Transcript The Respiratory System

The Respiratory
System
Functions
 The major function:
 Supply the body with Oxygen
 Dispose of Carbon dioxide
4 distinct events
 Pulmonary ventilation: air is moved in and
out of the lungs
 External respiration: gas exchange between
blood and alveoli
 Respiratory gas transport: CV system
transports oxygen and carbon dioxide between
lungs & tissues
 Internal respiration: gas exchange between
blood & tissue cells
 Cellular respiration: actual use of oxygen &
production of carbon dioxide in the cells
Pulmonary Ventilation
External Respiration
Internal Respiration
Cellular Respiration
Functional Anatomy –
2 zones
 Respiratory zone:
 Actual site of gas exchange
 Respiratory bronchioles, alveolar ducts,
alveoli
 Conducting zone:
 conduits – purify, humidify, and warm
incoming air
 Include all other respiratory passageways
Nose – 5 functions
 Provide airway for
respiration
 Moisten & warm air
 Filter air
 Resonating chamber
 Site of smell receptors
Cold day = Runny nose
 The cilia in your nose become sluggish &
slow when they are cold & does not
move the mucus down your throat
 Mucus in the nasal cavity accumulates &
dribbles out
Paranasal sinuses
functions
 Lighten skull
 Act a resonance chamber
 Produce mucus
Imbalances – add to back
of notes
 Rhinitis: inflammation of nasal mucosa
 Excessive mucus production, nasal congestion,
postnasal drip
 Sinusitis: inflamed sinuses
 Difficult to treat due to location
 Marked changes in voice quality
 Sinus headache:
 Caused by blocked passageways from nasal cavity
to sinuses, air in sinuses is absorbed, creates partial
vacuum, change in pressure causes headache over
inflamed areas.
Chronic Sinusitis
Pharynx – 3 basic parts
 Pharynx serves as common passageway
for food (& fluids) and air.
 Parts:
 Nasopharynx
 Oropharynx
 Laryngopharynx
Nasopharynx
 Serves only as an air passageway
 During swallowing
 Soft palate & uvula reflect upward
 Close off nasopharynx which prevents food
from entering
Pharyngeal Tonsils
 AKA: Adenoids
 Function: trap & dispose of pathogens
that enter the nasopharynx
 All tonsils are lymph nodes
Disorder
 When pharyngeal
tonsils become
inflamed
 Obstruct the air
passage
 Must mouth breath
 Air is not filtered,
warmed, etc. correctly
in this case
Eustachian tubes
 Auditory or eustachian tubes provide an
avenue for equalizing middle ear
pressure with atmospheric pressure via
the flow of gases
 Air will either move in or out of your ears
to cause this equalization
 This is the cause of your ears “popping”
Eustachian tubes
Middle ear infections
 The nasal mucosa is continuous
throughout your respiratory system so
infections can travel
 Pharyngeal infections can move into the
middle ear causing Otitis Media
Oropharynx &
Laryngopharynx
 Serves both respiratory & digestive
systems
 Oropharynx
 Food, fluid, & air passage
 Laryngopharynx
 Food, fluid, & air passage
 Becomes continuous with esophagus
 During swallowing, food/fluids have the “right of
way”
Larynx – 3 Functions
 Provides patent
(open) airway
 Act as a switching
mechanism (between
respiratory &
digestive systems)
 Voice production
(location of vocal
cords)
Adam’s apple
 Laryngeal
prominence
on the thyroid
cartilage
 Seen
externally as
Adam’s apple
Epiglottis
 9th cartilage
 When air is flowing into the larynx – free
edge projects upward
 During swallowing:
 Larynx is pulled upward
 Epiglottis is tipped to cover laryngeal inlet
 Routes food/fluid into esophagus
Epiglottis
Cough Reflex
 Initiated if anything other than air enters the
larynx
 Pressure from air moves object upward out of
the larynx
 Heimlich manuver is the same principle
 Used to press air out of lungs in case someone
cannot inhale to initiate a cough
 Reflex does not work when unconscious so not a
good idea:
 To give fluids to an unconscious person
 Also a reason why people in an alcoholic coma often die
from aspirating their own vomit.
Cilia
 Our entire upper respiratory tract is lined
with psuedostratified ciliated columnar
epithelium
 The power stroke motion of the cilia
move upward toward our nose & mouth
so that mucus is moved away from the
lungs
Cilia & Goblet Cells
Take Quiz #1
Voice Production
 Sound involves:
 Intermittant release of air
 Opening & closing of true vocal cords
 The length & tension of the cords
changes the pitch while the loudness
depends on the force of air
 The vocal cords do not move at all when
we whisper
Laryngitis
 Results in hoarseness
 Cause:
 Overuse of voice
 Infections
 Inhalation of irritating chemicals
Laryngitis on your left
Trachea (Windpipe)
 The mucociliary escalator continuously
propels the mucus which contains dust
particles and debris to the throat so it can
be expelled or swallowed.
Smoking
 Diminishes ciliary activity
 Coughing is ONLY method of preventing
mucus accumulation in the lungs
 Smokers should never be given
medications that INHIBIT the cough
reflex.
Effects of Smoking
Reinforcement
 Trachea is reinforced internally by 16-20
C shaped rings
 Outer portion of C – causes trachea to
stay patent (open) and not collapse
 Inner portion (open part) of C – allow
trachea to be flexible and gives
esophagus a place to expand into upon
swallowing.
Tracheostomy
 -ostomy = cut a hole into
 Used in cases of:




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Abnormalities
Cancers
Obstructions
Injuries to area
Etc.
Bronchial Tree
 Trachea divides into right and left primary
bronchi at the level of the sternal angle.
 Inhaled objects usually lodge in the right
primary bronchus since it is wider,
shorter, and at a more vertical angle
Respiratory Zone
Structures
 Begins as the
terminal bronchioles
which feed into the
respiratory
bronchioles which
end in the alveoli
chambers where gas
exchange (external
respiration) takes
place.
Alveoli
 Account for the largest portion of lung
volume and provide a tremendous
surface area for gas exchange
 Composed of simple squamous – much
thinner than a sheet of paper
 Membrane has gas on one side and
blood on the other.
Alveoli
 Gas exchanges occur through simple
diffusion
 A moist membrane is required so the
TYPE II cells secrete a substance called
surfactant that coats the membrane &
interferes with surface tension.
Lungs
 Left lung is smaller, consisting of 2 lobes
and contains a cardiac notch
 Right lung has 3 lobes
 Bronchopulmonary segments
 Served by own artery, vein, and individual
segmental bronchus
 Left lung has 8 segments while right lung
has 10.
Important Info
 Respiratory therapists and surgeons use
this info about the different
bronchopulmonary segments so they can
treat the patient as needed
 Even to the point of removing the diseased
segment and leaving the good tissue
 The lungs weigh approximately 2.5 pounds
Pleurae
 Parietal vs. visceral
 Function of pleural fluid
 Lubricate layers so they can slide across
each other
 Cause them to cling tightly to each other
through surface tension (helps maintain
pressure differences necessary for
inhaling/exhaling)
Pleurisy
 Wet pleurisy: excessive fluid production
puts pressure on lungs
 Dry pleurisy: fluid decrease causes
membranes to rub against each other –
causes pain and adhesions to form
Take Quiz #2
Remember – it includes the
diagrams!!