cardiovascular system Flashcards
(12 cards)
What are the fundamental components of the cardiovascular system?
Heart, blood vessels, and blood. It includes the systemic and pulmonary circulations.
What regulates blood flow through the heart?
Mechanical processes such as the opening and closing of valves and chamber contractions during the cardiac cycle.
How are cardiac action potentials initiated and propagated?
Initiated at the SA node and propagated through the atria, AV node, Bundle of His, bundle branches, and Purkinje fibers.
What ionic fluxes occur during the cardiac action potential?
Phase 0: Na⁺ influx; Phase 1: K⁺ efflux; Phase 2: Ca²⁺ influx and K⁺ efflux; Phase 3: K⁺ efflux; Phase 4: Resting membrane potential maintained.
How does the ECG relate to the cardiac cycle?
P wave = atrial depolarization, QRS = ventricular depolarization, T wave = ventricular repolarization.
How do structural features of arteries enable their function?
Thick walls with elastic tissue and smooth muscle allow arteries to withstand and regulate high pressure.
What is the function of veins?
Return blood to the heart; thin walls and valves prevent backflow and act as blood reservoirs.
What is the role of capillaries?
Enable exchange of gases, nutrients, and waste between blood and tissues through thin walls and large surface area.
How is arterial blood pressure measured?
Using a sphygmomanometer and stethoscope to detect Korotkoff sounds during cuff deflation.
How does the baroreceptor reflex control blood pressure?
By sensing pressure changes and adjusting heart rate, stroke volume, and vessel diameter via the autonomic nervous system.
How do vasoconstriction and vasodilation control peripheral resistance?
Vasoconstriction increases resistance and blood pressure; vasodilation decreases them.
What is the role of the RAAS in blood pressure regulation?
Renin from the kidney initiates a cascade converting angiotensinogen to angiotensin II, leading to vasoconstriction and aldosterone-mediated volume retention.
