Cardiovascular System Flashcards
(34 cards)
What is the pulmonary circuit?
carries deoxygenated blood to the lungs and oxygenated blood back to the heart
what is the systemic circuit?
carries oxygenated blood to the body and deoxygenated blood back to the heart
what are the different structures within the heart?
Left ventricle
Left atrium
Right ventricle
Right atrium
Aorta
Vena Cava (superior and inferior)
Pulmonary artery
Pulmonary vein
Semi lunar valves
Septum
Bicuspid valve
Tricuspid valve
what divides the heart into two sides?
septum, which separates deoxygenated and oxygenated blood
what are the two atrioventricular valves?
Tricuspid valve
Bicuspid valve
How many semi lunar valves are there?
Two
What is the pathway of blood?
- Deoxygenated blood is in the right atrium
- Deoxygenated blood enters the right ventricle
- Deoxygenated blood is pumped to the lungs via the pulmonary artery
- At the lungs gaseous exchange takes place and the blood becomes oxygenated
- The oxygenated blood travels back to the left atrium via the pulmonary vein
- Oxygenated blood travels to the left ventricle
- Oxygenated blood is pumped around the body by the aorta
- oxygen from the blood is used up by working cells
- deoxygenated blood travels back to the heart via the vena cava
What is the conduction system of the heart?
- Cardiac impulse is initiated from the SA node. This is the hearts pacemaker and located in the right atrium
- The impulse passes through the right + left atrium walls to the AV node
- AV node passes impulse down the bundle of his through the septum to the apex of the heart
- Impulse passes from bundle of his into the bundle branches
- Impulse travels into ventricles via. Purkunje fibres
What is diastole?
The relaxation phase of cardiac muscle, where chambers fill with blood
What is systole?
The contraction phase of cardiac muscle where blood is forcibly ejected into the aorta and pulmonary artery
What does one complete cardiac cycle represent?
The sequence of events involved in a single heartbeat
how long does a complete cycle of a cardiac cycle take?
0.8 seconds
.
what happens during diastole?
atria relax and expand and draw blood in
The pressure in atria increases above ventricular pressure = AV valves open
Blood passively enters ventricles
SL valves are closed, to prevent blood leaving heart
how long does diastole last?
0.8 seconds
what happens during systole?
ATRIAL SYSTOLE:
-Atria contract, forcing remaining blood into ventricles
VENTRICULAR SYSTOLE:
-Ventricles contract, increasing the pressure, closing the AV valves to prevent backflow to the atria
-SL valves are force open as blood is ejected from the ventricles into the aorta and pulmonary artery
how long does systole last?
0.3 seconds
Why is the heart said to be myogenic?
Generates its own electrical impulse
how does the conduction system control the cardiac cycle?
-No electrical impulse = diastole (cardiac muscle relaxes) = SL valves close, atria fill with blood opening AV valves.
-SA node fires impulse through atrial walls to AV node, which the delays the impulse = Atrial Systole (atrial muscle contracts) = AV valves are force open and blood is pushed into the ventricles until atria finish contracting
-Bundle of his splits and passes impulse through two branches to the purkunje fibres = ventricular systole (ventricular muscle contracts) = AV valves close blood is pushed into the arteries, forcing the SL valves to open until ventricles finish contracting
what is heart rate?
The number of times the heartbeats per minute
what is the average resting heart rate?
72 bpm
what is bradycardia?
When you have a resting heart rate lower than 60 bpm
how do you calculate max heart rate?
220 - age
what are resting heart rate indicate?
High level of aerobic fitness
What is stroke volume?
The volume of blood ejected from the left ventricle per beat
