Gas Exchange in Mammals" Flashcards
, trWhat is found in the thorax?
= 2 lungs
= protected by ribs
= intercostal muscles
= diagphram
What happens when humans breathe through their nose?
= air passes through nasal cavity- has hairs that trap dust particles and pathogens + warms and moistens the air before enters lungs
Where does the air go from the nasal cavity?
= passes through tracheae
What is the trachea made from?
= made from cartilage- prevents wall from collapsing inhalation
= C shape: allows movement and flexibility- food can pass
= walls are lined with celial epithelial and gblet cells
What do goblet and celilal epithelial cells do?
goblet: secrete mucus, traps dust and pathogens
celilated epithelial cells: have hair like cilia, tosses mucus to the throat where it is swallowed and dust and pathogens are digested
What does the trachea divide into?
=2 bronchi
= carries air into one of the lungs
= contain cartillage, celial epithelial and goblet cells
=
What does the bronchus split into?
= bronchioles- narrow airways + supported by cartillage
= contain smooth muscle- relaxes, the bronchioles widen, increasing volume
=
What do the bronchioles split into?
= alveoli- air sacs- lots
= where gas exchange happens
= covered in moisture
= great supply in blood cappillaries
What/how do gases move into the alveoli?
= oxygen from air dissolves in the moisture inside the alveoli- diffuses into red blood cells to be oxygenated
= carbon dioxide diffuses from blood into alveoli air space
=
What do the elastic fibres do?
= stretch and recoil during breathing
How are alveoli adapted to maximise the rate of diffusion?
= lots of alveoli- surface area for diffusion of gases
= wall of the alveolous and wall of cappilar are one cell thick- short diffusion pathway between air in alveoli and red blood cells
= when oxygen diffuses into the blood it is rapildy carried away from the alveoli
=- allows steep concentration gradient
= also maintained by breathing brings fresh air- allows high concentration in alveoli and low co2
