Respiratory Physiology Two

Question 1

What is the factors determining resistance

Answer 1

Lung volume and branching
Bronchiolar smooth muscle tone
Density and viscosity of gases
- affected by altitude
- important consideration in artificial envoirments (scape deep sea)
- laminar flow is a function of gas viscosity but turbulent flow depends on gas density

Question 2

what is the bronchiolar smooth muscle upper airways

Answer 2

Lines the upper airway
alterations in tone alter radius
‘tube’ radius decreased by muscular contraction– Parasympathetic activity,– Ach neurotransmission– Irritants (smoke, allergens),– Decreased alveolar PCO2 (see next lecture

Question 3

why does the tube radius increase

Answer 3

muscular relaxation
symapethic activity
pulmonary stretch
NDR (neutral - weak)
ADR (b2 circulating strong) and salbultomol

Question 4

Asthma and Reistance

Answer 4

due to hyper reactivity of the airways smooth muscle contraction due to allergic inflammation of the airways
bronchial smooth muscle thickening means smaller airways making it deadly next asthma attack

Question 5

Asthma and resistance test

Answer 5

Convective gas flow in lungs much less efficientGas flow slows to the molecular diffusion ratein the upper airway resulting in poor gas exchangein the respiratory acinusGas fails to penetrate to distal regions of respiratoryzone causing alveolar pCO2 to riseLung ceases to oxygenate Hb efficiently due toReversal of proper alveolar Bohr and Haldaneeffects

Question 5

Asthma and resistance test

Answer 5

Convective gas flow in lungs much less efficientGas flow slows to the molecular diffusion ratein the upper airway resulting in poor gas exchangein the respiratory acinusGas fails to penetrate to distal regions of respiratoryzone causing alveolar pCO2 to riseLung ceases to oxygenate Hb efficiently due toReversal of proper alveolar Bohr and Haldaneeffects