B4 Heart part Flashcards
What is blood made of?
Based on plasma, carrying red blood cells, white blood cells and platelets. It also carries many dissolved substances, carrying around 5 litres of it.
What does blood/plasma do?(3)
- Waste carbon dioxide carried to the lungs
- Urea formed in your liver from the breakdown of excess proteins is taken to your kindneys where it is taken out of your blood to make urine.
- The small soluble products or digestion are taken from the small intestine into the plasma and then given to needing cells.
What do red blood cells do?
They pick up oxygen from the air in your lungs and carry it to cells where it is needed.
What are red blood cells adaptations?(3)
- They are biconcave discs(pushed in on both sides), giving them an increased surface area to volume ratio for diffusion
- They are full of haemoglobin- a red pigment that binds to oxygen
- No nuclues making more space for haemoglobin
What are white blood cells?
They form a part of your bodies’ defence system against pathogens. Some form antibodies(lympthocytes), some form antitoxins and some engulf and digest invading bacteria and viruses(phagocytes).
What are platelets?
Small fragments of cells that have no nucleus, but help blood to clot at the site of a wound.
What is blood clotting?
A series of enzyme-controlled reactions converting fibrinogen into fibrin, producng a network ofprotein fibres that capture lots of red blood cells and more platelets to form a clot to stop you bleeding to death.
What is an artery?
It carries blood from your heart to organs, usually oxegenated apart from the pulmonary artery. They stretch as blood passes which you feel as a pulse. They have thick walls full of muscle and elastic fibres and a small lumen.(high pressure). more collagen
What are veins?
Carry blood into your heart, low in oxygen, they have no pulse. Thin walls and valves to stop back flow. Blood is squezzed by surrounding muscles up back to the heart. They have a large lumen and less collagen.
What is a capillary?
They form huge networks of tiny vessels linking the arteries and veins. they are narrow and have 1 cell thick walls.This enables substances to diffuse out of your blood and into cells.The substances produced by your cells pass easily into blood through the walls of the capillaries. Narrow lumen.
What artery supplies oxygen to the heart.
The coronary artery.
How does blood pump around the body?
- Blood enters the top chambers-the atrias
- The blood coming into the right atrium from the vena cava is deoxegenated and from your body
- The blood coming from your left atrium in the pulmonary vein is oxygenated from your lungs
- The atria then contracts to force blood to the ventricles, and valves close to prevent backflow out of the heart
- The ventricles then contract forcing blood out of the heart
- The right ventricle forces deoxegenated blood to the lungs in the pulmonary artery.
- The left ventricle pumps oxegenated blood around the body in a big artery called the aorta.
What is CHD?
Coronary Heart Disease-the coronary arteries become narrow. A common cause is a buildup of cholestorol, lowering the blood flow, taking away the supply of oxygen to the heart which can cause pain, heart attacks or even death.
What is a stent?
A stent is a metal mesh put in the artery with a balloon inflated to open up the blood vessel and stent at the same time, then the balloon is removed but the stent stays holding the vessel open, letting the blood flow freely.
What is bypass surgery?
Replacing the coronary arteries with veins from other parts of the body. This is useful for bad cases where stents don’t work but it is expensive and comes with the risk of a general anaesthetic.
