respi - phyanalec Flashcards
- Ventilation /Breathing – movement of air into and out of the lungs
- Exchange of O2 and CO2 in lungs and blood
- Transport of O2 and CO2 in blood
- Exchange of O2 and CO2 between blood and tissues
4 processes of respiration
-process of moving air into and out of the lungs
VENTILATION OR BREATHING
Two Phases VENTILATION OR BREATHING
- Inspiration- movement of air into the lungs, inhalation
2. Expiration – movement of air out of the lungs, exhalation
Muscles of Inspiration)
– diaphragm & muscles that innervate ribs and sternum (external intercostals
– large dome of skeletal muscles that separates the thoracic cavity from abdominal cavity
• Diaphragm
depress ribs and sternum (ex. Internal intercostals)
Muscles of Expiration –
type of breathing
– all inspiratory muscles are active
-muscles contract more forcefully → greater increase in thoracic volume → faster and greater decrease in thoracic volume
labored
Principles governing Airflow
- ↑Pressure, ↑Volume
- Air flows from an area of higher pressure to an area of lower pressure
Greater the pressure difference, greater rate of airflow
phase
– alveolar pressure = atmospheric pressure
end of expi
phase
– contraction of muscles of inspiration, ↑thoracic volume, ↑lung expansion, ↑alveolar volume, AVP < ATP, air enters alveoli
during inspi
phase
– thorax and alveoli stop expanding
- AVP = ATP, airflow stops
end of inspi
phase
↓ thoracic volume, ↓ alveolar volume, AVP > ATP, air leaves alveoli
- During Expiration -
-tendency for an expanded lung to decrease in size
LUNG RECOIL
causes of LUNG RECOIL
elastic tissue
surface tension
– exists because oppositely charged ends of water molecules are attracted to each other
-as water molecules pull together, they pull on alveolar walls, causing alveoli to recoil and become smaller
surface tension
FACTORS THAT KEEP THE LUNGS FROM COLLAPSING
surfactant pleural pressure
mixture of lipoprotein molecules produced by secretory cells of alveolar epithelium
-its molecules form a single layer on the surface of the thin fluid layer lining the alveoli, reducing surface tension
- Surfactant –