Chapter 17 A&P
Rank from the first to the last steps to describe correct order of events of a cardiac contractile cell action potential. Refer to the graph 〽️ contractile cell action potential as you rank the events.
1- rapid depolarization phase 2- initial polarization phase 3- plateau phase 4- polarization phase
Which best described the is volumetric contraction phase of cardiac cycle
As ventricular systole starts, the Av valve are closed and the semolina valves are closed. Because the ventricular are contractinig and both valves are closed, pressure increase rapidly leading to ejection.
The P wave on an electrocardiogram (ECG) represents the depolarization of cells in the
Atria
The P wave on an electrocardiogram represent
Atrial depolarization
Which hormone decreases cardiac output by decreasing blood volume and preload?
Atrial natriuretic peptide
The cardiac output will remain the same because
CO=HR*SV= 2HR*SV/2
Articles slightly increase blood 💉 volume in the ventricles
False
The papilary muscles contract after the other ventricular muscles so that they can take up slack on the chordae tendineae before the full force of ventricular contractions sends blood against the atrioventricular (AV) valve flaps.
False
The apex of the heart is
Inferior
The systemic circuit
Is between the heart and the tissue of the body.
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 parietal pericardium
Lines the internal surface of the fibrous pericardium.
The arotic valve closes when
Pressure in the left ventricle falls below aortic pressure.
What vessel(s) deliver oxygenated blood to the left atrium?
Pulmonary veins
What valve represents the backflow of blood from the right ventricle into the right atrium
Right atrioventricular valve( tricuspid valve)
The two veins that drain the majority of systemic circuit are
Superior and inferior venae cavae
The vessel 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
After the atrial depolarization p wave
The atria contract allowing them to empty and causing the ventricles to reach their EDV
Which of the following events will immediately follow the phase of the cardiac cycle depicted in the figure (end systolic volume (ESV))
The atrioventricular valves open. This is the isovolumetric relaxation phase.
The P wave reflect
The depolarization of the atria
Select the correct statement about the function of myocardial cells.
The entire heart contracts as a unit or it does not contract at all.
After load is described as
The force the ventricles must overcome to eject blood into their respective arteries.
The arotic valve closes
To prevent black flow of the blood into ventricle.
The plateau phase of the cardiac action potential is due
To the opening of calcium ions channels
The left side of the heart pumps the same volume of blood as the right
True
When released in large quantities, thyroxine, a thyroid gland hormone, causes a sustained increase in heart rate.
True
Match the following
Vagal tone: Heart rate at rest under both autonomic divisions signaling. Bradycardia: an abnormally slow heart rate Tachycardia: an abnormally fast heart rate Cardiac reserve: Difference between resting an maximal cardiac output.
During what phase does flow from the ventricles into the pulmonary trunk and aorta.
Ventricular injection phase
The arotic valve opens
When the pressure in the ventricle rise above the arotic pressure (B)
What vessel delivers oxygenated blood to systemic capillaries for gas exchange?
aorta
Autorhythmicity is the responsibility of
cardiac pacemaker cells
What largely determines preload
end-diastolic volume (EDV)
Which of the following increases stroke volume
exercise Exercise increases venous return, which would in turn increase the amount of blood in the presystolic ventricle (preload)
The apex of the heart is
inferior tip of the heart and point toward the left side
What characteristic differentiates cardiac muscle cells from skeletal muscle cells
intercalated discs
What surface groove separates the right and left ventricles
interventricular sulcus
Unlike skeletal muscle action potentials, cardiac muscle action potentials
involve calcium voltage-gated channels
The second heart sound is heard during which phase of the cardiac cycle
isovolumetric relaxation "DUB"
The pulmonary circuit involves blood flow from the heart to and from the
lungs
The right side of the heart pumps deoxygenated Blood into
pulmonary arteries
Which of the following vessels carries oxygenated blood
pulmonary vein
What normally serves as the pacemaker of the entire heart?
sinoatrial (SA) node
What two values are needed in order to calculate cardiac output (CO) for a ventricle?
stroke volume (SV) and heart rate (HR)
Blood from the systemic circuit returns to the heart via the
vena cavae
