1.1 Cardiovascular system (add more detail) Flashcards
What does the Cardiac conduction system refer to?
How the heart contracts/how the heart creates its own heart beat
List the CCS in order of impulse travel
SA node (sinoatrial node)
AV node (atrioventricular node)
Bundle of HIS
Purkinje fibers
Explain the function of the SA node?
Sinoartial node
- Sends electrical impulses to spread throughout both atria to stimulate atrial systole.
- Initiates all heart beat and detriments heart rate.
- Natural pace maker of the heart.
Explain the function of the AV node?
Atrioventricular node
- Delays the cardiac impulse, from SA node, to ensures the atria have ejected all the blood into the ventricles before ventricles contacts.
- The AV node receives signals from the SA node and passes them onto the Bundle of HIS.
Explain the function of the Bundle of HIS?
The Bundle is divided into left and right bundle branches and into purkinje fibres
-Conduct the impulses to the apex of the heart. The signals are then passed to Purkinje fibers
Explain the function of the Purkinjie fibers?
- Purkinjie fibres spreads signal throughout the ventricular myocardium causing Ventricular systole
Identify and explain the order in which a cardiac impulse travels?
- SA node initiates heart beat and spreads impulse across top two chambers (atria) creating atrial systole.
- AV node delays impulse (0.1sec) from SA node to ensure atria have ejected all blood into ventricles and sends impulse to Bundle of HIS.
- Conducts impulse to the apex of the heart and then sent to Purkinjie fibers.
- Purkinjie fibers cause ventricular systole
Key terms brain dump
Conducts Electrical impulses Systole Diastole Eject CCS Myogenic Symp
What is the term used when the heart is contracting and relaxing
Systole and diastole
Name all the chambers of the heart
Artia (left and right
Ventricles (left and right)
Ventricle (left+right)
What is the first things that happens during a heart beat?
SA node sends impulse across both atriums causing ATRIAL SYSTOLE
How does the heart control the rate at which it beats
SA node sends impulse to create atrial systole. Impulse reaches AV node which delays cardiac impulse to ensure all blood has been ejected out the atria and into the ventricles. Impulse then sent down to Bundle of HIS and conducts into Purkinje fibres. This will achieve ventricular systole.
How do you measure the electrical activity and rhythm of the heart?
ECG: Electrocardiogram
Why is one side of the heart’s walls bigger than the other?
The ventricles of the heart have thicker muscular walls than the atria. This is because blood is pumped out of the heart at greater force from these chambers compared to the atria. Therefore need to withstand higher pressure.
Which chamber in the heart are larger and explain why?
The left ventricle is the biggest chamber as it has to pump blood to the rest of the body (further distance) whereas the right ventricle only pumps to the lungs.
Name the main blood vessels that enter and leave the heart
Aorta, vena cava and pulmonary artery = AWAY
Pulmonary vein = TOWARDS
Which blood vessel brings deoxygenated blood back to the heart?
Vena cava brings deoxygenated blood to right atrium
Which blood vessel delivers oxygenated blood to the heart?
The Pulmonary vein delivers oxygenated blood to the left atrium.
Whats the difference between arteries and veins?
Arteries carry blood AwAy from the heart, and veins carry blood towards the heart.
What is the function of the Aorta?
Leaves the left ventricle with oxygenated blood to the rest of the body
What is the function of the pulmonary artery?
Leaves the right ventricle with deoxygenated blood to the lungs
The heart acts as a _______ forcing blood around the body
The heart acts as a DOUBLE PUMP forcing blood around the body
Name the hearts two circuits
Pulmonary circulation
Systemic circulation
Systemic circulation
Explain the difference between the hearts circulatory systems
Pulmonary circulation: Deoxygenated blood from the heart to the lungs and oxygenated blood back to the heart
Systemic circulation: Oxygenated blood to the body from the heart and deoxygenated blood from body back to heart.