Page 190 - Physiology and Pathophysiology MNU 2024-2025 نظرى

Clinical pharmacy 2024/2025 Level 2 Pharm D Physiology and Pathophysiology (MD303)
The respiratory system

The primary functions of the respiratory system are:

1- Obtaining oxygen from external environment & supplying it to body’s cells

2- Eliminating carbon dioxide produced by cellular metabolism from body

Airways

The airways of the lungs consist of a series of branching tubes  as they branch, the airways become

narrower, shorter, and more numerous.

A- Conducting airways B- The respiratory zone

 The trachea  divides into the right & left main  Terminal bronchioles 
bronchi (primary bronchi)  each supply a lung. branch  respiratory
 The primary bronchi branch  form the secondary
bronchioles (the first
(lobar) bronchi  one for each lobe of lung (The left
lung consists of 2 lobes & the right lung has three generation of airways
Branching lobes. having alveoli in their
 The lobar bronchi branch  form the tertiary walls).
(segmental) bronchi  branch & move outward
 Finally alveolar ducts 
toward the periphery of the lungs  terminal
bronchioles (the smallest airways without alveoli) completely lined with
alveolar sacs.

contains no alveoli  no gas exchange  anatomical dead

space. Gas exchange

1- Lead inspired air to the more distal gas-exchanging
regions of the lungs.
Functions:
2- Warm & humidify the inspired air as it flows through
them  because the alveoli are delicate structures 

may be damaged by excessive exposure to cold, dry
air.

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