Heart Flashcards
Which arteries deliver blood to the myocardium?
Coronary arteries
What delivers oxygen poor blood to the coronary sinus from the heart?
Cardiac veins
Why does the heart need no external nerves to beat?
The heart is made up of cardiomyocytes. Waves of excitation are sent from the SAN which allow the heart to beat. No external nerves are needed for the heart to beat. But vagus nerve and sympathetic cardiac nerves control the SAN.
How does the parasympathetic nervous system affect heart rate?
Decreases heart rate.
Parents want you to slow down while driving
Which nerve controls the parasympathetic heart rate ?
Vagus nerve
How does the sympathetic nervous system affect heart rate?
Increases heart rate
What nerve controls the sympathetic nervous system ?
Sympathetic cardiac nerves
What nerve controls the sympathetic nervous system ?
Sympathetic cardiac nerves
How many beats per minute is normal heart rate ?
60-100 beats per minute
What is Tachycardia?
Heart rate over 100 beats per minute. Tach = too fast
Bradycardia
Heart rate under 60 beats per minute
What is the function of the atrioventricular node?
Adds a brief delay between contraction of the atria and ventricles.
Describe the cardiac conduction system ?
SA node
Atrioventricular node
Bundle of his
Left and Right bundles
Purkinje fibers = coordinate ventricular contraction
Where are the purkinje fibers found?
Walls of the ventricles
Another name for systole?
Ventricular contraction
Another name for diastole?
Ventricular relaxation
At what point is the pressure in the arteries the lowest?
ventricular relaxation. When blood is coming out of the atria into the ventricles.
At what point is the pressure in the arteries the lowest?
ventricular relaxation. When blood is coming out of the atria into the ventricles.
What causes the lub and dub sounds of the heart?
Closing of the atrioventricular or semilunar valves
What causes the ‘lub’ sound
Atrioventricular valve closing
What causes the ‘dub’ sound
Semilunar valve closing
Systole occurs between which sounds?
lub and dub
Diastole occurs between which sounds ?
dub and lub
What connects cardiomyocytes togther?
Intercalated discs