RESPIRATORY TERMS:
Total Lung Capacity
-total volume of air that lungs can hold
Tidal Volume
-amount of air in a normal breath
Vital Capacity
-maximum volume of air that can be exhaled after a maximum
inhalation
Residual Volume
-volume of air that remains in the lungs at all times
ASSESSMENT OF RESPIRATORY FUNCTION
Respirations per minute
Spirometer
-measures capacity of the lungs
NON-RESPIRATORY AIR MOVEMENTS
Coughing
-clears respiratory system
Sneezing
-clears upper respiratory system
Laughing
-emotion
Crying
-emotion
Hiccuping
-spasmodic contractions of the diaphragm, no useful function
Yawning
-ventilates a large portion of alveoli, oxygenates blood -alertness
CONTROL OF RESPIRATION
Neural
Respiratory Center
found in the medulla oblongata
Chemical
pH
7.4 normal pH
Acidosis -less than 7.4
*Can result from an increase in carbon dioxide in the blood or from toxicological
effects of a poison, obstruction of air passageways, diseases that reduce air
exchange like emphysema, or an injury to the brain stem
Symptoms: depression of the CNS, drowsiness, cyanosis, labored breathing.
Alkalosis -less than 7.4
*Can result from hyperventilation, which results in the excessive loss of carbon
dioxide. Causes include anxiety, fever, and poisoning, high altitude.
Symptoms: light headedness, agitation, dizziness, and tingling sensation
Decrease in carbon dioxide in the blood results in a decrease in respirations due to
the action on the respiratory center.
pCO2
pO2
Respiratory Rate
-
-
the partial pressure of carbon dioxide in the blood.
-active tissue causes an increase of carbon dioxide in the
blood due to increases in cell respiration
-carbon dioxide combines with water to make carbonic acid –
acidosis
-respiratory rate increases in order to blow off carbon dioxide and
increase pH.
-the control factor on respiratory rate
The partial pressure of oxygen in the blood.
-no control over respiratory rate
-breaths per minute
THE EFFECT OF ALTITUDE ON RESPIRATION
Large changes in altitude causes specific symptoms: gasp for air, light headed
Air pressure -significantly less than at lower elevations -but change in oxygen
concentration is minimal.
Pressure differential -less difference than at lower elevations. You take in less
air.
Adaptations of people who live at high altitude.
-enlarged thoracic cavity
-larger number of red blood cells
adaptations take a minimum of 2 weeks to occur
THE EFFECT OF DEPTH ON RESPIRATION
Conditions: the body is subjected to pressures greater than normal. SCUBA divers
Divers
*increase oxygen consumption
*Increase carbon dioxide output
The effect of increased pressure on molecular nitrogen:
*Gas laws –increased pressure means that there is more gas in the water –here nitrogen
*blood takes up gases in direct proportion to their partial pressures. 20 % oxygen etc.
*Nitrogen gas taken into blood but is not used or expelled
*blood and tissues become saturated with nitrogen
*nitrogen absorbed 5X faster in fats than water
-lipids make up important part of nervous system
-nitrogen affects nervous system
Nitrogen narcosis -drunk-like state reflecting the action of nitrogen on the nervous system
-impaired judgement
-feeling of well being
-resurfaces too fast
The Bends
-during resurfacing -too fast
-Nitrogen bubbles form -congregate around joints PAINFUL
GAS EXCHANGE IN ALVEOLI
simple diffusion