Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
20 Cards in this Set
- Front
- Back
|
How does the heart pump blood around the body (right side) |
Unoxygenated blood flows into the right atrium which contracts, opening the valve and the blood flows into the right ventricle. The ventricle contracts, opening the valve and pushes the blood up and out of the pulmonary artery to the lungs. |
|
|
How does the heart pump blood (left side) |
Oxygenated blood flows from the lungs into the heart through the pulmonary vein into the left atrium. The atrium contracts, opening the valve so it flows into the left ventricle. This ventricle then contracts which pushes it up through the valve and out the aorta where it can be pumped around the body. |
|
|
What are the three types of blood vessels |
Arteries - carry blood away from heart Capillaries - involved in exchange of materials at the tissues Veins - carry the blood to the heart |
|
|
Describe the design of the capillaries |
Thin walls (no muscle/elastic fibres) Semi permeable wall Narrow lumen (only RBC pass through) |
|
|
Describe the design of veins |
Large lumen Thin walls (little elastic fibres and smooth muscle) Often have valves (prevent backflow) |
|
|
Describe the design of arteries |
Small lumen Thick layer of muscle/elastic fibres (allows arteries to expand under high pressure) Thick walls |
|
|
How are RBC specialised |
Concave surface for more surface area for absorbing oxygen. No nucleus; more room for oxygen. |
|
|
What is oxyhaemoglobin |
In the lungs haemoglobin combines with oxygen to become oxyhaemoglobin. In body tissues the reverse happens. It splits up to release oxygen into the cells. |
|
|
What are platelets |
They help the blood to clot at wounds to stop blood pouring out and microorganisms getting in. They are small fragments of cells which have no nucleus. |
|
|
What is plasma |
It is the liquid that carries everything in blood. It carries RBC, WBC, platelets, nutrients, CO2, urea, hormones and antibodies. |
|
|
What is artificle blood |
It can keep you a live in an emergency as it is a blood substitute e.g. a salt solution. It's safe and may give the patient enough time to produce new blood cells. If not a blood transfusion is needed. |
|
|
What are artificle hearts |
Mechanical devices that pump the person blood of their own heart fails. They're temporary. They're made with plastics or metals so they are less likely to be rejected by the body as they aren't recognized as foreign objects like a donor heart might be. |
|
|
What are stents |
Tubes inserted inside arteries which are blocked or narrow to keep them open and improve blood flow by compressing the plaque. |
|
|
How do stents work |
They are insterted in a catheter in a guide line with a balloon. The balloon is inflated and the mesh pushed out around it, compressing plaque. The balloon is removed and after time cells will grow around the stent and keep it open. |
|
|
What is honeostasis |
The maintenance of a constant internal environment |
|
|
What are the six main things that need to be controlled in the body. |
Body temperature Water levels Ion content Blood sugar levels Carbon dioxide Urea |
|
|
Why/how is body temperature controlled |
Enzymes work best at 37°C If it gets too hot or cold the enzymes won't work and important reactions could be disrupted. The thermotegulatory centre in the brain controls the temperature and reaponda when you get too hot or cold. |
|
|
What are the three main roles of the kidney |
Removal of urea Adjustment of ions Adjustment of water content |
|
|
Describe the removal of urea |
Proteins can't be stored in the body so excess amino acids are converted into days or carbohydrates and this occurs in the liver. Urea is a waste product. Urea is poisonous. It's release into the bloodstream by the liver and the kidneys then filter it out of the blood. It's stored in the bladder until it's excreted in urine. |
|
|
Why is kidney failure bad |
If the kidneys aren't working properly the waste substances build up in the blood and eventually you can't control the levels of ions and water. This will result in death. |
