Respiratory Pt. 2 Flashcards
What are the three steps of Respiratory Physiology?
1) Pulmonary Ventilation
2) Gas Exchange
3) Gas Transport
What is Pulmonary Ventilation?
Physical movement of air into and out of lungs
What is Gas Exchange?
Diffusion of gasses across the respiratory membrane into alveolar capillaries, and from capillaries into other tissues
What is Gas Transport?
Movement of oxygen and carbon dioxide b/w lungs and other tissues
What occurs in Pulmonary Ventilation?
1) Physical movement of air into and out of the Respiratory Tract
2) Primary function is to maintain alveolar ventilation
3) Alveolar ventilation prevents build up of CO2 and maintains adequate O2
What occurs in the movement of air? What is the movement of air?
1) Air movement depends on changing the pressure inside the respiratory tract
a) Air flows from an area of higher pressure to an area of lower pressure
2) Air moves into or out of the Respiratory Tract based on changes in Thoracic Cavity Size (V) and Internal Pressure (P)
What is Boyle’s Law?
P = I/V
What happens to pressure when the volume of gas is increased?
Pressure decreases [Inhalation]
What happens to pressure when the volume of gas is decreased?
Pressure increases [Exhalation]
What is Compliance?
Indication of lung expandability
What effect does Compliance have?
1) Higher Compliance = Easier Expansion
2) Lower Compliance = Harder to Expand
What factors impact compliance?
1) Connective-Tissue structure
a) Emphysema results in supporting tissue damage and increases compliance
2) Surfactant
a) Decreased surfactant results in decreased compliance, as in Respiratory Distress Syndrome [RDS]
3) Mobility of Thoracic Cage
a) Skeletal disorders that affect ribs or spinal column can reduce compliance
What is the Respiratory Cycle?
Single Inhalation and Exhalation.
Often measured as Tidal Volume [TV]
What is Tidal Volume?
Amount of air moving into or out of your lungs during a single respiratory cycle
What is Respiratory Rate?
of Breaths/min
What is the Respiratory Minute Volume [VE]?
VE = Amount [volume] of air moved each minute
VE = RR * TV
Measure of Pulmonary ventilation
What is Anatomic Dead Space [VD]?
Volume of air that remains in conducting pathways and does not enter the alveoli
What is Alveolar Ventilation [VA]?
Amount of air reaching the alveoli each minute
What happens in Gas Transport?
1) Oxygen binds to Haemoglobin [Hb] (1 Hb = 4x O2)
2) Each RBC has approx. 280 million Hb molecules
What is Oxygen Saturation?
1) % of Haem units containing bound oxygen [termed Haemoglobin saturation]
2) Each time Hb molecule binds an O2 molecule, the change in shape enhances the ability to bind another O2 molecule
What affect does pH on Respiration?
Active tissues generate acids that lower the pH of interstitial fluid:
1) As pH drops, Hb releases O2 and sats drop
2) Mostly due to CO2 in blood
What affect does temperature have on Respiration?
Active tissues generate heat, causing Hb molecules to release more O2:
1) Mostly due to Skeletal muscle contractions warming the blood and organs
