B4 Flashcards
What is a consequence of cardiovascular disease
Sometimes cardiovascular disease means heart failure, where the heart can’t function or pump blood around tne body.
Heart transplants
Used to treat heart failure by replacing a failing heart with a donor heart
Advantages of donor hearts
May be the only solution to heart failure
Less risky and more natural than artificial hearts
What is an artificial heart
A man made device that temporarily pumps blood in a patient, giving the heart time to to rest/heal
What are immunosuppressants
Drugs which suppress the immune system to reduce the risk of an immune response against the transplanted heart
Disadvantages of immunosuppressants
Can weaken the body’s natural defences if there are immunosuppressants
Advantages of artificial hearts
Are man-made, so are less likely to be immunologically rejected
Removes strain of keeping blood circulating
Disadvantages of artificial hearts
Require invasive surgery, meaning risks like thrombosis and other complications
Risk of blood clots
Faulty valves effects on person
Valves can become leaky and stiff, with infection, heartconditions and age
causing damage to the valves and making them leaky, causing the back flow of blood.
Stiff valves stops the valves from opening properly
Blood in the heart goes in more than one direction- uncontrolled blood flow and substances aren’t transferred efficiently or successfully
Less oxygenated blood pumped around body - difficult for cells to respire and person is out of breath
Some blood flows back into the ventricle
Person will eventually die
Mechanical valves
Man-made, surgery required for valve replacement and there are risks of thrombosis or complication
Advantages of replacing valves
Less invasive than a heart transplant
Disadvantages of replacing valves
They may need to be replaced regularly
Advantages of biological valves
Less risk of bleeding during pregnancy
No risk to fetus
No anticoagulation medicine needed(unlike in mechanical valves)
No high-pitched click sound(like in mechanical valves)
Let blood flow through them
Lower risk of rejection than for mechanical valves
Disadvantages of biological valves
Don’t last for as long as mechanical valves as they wear and stiffen out so need to be replaced quick
Need immunosuppressant drugs
Advantages of mechanical valves
Last for longer than biological valves in ideal conditions
Disadvantages of mechanical valves
Form blood clots
Require anti-clotting drugs
Make an annoying click sound
Cardiovascular disease
A term describing a range of diseases affecting the heart and blood vessels, including conditions like coronary artery disease, heart attacks, angina, heart failure and stroke
Causes of cardiovascular disease
Unhealthy diet
Lack of physical activity
Smoking
High blood pressure
High cholesterol
Family history of disease
Who can receive an artificial heart
People with end-stage heart failure who aren’t eligible for heart transplantation, based on the person’s health and the severity of the heart disease
Who is eligible for a heart transplant
Depends on the severity of the heart disease, overall health of the patient and availability of a suitable donor heart.
Risks of heart transplantation
Rejection of the transplanted heart
Infections
Bleeding
Blood clots
Medication side effects
Heart transplant rejection
Chronic diseases
Substances in the plasma
Waste carbon dioxide produced by the cells is carried to the lungs
Urea formed in your liver from the breakdown of excess proteins is carried to the kidneys where it’s removed from the blood to form urine
Small soluble products of digestion are transferred from the plasma to the small intestine and are transported to the individual cells
Adaptations of red blood cells
Biconcave discs give an increased surface area to volume ratio
Packed with a red pigment called haemoglobin that binds to oxygen
No nucleus means more space for haemoglobin
White blood cells
Larger, have a nucleus and are part of the body’s defence system against harmful microrganisms
Lymphocytes
White blood cells that form antibodies against microrganisms and antitoxins against poisons in microrganisms
Phagocytes
White blood cells that engulf and digest invading bacteria and viruses
Platelets
Small fragments of cells that help with blood clotting
Blood clotting
Enzyme-controlled reactions that convert fibrinogen to fibrin
Network of protein fibres that capture red blood cells to form a jelly-like clot that stops bleeding
The clot dries and hardens to form a scab which protects the new skin
What system are our blood vessels arranged into?
A double circulatory system:
One transport system carries blood from your heart to your lungs and back again
The other transport system transfers blood from your heart to the other organs of your body and back again
Fully oxygenated blood returns to the heart from your lungs
What muscle supplies the heart with oxygen?
The coronary arteries
What happens in coronary artery disease
The coronary arteries supplying blood to the heart muscle is narrow, due to fatty material on the lining of the vessels and the supply of oxygen to the heart muscle is also reduced, causing pain or a heart attack.
Stent
A metal mesh placed in the artery
A balloon opens up the blood vessel and stent at the same time; the balloon is deflated but the stent remains to hold the blood vessel open
Blood in the coronary artery flows freely
Advantages of stents
Can be put in place without a general anaesthetic
Open a blocked artery anywhere in the body
Release drugs to prevent the blood clotting