Topic 2a- Tissues, Organs and Organ Systems Flashcards
What are large multicellular organisms made up of?
Why are multicellular organisms organised?
Large multicellular organ systems are made up of organ systems.
Multicellular organisms (like humans) can have millions of cells. To keep the organism going, those cells have to work together- which need organisation.
Define cells…
Cells are the BASIC BUILDING BLOCKS of all living organisms.
What are specialised cells?
Specialised cells carry out a PARTICULAR FUNCTION.
What is differentiation and when does it occur?
The PROCESS by which cells become specialised for a particular job is called DIFFERENTIATION.
Differentiation occurs during the DEVELOPMENT of a multicellular organism.
What do specialised cells form?
These specialised cells form TISSUES, which forms ORGANS, which form ORGAN SYSTEMS.
What types of systems do large multicellular organisms have?
LARGE MULTICELLULAR ORGANISMS (e.g. squirrels) have different SYSTEMS inside them for EXCHANGING and TRANSPORTING materials.
Example- Mammals have a breathing system-including airways and lungs. The breathing system is needed to take air into and out of the lungs, so that oxygen and carbon dioxide can be exchanged between the body and the environment.
How are similar cells organised?
Similar CELLS are organised into TISSUES.
what is the definition of a tissue?
A TISSUE is a GROUP of SIMILAR CELLS that work together to carry out a particular function. It can include MORE THAN ONE TYPE OF CELL.
On spec- A tissue is a group of cells with a SIMILAR STRUCTURE and FUNCTION.
How are tissues organised?
Tissues are organised into organ systems.
What is an organ?
An ORGAN is a group of DIFFERENT TISSUES (aggregations of tissues) that work together to perform a certain FUNCTION.
How are organs organised?
Organs are organised into ORGAN SYSTEMS.
What is an organ system?
An ORGAN SYSTEM is a GROUP OF ORGANISMS working together to form ORGANISMS.
What is the purpose of the lungs?
You need to get OXYGEN into your BLOODSTREAM to supply your CELLS for RESPIRATION. You also need to get rid of CARBON DIOXIDE from your blood.
This exchange of gases all happens inside your LUNGS. Air is forced in and out of your lungs by the action of breathing.
Where are the lungs located and what is the structure of lungs in mammals?
- The lungs are in the THORAX. The THORAx is th stop part of your body.
- It’s separated from the lower part of the body by the DIAPHRAGM.
-The LUNGS are like big pink SPONGES and are protected by the RIBCAGE.
They’re surrounded by the PLEURAL MEMBRANES.
- The air that you breathe in goes through the TRACHEA (windpipe). This splits into two tubes called BRONCHI (each one is a bronchus), one going to each lung.
- The bronchi split into progressively smaller tubes called BRONCHIOLES.
- The bronchioles finally end at small bags called ALVEOLI where the gas exchange takes place.
How do alveoli carry out gas exchange in the body?
1) The lungs contain millions and millions of little air sacs called ALVEOLI, surrounded by a NETWORK of BLOOD CAPILLARIES. This is where GAS EXCHANGE happens.
2) The BLOOD passing next to the alveoli has just returned to the lungs from the rest of the body, so it contains LOTS of CARBON DIOXIDE and VERY LITTLE OXYGEN. OXYGEN diffuses OUT of the ALVEOLUS (high concentration) and into the BLOOD (low concentration). CARBON DIOXIDE diffuses OUT of the BLOOD (high conc) into the alveolus (low conc) to be breathed out.
3) When the blood reaches body cells OXYGEN is released from the RED BLOOD CELLS (where there’s a high concentration) and diffuses into the BODY CELLS (where there’s a low concentration).
4) At the same time, CARBON DIOXIDE diffuses out of the BODY CELLS (where there’s a high concentration) into the BLOOD (where there’s a low concentration). It’s then carried back to the LUNGS.
How are alveoli adapted for gas exchange?
The alveoli have:
1) An enormous surface area
2) A moist lining
3) Very thin walls
4) Good blood supply to maximise gas exchange
5) Ventilation (provides a steep concentration gradient)
How do you calculate the breathing rate?
