Biology B1.P3 Flashcards
P wave
Is the wave of depolarization that spreads from SAN across the atria and causes atrial systole.
PR interval
Time taken for a wave of depolarization to move electrical impulse from SAN to ventricles by AVN.
QRS complex
When wave of depolarization spreads across ventricles and causes ventricular systole.
ST segment
Is the interval between the end of ventricular depolarization and the start of ventricular repolarisation.
T wave
Is the repolarization of ventricles during diastole.
Types of heart beat.
-Arrhythmias- irregular heartbeats
-Tachycardia- fast heartbeat
-Bradycardia- Too slow heartbeat
-Sinus rhythm- normal heartbeat
-Flat line- no heartbeat
Atheroma
Atherosclerosis
-Build up of fatty deposits which forms within endothelium arteries
-Cause of coronary heart disease, where layers of fatty material build up in arteries which narrows them and reduces blood flow.
How cardiovascular disease develops
Damage to endothelial cells by fatty deposits which leads to inflammatory response where it causes white blood cells to come into the area and from that it slowly builds up cholesterol due to atheroma which overall then narrows the lumen.
1st treatment for Atherosclerosis (coronary heart disease)
STENT
Stents are metal cylinder grids
inserted into an artery to maintain blood flow by keeping the artery open so that the heart
Allows one to receive enough oxygen to function effectively.
2nd treatment for Atherosclerosis (coronary heart disease)
STATINS- drug
Statins lowers harmful cholesterol in the blood and stop the
liver producing too much cholesterol and reduce the rate at which it is deposited.
Risk of heart transplant
-Rejection of the donor heart: this occurs when the immune system mistakes the new heart as foreign and attacks it.
Infection- weakening the immune system
-Failure to pump properly
-Narrowing of the arteries that are connected to the heart
Faulty valves
–Symptoms can include:
Being short of breath
Swelling in the ankles and feet
Feeling unusually tired
–Causes:
Being born with it (heart disease)
Getting older
damage to heart and muscle
