Respiratory System

Question 1

What are the functions of the respiratory system?

Answer 1

Provide extensive surface area for gas exchange
Moving air to & from exchange surfaces of lungs
Protecting respiratory surfaces from dehydration, temperature changes, or other environmental variations & pathogens
Providing sounds for communication (speaking, singing etc.)
Detection of odours from olfactory receptors
Sport performance: Stability, force generation, buoyancy

Question 2

Which body parts are in the upper respiratory system?

Answer 2

Nose
Nasal Cavity
Sinuses
Pharynx

Question 3

Which body parts are in the lower part of the respiratory system?

Answer 3

Larynx
Trachea
Bronchus
Lungs
Bronchioles

Question 4

What is the make up of the lungs?

Answer 4

• Superior lobe
  
  • Middle Lobe
  • Inferior lobe
  • Cardiac notch
  • Apex
  • Base

Question 5

Discuss the generations of airways

Answer 5

23 generations of airways
1-16 = -15 respiratory bronchioles = are for ventilation, not respiration as there’s no alveoli
17-23 are for respiration through gas exchange

Question 6

Explain the route of circulation

Answer 6

Deoxygenated blood is oxygenated in capillary beds of lungs is where gas exchange occurs
Turns to oxygenated blood
Oxygenated blood runs to heart through pulmonary veins into left ventricle
Pumped out to aorta and branches which goes down to capillary beds of all body tissues where gas exchange occurs

Deoxygenated blood goes up back to heart through Venae Cavave into right ventricle
Deoxygenated blood goes into pulmonary arteries up to capillary beds of lungs where gas exchange occurs and blood is oxygenated

Question 6

What are the different circuits that pump blood around the body?

Answer 6

Pulmonary circuit provides oxygenated blood back to heart before it returns to left atrium in left ventricle & pumped around body in systemic circuit
Capillary beds all over body utilise oxygen provide additional CO2 to the body before process starts again

Question 7

Explain the difference between ventilation and respiration

Answer 7

Ventilation = mechanical & involves the movement of air

Respiration = exchange of oxygen & carbon dioxide
Involves exchange of gases in alveoli (external
respiration) & in cells (internal respiration)

Question 8

Explain Boyle’s Law

Answer 8

Gas Pressure & Volume:
You can change pressure within a sealed container by changing the volume of that container
Increase volume = pressure falls
Decrease volume = pressure rises

Question 9

Explain Boyle’s Law in the context of respiration

Answer 9

Air flows from area of high pressure to area of lower pressure
Inhalation: Increase in volume decrease in pressure
Exhalation: Decrease in volume increase in pressure
These are pressure gradients which move air into & out of lungs

Question 10

Explain the bodily mechanics of inspiration and expiration

Answer 10

Inspiration = Thorax expanded from inspiration
Expiration = Ribs & sternum return downward, diaphragm relaxes & pushed upwards & lung tissue recoils

Question 12

Explain the process of pressure during inspiration & expiration

Answer 12

Pressure at rest: Lung pressure = atmospheric pressure

Muscles contract, lungs expand: Lung pressure < atmospheric pressure

Inspiration: Air rushes into lungs to balance pressure

After inspiration, thorax expanded, Lung pressure = atmospheric pressure

Thorax returns to resting dimensions: Lung pressure > atmospheric pressure

Expiration: Air rushes out of lungs to balance pressure

Question 13

Explain Dalton’s Law

Answer 13

Partial Pressures:
States that total pressure of a mixture of gases = sum of partial pressures of component gases

Question 14

Explain Dalton’s Law in the context of human physiology

Answer 14

Total pressure of mixture of gases = sum of partial pressures of component gases
Air we breathe =
* 20.9% O2
* 0.04% CO2
* 78.6% Nitrogen
* 0.5% Water vapour
Dalton’s Law - Total pressure 760mm Hg = PO2 + PCO2 + PN2 + PH2O
Partial pressures:
159 mmHg Oxygen
0.3 mmHg Carbon
597 mmHg Nitrogen
3.7 mmHg Water vapour

Exact same percentages & concentration of O2, CO2, etc. but pressure is less so less partial pressure, effecting gas transfer & diffusion

Question 15

Explain Henry’s Law

Answer 15

Diffusion of Liquids & Gases:
Amount of a particular gas in a solution is directionally proportional to partial pressure of gas
There’s 159 mmHg Oxygen in air but needs pressure gradient to get to the 100 mmHg in alveolar air, so diffuses
Diffusion occurs within lungs but also internal respiration - movement of gases at systemic levels around the body

Question 16

Why is the respiratory membrane so efficient?

Answer 16

Differences in partial pressure across membrane are substantial
Distances in gas exchange are short
Gases are lipid soluble
Total surface area is large
Blood flow & airflow are coordinated