Breaths per minute =
number of breaths ÷ number of minutes
How do you calculate heart rate?
You can calculate heart rate in beats per minute in the same was as breathing rate. Just replace the number of breaths with the number of beats.
heart rate= number of beats ÷ number of minutes
How do multicellular organisms like human transport materials between their cells?
Multicellular organisms need a way to transport materials between their cells. Humans (like many animals) have a transport system called the circulatory system to do this. The heart has a major role to play with it.
What is the function of the circulatory system?
The circulatory system’s main function is to get FOOD and OXYGEN to every cell in the body.
As well as transporting things it is also a WASTE COLLECTION SERVICE- it carries CARBON DIOXIDE and UREA to where they can be removed from the body.
What does the circulatory system include?
The circulatory system includes:
- HEART
- BLOOD VESSELS
- BLOOD
What circulatory system do humans have?
Humans have a DOUBLE circulatory system- two circuits joined together.
Mammals have a double circulatory system.
What are the two circuits called?
- The pulmonary circulatory system
- The systemic circulatory system.
The human circulatory system is made up of two separate circuits. What is the function of each circuit?
- In the first circuit, the RIGHT VENTRICLE pumps DEOXYGENATED good to the LUNGS to take in OXYGEN. The blood then RETURNS to the heart.
- In the second circuit, the LEFT VENTRICLE pumps OXYGENATED blood around all the OTHER ORGANS of the BODY. The blood GIVES UP its oxygen at the body cells and the DEOXYGENATED blood RETURNS to the heart to be pumped out to the LUNGS again.
Describe the function of the heart…
The heart is an ORGAN that PUMPS blood around the BODY in a double circulatory system. The right ventricle pumps blood to theLUNGS where gas exchange takes place. The left ventricle pumps blood around the rest of the body.
What are the walls of the heart made from?
The heart is a pumping organ that keeps the blood flowing around the body.
-The walls of the heart are mostly made of MUSCLE TISSUE.
Why does the heart contain valves?
How many valves are in the heart?
What do the valves create?
The heart has valves to make sure that blood flows in the right direction- they prevent it flowing BACKWARDS.
There are 4 valves.
There are 2 between the atria and ventricles.
There are 2 at the base of the arteries leading from the ventricles.
The valves create a ONE WAY SYSTEM!
How many chambers does the heart have and what are they called?
The heart has four chambers; the RIGHT ATRIUM, RIGHT VENTRICLE, LEFT ATRIUM and LEFT VENTRICLE, which it uses to pump blood around.
What are the main blood vessels leading into and out of the chambers?
The main blood vessels leading into and out of theses chambers are:
1) Vena cava
2) Pulmonary artery
3) Aorta
4) Pulmonary vein
What is the function of coronary arteries?
The heart also needs its own supply of OXYGENATED blood. Arteries called CORONARY ARTERIES branch off the aorta and surround the heart, making sure that it gets all the OXYGENATED blood it needs.
Why are the coronary arteries vital in our health?
The coronary arteries are really important. If they become blocked, the heart can become starved of oxygen, potentially leading to a heart attack and heart failure.
How does the heart use its four chambers to pump blood around the body?
1) BLOOD FLOWS INTO the two ATRIA from the VENA CAVA and the PULMONARY VEIN.
2) The ATRIA CONTRACT, forcing the blood into the VENTRICLES.
3) The VENTRICLES CONTRACT, forcing the blood into the PULMONARY ARTERY and the AORTA, and OUT of the HEART.
4) The pulmonary artery carries deoxygenated blood to the lungs. The aorta carries oxygenated blood to the tissues.
4) The blood then flows to the ORGANS through the ARTERIES, and RETURNS through VEINS.
Remember Arteries Away, Veins Towards.
5) The atria fill again and the whole cycle STARTS OVER.
How is your resting heart rate controlled?
How do these cells work?
- Your resting heart rate is controlled by a group of cells in the RIGHT ATRIUM wall that act as a PACEMAKER.
