Chapter 9 : The respiratory system : Exchange of gases
Respiration takes place throughout the body in 4 processes
Breathing
External respiration : exch gases between blood and inhaled air. (in lungs)
Internal respiration : exch gases between blood and tissue fluids.
Cellular respiration : using O2 to produce ATP in cells => generates CO2 as waste.
The RESPIRATORY SYSTEM consists of upper and lower respiratory tracts
Respiratory system
The upper respiratory tract (nose, nasal cavity, and pharynx-structures above the ‘Adam’s apple)
The lower respiratory tract (larynx, trachea, two bronchi, lungs)
The UPPER RESPIRATORY TRACT filters, warms and humdifies air
Air enters tru nostrils
Then to nasal cavity (divided in 2 chambers by nasal septum) : lined with EPITHELIAL TISSUE :
o Secretes mucus : humidifies the air, traps dust & particles
o Supplied with vessels => warms the air
o Covered with CILIA : tiny hairlikes, gently move particle-full mucus to back of nasal cavity and pharynx.
(Cold temps can slow down => mucus pools in cavity => drip nose)
Sinuses = air spaces in skull (also secrete mucus to trap particles) that drain into nasal cavity via small passageways.
Tear ducts ; also drain into nasal caity => Crying also makes your nose running
From nasal cavity to pharynx (throat) : Connects mouth &nasal cavity to larynx (voice box).
o Upper pharynx : from nasal cavity to roof of mouth. Into it come 2 ‘auditory tubes’ (eustachian tubes).
o Lower pharynx : passageway for food and air. Food goes to esophagus, air to the lower respiratory tract.
Respiration takes place throughout the body in 4 processes
Breathing
External respiration : exch gases between blood and inhaled air. (in lungs)
Internal respiration : exch gases between blood and tissue fluids.
Cellular respiration : using O2 to produce ATP in cells => generates CO2 as waste.
The RESPIRATORY SYSTEM consists of upper and lower respiratory tracts
Respiratory system
The upper respiratory tract (nose, nasal cavity, and pharynx-structures above the ‘Adam’s apple)
The lower respiratory tract (larynx, trachea, two bronchi, lungs)
The UPPER RESPIRATORY TRACT filters, warms and humdifies air
Air enters tru nostrils
Then to nasal cavity (divided in 2 chambers by nasal septum) : lined with EPITHELIAL TISSUE :
o Secretes mucus : humidifies the air, traps dust & particles
o Supplied with vessels => warms the air
o Covered with CILIA : tiny hairlikes, gently move particle-full mucus to back of nasal cavity and pharynx.
(Cold temps can slow down => mucus pools in cavity => drip nose)
Sinuses = air spaces in skull (also secrete mucus to trap particles) that drain into nasal cavity via small passageways.
Tear ducts ; also drain into nasal caity => Crying also makes your nose running
From nasal cavity to pharynx (throat) : Connects mouth &nasal cavity to larynx (voice box).
o Upper pharynx : from nasal cavity to roof of mouth. Into it come 2 ‘auditory tubes’ (eustachian tubes).
o Lower pharynx : passageway for food and air. Food goes to esophagus, air to the lower respiratory tract.
