Flashcards in Cardiovascular System Deck (38)
What is the cardiovascular system made up of?
Blood vessels and the heart
What does blood transport around the body?
Oxygen to respiring cells
Carbon dioxide away from respiring cells
Digested food to the liver for processing and storage
Urea from the liver to kidneys
Hormones and antibodies
What does blood travel away from the hear in?
What special feature does the artery wall have to withstand the high pressure generated by one contraction of the heart muscle tissue
It has a thick layer of muscle and extra elastic layers
What do arteries divide into?
Smaller arterioles and continue to divide until they become capillaries
What travels through capillaries?
Red blood cells only, travelling in singe file
Why is the capillary one cell thick?
So that materials can diffuse easily to and from the blood.
What do capillaries join together to form?
What do venules join together to form?
What do veins carry?
Low pressure blood
What is the structure of a vein?
Thin layer of muscle and may include valves
What is the purpose of the valves?
To prevent blood flowing back
What is the myocardium made up of?
What is the structure of the cardiac muscle?
Small interconnected cells
What do the interconnections allow?
The rapid spread impulses that cause the contractions of the heart from cell to cell
Where are these impulses initiated?
By the sinoartial node high in the right atrium
What is the spread of the impulses coordinated to do?
To make the atria contract first to pump the blood into the ventricle
What follows the contraction of the atria?
The contraction of the ventricles, this contraction of the ventricle starts at the base of the ventricles and pumps blood out of the heart at high pressure.
What is diastole?
Relaxation of the ventricle and the atria are pumping blood into the ventricles.
What is systole?
When the ventricles contract
What does Dr sync
Diastole is Relaxation. Systole is when the ventricles Contract.
What is heart rate? (HR)
The number of heart contractions in one minute
What is stroke volume? (SV)
The volume of blood pumped out by one ventricle during one systole
What is cardiac output?
The volume of blood pumped by one ventrical in one minute. CO = HR x SV
What is blood pressure?
The pressure during systole and diastole (measured in millimetres of mercury)
Why does the CVS have to deliver of more oxygen during exercise?
To provide for increased respiration in skeletal muscles
What happens to cardiac output during exercise
What happens to heart rate during exercise?
What happens to the atria walls when HR increases?
The atria receives more blood back from the body, so the atrial walls become more distended.