PULMONARY:

Dr. Dalay Olson Email: [email protected] Office: 3-120 Jackson Hall OUTLINE

✓ Control of ventilation

✓ Applications for the pulmonary system

✓ Review of difficult topics in pulmonary (if we have time) LEARNING OBJECTIVES

• Explain the role of the in determining the basic pattern of • Describe the location and function of the central and peripheral + • Discuss the mechanisms of levels of CO2 and O2 and H in the control of ventilation + • Identify plasma CSF levels of O2, CO2 and H that would increase or decrease ventilation through central, peripheral or both sets of receptor. • Physiological applications for what we have learned • at altitude • doping • poisoning BIG PICTURE: RCC=Respiratory RESPIRATORY CONTROL SYSTEM control center

PaO2 or PaCO2

Decreased PaO2

Chemoreceptors

Afferent

RCC Increase PaO2 back to normal levels

Somatic motor nerves

Intercostal and diaphragm

Increased contraction Central Chemorecpetors

(responsible for detecting changes in PaCO2) How do central chemorecpetors

sense CO2? Peripheral Chemorecpetors

(responsible for detecting changes in PaO2 & PaCO2) Where are the peripheral chemoreceptors located?

1. Aortic Arch 2.

What do they sense?

Changes in arterial PaO2, PaCO2 and pH

Vander Fig 13-33 How do peripheral chemorecpetors sense changes in arterial ?

Peripheral chemoreceptors sense

changes in PaO2, PaCO2 and pH.

Central chemoreceptors

only sense PaCO2 levels. (L/min) Your cares body CO about a lot 20 10 30 20 Arterial P Arterial Control of Breathing 40 O 2 (mmHg) 60 about maintaining the pH! the maintaining about 80 100

Minute Ventilation (L/min) 20 10 30 2 levels because it cares Carbon Arterial P Arterial 40 CO 44 2 (mmHg) 48 Concept map– be able to follow each of these pathways for the exam Changing our oxygen carrying capacity

What happens when you… What happens when you magically appear on the top of Everest?

You have magically just appeared at the peak of Mount Everest, the highest point in the world! After taking in the view for a few minutes, you begin to feel uncomfortable. Physiologically, your

alveolar PO2 has fallen from 100mmHg (in Minneapolis) to only 28mmHg!!!

What is your percent saturation at this new PalvO2?

How will your respond to this situation?

What else could you do to restore your

PalvO2 and PaO2?

What causes altitude sickness? Respiratory alkalosis at altitude WHAT HAPPENS WHEN YOU BLOOD DOPE?

• Injections of EPO • is a hormone produced by the kidneys that regulates the production of blood cells • Are there natural ways to enhance EPO production? • Injections of synthetic oxygen carriers • Perfluorocarbons (PFC’s) • Transfusion with (autotransfusion) BLOOD DOPING: AUTO-TRANSFUSION WHAT HAPPENS WHEN YOU BREATH CARBON MONOXIDE? “THE QUIET KILLER”

Properties 1. Colorless, tasteless and odorless

2. Binds over 200x more than O2 to hemoglobin

3. Binding of CO blocks oxygen binding

Critical thinking…

Do you think PaO2 will change dramatically in the plasma? How about oxy-hemoglobin percent saturation? Total oxygen content?

Would ventilation change as a result of exposure to CO? Why or why not? What do the chemoreceptors (central and peripheral) sense? Are these parameters changing? REVIEW OF DIFFICULT TOPICS IN PULMONARY PHYSIOLOGY (IF WE HAVE TIME) O2 AND CO2 LEVELS IN THE BODY

Lung:

[O2] [CO2] Both oxygen and

CO2 will move from regions of high to low Blood: concentration [O ] [CO ] throughout the body 2 2

Tissue:

[O2] [CO2]

Pearson Education 2013 Air movement in the 2 Alveoli 1

At rest 0

-1

intrapleural -3

-4

Exhalation -5 Various during breathing (mmHg) breathing during pressures Various -6

-7

Lung volume 500

250 (mL) Volume Tidal

0

Changes in are all compared to atmospheric which is usually set to 0 and The Law of LaPlace Pressure inside of a formed by a film is the function of two factors:

1. Surface tension 2. The Radius

Law of LaPlace

More decreases surface tension. Larger bubble Smaller bubble P = pressure r = 2 r = 1 T = surface tension r = 2 r = 1 T = 3 T = 3 r = radius T = 2 T = 1 P = (2  3)/2 P = (2  3)/1 According to the law of LaPlace, P = (2  2)/2 P = (2  1)/1 P = 3 P = 6 if two bubbles have the same P = 2 P = 2 surface tension, the smaller bubble will have higher pressure. Surfactant ( ) DISSOLVED VS. BOUND

Dissolved and bound to Dissolved hemoglobin DISSOLVED CONTENT

Dissolved Dissolved Content TOTAL CONTENT AND PERCENT SATURATION

Dissolved and bound to Bound Content hemoglobin

Total Oxygen Content (total amt O2 in the blood.) = Bound Content + Dissolved Content

Percent Saturation– percent of

available hemoglobin sites bound to O2