Ch 12- Cardiovascular system disorders Flashcards
Atrial contraction is represented by the depolarization in the
P wave (1st)
Ventricular contraction is shown by the large wave of depolarization in the ventricles
QRS (2nd)
This wave masks the effect of atrial repolarization
Represents the repolarization of the ventricles, or recovery phase
T wave (3rd)
ECG or EKG
Detect arrhythmias or dysrhythmias, May indicate acute problems such as infarction or systemic problems such as electrolyte imbalance (k deficiency)
Heart rate and force of contraction or controlled by the
Cardiac control center, in the medulla of the brain
Sympathetic nervous system OR the parasympathetic nervous system
Alters the rates and force of cardiac contractions as required (BP)
Sympathetic innervation
Increases the heart rate (tachycardia)
Beta-adrenergic receptors in the hearts are important site of action for some drugs such as beta blockers (these drugs block any increase in rates and force of contractions)
Parasympathetic stimulation by the Vegas nerve
Slows the heart rate (bradycardia)
Another name for a bicuspid valve
Mitral valve
Diastolic
Relaxation phase of cardiac activity
- atria fills (all valves closed)
- increased atrial pressure opens AV valves, filling ventricles
Systolic
Cardiac contraction
-ventricles are full - injects into aorta and pulmonary artery
Murmurs
-Defective valves that leak or do not open completely.
-A hole in the heart septum

Cardiac output
Volume of blood ejected by a ventricle and one minute
Depends on heart rate and stroke volume (The volume pumps from one ventricle and one contraction)
Cardiac function can be measured in a number of ways
- cardiac output
- stroke volume
- cardiac reserve
- preload
- afterload
Dysrhythmias VS arrhythmias
- dysrhythmias is a disturbance in a normal rhythm (valves not working)
- arrhythmias is an irregular heartbeat
