the respiratory system (week 16) Flashcards
(26 cards)
what is the main function of the respiratory system?
gas exchange (oxygen and carbon dioxide) between the blood and external environment
list the main organs of the human respiratory system (10 total)
nose (nasal cavity), pharynx, larynx, epiglottis, trachea, lungs, bronchi, bronchioles, alveoli, diaphragm
what is the function of mucus in the nasal cavity and pharynx?
moistens air and traps foreign particles to prevent them from entering the lungs
what happens to mucus trapped in the respiratory system?
it is eventually digested by the stomach
what is the larynx also known as?
the voice box
what is the function of the epiglottis?
it covers the trachea when eating to prevent food from entering the airways
what is the trachea also called?
the windpipe
where is the trachea located relative to the esophagus?
in front of the esphagus
what keeps the trachea open?
cartilage and ligaments
what is the role of cilia in the trachea?
cilia move back and forth to push foreign particles toward the pharynx for removal
how does air move from the trachea to the lungs?
the trachea branches into bronchi, which divide into smaller bronchioles within the lungs
where does gas exchange occur in the lungs?
in the alveoli
what is the size range of alveoli?
0.2-0.5mm i n diameter
why do lungs have many alveoli?
to increase the surface area for gas exchange
what is pulmonary surfactant?
a substance that reduces surface tension in alveoli to prevent collapse
why are alveolar surfaces moise?
to allow oxygen and carbon dioxide to dissolve for diffusion across membranes
what feature of alveoli aids gas exchange?
very thin walls filled with many blood vessles
how does oxygen move into the blood?
oxygen diffuses from high concentration in alveoli to low concentration in blood
how is oxygen transported in the blood?
it attaches to haemoglobin molecules in red blood cells
how many oxygen molecules can one haemoglobin carry?
four oxygen molecules
how is carbon dioxide transported in the blood?
it is carried dissolved in the blood and diffuses into the lungs to be exhaled
what is the pressure of blood leaving the lungs?
approx. 100mmHg
what is the pressure of oxygen in the body tissues at rest?
approx. 40mmHg
how does the pressure difference between blood and tissues affect oxygen delivery?
it causes haemoglobin to release oxygen, which then diffuses into tissues
