Unit 8 Study Guide Flashcards
Pulmonary Ventilation
respiratory gases between atmosphere and alveoli of the lungs
- Net movement of oxygen from atmosphere to alveoli during inspiration
- net movement of carbon dioxide from alveoli to atmosphere during expiration
Alveolar Gas Exchange
exchange of respiratory gases between alveoli and blood in the pulmonary capillaries
- oxygen diffused from alveoli into blood
- carbon dioxide from blood into alveoli
Gas Transport
transport of respiratory gases in blood between lungs and systemic cells of the body
- oxygen is transported from lungs to systemic cells
- Carbon dioxide is transported from system cells to lungs
Systemic Gas Exchange
exchange of respiratory gases between the blood and the systemic capillaries and systemic cells of the body
- Oxygen diffuses from blood into systemic cells
- Carbon Dioxide diffuses from systemic cells into blood
Intrapleural pressure vs intrapulmonary pressure?
intrapleural pressure:
- pressure in pleural cavity
- fluctuates with breathing
intrapulmonary pressure
- pressure in alveoli of the lungs
- fluctuates with breathing
How do lungs remain inflated?
- intrapulmonary pressure is greater than intracellular pressure
- the pressure insides greater than the pressure outside
- about 4mm Hg lower than intrapulmonary pressure between breaths
- Difference in pressure keeps the lungs inflated due to output pull of chest and inward pull of lungs with consequent “suction”
How do the pressure gradient between the atmosphere and lungs drive inspiration and expiration?
- air moves from area of high pressure to area of low pressure when pressure gradients are established by changes in volume.
What are the muscles involved in quiet breathing?
increase the dimensions of the thoracic cavity
- Diaphragm and external intercostals
- involved in normal rhymic breathing at rest
- alternatively contract and relax, resulting into movement of air into and out of the lungs
what is the relationship between volume and pressure?
Boyle’s law- volume and pressure are inversely related
How does the relationship between volume and pressure exhibited in inspiration?
In inspiration, the diaphragm contracts, which increases the volume of the lungs. Therefore, the intrapulmonary pressure becomes less than atmospheric pressure and air flows in.
How does the relationship between volume and pressure exhibited in exspiration?
In expiration, the diaphragm relaxes, which decreases the volume of the lungs. Therefore, the intrapulmonary pressure becomes greater than atmospheric pressure and air flows out.
What are the structures of the respiratory zone? and describe
composed of respiratory bronchioles, alveolar ducts, and alveoli
-Respiratory bronchioles subdivide to alveolar ducts that lead to alveolar sacs (clusters of alveoli)
Alveoli
saccular outpocketings
-each lung contains 300 to 400 million alveoli
Alveolar pores
openings providing collateral ventilation (inflate at once)
-surrounds by pulmonary capillaries
What are the two cells that form the alveolar cell wall
Type I
Type II
Type I cells
- simple squamous alveolar cells
- 85% of alveolar surface area
- part of thin barrier separating air from blood