- These cells produce a small ELECTRIC IMPULSE which spreads to the surrounding muscle cells, causing them to CONTRACT.
What is heart rate?
Heart rate is the number of HEARTBEATS PER unit of TIME, e.g. the number of beats per minute (BPM).
What factors can lead to an increase or decrease in heart rate?
Some of the factors that may increase or decrease heart rate are;
INCREASE:
- exercise
- happy
- nervous/worried
- artificially (medicine)
DECREASE:
- relaxed
- sad
- artificially (medicine)
What is an artificial pacemaker and when is it used?
An ARTIFICIAL PACEMAKER is often used to control the heartbeat if there are IRREGULARITIES as the natural pacemaker cells do’t work properly (e.g. if the patient has an IRREGULAR HEARTBEAT). It’s a little device that’s implanted under the skin and a wire going to the heart. It produces an ELECTRIC CURRENT to keep the heart BEATING REGULARLY.
Is the blood in the heart at a low/high pressure?
-The blood flowing through left side (right atrium and ventricle) carries blood at a low pressure.
Whereas, the blood flowing through the right side (left atrium and ventricle) is at a high pressure.
What is the connection between muscle thickness in the heart and blood pressure?
The wall of the RIGHT VENTRICLE is LESS muscular than the left ventricle since it only needs to force the blood (at a low pressure) along the PULMONARY ARTERIES to the LUNGS.
The wall of the LEFT VENTRICLE- THICK and MUSCULAR since it must force blood through the ARTERIES to all the TISSUES of the body.
AORTA- The MAIN ARTERY of the body which carries oxygenated blood out to the TISSUES. Blood pressure is at its highest here in the aorta so the muscle is THICKER.
How many types of blood vessel are there?
There are 3 types of blood vessel, they transport the blood around our body.
What are the three blood vessels called?
The three different types of blood vessel are:
1) Arteries
2) Capillaries
3) Veins
What is the function of arteries?
Arteries are blood vessels which carry blood AWAY from the heart, towards the organs.
Explain how the structure of arteries are adapted to allow them to perform their function’s?
1) The heart pumps blood out at HIGH PRESSURE so the artery walls are STRONG and ELASTIC.
They contain thick layers of MUSCLES to make them STRONG, and ELASTIC FIBRES to allow them to stretch and SPRING BACK.
2) The walls are THICK compared to the size of the hole down the middle (lumen).
Why is the blood carried by the arteries at high pressure?
Pressure is caused by the contractions of the heart cardiac muscle.
What do arteries branch into?
Arteries branch into CAPILLARIES.
What is the function of capillaries?
- Capillaries are involved in the EXCHANGE of materials at the TISSUES.
- They supply FOOD and OXYGEN, and take away WASTE like CO2.
- Capillaries carry blood REALLY CLOSE to EVERY CELL in the body to EXCHANGE SUBSTANCES with them.
Explain how the structure of capillaries are adapted to allow them to perform their function?
1) Capillaries are really TINY-to small to see.
2) They have PERMEABLE walls, so substances could diffuse in and out.
3) Their walls are usually ONLY ONE CELL THICK. This INCREASES the rate of diffusion by DECREASING the DISTANCE over which it occurs.
4) Capillaries are very NARROW. This gives them a LARGE SURFACE AREA compared to their VOLUME, which also increases the rate of diffusion.
What do capillaries eventually join?
Capillaries eventually JOIN UP to form VEINS.
What is the function of veins?
Veins carry blood towards the HEART.
At what pressure does blood travel through veins?
The blood is at LOWER PRESSURE in the veins so the walls don’t need to be as THICK as artery walls.
Why is the blood travelling at a low pressure in the veins?
There is a reduced pressure as it has already carried carried the blood through the arteries and organs.
How are veins adapted to transport blood back to the heart?
1) Veins have a BIGGER LUMEN than arteries to help the blood FLOW despite the lower pressure.
2) They also have VALVES to help keep the blood flowing in the RIGHT DIRECTION.
3) Veins have ELASTIC FIBRES and SMOOTH MUSCLE.
