Flashcards in Organisation Deck (86)
In the lungs, where does air you breathe go?
What happens in the alveoli?
oxygen diffuses out of the alveoli into the blood
carbon dioxide diffuses out of the blood into the alveloi
Why is the circulatory system a DOUBLE circulatory system?
There are two circuits joined together.
For each full circuit, the blood passes through the heart twice.
What is carried in the right side of the heart?
(from body, going to lungs)
What is carried in the left side of the heart?
(from lungs, going to body)
What does the vena carva do?
Carries deoxygenated blood from body into the right atrium (in the heart)
What does the pulmonary artery do?
Carries deoxygenated blood away from the right ventricle (in the heart) to the lungs
What does the pulmonary vein do?
Carries oxygenated blood from the lungs into the left atrium (in the heart)
What does the aorta do?
Carries oxygenated blood away from the left ventricle (in the heart) to the rest of the body
What is the pacemaker in the heart?
group of cells in the right atrium wall that control your resting heart rate by releasing a small electrical impulse to make the muscle cells contract
What do arteries do?
Carry blood away from heart
What do veins do?
Carry blood into the heart
What do capillaries do?
Join up arteries and veins
Involved in gas exchange
How are arteries adapted? (And why?)
Strong and elastic walls (to withstand high pressure)
Thick walls with layers of muscle and elastic fibre (to help them to stretch and spring back)
How are capillaries adapted? (And why?)
Permeable walls (so that substances can diffuse in and out)
Walls are usually only one cell thick (to increase rate of diffusion by decreasing the distance which diffusion occurs)
How are veins adapted? (And why?)
Big lumen (to help blood to flow despite it being at low pressure)
Valves (to keep blood flowing in the right direction)
What are the main four components in blood?
Red blood cells
White blood cells
What do red blood cells do?
Carry oxygen from the lungs to all the cells in the body
How are red blood cells adapted? (And why?)
biconcave disc shape and no nucleus (gives the cells a large surface area for absorbing oxygen)
contains haemoglobin (pigment that binds to oxygen to become oxyhaemoglobin)
What are the two types of white blood cells and what do they each do?
Lymphocytes -create antibodies and antitoxins to fight microorganisms and neutralise toxins
Phagocytes -engulf microorganisms
What do platelets do?
Help to clot blood at a wound (to stop blood loss and to prevent microorganisms coming in)
What are platelets?
Small fragments of cells (without a nucleus) in the blood
What is plasma? And what does it do?
Liquid in the blood which carries:
- red and white blood cells and platelets
nutrients (eg. amino acids and glucose)
- carbon dioxide
- antibodies and antitoxins
What are cardiovascular diseases?
diseases involving the heat or blood vessels, eg coronary heart disease
What is coronary heart disease?
when the coronary arteries (arteries supplying blood to the muscle of the heart) get blocked by layers of fatty material.
This causes the arteries to become narrow so that blood flow can become restricted and there may be a lack of oxygen, resulting in heart attack.
What are stents?
Tubes inserted inside arteries to keep them open to make sure blood can flow through to the heart muscles.
What are the advantages of stents?
-effective for a long time
-recovery time from surgery is quick
What are the disadvantages of stents?
-risk of complications during surgery
-risk of infection from surgery
-risk of thrombosis (blood clotting near stent)
What are statins?
Drugs that reduce the amount of bad cholesterol in the blood, which slows down the rate of formation of fatty acids.