cardio lec 1-3 learning objectives

what is the main function of the cardiovascular system?

transportation of gases, nutrients, waste,

thermoregulation

acid/base balance

immune defense

what are the three main components of the cardiovascular system?

heart, blood, blood vessels

what is plasma

the liquid portion of blood

• carries electrolytes

• nutrients

• gases

• hormones

• proteins

what are the 4 chambers of the heart?

left atria, right atria

left ventricle, right ventricle

what are the 4 valves of the heart

tricuspid (right aortic valve), bicuspid (left AV valve)

pulmonary semilunar, aortic semilunar

what is the function of of the valve

one way flow via pressure differences

what does first heart sound stand for

av valve closing (lub)

what does the second heart sound stand for

semilunar valves closing (dub)

what are the heart wall layers

endocardium, myocardium, epicardium + pericardium

what is the endocardium

inner lining

what is the myocardium

contractile layer

major component of the heart 

what are the epicardium and pericardium

protection and lubrication

red blood cells traits

carry o2, co2

has no nucleus/mitochondria

uses glycolysis

function of the pericardial fluid

serves as lubricant as the heart contracts

kidneys make Erythropoietin which …

tells your bone marrow to make more blood cells

cardiac myocytes make 99% and are

• contractile

• striated

• connected by intercalated discs

desmosomes are

mechanical strength

pacemaker cells make up 1% and are

autorythmic

has no resting membrane potential

generate pacemaker potentials

do not contract

why does the plateau matter in cardiac potential

• Long refractory period

• Prevents tetanus

• Maintains continuous blood flow

Pacemaker cell action potential have

• No true resting potential

• Funny Na⁺ channels (f-channels)

• T-type Ca²⁺ channels

• AP upstroke = L-type Ca²⁺, NOT Na⁺

Slope of pacemaker potential =

heart rate

what is the P wave

atrial depolarization

what is the QRS

ventricular depolarization

what is the T wave

ventricular depolarization

1st step of cardiac cycle

Isovolumetric contraction (AV valves close)

2nd step of cardiac cycle

Ejection (semilunar valves open)

3rd step of cardiac cycle

Isovolumetric relaxation (semilunar valves close)

4th step of cardiac cycle

Passive filling

5th step of cardiac cycle

Active filling (atrial contraction)

does parasympathetic stimulation weaken the heart

no it slows it