Last of notes complete questions Flashcards
(106 cards)
Cardiovascular Elements?
Heart, blood vessels, blood.
Main function of the cardiovascular system?
Delivers O₂/nutrients, removes CO₂/waste, transports hormones, regulates temperature/fluid balance, maintains acid–base balance, supports immunity.
Heart chambers?
Right atrium, right ventricle, left atrium, left ventricle.
Blood flow (right heart)?
Venae cavae → RA → RV → pulmonary valve → pulmonary arteries → lungs.
Blood flow (left heart)?
Pulmonary veins → LA → LV → aortic valve → aorta → body.
Why is the LV thick?
It pumps blood to the entire body and must generate high pressure.
Myocardium features?
Highly oxidative, dense capillaries, many mitochondria, intercalated discs for coordinated contraction.
Difference: Cardiac vs. Skeletal muscle?
Cardiac: small, branched, single nucleus, continuous involuntary contractions; Skeletal: large, long, multinucleated, voluntary intermittent contractions.
Coronary arteries?
Right coronary (supplies right heart) and left coronary (supplies left heart).
Intrinsic control of the heart?
Cardiac conduction system: SA node, AV node, AV bundle, and Purkinje fibers.
Intrinsic HR value?
Approximately 100 beats/min.
Role of the SA node?
Initiates the heartbeat with spontaneous depolarization.
Function of the AV node?
Delays the electrical signal to allow atrial contraction before ventricular contraction.
Purpose of Purkinje fibers?
Rapidly distribute impulses to ensure coordinated ventricular contraction.
Define the cardiac cycle.
The sequence of electrical and mechanical events during one heartbeat (systole and diastole).
Systole vs. diastole?
Systole: contraction/ejection phase; Diastole: relaxation/filling phase (diastole is about 2/3 of the cycle).
Stroke volume (SV) formula?
SV = EDV − ESV (e.g., 100 mL EDV − 40 mL ESV = 60 mL).
What is ejection fraction?
The ratio SV/EDV (e.g., 60 mL/100 mL = 60%).
Cardiac output formula?
CO = HR × SV (e.g., 70 bpm × 70 mL = 4900 mL/min, ~5 L/min).
Typical resting HR?
Between 60 and 100 beats/min; trained athletes may be as low as 35–40 bpm.
Estimated maximal heart rate?
220 minus age (e.g., for a 20-year-old: 220 − 20 = 200 bpm).
Extrinsic control: Parasympathetic NS?
Via the vagus nerve; decreases HR and contractility using acetylcholine.
Extrinsic control: Sympathetic NS?
Releases norepinephrine to increase HR and contractility.
Normal resting blood pressure?
Systolic: ~110–120 mmHg; Diastolic: ~70–80 mmHg.