Respiratory Physiology Lecture 1.6: Inspiration and Expiration

Question 1

Inspiration at rest

Answer 1

• Diaphragm contracts
  
  • pushes abdominal content down and expands the thoracic cavity
• External intercostal muscles pull ribs up and out

Question 2

Inspiration during forced respiration

Answer 2

more air comes in and accessory muscles are recruited

• Diaphragm contracts more
• Sternocleidomastoid elevates sternum
• Sternum moves up and out
• Pectoralis minor elevates ribs

Question 3

Expiration at rest

Answer 3

• Diaphragm relax
• Abdominal organs recoil and press diaphragm upward

Question 4

Expiration during forced respiration

Answer 4

During forced (Active) expiration abdominal muscles contract and push abdominal content and diaphragm upward to reduce thoracic volume

• Posterior internal intercostal muscles pull ribs down and inward
• Abdominal organs force diaphragm higher
• Abdominal wall muscles contract and compress abdominal organs

Question 5

What must be open for inspiratory pump muscles to generate airflow?

Answer 5

the upper airway must be open

Question 6

What muscles contribute to opening the upper airway?

Answer 6

• Tongue protruders
• Alae nasi
• Pharyngeal and laryngeal dilators
  
  • Inspiratory
• Pharyngeal and laryngeal constrictors
  
  • Expiratory

Question 7

Obstructive sleep apnea

Answer 7

Reduction in upper airway patency (openness) during sleep (Snoring, apneas, sleep disturbances)

• Reduction in muscle tone
• Anatomical defects

Question 8

population that has obstructive sleep apnea

Answer 8

• 50% male
• 6% female