HEART 1 Flashcards
The human heart is an efficient organ that can pump around
7500l/day
female heart weight
250-320g
male heart weight
300-360g
right ventricle thickness
0.3-0.5cm
left ventricle thickness
1.3-1.5cm
increased in weight/thockness
hypertrophy
enlarged ventricular chamber size
dilation
increased cardiac weight/size resulting from hypertrophy and/or dilatation
cardiomegaly
additional fxn of cardiomyocytes
endocrine (anp and bnp)
pumping fxn
myocardium
coordinated contraction: systole; coordinated relaxation:_____
diastole
left ventricular myocytes are arranged in a_________
spiral circumferential orientation
endocrine fxn:
B-type natriuretic peptide
Ventricle
generates overall less robust contractile force
right ventricular myocytes
shortening of serial contractile elements aka sarcomeres within parallel myofibrils
contraction
atrioventricular valves
tricuspid and mitral valve
semilunar valves
aortic and pulmonary
dilatation of the aortic root can result in
valvular regurgitation
atrioventricular valves depends on the proper function not only of the leaflets but also
the tendinous cords and the attached papillary muscles of the ventricular wall.
Left ventricular dilation, a ruptured cord, or papillary muscle dysfunction can all interfere with mitral valve closure, causing
valvular insufficiency
A dense collagenous layer at the outflow surface, connected to the valvular supporting structures and providing mechanical integrity
fibrosa layer
A central core of loose connective tissue
spongiosa layer
A layer rich in elastin on the inflow surface, providing leaflet recoil
ventricularis or atrialis layer
pacemaker
at the junction of the right atrial appendage and SVC
SA node
located in the RA along the interatrial septum
AV node
connecting the RA to the ventricular septum
bundle of his
stimulates ventricles via
arborization into the Purkinje
network
R and L bundle branch divisions
Nutrients and oxygen are delivered via
the
coronary arteries
external surface of the heart
epicardial coronary arteries
myocardium
intramural arteries
Blood flow to the myocardium occurs during
ventricular diastole
changes in aging heart (chambers)
increased left atrial cavity size
decreased left ventricular cavity size
sigmoid-shaped ventricular septum
changes in the aging heart (valves)
aortic valve calcific deposits mitral valve annular calcific deposits fibrous thickening of leaflets buckling of mitral leaflets toward the left atrium lambl excrescences
Epicardial Coronary arteries
Tortuosity
Diminished compliance
Calcific deposits
Atherosclerotic plaques
Changes in the aging heart (myocardium)
Decreased mass Increased subepicardial fat brown atrophy Lipofuscin deposition Basophilic Degeneration Amyloid deposits
Changes in the aging heart (aorta)
Dilated ascending aorta with rightward shift
elongated thoracic aorta
Sinotubular junction calcific deposits
Elastic fragmentation and collagen accumulation
Atherosclerotic plaque
increased filling volumes of the hearts, thereby increasing actin-myosin cross-bridge formation, and enhancing contractility and stroke volume
Frank-starling mechanism
These augment heart function and/or regulate filling volumes and pressures (and many of the therapies for CHF affect
these systems when they become maladaptive).
activation of neurohumoral systems
counterbalance for RAAS, because it stimulates diuresis
ANP
is the general term applied to the collective molecular, cellular, and structural changes that
occur in response to injury or altered ventricular loading.
Ventricular remodeling
new sarcomeres are predominantly assembled parallel to the long axes of cells, expanding cross-sectional area of myocytes in ventricles and causing a concentric increase in wall thickness
Pressure-overload hypertrophy (due to hypertension or aortic stenosis)
new sarcomeres being assembled in series, elongating the myocyte. (eccentric hypertrophy)
Volume-overload hypertrophy (due to valvular regurgitation, valvular insufficiency
hypertrophy is also typically accompanies by
fibrous tissue deposition
promote cellular growth and alters protein expression
FOS
JUN
MYC
EGR1
there is generally heavy and
dilated heart with variable degrees of myocardial hypertrophy
CHF
loss of myocardial mass
because of the death of myocardium leads to the hypertrophy of surrounding myocardium
acute MI
overload due to problems on cusps
valvular heart diseases
associated with volume load
hypertrophy with increases in capillary density
aerobic exercise
regular aerobic activity
decreases the resting heart rate and blood pressure
induces mild pressure hypertrophy
purely static exercise
end point if most forms of cardiac diseases
heart failure
abrupt onset of CHF
Large MI
Acute valve dysfunction
deposition of fibrous tissue limiting its pumping relaxation movements can cause ______.
Passive congestion of the pulmonary circulation
lett sided heart failure
causes of Left sided heart failure
Ischemic heart dse
Systemic HTN
aortic and mitral valvular dse
primary myocardial dse
in microscopic findings, if caused by ischemia, tthere is _________
coagulative necrosis and significant numbers of acute inflammatory cells
pulmonary congestion and edema
heavy, wet lungs
telltale signs of previous episodes of pulmonary edema
hemosiderin-laden macrophages
arise from
elevated pleural capillary and lymphatic pressure and the resultant transudation of fluid into the pleural cavities.
pleural effusions
Early left-sided heart failure symptoms are related to
pulmonary congestion and edema
3rd heart sound due to
volume overload
4th heart sound
due to increase myocardial stiffness
If heart failure is associated with progressive ventricular dilation, the papillary muscles are displaced outward, causing
mitral regurgitation
Subsequent chronic dilation of the left atrium can cause
atrial fibrillation
In moderate CHF, a reduced ejection fraction
leads to diminished renal perfusion, causing
activation of RAAS
if the hypoperfusion of the kidney becomes sufficiently severe,
impaired excretion of nitrogenous products may cause azotemia
insufficient ejection fraction
systolic failure
caused by any disorder that
damages the contractile function of the left ventricle. So, you can have ischemia there, fibrosis, tumor in the left ventricle
pump failure
is secondary to abnormally stiff left ventricle during diastole
diastolic failure
can also limit myocardial
relaxation and therefore mimics primary diastolic
dysfunction.
constrictive pericarditis
Consequence of left-sided heart failure.
right sided heart failure
Isolated right- sided heart failure is infrequent
and typically occurs in patients with one of a
variety of disorders affecting the lungs; hence it
is often referred to as
cor pulmonale
In some instances, especially when left-sided
heart failure with hypoperfusion is also present, severe centrilobular hypoxia
centrilobular necrosis
hallmark of right-sided heart failure.
Edema of the peripheral
and dependent portions of the body, especially foot/ankle (pedal) and pretibial edema
tool to quantitatively assess the extent of CHF.
serum levels of B-type Natriuretic Factor
is also an extremely valuable
tool in following patients with CHF, providing a measure of ejection fraction, wall motion, valvular function, and possible mural thrombosis.
echocardiograophy
