Heart Flashcards
Definition of the cardiac cycle
It’s the circulation of blood through the heart per heart beat
How long does each cardiac cycle last
Less then one second
How many steps are there in each cardiac cycle (heart beat)
There are two main steps ,diastole and systole.
What is diastole (relax)
When the heart relaxes and the chamber is filled with blood
What is systole (squeeze)
When the heart contracts and pumps blood out to the body.
What happens during the cardiac cycle
Start with venous blood going into right atrium of heart
1.Venous blood goes from body to vena cava(vein) to right atrium
2.venous blood in right atrium –> right ventricle
3. Ventricle contracts and sends blood to lungs
4. O2 blood –>pulmonary vein –> left atrium
5. From left atrium blood goes thro mitral valve to left ventricle
6. Goes to rest of the body
What is cardiac output
Amount of blood expelled from heart per minute
How do you work out cardiac output
Heart rate X stroke volume =cardiac output
What is stroke volume
Amount of blood pumped from left ventricle per beat
What controls the heart
Controlled by automatic nervous system
What are the 2 branches of the automatic nervous system
Parasympathetic system
Sympathetic system
What is the parasympathetic system
It controls and puts the body into a resting state
What is the sympathetic system
It puts the body into the flight and fight mode and releases adrenaline into body
What are the purpose of valves
They help control the flow of blood and make sure it goes in the right direction and don’t back flow
What is the pulmonary circuit
The pulmonary circuit is the part which the left ventricle pumps de02 blood to the lungs for oxygenation
then back into right atrium
