Respiratory System Flashcards
Functions of the Respiratory System
provide oxygen for cells and remove the waste product carbon dioxide from the body
(or pick up oxygen from the air we inhale and release carbon dioxide into the air we exhale)
Parts of the respiratory system
nasal cavity, pharynx, epiglottis, larynx, trachea, bronchi, bronchioles, alveoli, diaphragm, lungs
nasal cavity
warms and moistens air; filters out dust and particles
pharynx
connects respiratory and digestive systems
trachea
the windpipe; contains cilia which lines the trachea and filters air
How does cilia filter air?
sweeps mucus and trapped particles away from the lungs and toward the pharynx to be swallowed or spat out
bronchi
large tubes in the chest cavity that branches off to one lung each
(singular is bronchus)
bronchioles
a division of bronchi that are even smaller passage ways
(singular is bronchiole)
alveoli
tiny air sacs at the end of bronchioles where gas exchange occurs
What controls the contraction and relaxation of bronchi and bronchioles?
autonomic nervous system controls (brain stem), smooth muscles
Path of air in
nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles, alveoli
Path of air out
alveoli, bronchioles, bronchi, trachea, larynx, pharynx, nasal cavity
How is gas exchanged with the circulatory system?
- air enters the alveoli
- blood full of carbon dioxide in capillaries near the alveoli flow through
- both oxygen and carbon dioxide diffuse from high to low (so oxygen diffuses out of blood and binds to hemoglobin, and CO2 diffuses into the alveoli)
- blood now filled with oxygen (not entirely) flows back into the heart
and air from alveoli (now filled with carbon dioxide) gets exhaled
What do the mechanics of breathing involve?
rib cage, diaphragm, differences in air pressure
Mechanics of inhalation
- muscles in between ribs contract (raises rib cage)
- diaphragm contracts (flattens)
- chest capacity increases
- internal air pressure decreases
- higher air pressure outside than inside
What does the rib cage do during inhalation?
muscles in between contract, raising the rib cage
What does the diaphragm do during inhalation?
contracts, flattens the diaphragm
How is the air pressure inside of the body compared to the outside during inhalation?
internal air pressure is lower
external air pressure is higher
How does having a lower air pressure inside help inhalation?
creates a partial vacumn
Mechanics of Exhalation
- muscles in between ribs relax (ribcage lowers)
- diaphragm relaxes (moves up)
- internal chest capacity decreases
- internal air pressure increases
- higher air pressure inside than outside
- air flows out
What does the rib cage do during exhalation?
relaxes, goes down and inward
What does the diaphragm do during exhalation?
relaxes, moves up
How is the air pressure inside of the body compared to the outside during exhalation?
internal air pressure is higher
external air pressure is lower
What is the regulation of breathing controlled by?
medulla oblongata (part of brain stem)
What causes the rate of breathing to increase?
more CO2
How does the medulla oblongata help maintain homeostasis?
regulates carbon dioxide levels and ensures there is not too mcuh
How does the medulla oblongata regulate carbon dioxide levels?
CO2 lowers blood pH slightly (creates carbonic acid)
sends impulses to muscles in between ribs and diaphragm to contract to get rid of the CO2
