Overview of the Pulmonary System

Question 1

Gas exchange requires coordination of which organs

Answer 1

1. lung, chest wall, respiratory muscles
2. heart and pulmonary circulation
3. central and peripheral nerve receptors

Question 2

Pleura characteristics/fxn

Answer 2

• two layers: visceral and parietal
• visceral=lines lungs
• pariental=lines inside of chest wall
• pleural space=fluid filled space between pleural layers
• fxn=allows smooth movement of lungs within the thoracic cavity during inspiration and expiration

Question 3

Main components of respiratory anatomy

Answer 3

Question 4

Lobes of the lung

Answer 4

• 2 Left: Left Upper Lobe, Left Lower Lobe
• 3 Right: Right Upper Lobe, Right Middle Lobe, Right Lower Lobe

Question 5

Conducting airways vs. Gas exchange units

Answer 5

• Conducting airways: trachea, bronchi, bronchioles
• Gas exchange units: respiratory bronchioles, alveolar ducts, alveoli

Question 6

Structure of conducting airways

Answer 6

• inner mucosal surface: epithelium, cilia, goblet cells
• smooth muscle layer
• outer connective tissue
• @ transition from bronchi –> bronchioles: loss of outer cartilage

Question 7

Acinus definition

Answer 7

• =gas-exchange region
• =respiratory bronchioles + alveolar ducts + alveoli

Question 8

Types of alveolar epithelial cells

Answer 8

• Type I cells = “pneumocytes” = squamous lining fused w/capillary for gas exchange
• Type II cells = “secretory cells” =
  
  • repair/replace injured Type I cells
  • secrete surfacant (lowers alveolar surface tension)

Question 9

Embryonic stage of lung development: events & human age

Answer 9

• foregut endoderm extends into mesenchyme
• 3 rounds of branching –> lung lobes
• age: 26 days – 6 wks

Question 10

Pseudoglandular stage of lung development: events & human age

Answer 10

• 4 rounds of branching form terminal bronchioles
• age: 6 - 16 wks

Question 11

Canalicular stage of lung development: events & human age

Answer 11

• Terminal bronchiole divides into 2+ respiratory bronchioles
• Surfactant production begins and increases as weeks progress
• Age: 16 - 28 wks

Question 12

Saccular stage of lung development: events & human age

Answer 12

• Respiratory bronchioles subdivide to produce terminal sacs (these continue to develop well into childhood)
• Age: 28 - 36 wks

Question 13

Alveolar stage of lung development: events & human age

Answer 13

• Lung grows & alveoli mature:
• Septea thin
• Single capillary network in alveolar wall
• Gas exchange unit established
• Age: 36 wks – 5 yrs