respiration part 1 Flashcards
what are the Respiratory systems functions? (theres 7)
1) provide oxygen
2) eliminate CO2
3) regulate blood pH
4) facilitate speech
5) provide microbial defense
6) activate/inactivate chemical messengers in blood
7) defend against blood clots
what are the 3 airway zones?
1) Upper airway
2) conducting zone
3) respiratory zone
what structures make up the upper airway?
structures outside of the thoracic cavity:
mouth/nose → pharynx → larynx → top of trachea
what structures make up the conducting zone?
structures in thoracic cavity, but no gas exchange:
trachea → primary bronchi → secondary bronchi → → bronchioles → terminal bronchioles
the ________ and _______ include cartilaginous rings and mucous glands
trachea and bronchi
in the conduction zone, the _______ have layers of smooth muscle, but lacks cartilage and lands
bronchioles
the respiratory zone includes structures where ____________ can occur
gas exchange
what structures make up the respiratory zone?
respiratory bronchioles → alveolar ducts → alveolar sacs
T/F: respiratory bronchioles very thin-walled; have alveoli in walls
true
__________ is important for respiratory function
Branching
what are the functions of the conducting zone?
- branching: reduce airflow resistance
- warm/moisten air
- microbial defense
the functions of the conducting zone are impaired by what disease?
cystic fibrosis
_______ cells secrete mucus which can trap airborne particles and pathogens
goblet
cilia on epithelial cells move mucus upwards to the _______ where it can be swallowed or expelled
pharynx
what mutation causes cystic fibrosis?
mutation in genetic code for Cl- channel
what is the effect of the deficient Cl- channels in cystic fibrosis patients?
reduces the amount of Na+ and Cl- secreted across the epithelium into mucus
→ less water in mucus (due to osmosis)
→ mucus is thick and dry
what are the consequences of abnormal mucus?
infectious agents are trapped, but not expelled
airways are obstructed
what are the functions of the respiratory zone
- regulate airflow
- site of gas exchange
- microbial defense
__________ in bronchioles regulate airflow
Smooth muscles
how are Alveoli well-suited for optimizing gas exchange?
high surface area
highly vascularized
respiratory surface very thin
low rate of bloodflow provides time for exchange
how is Microbial defense is provided in the respiratory zone?
by pulmonary macrophages
there are ____ types of cells in the alveoli…. name them
3 types of cells:
- Type 1
- Type 2
- macrophages
______ alveoli cells are epithelial, and are the gas exchange surface
Type 1 alveoli
name the functions of type 2 alveoli cells
Type II – secrete surfactant
O2 and CO2 diffuse at different rates due to different ________
solubilities
what is the solubility rate of CO2? O2?
CO2 solubility = 77 mmol/L
O2 = 2.2 mmol/L
T/F: Respiratory surface includes several layers that gases must cross
true
what structure adheres to the underside of the thoracic wall and the top of the diaphragm
parietal (outer) pleura
the visceral (inner) pleura covers what structures?
covers the outer surface of the lung
the space between the two pleural layers is the ________
pleural sac
what is the function of the Intrapleural fluid?
lubricates surfaces
____________ is subject to pressure changes when thoracic cage expands or contracts
pleural sac (interpleural fluid)
airflow is proportional to _________, and inversely proportional to __________
proportional to pressure differences
inversely proportional to resistance to flow
describe what muscles are active during inspiration
diaphragm contracts → lowers floor of cavity → increases volume
external intercostals contract → raise ribcage → increase volume
describe what muscles are active during Expiration
diaphragm relaxes → raises floor of cavity → reduces volume
external intercostals relax → lower ribcage → reduces volume
when does Palv equal Patm?
between breaths (no air is moving)
T/F: the pressure of the interpleural cavity is usually above atmospheric pressure
False- its below
A ________ occurs when lung (actually, the pleural sac) is punctured
pneumthorax
an increase in the volume of the thorax is associated with a ________ in transpulmonary pressure
increase
what occurs when Palv becomes sub-atmospheric?
air flows into the alveoli
______ recoil is critical for lung function
elastic
