The heart Flashcards
What is the hearts job?
It’s job is to pump blood around the body and deoxygenated blood to the lungs
Which of the two ventricles needs to be thicker and why?
The left ventricle as it needs to pump blood all around the body where as the right only needs to pump blood to the lungs
Which out of the ventricles and the atria’s need to have thicker walls and why?
The ventricles as they are pumping blood out the heart whereas the atria’s only need to pump blood to the ventricles
What does the Atrioventricular valve (AV) link together and why?
It links the atria to the ventricles and stops blood flowing back into the atria when the ventricles contract
What does the Semi-lunar valve link and why?
They link the ventricles to the pulmonary artery and aorta which stops blood from flowing back into the heart after the ventricles contract
What does the cord attach?
Attaches the AV to the ventricles
Why are the heart valves adapted and what does this ensure?
So that they only open when there is a high amount of pressure behind them. This ensures that the blood only flows one way
What could a backflow of blood mean?
That not enough oxygenated blood is getting to the rest of the body.
What are the 2 main types of valves in the heart?
The bicuspid valves and the tricuspid valves
Where is the Bicuspid valve located?
Once the oxygenated blood flows from the atrium to the ventricles what does the bicuspid valve do?
Why is it known as a bicuspid valve?
Between the left atrium and left ventricle
It closes to prevent the blood from flowing back
Because it has 2 flaps
Where is the Tricuspid valve located?
Why is it known as a Tricuspid valve?
Between the right atrium and the right ventricle
Because it has 3 flaps
What is the SA node?
What does it consist of?
What does the SA node generate?
Where do these electrical signals move?
It is the natural pacemaker of the heart
Consists of a cluster of cells that are situated in the upper part of the right atrium
They generate electrical impulses
Move down from cell to cell through the heart until it reaches the AV node
What does the AV node act as?
What does this delay ensure?
It acts as a gate which slows down the electrical impulses before they are permitted to pass down through the ventricles
It ensures that all the atria’s have time to fully contract before the ventricles are stimulated
What is the ‘bundle of his’?
What does it transmit?
What do the branches lead to?
The bundle of his is a collection of heart muscle cells specialised for electrical conduction.
It transmits the electrical impulses from the AV node along the bundle branches
Leads to the purkinje fibres
Where are purkinje fibres located?
What is their function?
They are located in the ventricle walls.
Their function is to send nerve impulses to the cells in the ventricles of the heart and cause them to contract and pump blood either out the body or to the lungs
