The Blood Stream Flashcards
What is the heart and what does do?
It is a muscular organ that pumps blood around the body. Much of the wall of the heart is made from muscle tissue
What are the main chamber in the heart?
Right atrium on top of the right ventricle
Left atrium on top of the left ventricle
What is the circulatory system?
It transports substances around the body
It consists of blood vessels, the heart and blood
What is the process of blood as it enters the heart?
Blood enters atria of the heart.
The atria contract and force blood into the ventricles
The ventricles contract and force blood out of the heart
Valves in the heart ensure that the blood flows in the correct direction
Blood flows from the heart to the organs through arteries and returns through veins
There are 2 separate circulation systems, one for the lungs and one for all other organs in the body
What are the differences between arteries and veins?
Arteries have thick walls containing muscle and elastic fibers, they carry blood away from the heart
Veins have thinner walls and often have valves to prevent back-flow of blood, they often have valves along their length to prevent back flow of blood
What does blood plasma transport?
CO2 form the organs to the lungs
Soluble products of digestion from the small intestine to other organs
Urea form the liver to the kidney
Hormones
What are red blood cells and what do they transport?
Red blood cells are biconcave disks with no nuclear
They use their haemoglobin which combines with oxygen to form oxyhaemoglobin in the lungs. They carry the oxygen to all the organs where the oxyhaemoglobin splits into haemoglobin and oxygen
In the lungs haemoglobin combines with oxygen to form…
Oxyhaemoglobin.
In other organs oxyhaemoglobin splits up into haemoglobin and oxygen
What are red blood cell packed with?
With a red pigment called harmoglobin
What do white blood cells so?
They have a nucleus and they form part of the body’s defence system against microorganisms. They ingest and destroy pathogens, price antibodies to destroy pathogens and produce antitoxins the pat neutralise the toxins released by pathogens
What does platelets do and what are they?
They are small fragments of cells with irregularly shaped bodies and no nucleus. They help to form clots to stop bleeding
Which part of the heart does the deoxygenated blood enter? And then what happens?
The right atrium
The right atrium then contracts to pump blood through valve into the right ventricle
The right ventricle contracts, the valve opens and deoxygenated blood travels back to the lungs
Which part of the heart does the oxygenated blood enter? And then what happens?
The left atrium
The left atrium contracts to pump blood through a valve into the left ventricle
The left ventricle contracts, the valve opens and oxygenated blood travels around the body
What does the pulmonary artery do?
It takes deoxygenated blood to the lungs
What does the pulmonary vein do?
Brings oxygenated blood from the lungs
What does the aorta do?
Carries oxygenated blood around the body
What does the vena cava do?
It brings deoxygenated blood into the heart
Describe capillaries and their function
They are narrow, thin-walled blood vessels
They carry the blood through the organs and the substances needed by the cells in the body tissue pass out of the blood, and substances produced by the cells pass into the blood, through the walls of the capillaries
What happens if blood vessels are blocked or too narrow the blood?
The blood will not flow efficiently. Then organs will be deprived of nutrients and oxygen
What do stents do?
They can be inserted to keep blood vessels open. This is particular beneficial when coronary arteries become narrow due to fatty deposits, cutting of blood supple to the heart.
Why are stents used?
To open up blood vessels which have become narrow due to fatty deposits, cutting of blood supple to the heart.
What does leaky valves mean and what can be done to prevent this?
It means the blood could flow in the wrong direction
Artificial or animal valves can be inserted in the heart to replace damaged valves
Give an example of the gas transported by the plasma
Carbon dioxide
Why is plasma given to patients?
In an emergency to increase blood volume when a lot of blood has been lost by the patient
What to the advantages of an artificial heart?
They do not need to match the person’s tissue and there is no need for immunosuppressant drugs
What to the disadvantages of an artificial heart?
Problems with blood clotting, long stays in the hospital and expansive
Is the muscle around the heart thin or thick and why?
It is thick so more pressure so it will contract with more force and pump it to the body
Describe the shape of red blood cells and what they do
Red blood cells carry oxygen from the lungs to the restoring cells. They are a biconcave disc shape, increasing their surface area to volume ration fro oxygen to diffuse in and out.
They do not have a nucleus, allowing more space for the carriage of oxygen.
They are full of haemoglobin, which can bind to oxygen in June lungs to form a bright red oxyhaemoglobin.
In low concentrations of the tissues it breaks back down again to release the oxygen and turns a purple-red colour
What are platelets and what to they do?
They are small fragments of cells, without a nucleus.
They form a clot at the site of a wound by forming a mesh of protein fibres that trap other blood cells to form a scab.
This prevents further blood loss and prevents infection.
Advantages of stents
Quicker recovery
Smaller vessels - can be used throughout the body
Done without general anaesthetic
What is an alternative to stents?
Bypass surgery
What does bypass surgery involve?
Replacing narrow or block arteries with veins from another part of the body
Advantages of bypass surgery
More permanent surgery
Used when arteries are fully blocked
When you have a heart attack
Multiple at once
Disadvantages of bypass surgery
Longer recovery
More prone to infection especially when you are old
More expensive
Requires general anaesthetic
When is valve replacement used and what are hue he two options of valve replacement?
It is used if a person’s natural heart valves begins to fail under the constant high pressure
Mechanical valves or biological valves
Advantages of mechanical valves
Last forever
Disadvantages of mechanical valves
Requires patients to take drugs to prevent blood clots forming.
Tends to make a scan on the mechanical valves, the scab will then travel around the body and may get stuck in small vessels and this may lead to brain stroke
Advantages of biological valves
Not requires medications
Not much rejection with genetic engineering animals
Disadvantages of biological valves
Doesn’t last long, up to 15 years
Artificial hearts - what do they do and what do the restrict?
They can save many lives,as there are never enough hearts to use in transplants
They are primarily used as a temporary fix until a replacement human heart can be provided
They require lots of machinery so the patient must stay in hospital
Mobile artificial hearts are still being experimented with for the furture
When is blood transfusion used?
A blood transfusion from a matched donor can be used to replace blood lost in an accident or during an operation
Disadvantages of blood transfusion
It can only be stored for a limited time, is often in short supply and may be refused for religious reasons
What is the problem with loss of blood?
Not able to carry out aerobic respiration so have to relay on anaerobic. Not enough energy, lactic acid, cannot survive on it
What is plasma used for?
It helps to boost. The volume of the blood and restore blood pressure, but does not carry much oxygen so it only a temporary fix
What are PFCs (perfluorocarbons)?
They are non-reactive chemicals which can carry dissolved gasses like oxygen around the body
Advantages of PFCs
They can be kept for a long time
They do not carry diseases or trigger an immune response so no ‘matching’ required
They can flow through damaged caulk aired that have been narrowed, preventing red blood cell access
Disadvantages of PFCs
They do not carry as much oxygen as normal blood, so logs needed
It does not dissolve in water, so must be mixed into an emulsion t be administered, which is difficult
It is broken down quickly by the body so must be replaces
There have been some sever side effects
What is pure haemoglobin substitutes?
Pure haemoglobin, rather than whole red blood cells can be extracted from human or animal blood, created synthetically or produced by genetically engineered bacteria
Advantages of haemoglobin substitute
Carries more blood than normal blood
Keeps well, without the need for refrigerating
Disadvantages of haemoglobin substitute
It is broken down by the body in around a day, so must be replaced for long term use
There have been some server side effects
