Mastering A and P cardiovascular system Ch 17
What normally serves as the pacemaker of the entire heart?
SA node
what two values are needed in order to calculate cardiac output (CO) for a ventricle?
stroke volume and heart rate
what vessel delivers oxygenated blood to systemic capillaries for gas exchange
aorta
the P wave on an ECG represents the depolarization of cells in the
atria
which hormone decreases cardiac output by decreasing blood volume preload
atrial natriuretic peptide (ANP)
audtorhythmicity in the heart is the responsibility of
cardiac pacemaker cells
what largely determines preload?
end-diastolic volume (EDV)
the apex of the heart is
inferior tip of the heart, points towards the left side
what surface groove separates the right and left ventricles
inter ventricular sulcus
what characteristic differentiates cardiac muscle cells from skeletal muscle cells
intercalated discs
unlike skeletal muscle action potentials, cardiac muscle action potentials
involve calcium voltage gated ion channels
how will the cardiac output change if you double the heart rate but reduce the stroke volume by one half
it will not change
the pulmonary circuit involves blood flow from the heart to the
lungs
the aortic valve closes when
pressure in the left ventricle falls below aortic pressure
the aortic valve opens when...
pressure in the ventricle rises above aortic pressure
which of the following vessels carries oxygenated blood? pulmonary vein pulmonary artery pulmonary trunk superior vena cava
pulmonary vein
what vessels deliver oxygenated blood to the left atrium
pulmonary veins
vessels that deliver oxygen to the tissues of the body are part of the
systemic circuit
which of the following happens immediately after the P wave?
the atria contract, allowing them to empty and causing the ventricles to reach their end diastolic volume
afterload is described as
the force the ventricles must overcome to eject blood into their respective targets
the right side of the heart pumps deoxygenated blood into
the pulmonary arteries
what valve prevents the back flow of blood from the right ventricle into the right atrium
tricuspid valve
blood from the systemic circuit returns to the heart via the
vena cavae
during what phase does blood flow from the ventricles into the pulmonary trunk and aorta?
ventricular ejection phase