Nursing Fundamentals: Exam 3 blue print keiser university Exam Questions And Answers Already Graded A+

Anatomy and physiology of the *CARDIAC SYSTEM:* - Heart: ▪ Hollow, cone-shaped, size of fist ▪ Located in mediastinum ▪ Enclosed by the *pericardium* = LAYERS INCLUDE = ▪ *epicardium* (a serous membrane that forms the innermost layer of the pericardium) ▪ *myocardium* (the middle and thickest layer of the heart wall) ▪ *endocardium* (lines the inside of the chambers of the heart and forms the surface of the valves ▪ Chambers are two upper atria, two lower ventricles separated by septum, Atrioventricular (AV) valves ▪ Atrioventricular (AV) valves separate atria from ventricles: *Tricuspid* (right) and *Bicuspid or mitral* (left) ▪ Ventricles from great vessels separated by Semilunar (half-moon) valves *Pulmonic* (Right) and *Aortic* (Left) ↓ - - *Deoxygenated blood* enters right side of heart, exits to lungs; *oxygenated blood* returns via left side of heart, exits to body ↓ - - *Function of the valves: direct the blood flow from atria to ventricles, and ventricles to great vessels, *prevent backflow of blood* ▪ Ventricles keep the blood flowing in the right direction ↓ - *Blood supply* of the heart = - *The coronary arteries supply the heart muscle with oxygenated blood.* ↓ - *Conduction system* of the heart = controls the electrical activity of the heart -The cardiac conduction system is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components of the cardiac conduction system are the *SA node, AV node, bundle of His, bundle branches, and Purkinje fibers.* *SA node* = pacemaker = 60-100bpm = reads normal sinus rhythm on the monitor *Pacemaker* = regulates heart rate ↓ - CARDIAC CYCLE - *Systole* = blood is ejected into the pulmonary & systemic circulation *S1* = first heart sound = caused by the closing of the atrioventricular valves (the tricuspid and mitral (bicuspid) valves) *Diastole* = Ventricles fill with blood *S2* = second heart sound = caused by the closing of the semilunar valves (pulmonic and aortic valves) ↓ - *CARDIAC OUTPUT* *Causes of decreased CO* = MI, CHF, dysrhythmias, valve deformities & structural problems Decreased CO = impaired tissue perfusion - ▪ *Cardiac output (CO)* = amount of blood ejected from the heart each minute CO = Indicator for heart functioning as pump Normal CO is 4 to 8 L/min ▪ *Stroke volume* (SV) = amount of blood ejected from the heart with each beat *SV X HR = cardiac output* Normal stroke volume = 70mL ▪ *Heart rate* = number of beats per minute ↓ - - HEART RATE: *↑ Increased HR* = ↑ Increased CO*↓ Decreased HR* = ↓ decreased CO ▪ Sustained rapid HR more than 150 bpm = inadequate time for ventricles to fill = CO to fall ▪ HR influenced by: BP, hormones, medications & so on ↓ - Preload = - end diastolic volume that stretches the right or left ventricle of the heart *PRELOAD = VOLUME* = the more volume, the more it stretches ↓ - *CONTRACTILITY* = depends on calcium levels - ▪ Contractility = inherent ability of cardiac muscle to contract ▪ Contractility of heart depend on intracellular calcium *electrolytes effect the contractility of the heart ▪ Poor contractility = decrease SV & CO *Inotropic drugs* help with contraction of the heart most common *+ inotropic drug = Digoxin* = + inotropic drugs increase contractility *Normal therapeutic range of DIGOXIN = 0.5-2mcg/mL- intotropic medications = beta-blockers = ↓BP, ↓HR, ↓contractility = "lol" medications (ie. metoprolol) ↓ - - DO NOT give Digoxin = if HR is > 60bpm Digoxin toxicity = n/v/d, anorexia, tiredness, weakness ↓ - Afterload = - *Afterload* is the pressure in the wall of the left ventricle during ejection; resistance against which the heart must pump ▪ pressure within arteries that ventricles must overcome to push blood into circulation ▪ Left ventricle must work harder than right ▪ The higher the afterload = the harder the heart has to work to eject blood Ex. systemic vasoconstriction = increases arterial BP and afterload Vasodilation = reduces workload - The heart and blood vessels = The left side of the heart pumps oxygenated blood into the arteries. Deoxygenated blood returns via the venous system into the right side of the heart. ↓ - Life Span Considerations: *HEART RATE* - ▪ At *Birth - 2 wks* = 100-180bpm = normal for newborns ▪ *2 yrs old* = 80-120 bpm