How do you calculate the rate of blood flow?
rate of blood flow = volume of blood ÷ number of minutes
*Define blood?
*Blood is a tissue consisting of plasma, in which the red blood cells, white blood cells and platelets are suspended.
What is blood?
What is the function of blood?
Blood is a TISSUE- it’s a group of similar cells which work together to perform a specific function.
The function of blood is to TRANSPORT substances (e.g. oxygen) around the body.
What does blood consist of?
It’s made up of:
1) RED BLOOD CELLS
2) WHITE BLOOD CELLS
3) PLATELETS
which are all suspended in a liquid called PLASMA.
What is plasma?
Plasma is a pale straw-coloured LIQUID which CARRIES JUST ABOUT EVERYTHING.
What does plasma carry?
It carries:
1) RED and WHITE BLOOD CELLS and PLATELETS.
2) Nutrients like GLUCOSE and AMINO ACIDS.
3) CARBON DIOXIDE from the organs to the lungs.
4) UREA from the liver to the kidneys. (urea is a waste product produced from the breakdown of amino acids in the liver)
5) HORMONES.
6) PROTEINS.
7) ANTIBODIES and ANTITOXINS produced by the white blood cells.
What is the function of red blood cells?
The job of red blood cells it to carry OXYGEN from the lungs to all the cells in the body.
Outline three ways in which red blood cells are adapted to carry oxygen…
- They have a BICONCAVE DISC shape to give them a LARGE SURFACE AREA for absorbing OXYGEN.
- They contain a red pigment called HAEMOGLOBIN, which carries OXYGEN.
- They DON’T have a nucleus- this allows more room for haemoglobin, which means they can then carry MORE oxygen.
What is haemoglobin?
-Haemoglobin is a PROTEIN.
Describe the role of this red pigment in transporting oxygen…
All body cells need oxygen for respiration- a process which releases energy. Oxygen enters the blood when you breathe in, then red blood cells transport the oxygen from the lungs to all the cells in the body.
-As blood flows through the alveoli in the lungs, haemoglobin combines with oxygen to form oxyhemoglobin. When blood flows through RESPIRING tissues, oxyhemoglobin splits up into haemoglobin and oxygen. The oxygen that is released is used up by cells for RESPIRATION.
In the lungs: haemoglobin + oxygen ͢ oxyhaemoglobin
In respiring tissues:
oxyhemoglobin ͢ haemoglobin + oxygen
What is the function of white blood cells?
They defend against microorganisms that cause disease.
How do white blood cells defend against microorganisms?
They can do this in different ways:
- They can ENGULF unwelcome microorganisms (in a process called PHAGOCYTOSIS) and DIGEST them using enzymes.
- They can produce ANTIBODIES to fight microorganisms.
- They can produce ANTITOXINS to NEUTRALISE any toxins produced by the microorganisms.
True or false? White blood cells don’t have a nucleus.
False. Unlike red blood cells, they do have a nucleus.
What are platelets?
Platelets are SMALL FRAGMENTS of CELLS.
Describe the purpose of platelets in blood.
They help the blood to CLOT (clump together) at a wound-this seals the wound to stop you from LOSING too much BLOOD.
It also stops MICROORGANISMS getting in at the wound.
What is the result of a lack of platelets?
A lack of platelets can cause excessive BLEEDING and BRUISING.
How do people adapt to live at high altitudes where there’s less oxygen in the air?
The more red blood cells you’ve got the more oxygen can get to your cells. At high altitudes there’s less oxygen in the air-so people who live their produce more red blood cells to compensate.
Do platelets contain a nucleus?
They have NO nucleus.
How does plasma help transport carbon dioxide?
Carbon dioxide is produced as a waste product of respiration. Carbon dioxide is transported in plasma from respiring cells to the alveoli in the lungs. As blood flows around the alveoli, carbon dioxide is removed from the blood by diffusion and then breathed out.
How does plasma help transport the products of digestion?
SOLUBLE SUGARS, AMINO ACIDS, FATTY ACIDS and GLYCEROL are produced as products of digestion in the small intestine. These soluble products are absorbed from the small intestine and transported in plasma to other body organs.
