contract.
bundle of his:

#### cardiac simulation

explanation 3

### controlling heart rate

chemoreceptors
baroreceptors
artificial pacemakers

### Study Task

Work to do to understand this topic e.g. research, analysis

### Careers and Organisations

Carry out some research into these jobs in this area. (Feel free to add other jobs you find.)
| Research these roles: | What are the benefits of this role to society? | What organisations would employ someone in this role?  (Where would they work?) | What would someone in this role have to do within the organisation? | What scientifically-related skills do they need to have?  What techniques do they need to have mastered? | What experience is needed to undertake this role and its responsibilities within an organisation? | What other science personnel will they work with in their organisation. |
| Job 1 | | | | | | |
| Job 2 | | | | | | |

### Relevant practical/s

– relating to criteria skills

### Quick questions

* what is the function of the AV node?
* what is the name of the bottom chambers of the heart?
* what is bicuspid valve?
* to delay the current sent by the SA node to make sure that the atrium contract fully.
* atrium.
* a form of heart disease where parts of the aortic valve fuse together.

### Exam-style questions

– can we use old AQA qs… e.g. from more than 5 years ago? With Examiner comments
click to reveal answer

### Links

to other sections within this book
to good external websites (including AQA website, wikipedia, relevant applications / companies) - also considering links in spec

### References / Bibliography

of recommended text books
including mapped refs to existing books
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