Size of heart? like a clenched firstHeart location? mediastinum of thoraxHeart is enclosed in a double sac made of _________ parietal outer layer and ___________ visceral inner layer. Outer Fibrous pericardium and
Inner Serous pericardiumPericardial cavity between serous layers contains _________serous fluid, for lubricationHeart wall layers from inside out are __________, _________, and _______Endocardium
Myocardium, which is reinforced by fibrous skeleton
Epicardium, visceral layer of the serous pericardium
Heart is single or double pump? DOUBLE. It’s only single as a fetus. Entering the Right Atrium are the…………. superior vena cava, inferior vena cava, and coronary sinusWhat enters the Left Atrium? 4 pulmonary veinsRight Ventricle discharges blood into the _________pulmonary trunkLeft Ventricle pumps blood into the __________aortaThe Right side of the Heart is the ___________ circuit pumppulmonary circuit pump.
Oxygen poor blood enters Right Atrium, then right ventricle, through the pulmonary trunk to the lungs, and back to the Left Atrium via Pulmonary Veins
Left side of Heart is the _________ circuit pumpSystemic circuit pump.
Oxygen Rich blood enters Left Atrium from Lungs flows into Left Ventricle, then into Aorta, which provides supply to all body.
Systemic veins return the oxygen depleted blood to the Right Atrium
Right and Left Coronary arteries branch from the _______Aorta and via their main branches; ant and post interventricular, right marginal, and circumflex arteriesBlood delivery to myocardium occurs during ________heart relaxation2 kinds of Atrioventricular valves are ______ and _______tricuspids and mitralTricuspid valves do what? prevent back flow into atria when ventricles are contractingMitral valves do what? prevent back flow into atria when ventricles are contractingPulmonary and Aortic valves or Semilunar valves do what? prevent back flow into the ventricles when the ventricles are relaxingCardiac muscle structure descriptionbranching
striated
mostly uni nucleus cells
contain myofibrils that have sarcomeres
Adjascent cardiac cells are connected by _________Intercalated discs containing desmosomes and gap junctions. Myocardium behaves as a functional ___________ because of electrical coupling provided by gap junctionssynctiumMembrane depolarization of contractile __________ causes opening of sodium channels and sodium entrymyocytesDepolarization also opens slow _____ channelscalciumCalcium entry _______ period of depolarization, and creates a _______ on the line graphprolongs depolarization
plateau line graph
Compared to skeletal muscle, cardiac muscle has a prolonged __________ refractory period that prevents __________tetanyCardiac muscle has abundant __________ and depends almost entirely on _________ to make ATPmitochondria
Aerobic respiration
True or False?
Certain non-contractile cardiac muscle cells exhibit automaticity and rhythmicity and can independently initiate action potentials.
TrueWhat cells compose intrinsic conduction system of heart? non contractile cardiac muscle cells that exhibit automaticity, which means an automatic response pattern or habit, and rhythmicity thta can independently initiate APsNormal heart sounds arise fromturbulent blood flow during the closing of heart valves. Abnormal heart sounds are called __________, and usually reflect problems with ________murmurs reflect valve problemsDuring mid-to-late diastole… Ventricles fill, Atria contract. Ventricular systole consists of the… isovolumentric contraction phase and the ventricular ejection phaseDuring early diastole.. the ventricles are relaxed and are closed chambers until the atrial pressure exceeds the ventricular pressure, forcing the AV valves open. Normal heart rate is ______, and a cardiac cycle lasts ________75 beats per minute,
and
cardiac cycle lasts 0. 8 secondsPressure changes promote what? blood flow and valve opening and closingCardiac output is? the amount of blood pumped out by EACH Ventricle in 1 minuteStroke volume is? About 70 ml, it is the difference between end diastolic volume and end systolic volume. Anything that influences heart rate or blood volume, hence stroke volume
depending on how much cardiac muscle stretches due to venous return.
Activation of sympathetic nervous system increases ________ and ________heart rate and contracilityParasympathetic activation decreases _________ but has little effect on _________. decreases heart rate,
little effect on contractility. Chemical regulation of heart is effected by _________ and _________Hormones, like epinephrine and thyroxine,
and
Ions, like potassium and calcium.
Ion imbalances impair heart activity
Congestive heart failure occurs whenheart can’t pump enough to provide normal body circulation needsHeart begins as a simple ________ tubemesodermalHeart starts pumping by what week? 4th gestational week. Fetal heart has _____ number of lung bypasses. 2.
foramen ovale
and
Ductus arteriosus ONHEART CHAPTER 18 SUMMARY SPECIFICALLY FOR YOUFOR ONLY$13. 90/PAGEOrder Now