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FUNCTIONS of the respiratory system: #1 = obtaining oxygen & removing carbon dioxide = gas exchange filtering incoming air controlling the temp & water content of incoming air producing vocal sounds plays important roles in the sense of smell & regulation of blood pH
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THE RESPIRATORY SYSTEM
PASSAGEWAYS & LUNGS
FUNCTIONSFUNCTIONS of the respiratory system:
– #1 = obtaining oxygen & removing carbon dioxide = gas exchange
– filtering incoming air– controlling the temp & water content of
incoming air– producing vocal sounds– plays important roles in the sense of
smell & regulation of blood pH
cleaning dirty air:
– there’s millions of particles of foreign matter in air!
– air must be filtered before it reaches the lungs
– the nasal cavity, trachea, & bronchial tree are all lined with ciliated cells that secrete mucus via goblet cells
– the cilia beat upward towards the pharynx, where foreign matter is swallowed or coughed up
the EVENTS of respiration:
1) breathing / ventilation = moving air into or out of the lungs
2) external respiration = gas exchange between blood & the air in the lungs
3) gas transport in blood between the lungs & body cells
4) internal respiration = gas exchange between blood & body cells• cell respiration = using O2 to break
glucose & form ATP
PARTS of the respiratory system: upper respiratory tract
– nose w/ 2 nostrils– nasal cavity / nasal passages
• divided into R & L by the nasal septum (may be deviated)
– paranasal sinuses = air-filled spaces in the bones of the skull
– pharynx = a passageway for air & food
UPPER respiratory tract
PARTS of the respiratory system: lower respiratory tract
– larynx = contains the vocal cords– Trachea = “windpipe”– bronchial tree – branched air passages that
lead from the trachea to the air sacs, or alveoli
parts of the respiratory system: LOWER respiratory tract
– 2 lungs: the right lung has 3 lobes & the left has 2 lobes
– assisted by the diaphragm– controlled by the medulla oblongata & pons in the brain stem
lower respiratory tract
the PATH air takes:
– air is taken in through the nose or mouth = inspiration
– air flows into the pharynx & passes the epiglottis
– it moves through the larynx (voicebox)– it travels down the trachea which splits
into 2 tubes
the PATH air takes:
– a bronchial tube / bronchus leads into each lung
– It branches into smaller bronchioles– Bronchioles end in alveoli where gas
exchange takes place– this pathway is reversed for expiration
alveoli = the place of gas exchange:
– the bronchi branch like a tree (bronchus bronchioles alveoli)
– alveoli are the sacs of the lungs where O2 & CO2 are exchanged by diffusion between the air and blood
alveoli = the place of gas exchange:
– grape-like clusters of alveoli are surrounded by networks of tiny blood vessels / capillaries
– the walls of capillaries and of alveoli are only 1 cell thick
blood transport of gases:
– external respiration = the exchange of O2 & CO2 between the air in the alveoli and the blood that circulates through its capillaries
– once oxygen diffuses into the bloodstream, it is pumped by the heart to all cells in the body
blood transport of gases:
– cellular respiration = the process by which cells use oxygen to break down glucose (via glycolysis) & release energy to form ATP
blood transport of gases:
– carbon dioxide is a waste product & it diffuses into the blood which carries it back to the lungs, then it is exhaled
– blood going into the alveoli is low in O2 & high in CO2
– blood returning from the alveoli is higher in O2 & low in CO2
lung capacity:
– tidal volume = the amount of air that moves in during a respiratory cycle (1 inhalation + 1 expiration)
– residual volume = air remaining in lungs after a maximal exhale
– vital capacity = the maximum amount of air a person can exhale after taking in the deepest breath possible
– total lung capacity = the vital capacity + the residual volume
THE MECHANICS OF BREATHING
• breathing is accomplished via the action of the diaphragm & the muscles between the ribs & is assisted by air pressure
• inhaling contracts the muscles between the ribs & causes the rib cage to rise
• inhaling also contracts the diaphragm, flattening it, causing it to move lower in the chest cavity
THE MECHANICS OF BREATHING
• both of these muscular contractions increase the space in the chest cavity, which creates a slight vacuum
• air rushes to fill the space because the pressure outside your body is greater than the pressure inside your lungs
THE MECHANICS OF BREATHING
• when you exhale (expiration), the rib muscles & diaphragm relax which lowers the rib cage & diaphragm
• this decreases the volume of the chest cavity & forces air out of the alveoli
THE MECHANICS OF BREATHING
• healthy lungs are elastic: they stretch as you inhale & go back to their original size when you exhale
• they are never completely empty – even after exhaling (residual volume)
CONTROL OF RESPIRATION
• usually respiration is involuntary• the respiratory center is in the brain stem
& includes portions of the pons & medulla oblongata
• it is partially controlled by the medulla oblongata which maintains the homeostasis of blood chemistry
CONTROL OF RESPIRATION
• the medulla oblongata responds to higher levels of CO2 in blood by sending nerve impulses to the rib muscles & the diaphragm, causing these muscles to contract & you inhale
RELEVANT VOCABULARY
• apnea = temporary cessation of breathing• asphyxia = O2 deficiency & excess CO2 in
blood & tissues• bronchitis = inflammation of the bronchial
lining• cystic fibrosis = a genetic disorder which
causes the production of extremely thick, sticky mucus which encourages infection + clogs the pancreas + impairs absorption of nutrients + leads to salty sweat
RELEVANT VOCABULARY
• emphysema = a progressive, degenerative disease that destroys alveolar walls therefore reducing the volume of gas exchange
RELEVANT VOCABULARY
• hyperventilation = prolonged rapid & deep breathing
• pleurisy = inflammation of the pleural membranes
• rhinitis = inflammation of the nasal cavity lining
• sinusitis = inflammation of the sinus cavity lining
• spirometer = an instrument that measures respiratory air volume
• tracheotomy = incision in the trachea for exploration or for removal of a foreign object