Week 3 - Heart Flashcards
The heart is located in the ______ along with what structures?
mediastinum
esophagus, aorta
The function of fibrous pericardium is _______
protect & anchor HT, prevent overstretching
The function of serous pericardium is _______
prevent friction between contracting HT and fibrous pericardium
List and describe layers of the heart from exterior to interior
epicardium - visceral layer of serous pericardium
myocardium - cardiac muscle layer
endocardium - chamber lining & valves
The blood from right ventricle goes to the _______
pulmonary trunk -> right and left pulmonary arteries
The bicuspid valve is also known as _______
mitral valve
The _______ muscles attach to the atrioventricular valves via the __________ and contract to prevent inversion or prolapse of these valves
papillary
chordae tendineae
The foramen ovalis is ________
in developing fetus an opening in right atrium where blood bypasses the right ventricle and directly enters the left atrium
The ductus arteriosus is _________
in developing fetus a blood vessel connecting the pulmonary artery to the proximal descending aorta, bypassing the lungs
The fibrous skeleton of heart is composed of ________. Its functions are ________
dense connective tissue rings
support structure for heart valves
insertion point for cardiac muscle bundles
electrical insulator between atria and ventricles
Describe systemic blood circulation
left ventricle pumps oxygenated blood into aorta
aorta branches into many arteries that travel to organs
arteries branch into arterioles in tissue
arterioles branch into capillaries
deoxygenated blood begins return into venules
venules merge into veins and return to right atrium
Describe pulmonary blood circulation
right side of HT pumps deoxygenated blood to LU
right ventricle pumps blood to pulmonary trunk
pulmonary trunk branches into pulmonary arteries
pulmonary arteries carry blood to LU for exchange of gases
oxygenated blood returns to HT in pulmonary veins
Anastomoses are _______
connections between arteries supplying blood to the same region, providing alternate routes if one artery become occluded
Describe conduction system of HT
SA Node - cluster of autorhthymic cells in right atrium begins HT activity that spreads to both atria, excitation spreads to AV node
AV node transmits signal to AV bundle of His
AV bundle divides into right & left bundle branches & purkinje fibers
SA node fires spontaneously ____ times per minute
AV node fires at ______ times per minute
60-100
40-60
Ectopic pacemakers are _____ and can be caused by stimulants including _____
extra beats forming at other sites of the HT
caffeine, nicotine
In an electrocardiogram, the P wave denotes _____ while the QRS complex denotes ________
atrial depolarization
ventricular depolarization
In the normal cardiac cycle, the End diastolic volume (EDV) is about ___ml while the End systolic volume (ESV) is about ___ ml. The stroke volume is defined as ______
130 ml
60ml
EDV - ESV
List the phases of the cardiac cycle
Isovolumetric relaxation Ventricular filling Atrial systole Isovolumetric contraction Ventricular systole
In the cardiac cycle, isovolumetric relaxation is a brief period when volume in ventricle ________ as ventricles ______, pressure ____ and AV valves & semilunar valves are ______
does not change
relax
drops
closed
In the cardiac cycle, ventricular filling is the period when _____
blood flows from full atria into ventricle
diastasis - blood trickles into ventricle
atrial systole - pumps final 20-25ml blood into ventricle
In the cardiac cycle, isovolumetric contraction is the period when _____
atria, ventricles are all in contraction and AV/SL valves are closed
In the cardiac cycle, ventricular systole is the period when ________
ventricles pump blood into pulmonary trunk / ascending aorta
Cardiac output = ______
Stroke volume (SV) * Heart Rate (HR)
Cardiac reserve = _____
In the average person, cardiac reserve is _____
In atheletes, cardiac reserve is _______
maximum output / output at rest
4-5
7-8
List and define influences on Stroke Volume
Preload - affect of stretching
Contractility - force of contraction
Afterload - amount of pressure created by blood resisting flow
In cardiac output, what can influence the Preload?
amount of stretching of cardiac muscle
In cardiac output, what can influence contractility?
autonomic nerves, hormones, CA2+ or K+
In cardiac output, what can influence afterload?
arterial blood pressure in diastole
Heart rate is regulated by what part of the nervous system?
cardiovascular center in medulla oblongata
The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the _______
systolic ejection phase
The first heard sound (“lub”) is associated with the ____
closing of the AV valves
An increase in the rate of action potentials from baroreceptors will reflexively lead to what change in heart rate? in blood pressure?
decrease
decrease
