B4 - Circulatory System (Y10 - Autumn 2) Flashcards
🟢 What is a Septum Defect?
A septum defect can mean that there is a hole in the wall between the left and right hand side of the heart is there, meaning oxygenated blood can mix with un-oxygenated and vice versa, making the heart less efficient. This can lead to an abnormal heartbeat, a stroke, or even heart failure
🟢 What is a Stent used for?
When Coronary arteries become narrow (due to a buildup of fatty material on the lining) it means blood flow through the arteries is reduced, meaning the heart gets a smaller supply of blood, meaning less oxygen and less glucose. This can cause heart pains, heart attacks, and even death. One way to solve this problem of this coronary disease by using a stent. This is a metal mesh that is placed in the artery, with a tiny balloon inside of it being inflated to open up the blood vessel and the sent at the same time. After the vessel has beenwidened, the balloon is deflated and removed, while the stent remains where it is, holding the vessel open, meaning blood can now flow through the artery freely. Many stents also release drugs to stop the blood from them to stop the blood clotting. Another way for this to be treated is by using bypass surgery where other parts of veins are put into it instead, however this is high cost and high risk. (Stents only treat this one area, and do not help any of the underlying issues).
🟢 What are Statins
Nowadays, more and more doctors are prescribing statins to anyone at risk from cardiovascular disease. They reduce blood cholesterol levels and this slows down the rate at which fatty material is deposited in the coronary arteries.
🟢 How are Leaky Valves treated?
Heart valves are almost constantly exposed to very high amounts of pressure a lot of the time, which is why it is not uncommon for valves to start to leak, become still, and not open fully over time - which makes the heart less efficient. If this is not discovered or treated, it can affect people by making them breathless and eventually kill them. The good news is that doctors can operate and fully replace heart valves. You can get mechanical valves made of titanium and polymers which last a long time, but this does mean you will have to regularly take medicine to ensure there is no blood clotting. You can also get valve donors from humans and animals such as pigs and cattle, but only last for around 12-15 years.
🟢 What is an Artificial Pacemaker used for?
A group of cells in your right atrium control when you heart beats and helps it to keep a steady, regular and sustainable beat. If the natural pacemaker stops working properly, your heart can go out of sync and your heat can start to beat too quickly/slowly, causing serious problems in the amount of oxygen transferred around the body and how fast the blood is pumped. These problems can be solved by using an artificial pacemaker, which is a device used to correct your irregular heart rate. It sends strong electrical pulses which corrects and maintains a better, more regular beat. Some of these artificial pacemakers weigh as light as 20g-50g, and can even be designed so that it knows when to send more pulses when you exercise.(If you do get a pacemaker, you will need regular check-ups for life - a small price to pay)
🟢 When is an Artificial Heart used?
Sometimes an artificial pacemaker is simply not enough to restore a person’s health in some bad situations, so when a heart fails completely, a donor heart/heart and lungs and be transplanted in. However, with a heart transplant, you need to find a heart with the right tissue match, meaning some people may die before one is found. Some scientists have used temporary hearts that can support natural health until it can be properly replaced with a real one, with a small risk of getting a fatal blood clot. These hearts need a lot of machinery for them to work, with the patient having to stay in hospital until a real heart can be transplanted, however Matthew Green was the first person to go home with an artificial heart in a backpack, which lasted for two years until his proper transplant, just showing how far artificial hearts have come.
🟢 Can a Stent be be put in without a general Anaesthetic?
A stent can be put in without a general anaesthetic.
🟢 Why is the Circulatory System needed?
The Circulatory System is needed to transport oxygen around the body. This transport system is needed because diffusion alone isn’t adequate, due to the low Surface Area to Volume ratio.
❌ What is Blood made from?
Blood is made up of Plasma, White Blood Cells, platelets and Red Blood Cells, the average person carries around 4.7 litres-5 litres of blood.
❌ What is Plasma and how much of it is in the Blood? (+ What it transports)
Plasma: 55% of the Blood.
Your blood plasma is a yellow liquid, and it’s job is to transport all of your blood cells, and some other substances around the body, and it is largely made up of water.
The Plasma Transports:
- 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 your kidneys where it is removed from your blood ti form urine
- The small, soluble products of digestion pass into the plasma from your small intestine and are transported to the individual cells
❌ What are Red Blood Cells and how much of it is in the Blood?(+ RBC Adaptions)
Red Blood Cells: 45% of the Blood.
There are 5-6 million red blood cells per mm^3, meaning there are more red blood cells than any other type of blood cell in the body. These cells pick up the oxygen from the air in your lungs and carry it to the cells where they are needed, while their adaptations make them very efficient.
RBC Adaptions:
- They are biconcave discs. Being concave (pushed in) on both sides, gives them and increased surface area to volume ratio for diffusion
- They are packed with a red pigment called haemoglobin that binds to oxygen
- They have no nucleus, making more space for haemoglobin
❌ What are White Blood Cells and how much of it is in the Blood?
White Blood Cells: <1% of the Blood.
