EXCHANGE SURFACES

Question 1

Parts of respiratory system.

Answer 1

Nose, Trachea, Bronchi, Bronchioles, Alveoli, Diaphragm.

Question 2

Process of inhalation.

Answer 2

An active processes. External intercostal muscles contract/ internal relax. Diaphragm contracts and flattens. Ribs move up and out. Volume of thorax increases. Pressure in chest cavity drops below atmospheric pressure. Air moves into lungs, through nasal passage, don pressure gradient.

Question 3

Process of exhalation.

Answer 3

A passive processes. Internal intercostal muscles contract/ external relax. Diaphragm relaxes and pushed up. Ribs move in and down. Volume of thorax decreases. Pressure in chest cavity increaes above atmospheric pressure. Air moves out lungs, through nasal passage, down pressure gradient.

Question 4

Adaptations of alveoli.

Answer 4

One cell thick, network of capillaries surrounding, Large network (SA:V), Red blood cells (carry O2- maintain conc gradient), Ventilation (maintain conc gradient).

Question 5

Structure of bronchiole.

Answer 5

Smooth muscle, Ciliated epithelium, elastic fibres, goblet cells, blood vessels, lumen.

Question 6

Structure of trachea.

Answer 6

Cartilage, Smooth muscle, Elastic fibres, Ciliated epithelium, Goblet cells, Small blood vessel, Mucus-secreting gland.

Question 7

Role of cartilage.

Answer 7

Structure + support, Protection, Keeps trachea open, Shape allows dilation of lumen.

Question 8

Smooth muscle + Elastic fibres.

Answer 8

Stretch and recoil to change shape of lumen.