Mammalian Gas Exchange Flashcards
What is cartilage?
-strong + flexible to move and flex
What is smooth muscle?
-walls of bronchi - regulates air flow
What are elastic fibres?
-all lung tissues - stretch + recoil
What is pleural cavity?
-each lung is enclosed in a double membrane (pleural membrane)
-the space between membranes is the cavity
-which is filled with small amount of pleural fluid
What is pleural fluid?
-lubricates the lungs
-adheres to outer walls to the chest cavity by water cohesion = lungs can expand
What is nasal cavity?
-large SA - good blood supply
-warms air as it passes
-hairy lining = traps dust + bacteria in mucus
-moist surface = increases humidity of incoming air - reduces evaporation in lungs
What is the trachea?
-held open by cartilage
-incomplete C rings - allows it to bend when swallowing
-lined with ciliated epithelial + goblet cells = prevents dust + bacteria entering
What are goblet cells?
-mucus producing cells - secrete mucus made of mucin
-traps microorganisms
-swept along by cilia then destroyed by acid in stomach
What are epithelial cells?
-along trachea to bronchi
-beat regularly to sweep mucus upwards away from lungs
-contains mitochondria for energy
Where is the capillary network?
-surrounds alveoli
-exchange surfaces between lungs + blood
What are bronchi?
-similar to trachea
-have thinner walls + smaller diameter
-cartilage are in full rings
What are bronchioles?
-self supporting tubes with thin walls
-held open by smooth muscle
-adjusts the size of the airway to increase/decreases airflow
-lined with thin epithelial tissues
What are alveoli?
-tiny air sacs
-thin walls
-large SA:V
-made of thin epithelial cells, collagen + elastic fibres
-lining of watery fluid - diffusion of gases
What happens during inhalation?
-chest cavity increases in volume
-lower pressure in lungs
-draws in air
What happens with a decrease in pressure?
-likely to collapse
-lung surfactant (a phospholipid)
-without it = lining would create surface tension = collapse
