Animal Respiratory System

Question 1

what is Boyle’s law?

Answer 1

• pressure of gas varies inversely with volume
  
  • (as P up V down, or P1V1 = P2V2)

Question 2

How do inhalation and exhalation work?

Answer 2

Inhalation

• the diaphragm contracts (moves downwards), which expands the chest cavity. Because volume increases, pressure decreases and air rushes in to fill the space
  
  • shallow breathing fills only the tops of the lungs; deep breathing fills them fully

Exhalation

• the diaphragm releases (moves back upwards), decreasing the chest cavity and the volume, which raises pressure and pushes air out

Question 3

Characteristics of alveoli (traits that help w diffusion)

Answer 3

• Spherical shape = large surface area
• capillary bed surrounds the alveoli so gasses don’t have to diffuse far
• the lining of an alveolus is one cell thick, making diffusion incredibly easy (remember that capillaries are also one cell thick)
• the moist lining of the alveoli makes diffusion easier as well

Question 4

gas exchange process

Answer 4

• air moves in and out of an alveolus
• blood low in oxygen and high in CO2 moves through the capillary bed
• when this blood meets an alveolus, oxygen diffuses into the blood through the alveolus and CO2 into the alveolus

Question 5

What are the 4 important structural features in a mammalian respiratory system?

Answer 5

• a thin permeable respiratory membrane through which diffusion can occur
• a large surface area for gas exchange
• a good supply of blood
• a breathing system for bringing oxygen-rich air to the respiratory membrane