Cardiovascular System Flashcards
Pulmonary
delivers blood from heart to lungs & back to heart
Peripheral
delivers blood from heart to body & back to heart
Arteries
large vessels that carry blood away from heart
Arterioles
small, branch arteries
Capillaries
smallest vessels; site of gas & nutrient exchange
Veins
vessels that carry blood toward heart
Venules
small veins that carry blood toward heart
Venous blood
blood returning to heart
Arterial blood
blood leaving heart and going to body or lungs
2 AV valves:
tricuspid (R side), bicuspid (L side)
2 semilunar valves:
pulmonary (R side), aortic (L side)
Pericardium
tough, membranous sac that encases heart
Anastomosis
intercommunication between 2 arteries ensuring blood flow to area even if one artery blocked
Systole
contraction phase; blood is pumped out of chamber
Diastole
relaxation phase; blood fills chamber
Intrinsic control of cardiac cycle
Autorhythmaticity
SA node
AV node
Purkinje fibers
Autorhythmaticity
ability to initiate impulse for contraction at regular intervals
Sinoatrial node
pacemaker of cardiac contraction
Atrioventricular node
delays impulse by 1/10 of second, allowing atria to contract before ventricles
Purkinje fibers
rapidly spreads impulse to contract throughout ventricles
Extrinsic control of cardiac cycle:
Parasympathetic nerve fibers
Sympathetic nerve fibers
Bradycardia
Endocrine glands
Parasympathetic nerve fibers
decrease heart rate
Sympathetic nerve fibers
increase heart rate
Bradycardia
slow heart rate; often training-induced
Syncytial contraction
fibers contract simultaneously
Cardiac Muscle (Myocardium)
Capable of contraction & force generation, like skeletal muscle
Capable of initiating impulse (autorhythmaticity)
Has intercalated discs that spread impulse to contract
Regular physical training & chronic hypertension result in
Thickening of L ventricle wall
Increase in L ventricular mass
Cardiac output
Amount of blood pumped per minute
What is cardiac output determined by?
heart rate (HR) & stroke volume (SV)
End-diastolic volume (EDV):
blood in ventricles at end of diastole
End-systolic volume (ESV):
blood in ventricles at end of systole
Ejection fraction (EF):
ratio of available blood to pumped blood
Calculate stroke volume:
SV (mL) = EDV (mL) − ESV (mL)
Calculate ejection fraction:
EF =SV/EDV
Plasma components:
90% water, 7% plasma proteins, 3% other
Hemoglobin
protein (globin) & iron-containing pigment (heme) necessary for binding oxygen
RBC
Transport oxygen via hemoglobin
Where are RBC produced in adults?
produced in bone marrow of long bones
Lifespan of RBC?
4 months
Arterial-venous oxygen difference
Amount of oxygen per 100 mL of arterial blood entering a tissue minus that leaving tissue
What factors affect the redistribution of blood?
parallel circuitry
vasodilation
vasoconstriction
precapillary sphincters
What does Release of norepinephrine by sympathetic nerves cause?
vasoconstriction
What does release of epinephrine by sympathetic nerves cause?
vasoconstriction and vasodilation
P wave
atrial depolarization
QRS interval
ventricular depolarization
ST segment
ventricular repolarization
QT interval
ventricular depolarization and repolarization