How does plasma help transport urea?
Urea is a waste product formed from EXCESS AMINO ACIDS. Urea is made in the liver and transported in blood plasma to the kidneys where it is removed from the body in urine.
What is meant by the term health?
*Health is the state of physical and mental well-being.
What is often the cause of ill health?
DISEASES, both communicable and non-communicable, are major causes of ill health. Other factors including DIET, STRESS and life SITUATIONS may have a profound effect on both physical and mental health.
Name the two types of disease.
Diseases can be communicable and non-communicable.
What are bacteria?
Bacteria are living cells and can multiply rapidly in favourable conditions. Once inside the body, they release poisons or toxins that can make us feel ill.
What are viruses?
Viruses are many times smaller than bacteria. They are among the smallest organisms known, consisting of a fragment of genetic material inside a protective protein coat.
Viruses can only reproduce inside host cells, damaging them when they do so. Once inside, they take over the cell and make hundreds of thousands of copies of themselves. Eventually, the virus copies fill the whole host cell and it bursts open. The viruses then pass out through the bloodstream, the airways, or by other routes.
What are pathogens?
What are the 2 main pathogens?
Pathogens are micro-organisms that cause infectious disease. Bacteria and viruses are the main pathogens.
What are communicable diseases?
What are the causes of communicable disease?
Communicable diseases are those that can SPREAD from PERSON TO PERSON or between ANIMALS and PEOLE.
They can be caused by things like BACTERIA, VIRUSES, PARASITES and FUNGI.
What are communicable diseases sometimes described as?
Give two examples of communicable diseases.
They’re sometimes described as CONTAGIOUS or INFECTIOUS diseases.
MEASLES and MALARIA are examples of communicable diseases.
What are non-communicable diseases?
Non-communicable diseases are those that CANNOT SPREAD between people or between animals and people. They generally last for a LONG TIME and GET WORSE SLOWLY.
Give two examples of non-communicable diseases.
Asthma, cancer and coronary heart disease are examples of non-communicable disease.
Can diseases interact?
Sometimes diseases can INTERACT and cause OTHER physical and mental health issues that don’t immediately seem related.
Name 4 diseases that can lead to other diseases…
*Different types of disease may interact.
- Defects in the IMMUNE SYSTEM mean that an individual is more likely to suffer from INFECTIOUS DISEASES.
- VIRUSES living in cells can be the trigger for CANCERS.
- IMMUNE REACTIONS initially caused by a pathogen can trigger ALLERGIES such as skin rashes and asthma.
- Severe PHYSICAL ILL HEALTH can lead to depression and other MENTAL ILLNESS.
Give 3 factors other than disease that can lead to ill health?
1) Whether or not you have a GOOOD BALANCED DIET that provides your body with EVERYTHING it needs, and in the RIGHT AMOUNTS. A poor diet can affect your physical and mental health.
2) The STRESS you are under- being constantly under lots of stress can lead to health issues.
3) Your LIFE SITUATION- for example, whether you have easy ACCESS to MEDICINE to treat lines, or ether you have ACCESS to things that can PREVENT you from getting ill in the first place, e.g. being able to buy HEALTHY FOOD or access CONDOMS to prevent the TRANSMISSION of some sexually transmitted diseases.
What physical health problems can stress cause?
Stress cause all sorts of physical health issues (e.g. high blood pressure, headaches and issues with the immune system) as well as mental health issues (e.g. depression).
Exam tip- in the exam, you may need to draw off a graph, or draw or explain tables, graphs and charts showing data on the incidence of disease.
What is the incidence of disease?
The incidence of disease is the number of new cases of the disease within a given time.
It may be given as e.g. the number of new cases per 100 00 persons per year, so make sure you know the units the data is shown in before answering the question.
Exam tip- in the exam you might need to identify a correlation between variables relating to disease incidence from a graph.
What is correlation?
Graphs are used to show the relationship between two variables. Data can show three different types of CORRELATION (relationship):
Positive correlation e.g. ⟋ -As one variable increases the other increases.
