Cardiac Force Generation Flashcards
Contraction of left ventricle
circular muscles - reduces diameter from apex to base
spiral muscles pull mitral valve towards apex - shortens length of heart = push blood towards base
much higher pressures due to CIRCULAR
Contraction of right ventricle
spiral muscles pull tricuspid valve towards apex - shortens length of heart = blood towards base. pulls free wall of heart towards the septum
septum bulges into the ight ventricle
cardiac output
amount of blood pumped by the heart per minute
heart rate
number of beats per minute
stroke volume
amount of blood in right/left ventricle at the end of diastolic filling
end diastolic volume
amount of blood in the right/left ventricle at the end of diastolic filing
end systolic volume
amount of blood in the right/left ventricle at the end of systolic contraction
intropy
cardiac contractility
chronotropy
heart rate
pre load
force exerted on the heart wall at the end of diastole
Cardiac output equation
Heart rate x stroke volume
Stroke volume equation
end diastolic volume - end systolic volume
Frank - Starling Mechanism
The amount of force the heart generates during systolic contraction, stroke volume, is directly related to the end diastolic volume
Length - Tension Relationship
Volume increases in diastole -> force exerted on muscle wall stretches muscle cells -> increased tension + stretch of sarcomeres = reduction of actin overlap -> more actin for myosin heads to bind too
Afterload
The force acting in opposition of blood exiting the heart
- mainly the product of pressure in the aorta
