Ventilatory System

Question 1

2.1.1 List the principal structures of the respiratory system

Answer 1

• Nose/mouth (Moistens air)
• Pharynx (moistens, filters air, offers low resistance pathway for airflow)
• Larynx: voice box (protects trachea from invasion of foods and fluids)
• Trachea (wind pipe)
• Bronchi
• Bronchioles
• Lungs
• Alveoli

Question 2

2.1.2 Outline the three main functions of the respiratory system

Answer 2

1. Low resistance pathway for airflow
2. Defense against chemicals and other harmful substances
3. Warming and moistening air

Question 3

2.1.3 Pulmonary ventilation

Answer 3

movement of air in and out of the lungs

Question 4

2.1.3 Total lung capacity

Answer 4

amount of air in the lungs after maximal inspiration

Question 5

2.1.3 Vital capacity

Answer 5

amount of air that can be exhaled after maximal inhalation

Question 6

2.1.3 Tidal volume

Answer 6

amount of air an individual can inhale or exhale during normal quiet breathing

Question 7

2.1.3 Expiratory reserve volume

Answer 7

amount of air individual can exhale beyond a tidal expiration

Question 8

2.1.3 Inspiratory volume

Answer 8

amount of air an individual can inhale beyond a tidal inspiration

Question 9

2.1.3 Residual volume

Answer 9

amount of air remaining in the lungs after a maximal exhalation

Question 10

2.1.4 Explain the mechanism on inhalation

Answer 10

• Diaphragm contracts and lowers
  -intercostal muscles contract
  -rib cage moves upwards and outwards
  -lung pressure decreases
  -air rushes into lungs

Question 11

2.1.4 Explain the mechanism on exhalation

Answer 11

• Diaphragm relaxes, becoming dome shaped
• Intercostal muscles relax
  -rib cage moves down and inwards
  -lung pressure increases
  -air expelled from lungs

Question 12

2.1.4 Impact of exercise on breathing

Answer 12

Before: regular breathing, breaths have less volume, muscles have enough oxygen

After: breathing is frantic, breaths have more volume, breathing is heavy, muscles are oxygen deficient

Question 13

2.1.5 describe the nervous and chemical control of ventilation

Answer 13

1. Chemoreceptors- responsible for detecting chemical change (levels of CO2 and PH)
2. Ventilation- increases as a result of increase in blood acidity levels (low pH) due to increases in carbon dioxide content in blood
3. Respiratory center- detects these changes and stimulates respiratory muscles

Question 14

2.16 Role of haemoglobin in oxygen transportation

Answer 14

Haemoglobin- substance found in red blood cells

-responsible for the transportation of oxygen

Question 15

2.1.7 Explain the process of gaseous exchange at the alveoli

Answer 15

• oxygen from inhaled air diffuses through the walls of the alveoli into the capillaries to the red blood cells (oxygenated blood to the body)
• deoxygenated blood is then returned to the lungs, where CO2 diffuses across capillary walls back into alveoli so it can be expired out of the body back into the atmosphere