Revision 4 Biology

1. 1 cell thick
   1. to reduce distance travelled
      1. Via Diffusion
2. large surface area
   1. increases rate of gas exchange
3. Moist
   1. Gasses diffuse quicker in wet conditions
4. Rib cage
   1. Protects:
      1. Lungs
      2. Heart
5. Diaphragm
   1. separates lungs from lower body
6. Alveoli
   1. where gas exchange takes place
7. Trachea
   1. Carries air to lungs
   2. has rings of cartilage
      1. to keep the trachea open
8. Bronchus
   1. transport air from trachea to bronchioles
9. Bronchioles
   1. Carry air from bronchi to alveoli
10. large blood supply:
    1. gas transport is quicker

1. left ventricle
2. left atrium
3. pulmonary vein
4. aorta
5. right ventricle
6. right atrium
7. vena cava
8. pulmonary artery

1. transports
   1. oxygen
   2. glucose
2. removes
   1. water
   2. Carbon dioxide

1. Blood
   1. oxygenated
      1. to the body
   2. deoxygenated
      1. to the lungs

1. artery
   1. Thick walled
   2. deep in body
   3. high blood pressure
   4. thick muscle and elastic layer
      1. stretches and springs back
   5. pumps blood to body
2. capillaries
   1. 1 cell thick
   2. where substance exchange occurs
   3. connects veins + arteries
3. veins
   1. low blood pressure
   2. thin walls
   3. Lumen
   4. takes blood to heart
   5. thin muscle and elastic layer
   6. smooth lining

1. red blood cells
   1. carries oxygen
2. white blood cells
   1. fight disease
3. plasma
   1. carries substances in blood
4. platelets
   1. clot a cut

Nota:

• Exercise regularly, eat healthy, don't smoke, limit drinking alcohol, low fat diet

1. caused by coronary arteries being blocked
   1. by fatty plaques of cholesterol
2. Statins
   1. reduce amount of cholesterol in blood
      1. blocks the action of an enzyme in the liver
   2. work well on the elderly
3. stents
   1. the stent is inserted into the artery
      1. is expanded to widen the arteries
         1. stent is then removed leaving the wire mesh behind

1. options
   1. artificial pacemaker
   2. transplant
   3. artificial heart
   4. drugs
   5. stents
   6. surgery

1. better quality of life after transplant
2. when successful organ will last a few years
3. must be transplanted soon after being donated
4. has to be kept refrigerated
5. organ can be rejected
6. patients have to take drugs for the rest of their lives

1. when valves become leaky
   1. blood can flow backwards
2. heart pumps faster

1. health is a state of mental, physical and social well being
2. factors
   1. astma
   2. exercise
   3. stress
   4. smoking
   5. cancer
   6. alcohol
   7. food allergies

1. cell growth
2. repair
   1. replace
   2. cell genetically identical
3. cell division
4. sexual reproduction

1. 14 units a day
2. vomiting
3. alcohol poisoning
4. liver failiure
5. pass out
6. addictive

1. the production of energy
2. occurs in every cell