How much do you know about The Respiratory System Website
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What does the Respiratory System do? The respiratory system.
Oversees gas exchanges between the blood and external environment
Exchange of gasses takes place within the lungs in the alveoli
Passageways to the lungs purify, warm, and humidify the incoming
air
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Structures of the Respiratory System The Nasal Cavity The Oral
Cavity Pharynx aka the throat Epigottis aka the guardian of the
airways Larynx aka the voice box Trachea aka the windpipe Bronchi
Bronchioli Alveoli
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4 the nose nares the nasal cavity conchae the palate the
sinuses
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5 The Nose Provides airway entry (nares) Inflammation of the
nasal mucosa is called rhinitis.
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6 Nasal cavity Olfactory receptors located in mucosa on
superior surface. Nasal septum divides nasal cavity in midline
Connects with pharynx posteriorly through nasopharynx
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7 Nasal cavity Lateral walls have projections called Conchae
Increases surface area Increases air turbulence within the nasal
cavity Resonating chamber for speech The nasal cavity is separated
from the oral cavity by the Palate Anterior hard palate (bone)
Posterior soft palate (muscle)
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8 Nasal Conchae Increases turbulence of air 3 scroll-like
structures Reclaims moisture on the way out
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9 Paranasal sinuses (open cavities w/in bones around nose)
Frontal, sphenoid, ethmoid and maxillary bones Lined by same mucosa
as nasal cavity Functions: Lighten the skull, Act as resonance
chambers for speech, Moisten air, & Produce mucus that drains
into the nasal cavity
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10 Respiratory Mucosa Pseudostratified ciliated columnar
epithelium with goblet cells. goblet cells secrete mucous Serous
cells secrete watery fluid with antibiotic enzymes, e.g. lysozyme
Cilia move the mucus toward the pharynx for swallowing. Even when
you're healthy, your body makes about a quart of mucus/day. Most of
that mucus trickles down your throat and you don't even notice
it.
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the pharynx tonsils the larynx epiglottis the trachea C rings
Anatomy of the Respiratory System
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12 The Pharynx (throat) Muscular passage from nasal cavity to
larynx Three regions of the pharynx Nasopharynx superior region
behind nasal cavity Oropharynx middle region behind mouth
Laryngopharynx inferior region attached to larynx The oropharynx
and laryngopharynx are common passageways for air and food
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13 The Pharynx (throat) Houses tonsils (they respond to inhaled
antigens) Uvula closes off nasopharynx during swallowing so food
doesnt go into nose Epiglottis (guardian of the airway) posterior
to the tongue: keeps food out of airway Lined with stratified
squamous epithelium for protection Intrenal Auditory tube enters
the nasopharynx Tonsils of the pharynx Pharyngeal tonsil (adenoids)
in the nasopharynx Palatine tonsils in the oropharynx Lingual
tonsils at the base of the tongue
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14 The Larynx (voicebox) Approx. same level as 4 th - 6 th
cervical vertebrae Attaches to hyoid bone superiorly Three
functions: 1.Produces vibrations resulting in speech. {true vocal
cords} 2.Provides an open airway (breathing) 3.Switching mechanism
to route air and food into proper channels Closed during swallowing
Open during breathing
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15 Framework of the larynx 8 cartilages connected by membranes
and ligaments Thyroid cartilage with laryngeal prominence (Adams
apple) anteriorly Cricoid cartilage inferior to thyroid cartilage:
the only complete ring of cartilage: signet shaped and wide
posteriorly
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16 Epiglottis Elastic cartilage attached to thyroid Cartilage
of larynx. Seen @ back of tongue During swallowing, it flips
inferiorly to cover and seal laryngeal opening. Keeps food out of
lower respiratory tract * Posterior views
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17 Vocal cords (vocal folds) Vibrate with expelled air to
create sound (speech) Glottis opening between vocal cords
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18 Trachea (the windpipe) Connects larynx with bronchi 16-20 C
-shaped rings of hyaline cartilage joined by fibroelastic
connective tissue Flexible for bending but stays open despite
pressure changes during breathing
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19 Trachea Lined with ciliated mucosa that beat continuously in
the opposite direction of incoming air to expel mucus loaded with
dust and other debris away from lungs Carina-Ridge on internal
aspect of last tracheal cartilage Divides into two main (primary)
bronchi Surgical opening of the trachea is called a
tracheostomy.
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20 Primary Bronchi Formed by division of the trachea Enters the
lung at the hilus (medial depression) Right bronchus is wider,
shorter, & straighter than left Bronchi subdivide into smaller
& smaller branches secondary & tertiary bronchi Rt.
bronchus is more common site for an inhaled object to get
lodged.
Bronchioles Smallest branches of the bronchi All but the
smallest branches have reinforcing cartilage
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Bronchioles Terminal bronchioles end in alveoli
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24 Alveoli air sacs are specialized for optimal diffusion moist
membrane large surface area thin walls for diffusion (1 cell thick)
- next to pulmonary capillaries, which are also 1 cell thick for
gas exchange. - the inner surface of the alveoli are covered with a
single layer of lipid called surfactant
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25 Surfactant Surfactant reduces the surface tension in the
alveoli allowing them to easily expand to twice their size with
each breath it decreases tension b/w the pleural walls. Aids in the
expansion of the alveoli Made of cuboidal epithelial cells are
scattered in alveolar walls Without it the walls would stick
together during exhalation
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Surfactant in Babies The first cry of new born is done without
the aid of surfactant The 1 st breath immediately activates body to
secrete the surfactant & breathing is easier. Premature babies
problem breathing is difficult because lack surfactant. Breathing
is assisted until the babys lungs fully develop.
