Respiratory Flashcards
(35 cards)
What is the most important control variable for the respiratory system?
CO2
Dalton’s Law
the pressure exerted by each gas is independent of pressure exerted by other gases. This is because the gases are so far apart from one another
Individual pressures in the total pressure are called?
Partial pressures
Henry’s Law
in equilibrium the mass of gas dissolved in water is proportional to partial pressure of the gas
Diaphragm
Skeletal (voluntary) muscle. Lungs are attached. When breath, diaphragm muscle flexes and fresh air flows into lungs
What is driving the process of expiration?
Lung elastic recoil (like a balloon). Passive process.
Emphysema
Lungs loose recoil-therefore lungs stay permanently inflated resulting in a barrel chest.
What connects lungs to the walls of the thorax?
Suction-created via an airtight bag called the pleura. Lungs are connected to one side and the thorax to the other.
What happens when the lung recoils and the chest expands?
Pneumothorax
What is a tension pneumothorax?
When the lung recoils and air enters into the pleural space-pushing against the other organs in the thorax (i.e. heart and lungs)
How many times does the bronchus split and why?
25 times
Enormous cross-section for easy gas movement to 300 million alveoli
What condition causes the bronchi diameter to be reduced and inflammed?
Asthma
How does albuterol work?
It relaxes smooth muscle on the bronchi
What causes bronchitis?
Bronchi lumen are filled with mucus
Genetic disease that is associated with continuous bronchial thick secretions?
Cystic fibrosis
What is the diameter of the aveolus?
0.3mm
What is the total exchange gas surface area of the aveolus?
75 m2-large area to facilitate gas exchange
What happens if alveoli get occupied by bacteria (i.e. phlegm)
Pneumonia
How is oxygen carried in the blood (use 1 L oxygenate arterial blood)?
3 mL of O2 is physically dissolved (1%)
197 mL of O2 is bound to Hb (99%)
How is pressure produced?
Pressure produced by molecules hitting the walls of a chamber:
Partial pressure of O2, N2, CO2 for air (760 mmHg)
P02 / Ptotal = 100% · 160/760 = 21%
PN2 / Ptotal = 100% · 600/760 = 79%
PCO2 = 0.3 mm Hg
PCO2 / Ptotal =100% · 0.3/760= 0.04%
The solubility of CO2 is ___x greater than the solubility of O2
20 x
Positive cooperativity
As one subunit on a hemoglobin releases an O2 molecule it changes its conformational shape. This change in shape reduces other subunits affinity to O2
Issues with Carbon Monoxide and hemoglobin
Carbon monoxide binds 240 times tighter to hemoglobin than O2. Therefore, CO displaces the O2