gas exchange in humans- key terms Flashcards
Define thin surface
Short distance to diffuse (one cell thick)
Define large surface area
Many molecules can diffuse at once/More alveoli
Define good ventilation
Regular fresh air supplies keep up concentration gradients for oxygen and carbon dioxide.
Define good blood supply
Gases can be carried to/from the cells that need/produce them
Structure of the Lungs: Define cartilage
(in the trachea), prevents the trachea from collapsing during the absence of air and protects it by keeping it open.
Structure of the Lungs: Define ribs
to protect vital organs and blood vessels and expand and contract (and efficient breathing).
Structure of the Lungs: Define intercostal (internal and external) muscles
situated between the ribs that create and move the chest wall.
Structure of the Lungs: Define diaphragm
produces volume and pressure changes in the thorax, leading to the ventilation of the lungs.
Define inspiration
-External intercostal muscles contract – pulls ribcage upwards and outwards
-Diaphragm muscles contract – the diaphragm moves downwards, and the volume of the thorax increases
-Atmospheric Pressure > Pressure in Thorax
-Air moves into the lungs
Define expiration
-External intercostal muscles relax – ribcage falls downwards and inwards
-Diaphragm muscles relax – return to a dome shape, and the volume of the thorax decreases
-Atmospheric Pressure < Pressure in Thorax
-Air moves out of the lungs
Define internal intercostal muscles
are used in coughing and sneezing.
Define mucus and cilia
goblet cells produce sticky mucus to trap and eliminate particulate matter and microorganisms.
Define cilliated cells
have cilia, little hairs which sweep/beat back and forward in a coordinated way to brush mucus up the lungs into the mouth.
