Terminology
The value known as beats per minute
heart rate
EDV - ESV = ?
120ml - 50ml = ?
stroke volume
The degree to which the sarcomeres in the ventricular cells are stretched before they contract
preload
Rate of this firing determines HR
SA node depolarizing
Innervation of a system with nerves that release NE to increase HR is dependent upon the body's needs
sympathetic nervous system
The amount of blood pumped into the pulmonary and systemic circuits in 1 minute - from the ventricles
cardiac output
HR x SV = ?
70 beats/min x 70ml/beat = ?
cardiac output
The pumping ability, or the ability to generate tension
contractility
chronotropic agents
positive chronotropic agents: anything that increases firing of SA node
negative chronotropic agents: opposite is true
The ions in which the sympathetic nervous system releases in order to increase HR
calcium ions
The amount of blood pumped into one heartbeat
stroke volume
Cardiac output is affected by what factors?
age/body size/gender and oxygen demand
The force that the right and left ventricles must overcome in order to eject blood into their respective arteries
afterload
Example of a positive chronotropic agent
sympatehtic nervous system, certain hormones, and elevated body temeprature
The sympathetic nervous system influences which node to fire faster to increase HR?
SA node
The amount of blood in the ventricle at the end of a contraction
end-systolic volume (ESV)
Can heart disease reduce CO?
True
Name some negative influences on SV
high blood pressure, sudden drop in blood pressure, sudden drop in blood volume, extremely fast HR
Example of a negative chronotropic hormone
parasympathetic nervous system and decreased body temperature
By increasing calcium ion concentration in cardiac cells and firing SA node faster, we can increase what?
contractility --> SV
The amount of blood in the ventricle after it has filled during diastole
end-diastolic volume (EDV)
Normal range for CO
5000mL or 5L
Name some positive influences on SV
increased sympathetic stimulation, increased venous return, slower HR, exercise, increased Ca++
Difference between agaonistic versus antagonistic
agonist: a drug that binds the receptor and mimic the effects of NE
anagonists: a drug that blocks the receptor and prevent the binding of NE to it
Hormones that are released into the blood by the endocrine system to influence cardiac output
Epi, NE, thyroid hormone, glucagon
by controlling water balance: aldosterone, ADH