Cardiovascular System Flashcards
name the key areas/structures of the heart
9
superior/inferior vena cava right/left pulmonary trunk right/left atria right/left pulmonary veins tricuspid valve right/left ventricles bicuspid valve semilunar valve chordae Tendinae
right side of heart function
receives blood from the body
pumps deoxygenated blood to the lungs through pulmonary circulation
left side of heart function
receives blood from the lungs
pumps oxygenated blood through the systemic circulation
blood flow through the heart
13
1 - Superior and Inferior Vena Cava 2 - Right Atrium 3 - Tricuspid Valve 4 - Right Ventricle 5 - Pulmonary Valve 6 - Pulmonary Trunk 7 - Pulmonary Arteries (L+R) 8 - Pulmonary Veins 9 - Left Atrium 10 - Bicuspid Valve 11 - Left Ventricle 12 - Aortic Valve 13 - Aorta
describe pulmonary circulation
5
- Deoxygenated blood returns to the heart via the superior + inferior vena cava into the right atrium
- It passes through the tricuspid valve into the right ventricle
- The tricuspid valve closes to prevent backflow
- The blood exits the right ventricle through the pulmonary trunk into either pulmonary artery
- Blood flows into the lungs to be reoxygenated in the pulmonary capillaries
describe systemic circulation
5
- Oxygenated blood flows from the lungs via the pulmonary vein into the left atrium
- The blood enters the left ventricle via the bicuspid/mitral valve
- The bicuspid valve closes as blood is forced into the aortic valve into the aorta
- The aortic valve closes to prevent backflow into the heart
- The aorta then carries oxygenated blood around the body via arteries, starting with the coronary arteries
cardiac output formula?
stroke volume x heart rate
excitability
The ability to respond to stimulus and generate action potential/nerve impulse
conductivity
The ability to transfer the action potential
automaticity
The autonomous skill of generating an impulse without external stimuli
contractility
The ability to transfer electrical energy - mechanical
why is left side cardiac tissue thicker + larger surface area?
pumping harder as needs to pump blood systemically
cardiac (atrial and ventricular) diastole
when the chambers are relaxed and filling passively
atrial systole
when the atria contract leading to ventricular filling
ventricular systole
when blood is ejected into both the pulmonary artery and aorta
describe the electrical conduction of the heart
5 stages
Sinoatrial (SA) node depolarises and spreads signal across the atrium
signal connects to neighbouring Atrioventricular (AV) node through internodal tracts
the AV pauses the impulse, to allow blood to drain from the atria into the ventricles
the AV node transmits the signal to the bundle of his branches both left and right
these branches split down either side of the heart into the Purkinje fibres which causes the ventricles to contract
why is the delay between atria and ventricles important
if the ventricles and atrium contracted simultaneously they would be squeezing blood against each other
the delay allows the atrial blood to enter the ventricles, then for the ventricles to transport the blood further
describe the perfusion triangle
3 parts
heart - pump function
blood vessels - container function
blood - content function
atheroma
the buildup of materials that adhere to arteries
includes: fat. cholesterol. calcium
why are atheromas dangerous
they can burst into the bloodstream, body recognises this as a breakage/injury and responds by clotting
3 layers of the heart
endocardium
myocardium
pericardium
purpose of coronary arteries
to supply the myocardium with its own blood supply
blood pressure
the pressure blood exerts onto the walls of the vessels
BP is higher in the large arteries and lower in large veins
systolic blood pressure
when the left ventricle contracts and pushes blood into the aorta
diastolic blood pressure
when the heart is relaxing following the ejection of blood
normal BP reading
120 systolic
80 diastolic
bp measured in?
mm/mg millimetres of mercury