The heart, blood, lungs, principles of organisation and coronary heart disease Flashcards
name parts of the ventilation system
- trachea
- bronchi/ bronchus
- bronchioles
- alveoli
describe the process of gas exchange
- alveoli are surrounded by blood capillaries
- blood passing next to alveoli contains lots of carbon dioxide + very little oxygen (just returned to lungs from rest of body)
- oxygen diffuses into blood (low conc.) + out of alveolus (high conc.)
- carbon dioxide diffuses out of blood + into alveoli = breathed out
- blood reaches body cells
- oxygen released from red blood cells (high conc) + diffused into body cells (low conc)
- carbon dioxide diffuses out of body cells (high conc) + diffused into blood (lwo conc)
- blood carried back to lungs
How are the lungs adapted for gas exchange?
- large surface area
- alveoli has folded surface
- short diffusion pathway
- one cell thick alveoli wall + capillary wall
- steep concentration gradient
- good blood supply from capillaries + ventilation
How do you calculate breaths per minute?
- number of breaths/ number of minutes
What is the heart?
- a muscle that pumps blood around the body
- a double circulatory system
What is a double circulatory system?
- one circuit pumping deoxygenated blood to lungs
- other circuit pumps oxygenated blood around body
label the diagram of the heart
describe blood flow in the heart
- deoxygenated blood goes into right atrium via vena cava
- blood goes into right ventricle
- right ventricle pumps blood out of heart to lungs
- oxygenated blood from lungs goes to left atrium via pulmonary vein
- goes into left ventricle
- left ventricle pumps blood out of heart to around the body
What do the valves do in the heart?
stop blood from flowing backwards
What controls the resting heart rate?
- group of cells in the right atrium
- acts as peacemaker
What is used to correct irregularities in heart rate?
an electrical pacemaker
Draw a diagram of an artery, vein and capillary
What is the funcion of an artery?
- carry blood at high pressure away from heart
What is the funcion of a capillary?
- exchange substances with cells
What is the function of a vein?
- return blood at low pressure to heart
What is the size of the lumen of an artery, capillary and vein?
artery - narrow to maintain pressure
capillary - very narrow to keep red blood cells close to tissue cells
vein - large, less resistance to blood flow
Describe the walls of an artery, capillary and vein
artery - elastic fibres strech and recoil to maintain pressure, thick wall resists busting
capillary - very thin, short diffusion distance
vein - thin walls, low pressure
Do arteries, capillaries, and veins have valves?
artery - no, high pressure keeps blood moving
capillary - no
vein - yes, prevents backflow of blood
What is coronary heart disease?
- plaque builds up in coronary arteries
- makes them narrower, reduces blood flow
- insufficient oxygen reaches heart
- causes heart attacks + damage to heart
Describe how statins could be used to treat CHD
- drugs lower cholesterol level in blood
- slows down build up of plaque in arteries
Describe how stents could be used to treat CHD
- short wire mesh tube inserted into arteries to support artery
Describe how heart transplants could be used to treat CHD
- entire organ is replaced from organ donor who has died
What are the disadvantages of using statins?
- long term treatment
- risk of side effects
- eg digestion issues/ liver damage
What are the disadvantages of using stents?
- greater risk of blood clots
- can become faulty
- requires surgery, risk of infection
