Respiratory 1 Flashcards
Does O2 or CO2 drive our desire to breath?
CO2
What is the desired arterial pH?
7.35-7.45
Definition:
Respiration
exchange of gasses between the atmosphere, blood and cells
What are the 3 processes of respiration?
- ventilation
- external (pulmonary) respiration
- internal (tissue) respiration
Definition:
Organs and structurs not directly involved in gas exchange
conducting zone
Definition:
Respiratory zone:
location where gas exchange occurs
What are the functions of the conducting zone?
- provide routine for incoming and outgoing air
- remove debris and pathogens from incoming air
- warm and humidify air
What is the main function of the bronchi?
passageway for air to move in and out of lungs, mucous memebrane traps debris and pathogens
What generation of the bronchial tree does the conducting zone end at?
16th generation
Where does the respiratory zone begin in the bronchiole tree?
Where the terminal bronchioles join the smalles type of bronchiole
The respiratory bronchiole leads to an alveolar duct which opens into an alveolar sac
What causes bronchoconstriction?
parasympathetic activation and histamine release (allergies, asthma)
What causes bronchodilation?
sympathetic activation, catecholamine release
Why do alveolus have elastic walls?
So they can stretch during air intake and increase SA for gas exchange
How is equal air pressure throughout the alveoli and lungs acheived?
The alveoli are connected by alveolar pores
Definition:
Highly permeable to gasses, 97% of all alveolar cells
Type I alveolar cells
Definition
Type II alveolar cells
- secrete surfactant which acts as a lubricant for the lungs and reduces surface tension
T/F: one arteriole and the accompanying venule supply and drain each pulomary lobe
True
What makes up the respiratory membrane?
the point where the capillary wall meets the alveolar wall
What are the major mechanisms driving pulmonary ventilation?
- atmospheric pressure
- air pressure within the alveoli (alveolar pressure)
- pressure within the pleural cavity (intrapleural cavity)
Definition:
Amount of force that is exerted by gases in the air surrounding an given surface such as the body
Atmospheric pressure
What is sea level pressure?
760 mmHg
In physiology, what is a negative pressure? Positive pressure?
Negative < Patm
Positive > Patm
Definition:
Intrapleural pressure
Pressure of air within the pleural cavity, between the visceral and parietal pleurae
What forces compete to cause negative intrapleural pressure?
- elasticity: pulls lungs inward and away from thoracic wall
- alveolar fluid tension: creates inward pull of the lung tissue
** chest wall wants to expand, but lungs want to recoil, causing a negative intrapleural pressure
