03 Respiratory System - Respiration

Question 1

Respiration = Gas Exchange

Answer 1

• Intake of oxygen for cellular respiration (necessary to break down glucose for energy)
• Release carbon dioxide

Question 2

Gas Exchange

Answer 2

• Occurs due to a difference in concentration (called a concentration gradient)
• Oxygen and carbon dioxide gas diffuse from high to low concentration

Question 3

How do gases move?

Answer 3

• Red blood cells transport 99% of oxygen gas (the rest dissolves in plasma)
• Red blood cells transport 95% of CO2 (the rest dissolves in plasma)

Question 4

Physiology of Respiration OR How do we breathe?

Answer 4

• Inhalation and exhalation need the intercostal muscles (muscles between ribs) and the diaphragm
• Pressure differences between the atmosphere and the chest cavity determine the quantity and rate of gas exchange

Question 5

Basic Principles of Gas Behaviour

Answer 5

Gases move from areas of high pressure to areas of low pressure

Question 6

Inhalation

Answer 6

• If internal pressure is less than atmospheric pressure…
• INhalation – gas drawn in
• The intercostal muscles contract - causes ribs to move upward & outward
• Diaphragm contracts & moves downward
• Volume (space inside) is increased – so pressure in lungs is decreased
• Air enters to equalize pressure

Question 7

Exhalation

Answer 7

• If internal pressure is greater than atmospheric pressure…
• EXhalation – gas moves out
• Diaphragm and intercostal muscles relax
• Ribs move inward and downward
• Diaphragm moves upward
• Volume decreases – so pressure in lungs increases
• Air is forced OUT