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

Diseases & gas exchange:

Emphysema

Fibrotic Lung

Pulmonary edema

Asthma

Compliance (easy to stretch) versus elastance

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 cavityassist 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

Peripheral chemo-receptors

Both of these are

Sensitive to O2, CO2 and pH

Hypothetical Peripheral receptor

Peripheral chemo-receptors talk to central neurons

Central Pattern Generator(medulla oblongata)

Dorsal Regulatory Group Ventral Regulatory Group

Inspiratory neurons 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 LungEmphysema

Pneumonia

Lung CancerLung 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

Air pollutionHigh risk occupations

Asbestos 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.