Transcript Respiratory System: Gas Exchange

Respiratory System
Topic Outline:
 Structure
 Function
 Control of breathing
 Pathologies
Structure of the
Mucous secreting cells
“Goblet Cells”
Look closely at the cells of the
alveolus.
Surfactant
water tension in the alveolus
Water tension

Compliance (easy to stretch) versus elastance
Diseases & gas exchange:

Emphysema

Fibrotic Lung

Pulmonary edema

Asthma
Pressure and Ventilation
1
2
Helps us
understand
how air gets in
and
out of the
lungs.
Important Functions of Respiratory
System
Oxygen (O2) and Carbon Dioxide
(CO2) Transport and Exchange
To the board!
One more time!
Breathing and Control of
Respiration
Why does air move in
and out of our lungs?
Lung volumes change with muscle contraction
Multiple Muscles of the Thoracic cavity
assist us in breathing.
What happens
if you puncture
your lung?
Lung Volumes Measurement
The amount of air we breathe can be measured
How much air we breathe
depends on many factors…
For example: Oxygen binding to Hb
A well studied curve
Oxygen Affinity Decreases for Hb
as

Body temperature
increases

pH decreases

CO2 increases

DPG increases
Now look at the curves!
Regulation of Ventilation
The mid-brain gets messages
from

Aortic bodies

Carotid bodies
Both of these are
Peripheral chemo-receptors
Sensitive to O2, CO2 and pH
Hypothetical
Peripheral receptor
Peripheral chemo-receptors talk to central neurons
Central Pattern Generator
(medulla oblongata)
Dorsal Regulatory Group
Inspiratory neurons
Ventral Regulatory Group
Active inspiratory neurons
&
Active Expiratory neurons
The brain also has its own
chemoreceptors also in the medulla.
Summary of ventilation control
Oh, no!
Normal and Diseased Lung
Emphysema
Pneumonia
Lung Cancer
Lung cancer is responsible for the most cancer deaths in both
men and women throughout the world. The American Cancer
Society estimates that 173,770 new cases of lung cancer in
the U.S. will be diagnosed and 160,440 deaths due to lung
cancer will occur in 2004.
Normal Lungs
Lung Cancer
Risk Factors
High risk occupations
Asbestos
Air pollution
Radon Gas
Types of Lung Cancer

Small Cell Lung Cancer

Non-Small Cell Lung Cancer



Adenocarcinomas
Squamous cell carinomas
Large cell carcinoma
Treatment & Prevention

Prevention is the key decreasing the number of lung cancer
patients.

Treatment may include: (not all types of lung cancer respond
equally to treatment regimes)




Radiation therapy
Surgery
Chemotherapy
Treatment is often difficult and may not be successful.