Cardiovascular system Flashcards
(26 cards)
Medulla controls what?
The cardiac centre, for heart rate force and contraction.
Baroreceptors
In the walls of the aorta, detect changes in blood pressure and the cardiac centre then responds through stimulation of the sympathetic nervous system. SNS increases heart rate. PNS decreases heart rate.
where is the mitral valve
chamber that seperates the right and left side of the heart, if there is a dysfunction it can lead to blood regurgitationm prolapse.
Factors increasing heart rate
Stress,
body temp,
exercise,
smoking,
pregnancy,
pain,
medications
dehydration
glycogen.
electrical system
SA node ; pacemaker, located in the wall of the atrium, generates the sinus rhythm, epinephrine can alter this process.
ECG
Atrial contracton : depolarization in the P wave,
Ventricular contraction : QRS
Can detect arrythemias or dysrhythmias
Anastomoses
Small connections between the left and right coronary arteries. Can open up and provide another source of blood. Collateral circulation. Aerobic exercise helps to build up the collateral system which may play a key role in the prevention of stroke, PE, or obstruction.
three ways the cardiac system can be impaired
Chronic hypertension,
Stress,
athersclerosis.
Diastolic
Atria fills- where the heart is in relaxation phase.
systolic
higher pressure, blood ejected from the left ventricle
Pause between atrial contraction and ventricular contraction
During a single cardiac cycle, the atria and ventricles do not beat simultaneously; the atrial contraction occurs prior to ventricular contraction. This timing delay allows for proper filling of all four chambers of the heart.
cardiac output
volume of blood ejected by ventricle in one minute
blood pressure
pressure of blood against arterial walls.
120/70 mm hg.
Troponins
blood proteins, that indicate if cardiac muscle has been damaged.
Vasodilators
reduce peripheral resistance, and the workload of the heart. Nitroglycerin.
Beta blockers
block adrenergic receptors which contribute to SNS activity and increase in HR.
Calcium channel blockers
Block the movement of calcium ions into the cardiac and smooth muscle fibres,
ACE
Block angiotension 1 and 11, a powerful vasoconstrictor. Stimulated by release of renin in the kidneys.
Anticoagulants
Reduce risk of blood clot formation, decrease platelet adhesion. Warfarin is a older school medication. Drugs such as apixaban, rivaroxaban offer an alternative to warfarin where it does not have to be as closely monitored. And vit K interference.
Angina pectoris
decrease in oxygen to the heart, can be due to increase demand in the heart. Autoregulation usually occurs, unless there is damage. Pallor, diaphoresis, and nausea.
Treatment;
- rest,
-sit upright,
-nitroglycerin,
-O2 if indicated,
-Second dose after 5 minutes if pain persists,
-no hx, emergency medical aid if pain does not subside.
MI
Death of Myocardial tissue, due to ischemia. Typcally those who survive an MI there is risk of stroke, CHF again. ST-elevation or non-st-elevation.
S/S
-pressure, heaviness in the chest,
-SOB, sweating, weakness fatique,
-anxiety and fear
-nausea.
Arrythmias
Damage to the hearts conduction system, fever, hypoxia, electrolyte imbalance, infection. Reduce the ability of the hearts conduction system which interfere with regular filling and emptying of the cycle.
Atrial conduction abnormalities
Common type of dysrhythmia, extra beats of the atria.
cardiac arrest
no conduction of impulses, ECG flat line. No cardiac outline occurs, thus brain death.
