1. The Respiratory System
PART 5
The Respiratory System

2. Neural Control of Ventilation
Most important respiratory center
VRG – ventral respiratory group
Located in reticular formation in the medulla oblongata
Neurons generate respiratory rhythm
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

3. Respiratory Centers in the Brain Stem
Figure 21.17
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

4. Neural Control of Ventilation
Respiratory center
Generates baseline respiration rate
In the reticular formation of the medulla oblongata
Chemoreceptors
Sensitive to rising and falling oxygen levels
Central chemoreceptors – located in medulla
Peripheral chemoreceptors
Aortic bodies
Carotid bodies
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

5. Location of Peripheral Chemoreceptors
Figure 21.18
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

6. Disorders of Lower Respiratory Structures
Bronchial asthma
A type of allergic inflammation
Hypersensitivity to irritants in the air or to stress
Asthma attacks characterized by
Contraction of bronchiole smooth muscle
Secretion of mucus in airways
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

7. Disorders of Lower Respiratory Structures
Chronic obstructive pulmonary disease (COPD)
Airflow into and out of the lungs is difficult
Obstructive emphysema
Chronic bronchitis
History of smoking
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

8. Alveolar Changes in Emphysema
Figure 21.19
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

9. Disorders of Lower Respiratory Structures
Cystic fibrosis (CF) – inherited disease
Exocrine gland function is disrupted
Respiratory system affected by
Oversecretion of viscous mucus
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

10. Disorders of Upper Respiratory Structures
Epistaxis – nosebleed
Epiglottitis – inflammation and swelling of the epiglottis
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

11. The Respiratory System Throughout Life
By week 4 of development
Olfactory placodes appear
Invaginate to form olfactory pits
Laryngotracheal bud
Forms trachea, bronchi, and bronchi subdivisions
Reaches functional maturity late in development
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

12. The Respiratory System Throughout Life
Figure 21.20a, b
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings

13. Aging of the Respiratory System
Number of glands in the nasal mucosa declines
Nose dries
Produces thickened mucus
Thoracic wall becomes more rigid
Lungs lose elasticity
Oxygen levels in the blood may fall
Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings