Life Processes long 3 Flashcards
Give a note about respiration in humans?
In humans air is taken into the body through the nostrils and is filtered by fine hairs and mucas that line the passage through the throat and into the lungs. Within the lungs, the passage divides into smaller tubes which finally terminate in balloon-like structures which are called alveoli which provide a surface where the exchange of gases can take place.
Explain the steps of respiration in humans?
When air is sucked into the lungs it fills the expanded alveoli. The blood brings carbon dioxide for release into the alveoli, and the oxygen in the alveolar air is taken up by blood to be transported to all the cells. When air is taken in and let out, the lungs always contain a residual volume of air so that there is time for oxygen to be absorbed and for the carbon dioxide to be released.
What happens in animals when diffusion pressure cannot take care of oxygen delivery ?
When the body size of animals is large the diffusion pressure alone cannot take care of oxygen delivery. Instead, respiratory pigments take up oxygen from the air in the lungs and carry it to tissues which are deficient in oxygen before releasing it.
What do the walls of the alveoli contain
A network of blood-vessels.