Inverse (negative) correlation e.g. ⟍ -As one variable increases the other decreases.
No correlation on a graph shows scattered results.
Exam tip- sampling is often used when collecting data related to health and patterns in diseases.
What is epidemiological data?
Why is sampling used when collecting epidemiological data?
- Epidemiological data is data related to health and patterns in diseases.
- Sampling is often used when collecting epidemiological data. This is because it would take too long and cost too much to collet data from the entire population.
What is cardiovascular disease?
Cardiovascular disease is a term used to describe diseases of the heart or blood vessels.
What is coronary heart disease?
Coronary heart disease is when the CORONARY ARTERIES that supply the BLOOD to the heart muscle get BLOCKED by LAYERS OF FATTY MATERIAL BUILDING UP. This causes the arteries to become NARROW, so blood flow is RESTRICTED and there’s a LACK OF OXYGEN to the heart muscle- this can result in a HEART ATTACK.
What is used to treat coronary heart disease?
Stents can be used to treat coronary heart disease.
What is a stent?
What is the role of a stent?
Stents are wire mesh TUBES that can be inserted INSIDE ARTERIES.
They are used to WIDEN the arteries and keep them OPEN. This makes sure BLOOD CAN PASS THROUGH to the heart muscles. This keeps the person’s HEART BEATING (and the person alive).
Describe how stents can be used to treat people with coronary heart disease.
They can be inserted into the coronary arteries to make sure blood can pass through to the heart muscles. This keeps the person’s heart beating and keeps the person alive.
How are stents inserted into arteries?
- To insert a stent, a CATHETER is inserted into a blood vessel in the leg or wrist.
- The catheter contains a balloon and a metal stent.
- It is directed to the coronary artery and when the narrowed section of artery is found, the balloon is inflated which causes the stent to expand, and it becomes lodged in the artery.
- The stent then acts to keep the artery open so that the heart continues to receive enough oxygen to function effectively.
What are the advantages of using stents to treat patients with CHD?
1) Stents are a way of LOWERING the risk of a HEART ATTACK in people with coronary heart disease.
2) They are EFFECTIVE for a LONG TIME and the RECOVERY TIME from the surgery is relatively QUICK.
3) Stents are good alternatives to more risky operations, like BY-PASS SURGERY, providing the patient’s heart disease is not too serious.
What are the disadvantages of using stents to treat patients with CHD?
- There is a risk of COMPLICATIONS during the operation (e.g. heart attack) and a risk of INFECTION from the surgery. There is also the risk of patients developing a BLOOD CLOT near the stent. This is called THROMBOSIS.
- Fatty deposits may build up on the stent over time- meaning that blood flow to the heart muscle may be reduced again.
What is cholesterol?
Cholesterol s an essential lipid that your body produces and needs t function properly.
Is cholesterol bad for your health?
What is the bad cholesterol called?
Too much of a certain type of CHOLESTEROL can cause HEALTH PROBLEMS.
Bad cholesterol is called LDL cholesterol.
What health problems are caused by having too much LDL cholesterol?
Having too much of this ‘bad’ cholesterol in the bloodstream can cause FATTY DEPOSITS to form inside ARTERIES, which can lead to CORONARY HEART DISEASE.
What are statins?
Statins are DRUGS that are WIDELY USED and can reduce the amount of ‘bad’ cholesterol PRESENT in the BLOODSTREAM. This SLOWS DOWN the rate of fatty acids forming.
What are the advantages of using statins?
1) By reducing the amount of ‘bad’ cholesterol in the blood, statins can REDUCE the risk of STROKES, CHD and HEART ATTACKS.
2) As well as reducing the amount of ‘bad’ cholesterol, statins can INCREASE the amount of a BENEFICIAL type of cholesterol (known as ‘GOOD’ or HDL cholesterol) in your bloodstream. This type can REMOVE ‘bad’ cholesterol from the blood.
3) Some studies suggest that statins may also help PREVENT some OTHER DISEASES.
What are the disadvantages of using statins?
