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
Where do Arteries carry blood?
What type of blood do Arteries carry?
Do Arteries have thin or thick muscular walls?
They carry blood away from the heart
Usually oxygenated blood
They have thick muscular walls
Where do Veins carry blood?
What type of blood do Veins carry?
Do Veins have thin or thick muscular walls?
They carry blood to the heart
Usually deoxygenated blood
They have thin muscular walls
Where do Capillaries transport blood?
How thick are capillaries?
They transport blood to cells
They are one cell thick
What is the Vena Cava and what does it do?
It is a large vein that carries deoxygenated blood from the lower and middle body into the right atrium of the heart
What are pulmonary vein’s responsible for?
They are responsible for carrying oxygenated blood from the lungs back to the left atrium
What does the Pulmonary artery do?
It carries blood from the right ventricle to the lungs for oxygenation
What is the aorta and what does it do?
Where do you find the aorta in a human?
It is the main artery of the body that supplies oxygenated blood to the circulatory system.
It is found over the heart from the left ventricle and runs down in front of the backbone
What is the cardiac cycle?
What are the three stages of the cycle?
It is an ongoing sequence of contraction and relaxation of the atria and ventricles which keeps blood continuously circulating around the body.
Ventricles contract-atria contract, ventricles contract-atria relaxes and ventricles relax-atria relax
