Circulatory System (Cardiovascular) Flashcards
system circulation
left ventricle (oxygenated) > aorta > arteries > arterioles > capillaries > venules > veins > superior/inferior vena cava > right atrium (deoxygenated) > right ventricle
pulmonary circulation
right ventricle > pulmonary arteries lungs > pulmonary veins > left atrium > left ventricle
most muscular chamber
left ventricle
cardiomyocytes
- have automaticity
- self excitable
- initiate AP without an external nerve
intercalated disks
- signal transduction
- connect cardiomyocytes
desmosomes
anchor and hold cells together
gap junctions
between cells and allow for rapid transmission of electrical signal
electrical pathway
SA node (R atrium) –> AV node (between atria) –> bundle of His –> Purkinje fiber
SA node
- pacemaker
- sends electrical signals by itself
- greatest automaticty
- contracts both atria = dumps blood into ventricles
- vagus nerve slows down SA node frequency
AV node
adds brief delay between atria and ventricles contraction
systole
= contraction
* right after ventricles contraction and eject blood into arteries
* blood pressure is HIGHEST in arteries
diastole
= relaxation
* right after atria contract to fill ventricle
* BP is the lowest in arteries
heart sounds
- S1 (LUB): AV valve closing
- S2 (DUB): semilunar valves closing
P wave
atrial depolarization
Q wave
depolarization through interventricular septum
R wave
ventricular depolarization
S wave
completion of ventricular depolarization
T wave
completion of ventricular depolarization
total peripheral resistance (TPR)
- total resistance blood faces when flowing through vessels
- vasoconstriction = increase TPR
- vasodilation = decrease TPR
mean arterial pressure (MAP)
average pressure during one cardiac cycle
* MAP = CO * TPR
blood vessels
all linded by endothelial cells
arteries/arterioles
elastic, smooth muscle
* higher BP
capillaries
tiny blood vessels, once cell thick, allow nutrients and gases to pass through
* lower BP
* movement of fluid regulated by osmotic vs. hydrostatic pressure
* osmotic pressure stays the same, hydrostatic pressure higher on arteriole side
veins
stores most of body’s blood
* one way valves to prevent backward flow
* lowest BP
where is blood flow the slowest?
slowest in the capillaries because they have most cross sectional area
what helps move blood through veins?
skeletal muscle contraction
