Respiratory System

Main Gases of the Atmosphere

Gas Symbol Approximate %

Nitrogen N2 78.6 Oxygen O2 20.9Carbon Dioxide CO2 0.04Water Vapor H2O 0.46

Boyle’s Law

Pressure and volume of a gas have an inverse relationship

P1V1=P2V2

As Volume increases pressure of the gas decreases

As Volume decreases pressure increases

Practice Equations

1. A gas occupies 12.3 liters at a pressure of 40.0 mm Hg. What is the volume when the pressure is increased to 60.0 mm Hg?

2. A sample of gas has a volume of 12.0 L and a pressure of 1.00 atm. If the pressure of gas is increased to 2.00 atm, what is the new volume of the gas?

Boyle’s Law and Breathing

Inspiration- Diaphragm contracts Lung volume increases what happens to the pressure inside the lungs?

Expiration: Diaphragm relaxes- Lung volume decreases- what happens to pressure?

Boyle’s Equation

PV = k (constant)

Eupnea: normal, quiet breathing at a rate of 12 to 20 breaths per minute in adults.

How do we breath?

Explain

Inspiration (inhale) Expiration (exhale) Role of: Diaphragm, Intercostal Muscles, Ribs Volume of Lungs- Pressure

inside/outside

Anatomy 1. Nose

2. Pharynx

3. Larynx

4. Trachea

5. Primary bronchus (2)

6. Lungs

7. Respiratory membranes

Upper Respiratory Tract

1.nose 2.oral cavity 3.throat pharynx larynx trachea

Lower Respiratory Tract

Sometimes includes the larynx and trachea

Nose: warms and filters air1.Divided by

nasal septum

2.Separated from oral cavity by plate

3.Lined with mucus

4.Note location of olfactory bulb

Pharynx: Throat

Muscular Tube-

Contains: Tonsils Respiration

only

Larynx: Voice Box

Contains1. Thyroid

cartlidge (Adams apple)

2. Glottis and epiglottis

3. Vocal Folds- vocal cords

Trachea: windpipe

Contains1. Ciliated mucosa2. Cartilaginous rings-

Tracheotomy:

Primary Bronchi (x2)

Extension of the trachea

Right: wider, shorter

Rt- more common for obstruction

Lungs: Note differences between right and left. Why?

When You Breath1. enters the body through the nose or the mouth

2. travels down the throat through the larynx (voice box) and trachea (windpipe)

3. goes into the lungs through tubes called main-stem bronchi

1. one main-stem bronchus leads to the right lung and one to the left lung

2. in the lungs, the main-stem bronchi divide into smaller bronchi

3. and then into even smaller tubes called bronchioles

4. bronchioles end in tiny air sacs called alveoli

LUNGS- Note the Pressure Difference

1. Pulmonary pleura

2. Pleural cavity

contains pleural fluid

3. Visceral pleura

A. The lung penetrated by the knife collapsed because the intrapleural pressure became equal to the atmospheric pressure, allowing the pleural membranes to separate.

b. Only the penetrated lung collapsed because it is isolated from the remaining mediastinal structures (and the other lung) by the pleural membranes. (p. 820)

Patient “A” presents in the ER with knife wound to the left of his thorax . Diagnosis: pneumothorax and a collapsed lung.

a. Explain why the lung collapsed.b. Why only one collapsed lung?

Gas Exchange Driven by

Diffusion

Oxygen- high in lung- diffuses into blood

CO2 high in blood- diffuses into lung

Respiratory System Disorders

Asthma/Allergies

COPD:

Smoking: Smokers

cough

Review Problems

Page 849-50

#6, 12, 17, 18, 21