heart Flashcards
Following a drop of blood
blood from the body tissues comes in from veins (inferior or supiror vena cava, or the cornoary sinus), then flows into the right artium. traveling thouhg the tricuspid AV valve the blood then enters the right ventricle, till going though the pulmonary semilunar valve into the pulmonary arteries. After flowing through the lungs it returns to the heart though the pulmonary veins into the left artium then through the bicuspid(mirtal) AV valve into the left ventricle. Finally leaving thought the aortic semilunar valve into the aorta to return to the bodies tissues.
returns to…
Deoxygenated blood
returns to the right side of the heart from the body tissues
returns to…
oxygenated blood
the left side of the heart from the lungs
veins bring blood to…
the heart
arteries bring blood to…
the body
SKIP 5/5
Sinoatrial node
-in the right artium
-pace maker of the heart
-causes artial to contract at the same time
P wave
atriole systole or atriole depolarization
Atrioventricular node
-bottom of right atrium
-delay singal from sinoartial node to the ventricles
-pushes signal to budle of His
Bundle of His
enters into the interventricular septum and splits into the budle branches
bundle branches
seperate into purkinje fibers
purkinje fibers
causes the ventricle to contract
QRS wave
ventricular systole or ventricular depolarization
atrial repolarization or atrial diastole also occurs here
T wave
ventricular repolarization or ventricular diastole
cardiac conduction as a whole
sinoartial node causes artials to contract (artial systole/depolarization) (The P Wave) then the artioventricular node slows the signal then pushes it to the bundle of His which splits into budle branches finally spiliting into purkinje fibers causing the ventricle to contract (venticular systole/depolarization) (The QRS Wave) while the atrium relaxes (atrial diastole/repolarization), once the ventricles are done contracting the ventricles relaxe (venticular diastole/repolarization) (The T Wave)
Cardiac Cycle
“starts” in passive ventricular filling, moves to artial systole, then isometric contraction, to ventricle systole, then isometric relaxation
Passive venticular filling
-blood is flowing from the atriums to ventricles thought open AV valves (SL valves are closed)
-about 80% of the blood from artiums
determined by venous return - blood coming from the vena cava or pulmoary veins
End Diastolic Volume
volume of blood in ventricles at the end of atrial systole and the “end” of ventricular diastole
Arital systole
the artia contracts and pushes the remainder (~20%) of the blood in the aritum from passice ventricular filling into the ventricle - AV Valves are still open while the SV valves are closed
isovolumetric contraction
all valves are closed
-very begining of ventricle systole
-needs x amount of pressure to ope the SL valves
Ventricular Systole
-SL valves open and AV vales stay closed
-causes rapid ejection of blood from ventricles
end systolic volume
volume of blood left in ventricles after systole (after rapid ejection)
-not all blood leaves ventricles in systole
-50-70% is rapidly ejected
isovolumetric relaxation
-all valves close
-SL vavles are closed, but now AV valves need to open (meaning that the heart need to relax to allow the AV valves to open)
Cardiac Output
Stoke Volume * Heart Rate
Stoke volume
amount of blood pumped out of your ventricles PER BEAT
Preload
stretch on ventricular myocardium caused by venous return
afterload
pressure ventricles must overcome to eject blood during systole
-determined by perhipheral resistance
chronotropic
affecting heart rate
inotropic
affecting contractility
-less venous return means…
-more venous return means…
in reference to preload
-less preload
-more preload
High blood pressure causes…
Low blood pressure causes…
in refrence to afterload
-high afterload
-low afterload
