respiratory system structures and functions parts of respiratory system nasal cavity pharynx larynx...
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Respiratory SystemRespiratory System
Structures and Functions
Parts of Respiratory SystemParts of Respiratory System
Nasal Cavity Pharynx Larynx Trachea Bronchi Bronchioles Alveoli
Lungs Pleura
Functions of the Respiratory Functions of the Respiratory SystemSystem
Provides oxygen for the body and removes carbon dioxoide through respiration
Production of sound
Respiratory SystemRespiratory System
Body has an average oxygen reserve to last about 4 –6 minutes
If reserve is not replenished , death is the outcome
Respiratory TractRespiratory Tract
Upper Respiratory Tract– Nose– Pharynx– Larynx
Lower Respiratory Tract– Trachea– All segments of the
bronchial tree– Lung
Nasal CavityNasal Cavity
Air enters body through nostrils (anterior nares)
Inside the nostrils, are 2 spaces known as nasal cavities
Nasal cavities are lined with mucous membranes
Nasal CavityNasal CavityNasal Septum—divides
nasal cavities into right and left sides
Three turbinates or bones that protrude into the nasal cavity—they increase surface area for filtering dust and dirt
Cilia—the hairs in your nose that trap larger dirt particles
Changes To The Air As It Comes InContact With the Lining of the Nose
Foreign bodies filtered out by cilia and mucous membrane
Air is warmedAir is moistened
Effect of Smoking on CiliaEffect of Smoking on Cilia Cigarette smoke paralyzes
the cilia and results in accumulations of mucus and the typical smoker’s cough, which is an effort to clear the secretions
Sense of SmellSense of SmellOriginates in your
nose!Olfactory nerves
(which provide the sense of smell) are located in the mucus membrane.
SinusesSinuses Cavities in skullDucts connect sinuses to
nasal cavityNamed: frontal,
maxillary, sphenoid, and ethmoid
Give resonance to voice (nasal sound when you have a cold due to blockage or sinuses)
PharynxPharynxThe throatCommon
passageway for air and food
5 inches long
PharynxPharynx When food is swallowed,
the EPIGLOTTIS closes over the opening to the larynx, preventing food from entering the lungs
Eustachian tube connect the middle ear to the nasopharynx
LarynxLarynx
The voice box Triangular chamber below
pharynx Within the larynx are vocal
cords (GLOTTIS) It is composed of several
pieces of cartilages – the largest is the Adams’s Apple
TracheaTrachea
Windpipe 41/2 inches long Walls are bands of C-
shaped rings of cartilage—to keep trachea open
Lined with ciliated mucous membrane
Coughing and expectoration gets rid of dust-laden mucous
Bronchi and BronchiolesBronchi and Bronchioles
Lower end of trachea divides into right and left bronchus
Bronchi—similar to trachea with ciliated mucous and rings of cartilage
As they enter lungs divide into smaller bronchial tubes
Bronchial tubes have cartilaginous plates instead of rings
Bronchial tubes lead to even smaller bronchioles
Bronchioles—thinner walls of smooth muscle
At the end of the bronchiole is the alveoli
Bronchi, Bronchial Tubes and Bronchi, Bronchial Tubes and BronchiolesBronchioles
AlveoliAlveoli
Composed of single layer of epithelial tissue
Inner surfaces covered with SURFACTANT (keeps alveoli from collapsing)
Each alveolus is surrounded by capillaries
Oxygen and carbon dioxide exchange takes place between alveoli and capillaries
LungsLungs
Fill thoracic cavity Upper part—apex Lower part—base Lung tissue is porous
and spongy—it floats Right lung—larger
and shorter (displaced by liver) Has 3 lobes
Left lung—smaller (displaced by heart) Has two lobes
PleuraPleura
Thin, moist, slippery membrane that covers lungs
Double-walled sac Space is pleural cavity
—filled with pleural fluid to prevent friction
Pulmonary Ventilation Pulmonary Ventilation (Breathing)(Breathing)
Inspiration Intercostal muscles
lift ribs outward Sternum rises Diaphragm contracts
and moves downward This increases the
volume of the lungs and air rushes in
Expiration (exhalation) Opposite action takes
place Exhalation is a passive
process
Breathing ProcessBreathing Process
Respiratory MovementsRespiratory Movements
1 inspiration + 1 expiration = 1 respiration
Respiratory rate for normal adult is 14-20
Factors that Affect Respiratory Factors that Affect Respiratory RateRate
Increases with exercise, fever, certain diseases
Age—newborn = 40-60 per minuteSleep—respirations decreaseEmotion can increase or decrease
CoughingCoughing
Deep breath followed by forceful expulsion of air—to clear lower respiratory tract
HiccupsHiccups
Spasm of the diaphragm and spasmotic closure of the glottis
Caused by irritation to diaphragm or phrenic nerve
SneezingSneezing
Air forced through nose to clear respiratory tract
YawningYawning
Deep prolonged breath that fills the lungs and increases oxygen within the blood
Control of BreathingControl of Breathing
Controlled by neural and chemical factors
Neural Factors Respiratory center in
medulla oblongota Increase in carbon
dioxide or decrease in oxygen will trigger respiratory center
Then the phrenic nerve stimulates the diaphragm
Chemical Factors Depends on levels of
carbon dioxide in blood Chemoreceptors in aorta
and carotid arteries are sensitive to the amount of oxygen in blood