For each of the following cases, check the column appropriate to your observations on the operation of the model lung:
(Boyle's Law)
...
Under what internal conditions does air tend to flow into the lungs?
When thoracic volume increases and thoracic pressure decreases
Under what internal conditions does air tend to flow out of the lungs?
When thoracic volume decreases and thoracic pressure increases
Activation of the diaphragm and the external intercostal muscles begins the inspiratory process. What effect does contraction of these muscles have on thoracic volume, and how is this accomplished?
Increases volume and decreases pressure and allows for gas to travel down its gas/pressure gradient
Volume of air present in the lungs after a forceful expiration:*
Residual volume
Volume of air that can be expired forcibly after a normal expiration:
Expiratory reserve volume/ ERV
Volume of air that is breathed in and out during a normal respiration:
Tidal Volume (Standard = 500 ml)
Volume of air that can be inspired forcibly after a normal inspiration:
Inspiratory reserve volume / IRV
Volume of air corresponding to TV + IRV + ERV:
Vital capacity (Standard = minimum of 4500 ml)
Where are the neural control centers of respiratory rhythm?
Medulla (rate)
Pons (rhythm)
Does the following factor generally increase or decrease the respiratory rate and depth?
Increase in blood carbon dioxide
Increase
Does the following factor generally increase or decrease the respiratory rate and depth?
Decrease in blood oxygen
Increase
Does the following factor generally increase or decrease the respiratory rate and depth?
Increase in blood pH
Decrease
Does the following factor generally increase or decrease the respiratory rate and depth?
Decrease in blood pH
Increase
Did it appear that carbon dioxide or oxygen had more effect on modifying the respiratory rate?
Carbon dioxide
Where are sensory receptors sensitive to changes in blood pressure located?
Carotid sinuses and aortic arch
Where are sensory receptors sensitive to changes in oxygen levels in the blood located?
Aortic arch, carotid sinuses and kidneys
What is the primary factor that initiates breathing in a newborn infant?
Increasing levels of carbon dioxide; which comes from agitation
Blood carbon dioxide levels and blood pH are related. When blood carbon dioxide levels increase, does the pH increase or decrease? Explain why.
Decrease. As carbon dioxide levels increase, hydrogen ions increase causing the blood pH to become more acidic.
Buffer
Anything that resists changes in pH
What buffer system operates in blood plasma?
carbonic acid bi-carbonate buffer system
Which component of the buffer system resists a drop in pH?
HCO3- (bi-carbonate ion)
Which component of the buffer system resists a rise in pH?
H2CO3 (carbonic acid)
Explain how the carbonic acid bi-carbonate buffer system of the blood operates:
CO2 + H2O back/forth H2CO3 back/forth H+ + HCO3-
H2CO3 is a weak acid and HCO3- is a strong base. They pass the hydrogen ion (H+) back and forth keeping it contained until expiration (I don't really know how to explain this any better verbally in my own w