1) Statins are a LONG-TERM drug that must be taken REGULARLY. There’s the risk that someone could FORGET to take them.
2) Statins can sometimes cause NEGATIVE SIDE EFFECTS, e.g. headaches. Some of these side effects can be SERIOUS, e.g. kidney failure, liver damage and memory loss.
3) The effect of the statins ISN’T INSTANT. It takes TIME for their EFFECT to kick in.
When are donor hearts transplanted?
If a patient has HEART FAILURE, doctors may perform a HEART TRANSPLANT (or HEART AND LUNGS TRANSPLANT if the LUNGS are also DISEASED) using DONOR ORGANS from people who have recently died.
What are artificial hearts?
ARTIFICIAL HEARTS are MECHANICAL DEVICES that PUMP BLOOD for a person whose own heart has FAILED.
When are artificial hearts used?
They are occasionally used as a temporary fix, to keep a person alive until a donor heart can be found or to help a person recover by allowing the heart to rest and heal. In some cases though they are used as a permanent fix, which reduces the need for a donor heart.
What are the advantages of using an artificial heart?
1) The main advantage of artificial hearts is that they’re LESS LIKELY TO BE REJECTED by the body’s immune system than a donor heart. This is because they’re made from METALS (titanium) or PLASTICS, so the body doesn’t recognise them as ‘FOREIGN’ and attack in the same way as it does with living tissue.
2) Used as a short term measure to keep patients alive until a biological donor heart can be found.
What are the disadvantages of using an artificial heart?
Surgery to fit an artificial heart (as with transplant surgery) can lead to BLEEDING and INFECTION. Also artificial hearts DON’T work as well as healthy NATURAL ones- parts of the heart could WEAR OUT or the ELECTRICAL MOTOR could FAIL. Blood doesn’t flow through artificial hearts as SMOOTHLY, which can cause BLOOD CLOTS and lead to STROKES. A patient receiving an artificial heart has to take DRUGS to THIN their blood and make sure CLOTS don’t occur. This can cause problems with bleeding if they’re HURT in an accident because their blood can’t clot normally to heal the wounds.
How can heart valves become damaged?
The VALVES in the heart can be damaged or weakened by HEART ATTACKS, INFECTION or OLD AGE.
What does damage to a heart valve cause?
The damage may cause the VALVE TISSUE to STIFFEN, so it WON’T OPEN PROPERLY. Or a valve may become LEAKY, allowing blood to flow in BOTH DIRECTIONS rather than just forward. This means that blood DOESN’T CIRCULATE as EFFECTIVELY as normal.
How is severe valve damage treated?
Severe valve damage can be treated by REPLACING the valve.
What two types of replacement valve are used to treat damaged valves?
Replacement valves can be ones taken from HUMANS or OTHER MAMMALS (e.g. cows or pigs)- these are BIOLOGICAL VALVES. Or they can be MAN-MADE- these are MECHANICAL VALVES.
What are the advantages of using biological valves?
1) They do not damage RED BLOOD CELLS as they pass through the open valves.
What are the advantages of using mechanical valves?
1) Very STRONG and DURABLE- able to last a lifetime.
What are the disadvantages of using biological valves?
1) Prone to becoming HARDENED over the course of several years.
2) For patient with long life expectancy, there is a higher chance of further operations to replace the valves (any operation carries risks).
What are the disadvantages of using mechanical valves?
1) Damage red blood cells as they pass through the open valves.
2) Require the patient to take anti-blood clotting drugs for the rest of their life.
3) Some people say they can hear the valves opening and closing.
What is a BLOOD PRODUCT?
A BLOOD PRODUCT is any component of the BLOOD which is collected from a donor for use in a BLOOD TRANSFUSION.
What do most blood products used in medicine consist of?
WHOLE BLOD is uncommonly used in TRANSFUSION MEDICINE at present; most blood products consist of specific processed components such as RED BLOOD CELLS, BLOOD PLASMA, OR PLATELETS.
What do blood products used in blood transfusions rely upon?
It relies on people being willing to donate their blood.
