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Physiology
Chapter 13
Question | Answer |
---|---|
Functions of Cardiovascular system | Transports: 1.O & nutrients to cells 2.waste from cells to liver&kidney 3.hormones,immune cells,clotting proteins to specific targets |
Weight of heart | 250-350 grams |
Valves of heart | 1. Atrial Ventricular Valves 2.Semilunar valves(between BV&ventricles) |
Functions of Valves | prevents back flow, have passive opening depending on pressure |
Pulmonary Circut | Supplied by heart, goes to lungs,blood pumped by R ventricles to lungs & returns from lungs to L atrium |
Systemic Circut | supplies blood to body, supplied by L heart, blood pumped from L Ventricles to systemic tissues, then back to R atrium |
Blood path | L Ventricle,Aorta,systemic circuit, vena cavae, R atrium, R ventricle, pulmonary veins, L atrium,L ventricle |
Autorhythmicity | Ability of heart to generate its own rhythm of contraction |
Auto-rhythmic cells | Small % of heart cells that can provide and coordinate rhythm to heart beat |
Pacemaker Cells | Can spontaneously depolarize a membrane potential to generate AP * can coordinate rhythm to beat |
conduction fibers | can regularly conduct AP initiated by pacemaker cells to rest of heart *speed is 4m per sec. *muscle cells is .4m per sec |
SA node | can generate 17-18 AP per min *determines heart rate |
AV node | 14-16 AP per min *back up of SA node *ECG to detect heart problems |
Systole | Ventricle contraction *blood pumped out of heart |
Diastole | Ventricle relaxation *blood fill into heart |
Stroke Volume | volume of blood ejected by ventricles during ea. beat *70mm normal stroke volume |
When do AV vales open | when pressure in atria is larger than pressure in ventricles |
When do semilunar vales open | when pressure in ventricle is larger than pressure in arteries |
1st heart sound | "lubb" caused by closure of AV valve |
2nd heart sound | "dubb" caused by closure of semilunar valve |
Cardiac output | Volume of blood pumped by ea. ventricle per min. *5L per min @ rest |
intrinsic regulation | situated within the heart |
Extrinsic regulation | originating outside the heart *includes nervous and hormonal mechanisms |