Mammalian Physiology Zoology 315

Study guide - Respiration

Spring 2002

Introduction:

What are the main functions of the respiratory system

List the names of the tubes that bring air to the alveoli? what are the functions of this tube and what types of tissues are needed to fulfill these funcitons?

What anatomical aspects of the alveoli are perfectly designed for the job it must do?

What is the difference between Bulk flow and Diffusion? where does each occur?

What are the pleural membranes and their significance to the respiratory system?

Ventilation

What is intrapleural pressure (Pip). What is alveolar pressure (Palv)? Atmospheric pressure (P atm)?

What factors generate the intrapleural pressure?

How does intrapleural pressure compare to alveolar pressure?

What is transpulmonary pressure? (know equation) -- why is it the distending pressure?

Explain why a lung collapses with a pneumothorax (using the pressures we have talked about)

List ALL the steps (the sequence of pressure changes and how they come about) involved with inpiration and expiration.

-What muscles are involved in quiet breathing? forced breathing?

List all the volumes and capacities associated with ventilation and know their approximate size.

What is special about FRC (functional residual capacity)?

-Draw a graph showing how intrapleural pressure --alveolar pressures -lung volume change with quiet inspiration and expiration. How would the lines change if the breaths were deeper?

What determines how much the lungs will expand with a given change in transpulmonary pressure?

What is compliance (explain in words and an equation)?

What two factors determine the compliance of the lungs?

Is the compliance of the normal lung High or Low? Draw a continum for compliance and show where you would find, arteries, veins, emphysemic lungs, fibrotic lungs, respiratory distress (premature lungs), asthmatic lungs. Know what it is about each conditions that changes its compliance.

What is the role of surfactant? (what cell produces this)

• -How does surfactant alter surface tension?
• -Why would two alveoli of different sizes be unstable?
• - How does surfactant prevent alveolar collapse?
• -Does surfactant increase or decrease the compliance of the lung? why?
• -What is respiratory distress syndrome?

How does edema (swelling) in the lungs increase the work of breathing?

What factors determine the Flow of air into the lungs?

• What respiratory structures offer resistance to air flow?
• What helps to hold the tubes open?
• Which tubes are most likely to collapse?
• What happens to these tubes during forced expiration?
• How does this happen (explain the mechanism that causes the collapse)

Describe the situation that exists with emphysema

• what causes it
• what tissue is damaged
• what the consequence are to transpulmonary pressures (and why)
• Why is expiration a problem and not inspiration?

What is obstructive lung disease

What is restrictive lung disease

What factors can increase the work of breathing.

Respiratory volumes:

What is

• tidal volume
• expiratory reserve
• inspiratory reserve
• vital capacity
• residual volume
• total lung capacity

What is respiratory minute volume? how would you calculate it?

What is anatomical dead space? (its anatomical basis and physiological significance?)

How does minute ventilation differ from alveolar ventilation?

What is involved with panting in animals? why do they do it? why don't they hyperventilate?

What determines the partial pressure of a gas?

• What is the Partial pressure of Oxygen at sea level?
• at the top of Mt. Rainier?

What is the partial pressure of oxygen(P_O2) in the alveoli?

• Is it the same as room air?
• Why not?

What determines the amount of gas that dissolves in a liquid?

• name the liquids in the body that gases are dissolved in.

How does the solubility of CO₂ in water compare to solubility of O₂ in water?

What is hemoglobin? components?

What is the function of hemoglobin? write out the mass balance equation for hemoglobin and oxygen

What determines the oxygen CONTENT of the blood? How can this change?

What determines how much oxygen is bound to hemoglobin?

Draw a oxgen dissociation curve for hemoglobin?

• What does the flat portion at the top of the curve indicate? over what Po2 is curve flat?
• what does the steep portion of the curve mean? over what Po2 is curve steep?

What does oxygen affinity mean and how is it altered by P_O2 of tissues

What can cause a shift of the curve to the right? to the left?

What is a Bohr effect?

How does fetal hemoglobin differ from adult Hb? Why is this difference necessary?

What alterations occur with brief trips to altitude? vs. living at high altitude ?

How does the oxyhemoglobin dissociation curve change if there is half as much hemoglobin in the blood?

What is myoglobin and what does it's dissociation curve look like?

------Transport of CO2------------

How is CO2 transported in the blood ?(three forms)

What is the Haldane effect?

Why does CO2 move into the RBC in the capilaries of working tissue?

What is carbonic anhydrase? Where is it found? What does it do for a living animal?

What is the chloride shift?

What has to happen to push the carbonic acid equation toward the formation of H⁺ and HCO₃^-?

How can you physically do this?

How does this alter the pH of the blood?

How does hyperventilation and hypoventilation alter the Pco2?

• how does Pco2 alter blood pH?

Control of Respiration--------------------------

Where is the Respiratory Center (RC) located in the Central Nervous System (CNS)

The neurons of the RC send action potentials (AP) to what other areas of the CNS?

How is the firing pattern of AP altered to change the depth and rate of breathing?

What types of inputs to the respiratory center can modify its behavior?

Where are the two types of chemoreceptors for the control of respiration found?

What is the indirect and primary stimulus for activation of the central chemoreceptors?

What stimuli can activate the peripheral chemoreceptors?

To what level must PO₂ drop before the peripheral chemoreceptors are activated?

Relate this number to the oxyhemoglobin dissociation curve.