Cardiovascular 1 and 2 Flashcards
3 necessary components of the CV system
Heart
Blood
Vasculature
Flow rate
Volume of blood that passes point in given time
Velocity of flow
Distance travelled in given time
Where in the vasculature is the greatest drop in pressure?
Arterioles
What is the most important determinant of blood flow?
Radius
6 major CV problems
Dysrhythmia Hypertension Valve malfunction Angina/ischemia/MI Infection Heart failure
Heart failure
Blood flow to tissues is insufficient to maintain homeostasis of interstitial fluid
Ejection failure
Systolic failure
Ventricles cannot generate sufficient ejection force
Filling failure
Diastolic failure
Ventricles cannot filly sufficiently
4 things needed for cardiac function
- Electrical signals (conducted to all working muscle in specific pattern)
- Coupling (electrical signals in working muscle coupled to contraction of the muscle
- Pumping action (orderly contraction of muscle cells with sufficient force leads to contraction of ventricles then relaxation
- Functional valves (if valves open properly and do not leak then blood fills ventricles and is pumped out into aorta/pulmonary artery)
5 parts of the cardiac pacemaker and conduction system
Sinoatrial node
Atrioventricular node
Bundle of His (connects AVN to bundle branches)
Bundle branches (relay APs down septum of the heart)
Purkinje fiber network (relays AP to ventricular myocytes)
L-type Ca channel
Membrane ion channel responsible for Ca influx into myocytes during AP plateau
Involved in contraction
Sarcoplasmic reticulum
Intracellular Ca storage organelle
Ryanodine receptor
Ca release channel located in the SR membrane
Involved in contraction
Sarcoplasmic reticulum Ca ATPase (SERCA)
ATP-dependent Ca pump located in the SR membrane
Involved in relaxation
Phospholamban (PLB)
Negative regulator of SERCA
Relaxation