Flashcards in Structure & Fxn of Pulm System Deck (35):
What are three parts of conducting airways?
1. upper airways
3. Lower airways
What connects upper and lower airways?
What are 3 gas-exchange airways?
1. respiratory bronchioles
2. alveolar ducts
Which type of epithelial cells in the alveoli are involved in alveolar structure?
Type I alveolar cells
Which type of epithelial cells in the alveoli are involved in surfactant production?
Type II alveolar cells
What are the primary gas-exchange units of the lungs?
What permit air to pass through the septa from alveolus to alveolus?
Pores of Kohn
How many alveoli do the lungs contain?
approximately 25 million at birth & 300 million by adulthood
Pulmonary circulation has a ____ pressure and resistance than systemic circulation (___ pulmonary artery vs ____ aorta)
lower; 18 mmHg vs 90 mmHg
How many of the vessels are filled with blood at any given time?
only one third
More vessels become perfused when ______; therefore, ____ delivery of blood to the lungs does not normally increase mean pulmonary artery pressure.
right CO increase; increased
The pulmonary artery divides and enters the lung at the ____.
T/F: Each bronchus and bronchiole has an accompanying artery or arteriole.
Arterioles are less than ___ in diameter.
What is formed by shared alveolar and capillary walls?
What all does the alveolocapillary membrane comprise?
thin membrane of alveolar epithelium
the alveolar basement membrane
the capillary basement membrane
the capillary endothelium
What does the chest wall encompass?
- skin, ribs, and intercostal muscles
- thoracic cavity
What does the pleura encompass?
- serous membrane
- parietal and visceral layers
- pleural space (cavity)
- pleural fluid
What are the functions of gas exchange?
- supply oxygen
- eliminate CO2
What are the functions of the lungs?
1. gas exchange
2. maintain pH
3. eliminate water
4. maintain normal body temperature
5. immune responses
6. Hormone secretion
What are the requirements for Ventilation, Perfusion, and Diffusion?
-Adequate inspired O2 – (FiO2)
-Ventilation and perfusion of alveoli
-A permeable alveolocapillary membrane
-Adequate blood flow
-Ability to transport O2 and CO2
-Ability of cell to use O2 and eliminate CO2
If you are in a city in which the barometric pressure is lower than sea level (760 mmHg), will the partial pressure of oxygen be higher or lower than it is at sea level?
Lower because the formula to calculate partial pressure of O2 is .21 x barometric pressure.
What is ventilation?
The mechanical movement of gas or air into and out of the lungs.
What is minute volume?
Ventilatory rate multiplied by the volume of air per breath
What is alveolar ventilation?
the volume of air entering and leaving the alveoli per minute
Lung volumes and capacities are based on what three things?
Age, gender and height
What is the expiratory reserve volume (ERV) of the lungs and about how many ml of air does it typically include?
Can be forcefully expired after normal expiration FEV1
What is the formula for forced vital capacity (FVC)?
TV + IRV + ERV ~4500-5000 ml
How would you define residual volume and how many ml of air are involved?
It is the air that remains in the alveoli and is usually around 1200 ml (constant)
What is the formula for minute ventilation?
RR x TV
Which system is in control of ventilation and stimulates the smooth muscle of the airway lumen diameter to contract/relax?
RR x (TV-DS)
Tried to look this up and couldn't find anything but you plug weight in for DS in his example.. 100 lb, RR 16, TV 500 ml
16 (500-100) = 6400 ml/min
What is hypoxia?
Low oxygen in the cell
What is hypoxemia?
Low oxygen in arterial blood (low O2 saturation)
What are the four steps to Gas Transport?
1. Ventilation of the lungs
2. Diffusion of oxygen from the alveoli into the capillary blood
3. Perfusion of systemic capillaries w/ oxygenated blood
4. Diffusion of oxygen from systemic capillaries into the cells