Cardiovascular System Flashcards
What is the function of the cardiovascular system?
Provides the body with nutrients, helps the body with the removal of waste products and provides the organs with oxygenated blood.
What does the three component model consist of?
A resevoir (blood), A pump, A circuit
What is the heart
A hollow bag of cardiac muscle
What does afterload mean?
The force opposing ventricular contraction. This can be either by stress imposed on the ventricular wall or the impendance by the aortic and systematic circulation to the ejaction of stroke volume
What are the three layers of the heart?
Pericardium, myocardium, epicardium
What is the proper term for heart attack?
Myocardium Infarction
What does the electrical muscle cells do?
Conduct the electricity for the heart.
Why is pressure important in the heart?
Pressure from the heart causes the aorta to push open the valves. Pushes the valves open so blood can flow through the heart and to the rest of the body.
What is the cardiac myofibril length in the end of diastole?
Preload
not capillaries
What has a three wall structure
Vessels
What do arteries do?
Carry blood away from the heart and to the rest of the body.
What is an arteriole?
A smaller branch of the arteries
What do arterioles do?
Arterioles branch into enormous networks of thin walled capillaries (tiny exchnage vessels) which allows nutrients, water and oxygen to diffuse into the tissues and cellular waste such as carbon dioxide to be diffused into the bloodstream and get transported away.
What are the three layers of tissue of the arteries and veins?
Tunica adventitia, Tunica media, Tunica intima
What is the tunica advenititia?
Outer layer of artery and vein. fibrous tissue containing large qunatities of collagen and other connective tissue components. It protects and supports the vessel.
What is the tunica media
The middle layer of the vein and artery. Contains variable amount of smooth muscle and elastic tissue.
What is the tunica intima (endothelium)?
A smooth lining of the vein and artery only one cell thick
What are the three layers of the heart?
Endocardium, Epicardium, Myocardium
What is the myocardium
Specialised cardiac cells that are striated. Also contains myocytes.
What are myocytes?
A muscle cell
What is included within the myocyte?
Myofibrils, Mitochondria, Sarcolemma, Sarcoplasmic reticulum, T-Tubules
What is a myofibril?
Within the myocyte, they are long contractile fibres that cause the production of contraction and relaxation of the cell.
What is the T-Tubule?
Allows calcium to be kept seperate and be on the outside of the cell where it goes to the heart for the contraction.
Why is calcium important
It helps blood clot normally and for the heart to beat normally.
What is the Sarcolemma?
outside layer of the myocyte
What does the cardiac cycle represent?
What happens during one heartbeat
What is an annulus fibrosis?
The outer circumferance portion of the disc. Are around the valves of the heart.
What is the role of annulus fibrosis?
To prevent electrical impulses from conducting to the ventricles by any other route.
What is the meaning of stroke volume?
The volume of blood that the heart pushes out from the left ventricle at each beat. Influenced by heart rate.
What do gap junctions within the myocyte allow?
They allow the next cells in line to activate
What do cell junctions do?
They hold the cells together
What do the gap junctions consist of?
They consist of 6 proteins and protein plots where selective ions can travel.
What does the frank stirling law state?
That the stroke volume of the left ventricle will increase as the left ventricular volume increases. This is due to the myocyte stretch causing a more forceful systolic contraction
What is cardiac output?
The amount of blood ejected from each ventrical in one minute.
How do you calculate the cardiac output?
Stroke volume x heart rate
What does pre load mean?
The amount of blood entering the ventricals during diastole. And the amount of stretch on the ventricular walls at the end of diastole.
When does afterload happen?
During systole, when the ventricals are contracting.
What is a definition of afterload?
The resistance the ventricals must overcome to circulate the blood
How do we work out the stroke volume?
End Diastolic Volume - End systolic volume
