cv system Flashcards
what is the pathflow of blood for deoxygenated blood
- vena cava to right atrium
- through the tricuspid valve into right ventricle
- deoxygenated blood leaves right side through semilunar valve into pulmonary artery to the lungs
what is the pathflow of blood for oxygenated blood
- oxygenated blood from lungs goes through pulmonary vein to left atrium
- through bicuspid valve into left ventricle
- blood leaves left side of heart, passing through semi lunar valves into aorta to rest of body
what is blood composed of
-plasma
-red blood cells
white blood cells
platelets
what are the types of blood vessles
arteries arterioles capillaries venuoles veins
arteries
- carries blood away from heart
- carrys oxygenated blood (except pulmonary artery which takes deoxygenated blood away from heart to lungs)
- elastic so it can accommodate changing volumes of blood passing through
- muscular walls that contract to maintain blood pressure when there is a reduction in blood flow
arterioles
- links arteries with capillaries
- similar properties and functions to arteries
- they have thinner muscular walls as blood is not at a high pressure
- muscular walls allow the arteriole to control blood flow into capillary
- uses vasodilation to increase blood flow during exercise and vasoconstriction to reduce blood flow at rest
capillaries
- one cell thick allowing gas exchange, nutrients and waste products between blood in capillary and surrounding tissue
- blood pressure is lower than in arterioles but higher than in venuoles
venuoles
- small but larger than capillaries
- carry deoxygenated blood
- take carbon dioxide from capillary to the veins
veins
-returns deoxygenated blood to heart
what are the functions of the cardiovascular system
- delivery and removal of nutrients and waste
- thermoregulation
- vasodilation and vasoconstriction
- clot blood
- fight infection
plasma
- plasma is liquid
- carrys blood cells, nutrients, gases and waste products around the body
platelets
- prevent blood loss
- gather and stick together to form a plug at the site of the injury
- stimulate fibrin (blood protein) to form a sticky net trapping red and white blood cells
what is vasodilation
increases blood flow through vessels so greater amount of blood can pass next to the skin and lose heat
what is vasoconstriction
reducing blood flow and heat loss
how is the cardiac cycle controlled
- sinoatrial node acts as a pacemaker that initiates the heartbeat
- the electrical impulse is transmitted causing the atria to contract
- the impulse is caught by the atrioventricular node which passes to cardiac muscle fibres known as the bundle of his
- the bundle of his travel the impulse through the muscular walls of the ventricles
- parkinje fibres receive the impulse and signal the ventricles to contract
what is the anticipatory rise
an increase in heart rate just before the start of physical activity, its caused by the release of adrenalin into the blood
increased heart rate during exercise
to speed up oxygen delivery and carbon dioxide removal during exercise
what are the responses to exercise
- changes in heat rate when exercising
- increased blood pressure
- increased cardiac output
- redirection of blood flow
caridac output
cardiac output = amount of blood leaving the heart per minute its calculated by multiplying heart rate by stroke volume
what is stroke volume
amount of blood leaving the heart per beat
what are the 7 adaptations
- cardiac hypertrophy
- stroke volume increases
- resting heart rate decreases
- decreased heart rate recovery time
- capillarisation
- reduction in resting blood pressure
- increase in blood volume
