Gaseous exchange in humans and plants

• 5 characteristics to having a large surface area to volume ratio for an organ

  1)Large surface area

  2)Thin epithelium

  3)Moist surface

  4)ventilation

  5)Good blood supply
• Name the parts of a leaf

  :

  A) upper epidermis

  B) palisade mesophyl

  C) spongy mesophyl

  D) stomata

  E) lower epidermis

  F) cuticle

  G) vascular bundle

  
• The cuticle is there to protect against pathogens
• The upper epidermis is a layer of clear cells which acts as a protective layer and dosent stop light from entering the leaf
• The paliside mesophyl is a layer of upright rectangular cells that carry out photosynthesis and allow maximum light absorbtion
• The spongy mesophyl are a layer of round cells that carry out photosynthesis and allow ventilation of gasses around the cells
• The lower epidermis is a layer of protective cells that stop pathogens
• The stomata is a hole in the epidermis which allows gas exchange. Guard cells control the opening and closing of the stomata
• Ventilation : guard cells are opening and closing the stomata creating currents 


  Large surface area : theres only 5-8 layers of cells which means they are very thin
• A good transpotr system : vascular bundle

  A steep/ high concentration gradient for faster diffusion
• Moist surface area to dissolve gasses
• The cartilage is c shaped to avoid abracing eachother

  A) for oxygen

  B) esophogus (food pipe)

  
• lable the diagram

  A) nasal cavity

  B) larynx

  C) Trachea

  D) bronchi

  E) lungs

  F) esophagus

  G) epiglottis

  H) uvula (bell)

  I) diaphram

  J) pleural cavity

  
• Nasal cavity


  The cavity is devided up by shelves (turbinates) which warms ,moistens, clwans and tests the air breathed in. Foriegn particles get caught in the mucus and are wafted by cilia towards the throat
• Pharynx (throat) 


  Point where the breathing and alimentary pathways cross
• Glottis (trachea enterance) 


  small hole through which air enters larynx
• Epiglottis


  Flap which closes over the glottis during swallowing thereby preventing "food going down the wrong pipe"
• Larynx (voice box)


  contains vocal chords which when vibrated make sounds
• Trachea (windpipe)


  Tube by which air passes to and from the lungs. incomplete rings of cartilage keep it permanently open. Foreign particles ge caught in mucus and are wafted by cilia towards the throat
• Bronchi 


  Like the trachea, carry air to and from left and right lung
• Bronchioles 


  Narrow, tree-like branches of bronchi through which gasses diffuse to and from alveoli
• Alveoli


  Tiny air sacs across whose thin , moist walls get gas exchange takes place. Very close association with capillaries. The vast number of alveoli provide a large surface area for gas exchange
• when inhaling:


  Ribs move upwards and diaphragm flattens. Lungs inflate and breastbones move forwards/outwards
• when exhaling:


  Ribs move downwards and diaphragm resumes its dome shape. The lungs deflate and breastbone moves doenwards/inwards
• inhaled exhaled

  Oxygen 21% 16.4

  Carbon dioxide 0.03% 4.1

  nitrogen and argon 79.04% 79.5
• lable the alveoli

  A) oxygenated blood

  B) red blood cell

  C) deoxygenated blood

  D) capillary

  
• The bad effects of a cigarette are

  1)shortness of breath

  2)Black lungs

  3)Infertility

  4)Lung cancer

  5) harms baby if pregnant

  6)yellow teeth and nails
• Bronchitis is the inflammation of bronchial tubes
• Emphysema is the destruction of the alveoli wall
• Lung cancer is when the walls of the bronchial tubes grow
• Carbon dioxide and sulfur dioxide cause bronchitis and So2 produces acid rain
• Carbon monoxide gas, lead and oxides of nitrogen caused faitness, lead harms the brain and oxides of nitrogen produce acid rain
• Air pollution can be reduced using chimney filters and carburettors (filter gasses)