Module 1 - Cardio Flashcards
How many circuits does the cardiovascular
system have?
2: Pulmonary & systemic
Which system has the highest pressure?
Systemic
How many chambers does the heart have?
4: right atrium, left atrium, right ventricle, and left ventricle
Which chamber is the most muscular?
Left ventricle
How many valves does the heart have?
2 atrioventricular valves (tricuspid & bicuspid)
2 semilunar valves (pulmonary & aortic)
Why are valves important?
To prevent backflow of blood
What are systole and diastole?
Systole: contraction phase of the heart, pumping blood out.
Diastole: relaxation phase, allowing the heart to fill with blood.
What is the function of the semilunar valves?
To permit blood flow into the arteries and prevent backflow into the ventricles.
What is the pericardium
A double-walled sac containing the heart and the roots of the great vessels, maintaining the heart’s position and preventing overfilling.
What are the atrioventricular valves and their locations?
The tricuspid valve (right side)
bicuspid/mitral valve (left side).
What is End Diastolic Volume (EDV)?
the volume of blood in the ventricle at the end of diastole, just before contraction. It represents the maximum volume of blood the ventricle will hold.
What is End Systolic Volume (ESV)?
End Systolic Volume (ESV) is the volume of blood remaining in the ventricle after contraction. It represents the minimum volume of blood in the ventricle.
What is preload, and how does it affect the heart?
Preload is the degree of stretch of the heart muscle at the end of diastole, just before contraction. It is primarily determined by the left ventricular end diastolic volume (EDV). Greater stretch (higher preload) results in a stronger contraction of the heart.
What is afterload, and what is its main determinant?
Afterload is the resistance the heart must overcome to eject blood during systole. Its main determinant is the resistance in the blood vessels, such as blood pressure.
What is venous return, and how does it impact cardiac output?
Venous return is the volume of blood returning to the heart from the veins each minute. Increased venous return increases EDV, which in turn increases stroke volume and cardiac output.
What does the Frank-Starling law of the heart state?
The Frank-Starling law of the heart states that the greater the end diastolic volume (EDV), the greater the force of contraction during systole, within physiological limits. This is the heart’s intrinsic ability to adapt to changing volumes of incoming blood.
What is a cardiac action potential?
A cardiac action potential is the electrical impulse that travels through the heart’s cells, triggering a coordinated contraction of the heart muscle.
What are the two main types of cells in the heart?
The heart contains contractile cardiac muscle cells (responsible for pumping) and pacemaker cells (responsible for generating action potentials).
What is the role of pacemaker cells in the heart?
Located in the sinoatrial (SA) node, can spontaneously generate action potentials, setting the rhythm for the entire heart without neural input.
What is the sinoatrial (SA) node?
Small group of cells in the right atrium that acts as the heart’s primary pacemaker by generating regular action potentials, initiating the heartbeat.
What is the atrioventricular (AV) node, and what is its function?
Secondary pacemaker located between the atria and ventricles. It delays the electrical impulse, ensuring that the atria contract before the ventricles, coordinating heart activity.
What is excitation-contraction coupling in the heart?
Process by which an action potential leads to the release of calcium ions, which then enable actin and myosin to bind, causing cardiac muscle contraction.
What is the Frank-Starling law of the heart?
States that the greater the end-diastolic volume (preload), the stronger the contraction of the heart, allowing it to eject more blood.
What is the role of gap junctions in the heart?
Gap junctions are channels between cardiac muscle cells that allow ions to pass freely, enabling rapid transmission of action potentials and coordinated contraction.
