Topic 24: Respiration/Excretion Flashcards
What are respiratory structures and what are some common characteristics?
structures adapted for gas exchange via air or water have common characteristics thin walls large surface area moist many blood vessels gills skin lungs
Define respiratory system
lungs and system if tubes that bring air to them
not direct contact with other parts of body
-> circulatory system required for gas exchange
SEQ mammalian respiration
pharynx -> larynx -> trachea -> bronchi -> bronchioles -> alveoli
What parts are in lungs?
bronchi
bronchioles
alveoli
What are lungs?
paired, spongy, elastic organs within thoracic cavity
What are alveoli?
tiny air sacs
What do each alveolus have?
single layer of epithelial cells
surrounded by capillary network - location of gas exchange
What is breathing?
mechanical process of moving air in/out of lungs
What is inhalation?
air in
What is exhalation?
air out
How is breathing achieved?
via negative pressure
When inhalation is active, how are the muscles? What else happens during inhalation?
muscles contract rib muscles contract -> rib cage expands diaphragm contracts -> moves DOWN Both of these increase volume of thoracic cavity -> pressure is LOWER inside than outside -> air flows IN
When exhalation occurs, how are the muscles? What else happens during exhalation?
passive - muscles relax
rib muscles relax -> rib cage gets smaller
diaphragm relaxes -> moves UP
Both of these decrease volume of thoracic cavity
-> pressure is HIGHER inside than outside
-> air flows OUT
What happens when gas exchange occurs during respiration?
more O2 in inhaled air than in blood
-> O2 diffuses INTO capillaries around alveoli
more CO2 in blood than inhaled air
-> CO2 diffuses OUT of capillaries, into air
CO2 + H2O -> ? -> ?
Carbonic acid -> bicarbonate ion
What happens when you have a higher metabolic rate?
-> higher CO2 -> lower pH -> medulla oblongata signals increase in rate and depth of breathing