cv system Flashcards
1
Q
what is the pathflow of blood for deoxygenated blood
A
- 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
2
Q
what is the pathflow of blood for oxygenated blood
A
- 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
3
Q
what is blood composed of
A
-plasma
-red blood cells
white blood cells
platelets
4
Q
what are the types of blood vessles
A
arteries arterioles capillaries venuoles veins
5
Q
arteries
A
- 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
6
Q
arterioles
A
- 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
7
Q
capillaries
A
- 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
8
Q
venuoles
A
- small but larger than capillaries
- carry deoxygenated blood
- take carbon dioxide from capillary to the veins
9
Q
veins
A
-returns deoxygenated blood to heart
10
Q
what are the functions of the cardiovascular system
A
- delivery and removal of nutrients and waste
- thermoregulation
- vasodilation and vasoconstriction
- clot blood
- fight infection
11
Q
plasma
A
- plasma is liquid
- carrys blood cells, nutrients, gases and waste products around the body
12
Q
platelets
A
- 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
13
Q
what is vasodilation
A
increases blood flow through vessels so greater amount of blood can pass next to the skin and lose heat
14
Q
what is vasoconstriction
A
reducing blood flow and heat loss
15
Q
how is the cardiac cycle controlled
A
- 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
