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Block 2.3
Day 1: Dr. Clark Cardiovascular Physiology Review
Question | Answer |
---|---|
What is the Pulmonary circuit? | Where blood travels from the heart to lungs and returns back to the heart |
What is the Systemic circuit? | Where blood travels from the heart to the body and returns back to the heart |
T/F Arteries carry blood away from the heart | T |
T/F Veins carry blood toward the heart | T |
What are capillaries? | Exchange vessels that allow the trading of gas, nutrients, and waste |
How many chambers does the heart contain? | 4, right atrium, right ventricle, left atrium, left ventricle |
What is the job of AV valves and semilunar valves? | Prevent backflow of blood |
Know the process of blood flow through the heart. | T |
What are the two types of cardiac cells involved in generation of a heartbeat? | Conducting system which initiates and distributes stimulus and contractile cells which contract and eject blood. |
What is known as the "natural pacemaker of the heart" ? | SA node, 60-100 impulses/min |
How many impulses/min does the AV conduct? | 40-60 |
What is the refractory period? | Allows for emptying of the ventricle before another contraction occurs |
What is the absolute refractory period? | Membrane cannot response, another action potential cannot be produced |
What is the relative refractory period? | In the presence of a stronger than normal stimulus, another action potential can be produced |
How does the Impulse conduction process work? | 1. SA node activity and atrial activation begin 2. Stimulus spreads across the atrial surfaces and reaches AV node. 3.) There is a 100-msec delay at AV node, Atrial contraction begins. 4.) Impulse travels along interventricular septum within the AV.. |
How does the Impulse conduction process work? Pt.2 | 4.) bundle and the bundle branches to the Purkinje fibers and, via the moderator band, to the papillary muscles of right ventricle. 5.) The impulse is distributed by Purkinje fibers and relayed throughout the ventricular myocardium... |
How does the Impulse conduction process work? Pt.3 | 5.) Atrial contraction is completed, and ventricular contraction beings. Elapsed= 225msec |
What does the P wave represent in an ECG or EKG? | atrial depolarization |
What does the QRS complex represent in an ECG or EKG? | ventricular depolarization |
What does the PR interval represent in an ECG or EKG? | time from atrial depolarization to beginning of ventricular depolarization |
What does the ST segment represent in an ECG or EKG? | interval between ventricular depolarization and repolarization |
What does the QT interval represent in an ECG or EKG? | time it takes for both ventricular depolarization and repolarization to occur |
What is the cardiac cycle? | Period between start of one heartbeat and beginning of next heartbeat |
What are the two phases of the cardiac cycle? | Systole which is contraction, chambers eject blood and Diastole, relaxation, chambers fill with blood. |
T/F Blood flows from high to low pressure during the cardiac cycle. | T |
What is the end-diastolic volume (EDV)? | Blood remaining at the end of ventricular diastole |
What is end-systolic volume (ESV)? | Blood remaining at the end of ventricular systole |
What is happening during the 1st heart sound? | "Lub", AV valves close |
What is happening during the 2nd heart sound? | "Dub", semilunar valves close |
What is stroke volume (SV)? What is the equation? | Amount of blood ejected from ventricles per beat. SV = EDV-ESV |
What is ejection fraction (EF)? | Fraction of blood ejected from ventricles relative to EDV. |
What is cardiac output (CO)? What is the equation? | Amount of blood pumped by left ventricle in one minute CO (mL/min) = HR (beats/min) x SV (mL/beat) (EDV-ESV) |
What is cardiac index (CI)? | Relationship between cardiac output and body surface area (BSA). |
What is preload? | Directly proportional to EDV. |
What is Systemic vascular resistance (SVR) aka peripheral vascular resistance (PVR)? | Resistance in circulatory system used to create blood pressure and the flow of blood. (MAP-CVP) / CO |
What is mean arterial pressure (MAP)? Normal range? Equation? | Average arterial pressure throughout one cardiac cycle. 70-105 mm Hg. 1/3 SBP + 2/3 DBP |
What is central venous pressure (CVP)? Normal range? | Measure of pressure in vena cava. 2-6 mm Hg |
What is afterload? | Amount of tension ventricles must overcome to open semilunar valves and eject blood. |
What is the Frank-starling law? | describes the relationship of myocardial stretch and contractility. Inc volume in ventricle → inc myocardial stretching. Inc myocardial stretching → inc SV |
What does the automatic nervous system comprise of? | Sympathetic nervous system (SNS) and Parasympathetic nervous system (PNS) |
T/F Heart is innervated by both SNS and PNS | T |
T/F SNS stimulation releases norepinephrine (NE) which stimulates adrenergic receptors on target organ | T |
T/F PNS stimulation releases acetylcholine (ACh) which stimulates cholinergic receptors | T |
What are the cardiac centers? | Control cardiac activity by monitoring baroreceptors and chemoreceptors |
What is Chronotropy? | heart rate |
What is Dromotropy? | conduction velocity |
What is Inotropy? | force of contraction |
T/F SNS activation causes positive chronotropy, dromotropy, and ionotropy | T |
T/F PNS activation causes negative chronotropy, dromotropy, and ionotropy | T |
What is ANP and BNP? | Atrial natriuretic peptide and brain natriuretic peptide respectively. Promotes vasodilation and induce natriuresis and diuresis. |
What is Neprilysin? | enzyme that degrades natriuretic peptides. |
What part of the adrenal gland produces Epi and NE? | Medulla |
What part of the adrenal gland produces Cortisol, Aldosterone, and androgens and estrogen? | Cortex |
What does the thyroid hormone do? | Regulates genes involved in myocardial contraction and electrochemical signaling |
What receptor does ACh bind to? What major location and what does it do? | Muscarinic, inhibition of cardiac muscle |
What receptors does NE and Epi bind to? What major location and what do they do? | Adrenergic, B1 = heart, inc heart rate and force of contraction, B2 = lungs, dilates blood vessels and bronchioles, A1 = blood vessels, constricts blood vessels, A2 = membrane of adrenergic axon terminals, inhibits NE release from adrenergic terminals |