6.6 Human gas exchange

Question 1

Explain why humans need lungs?

Answer 1

Require constant supply of oxygen to release energy, form of ATP.
CO2 produced needs to be removed

Question 2

Link structure to function of lungs?

Trachea

Answer 2

Lungs are pair of lobed structure, made up of branched tubules (bronchioles) which end in tiny air sacs, alveoli.
Trachea, flexible airway that is supported by rings of cartilage, which prevents the trachea from collapsing, muscle lined with ciliated epithelium and goblet cells

Question 3

Link structure to function (bronchi, bronchioles and alveoli)

Answer 3

Bronchi, 2 divisions of trachea. Each leading to one lung, similar to structure of trachea, cilia. Produce mucus to trap dirt particles and cilia move mucus to throat.
Bronchioles, series of branching subdivisions of bronchi. Walls made of muscle lined with epithelial cells. Muscle allows them to constrict so that they can control the flow of air in and out.

Question 4

Ficks law to explain how alveoli are adapted for gas exchange?

Answer 4

Alveoli are minute air sacs. Very large SA. Short diffusion distance between alveoli and bronchioles, therefore short diffusion distance. Very good bloody supply, capillary network around the alveoli, maintaining concentration gradient