White blood cells are much bigger than red blood cells, and there are also fewer. They have a nucleus, which it part of the body’s defence system against harmful microorganisms. Some white blood cells (lymphocytes) form antibodies against these, while some other form antitoxins against poisons made by microorganisms. Yet others (phagocytes) engulf and ingest invading bacteria and viruses.
❌ What are Platelets and how much of it is in the Blood?
Platelets: <1% of the Blood.
These are small fragments of cells which have no nucleus. They are very important in helping the blood to clot at the site of the wound. Blood-clotting is a series of enzyme-controlled reactions that result in converting fibrinogen in fibrin. This produces a network of protein fibres that capture lots of red blood cells and more platelets to form a clot to stop you bleeding to death, which eventually forms a scab, which protects the new skin and stops bacteria entering the wound.
🟢 What 3 main Vessels is the Blood transported by?
- Arteries
- Veins
- Capillaries
🟢 Why is a Double Circulation System Important?
A double circulation system like our is vital in warm-blooded, active animals such as humans. It makes our circulatory system very efficient. Fully oxygenated blood returns to the heart from the lungs. This blood can then be sent off to different parts of the body at high pressure, so more areas of your body can receive fully oxygenated blood quickly.
🟢 What is meant by a Closed Double System? (for the Heart)
Closed - The blood remains inside the pathways and tracks that are made for it, like the blood vessels (such as your arteries, veins, capillaries e.c.t)
Double System - This means that there are two parts of the system, the part that is oxygenated, and the other part that is de-oxygenated.
(One for the body, one for the lungs - one part is oxygenated, one part is not - it goes through the heart twice in one complete circuit)
🟢 What are your Arteries? (Properties and Function)
Properties:
Thick Walls, Small Lumen, Thick layer of muscle and elastic fibres
Function:
Your arteries carry blood away from your heart to the organs of your body. (This blood is usually bright-red oxygenated blood.) The arteries stretch as the blood is forced through them at high pressure, which is why you can feel, your pulse, because your arteries are near to the skin’s surface. Because the blood in the arteries is being transported at such high pressures, it is necessary for them to have such thick walls and elastic fibres.
🟢 What are your Veins? (Properties and Function)
Properties:
Relatively Thin Walls, Large Lumen, Often have Valves
Function:
The veins carry blood away from the organs towards your heart. This blood is usually low in oxygen and therefore a purple-red colour. They have much thinner walls than arteries, but do have valves to prevent the back-flow of blood, meaning it is let to go towards the heart, but blocked if it wants to go out. The blood is squeezed towards the heart by the action if the skeletal muscles.
🟢 What are your Capillaries? (Properties and Function)
Properties:
Wall are a Single Cell Thick, Is a Tiny Vessel with a narrow Lumen
Function:
The capillaries form a huge network of tiny vessels linking the arteries and the veins. Capillaries are narrow with very thin walls, which makes substances like oxygen and glucose to diffused easily out of the blood and into cells, while the substances produced by the cells like carbon dioxide can easily pass into the blood through these thin single cells walls.
🟢 What does the Heart do?
The structure of the human heart is perfectly adapted for pumping blood to your lungs and your body. The two sides of the heart fill and empty at the same time, giving a strong, coordinated heartbeat. Blood enters the top chambers of your heart, which are called the atria. The blood coming into the right atrium from the vena cava is deoxygenated blood from your body. The blood coming into the left atrium in the pulmonary vein is oxygenated blood from your lungs. The atria contract together and force the blood down into the ventricles, and the valves close to stop the blood flowing out. The ventricles contract and then force the blood out of the heart.
- The right ventricle forces deoxygenated blood to the lungs in the pulmonary artery
- The left ventricle pumps oxygenated blood around the body in a big artery called the aorta
The valves then close so blood doesn’t flow back into the heart.
🟢 Where does the Right Side pump to with what kind of blood?
The right side pumps de-oxygenated blood under low pressure to the lungs, meaning this part of the heart doesn’t need thick muscular walls, as not as much force is needed to get to blood to the lungs.
🟢 Where does the Left Side pump to with what kind of blood?
The left side pumps oxygenated blood to the rest of the body, meaning this part of the heart does need thick muscular walls, as a lot force is needed to get to blood to all the places in the body.
🟢 Why is does the Left side have more muscle than the right side in the heart?
The muscle wall of the left ventricle is noticeably thicker than the wall of the right ventricle. This allows the left ventricle to develop the pressure needed to force the blood through the arterial system all over your body. The blood leaving the right ventricle moves through the pulmonary arteries to your lungs, where high pressures would damage the delicate capillary network where the gas exchange takes place.
🟢 Function of the Pulmonary Vein
The Pulmonary Vein brings oxygenated blood from the lungs
🟢 Function of the Left Atrium
The left atrium receives blood full of oxygen from the lungs and then empties the blood into the left ventricle, with blood passing through the valve.
🟢 Function of the Left Ventricle
The left ventricle pumps the oxygen rich blood through the aorta out to the rest of the body, at a higher pressure than the right ventricle.
🟢 Function of the Heat Wall
The Heart wall is a thick wall of muscle that protects the heart, with the muscle considerably thicker around the left ventricle, as more force needs to be generated there to pump the blood.
