Circulatory System Flashcards
What colour are veins represent as
Blue
What colour are arteries represented as
Red
What are the main two arteries in the heart
1) pulmonary artery
2) aorta
What are the main two veins in the heart
1) pulmonary vein
2) vena cava
What does the pulmonary artery do
It brings deoxygenated blood from the heart to the lungs
What does the aorta do
It brings oxygenated blood from the heart to the rest of the body
What does the pulmonary vein do
It brings the oxygenated blood from the lungs to the heart
What does the vena cava do
It bring deoxygenated blood from the body to the heart
What are the properties of arteries
1) thick outer wall
2) small lumen
3) thick layer of muscle and elastic fibres
4) smooth inner lining
Why do arteries have thick outer walls and thick layers of muscles
to withstand high pressure of blood flowing from heart
Properties of veins
1) fairly thin outer walls
2) thin layer of muscle and elastic fibres
3) large lumen
4) smooth lining
Properties of capillaries
1) wall made of single layer cells
2)very small lumen
3) large overall cross sectional area (there are many of them around the body
Why is the outer wall of capillaries only one cell thick
To allow substances to diffuse in and out through them quicker and more efficiently
Why do the pulmonary artery and aorta cross over?
Because we have two lungs and we have a double circulatory system
What does it mean to have a double circulatory system
It means that the blood travels through the heart twice to complete its journey once, and has two different circuits for oxygenated and deoxygenated blood
Why do we have a double circulatory system
We are larger organisms, so blood needs to around the body quicker and a higher volume of blood is needed
What substances are transported in blood
Red blood cells
White blood cells
Plasma
Platelets
What do red blood cells do?
They are small biconcave cells that have no nucleus. They contain haemoglobin and carry oxygen around the body.
What are white blood cells
Large cells that contain a nucleus, they fight disease by making special proteins called antibodies, or by changing shape to engulf other microorganisms
What is plasma
straw-coloured liquid that blood cells float in.
Over 90% of plasma is water. Many materials are transported by being dissolved in plasma. These include digested food (such as amino acids and glucose), waste (such as carbon dioxide), hormones, and antibodies.
What are platelet
Tiny structures that help to clot blood, which prevents further infections in wounds or injuries
When haemoglobin binds to oxygen what does it become
Oxyhemoglobin
What chemicals is heamoglobin made out of
DNA
In a condition called sickle anaemia, the red blood cell can change shape. This reduces the amount of oxygen getting to cells in the body explain why (2 marks)
-> sickle RBC take up less oxygen than normal RBC
-> sickle cells have lower SA:V ratio meaning they get stuck in blood vessels
The table shows that blood flow to other organs has decreased by nearly 5 times when a person is doing exercise.
The blood flow to the muscles has increased by more than eighteen times.
Explain these changes to blood flow rate.
-> muscles need more energy meaning more oxygen needed for respiration
-> other organs not needed in respiration meaning less blood flow to them
Taking a drug called statins is a treatment for high cholesterol .
The drug is taken every day and lowers the level of cholesterol in a person’s blood.
Suggest one advantage and one disadvantage of taking statins.
Advantage - no need for operation
Disadvantage - may have to take medicine on daily basis which may lead to side affects
Oxygen enters red blood cells by diffusion.
Describe and explain how red blood cells are adapted for the efficient uptake and transport of oxygen.
(5 marks)
-> BIOCONCAVE shape meaning high SA:V ratio meaning diffusion happens quicker
-> NO NUCLEUS meaning more oxygen can be transported
-> SMALL and FLEXIBLE meaning they can fit through the small lumen of capillaries
-> has HAEMOGLOBIN whjch binds to oxygen to allow oxygen to be transported
Why is it bad if the tricuspid valve doesn’t function properly
-> blood back flows into heart
-> less blood goes to lungs
-> more ventilation needed for gas exchange
-> less oxygen available to tissues
Why is it bad if the bicuspid valve doesn’t function properly
-> backflow into the left atrium
-> less blood pumped to the body
-> heart works harder to compensate
-> increased risk of heart failure