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27 Lungs (made up of the many subdivisions of the bronchi,
bronchioli, & millions of alveoli) Each is cone-shaped with
anterior, lateral and posterior surfaces contacting ribs 3 lobes on
the right 2 lobes on the left Apex is near the clavicle (superior
portion) Base rests on the diaphragm (inferior portion)
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28 Hilus or (hilum) Indentation on medial surface Place where
blood vessels, bronchi, lymph vessel, and nerves enter and exit the
lung Smallest subdivision seen with the naked eye is the lobule
Medial view R lungMedial view of L lung
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Coverings of the Lungs Around each lung is a flattened sac of
serous membrane called pleura Parietal pleura (outer layer) lines
the walls of the thoracic cavity Visceral pleura directly on
lung
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Coverings of the Lungs Pleural fluid fills the area between
layers of pleura to allow gliding (like film between 2 plates of
glass). Pleura cling to thoracic wall and are forced to expand and
recoil as volume of thoracic cavity changes during breathing
Pleurisy is the swelling/irritation of the pleura.
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31 Lungs and Pleura Pleural cavity divides thoracic cavity in
three parts: Right & left pleural cavities, & mediastinal
cavity.
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32 The Respiratory Organs Conducting zone Respiratory passages
that carry air to the site of gas exchange Filters, humidifies and
warms air Respiratory zone Site of gas exchange Composed of
Respiratory bronchioles Alveolar ducts Alveolar sacs Conducting
zone labeled
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33 Respiratory Zone End-point of respiratory tree Gas exchange
occurs in the alveoli There are more than 300 million alveoli
making up the lungs
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34 Respiration Pulmonary ventilation Air moves in and out of
lungs Continuous replacement of gases in alveoli (air sacs)
External respiration Gas exchange between pulmonary blood and air
at alveoli O2 (oxygen) in air diffuses into blood CO2 (carbon
dioxide) in blood diffuses into air Transport of respiratory gases
Performed by the cardiovascular system Blood is the transporting
fluid Occurs b/w the lungs and the body tissues Internal
respiration Gas exchange in capillaries between blood and tissue
cells O2 in blood diffuses into systemic tissues CO2 waste in
systemic tissues diffuses into blood Gas Exchange &
Transport
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36 Cellular Respiration metabolic process occurring @ the
cellular level in which ATP is produced from the combination of
glucose & oxygen. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O + 34ATP
All body cells Carbon dioxide (CO 2 ) is produced as a waste
product The bodys cells die if either the respiratory or
cardiovascular system fails
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37 Ventilation Breathing = pulmonary ventilation Pulmonary
means related to the lungs Ventilation is air movement Two phases
1. Inspiration =inhalation-air in diaphragm and intercostal muscles
contract thoracic cavity expands 2. Expiration =exhalation -air out
diaphragm and intercostal muscles relax thoracic cavity
shrinks
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38 Ventilation Mechanical forces cause ventilation requires
energy. Diffusion of gases always flow from area of higher pressure
to areas of low pressure. For air to enter the chest, the pressure
of the air in the lungs has to be lower than atmospheric
pressure.
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39 Muscles of Inspiration During inspiration, the dome shaped
diaphragm flattens as it contracts This increases the height of the
thoracic cavity The external intercostal muscles contract to raise
the ribs This increases the circumference of the thoracic cavity
Together:
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40 Inspiration continued Diaphragm and intercostal muscles
contract The size of the thoracic cavity increases External air is
pulled into the lungs due to an increase in intrapulmonary
volume
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Expiration Largely a passive process which depends on natural
lung elasticity As muscles relax, air is pushed out of the lungs
Forced expiration can occur mostly by contracting internal
intercostal muscles to depress the rib cage
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42 Expiration Rib cage drops under force of gravity Relaxing
diaphragm moves superiorly (up) Elastic fibers in lung recoil
Volumes of thorax and lungs decrease simultaneously, increasing the
pressure Air is forced out
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43 Expiration continued Forced expiration is active process
Contraction of abdominal wall muscles Internal & External
Oblique & Transverse Abdomenus Increases intra-abdominal
pressure forcing the diaphragm upward. Depressing the rib cage,
decreases thoracic volume (try this on yourself to feel the
different muscles acting)
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Pressure Differences in the Thoracic Cavity Normal pressure
within the pleural space is always negative negative feedback
system Differences in lung and pleural space pressures keep lungs
from collapsing
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Factors Influencing Respiratory Rate and Depth Chemical factors
Carbon dioxide levels Level of carbon dioxide in the blood is the
main regulatory chemical for respiration Increased carbon dioxide
increases respiration Changes in carbon dioxide act directly on the
medulla oblongata
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Factors Influencing Respiratory Rate and Depth Chemical factors
(continued) Oxygen levels Changes in oxygen concentration in the
blood are detected by chemoreceptors in the aorta and carotid
artery Information is sent to the medulla oblongata
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Carbon Dioxide is transported three ways in the blood 7%
dissolved in the blood plasma 23% carried on the hemoglobin
molecule as carbaminohemoglobin (HbCO 2 ) 70% is carried as
carbonic acid/carbonate ion equilibrium
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Non-respiratory Air Movements Can be caused by reflexes or
voluntary actions Examples Cough (clears the lower respiratory
passage) Sneeze (uvula closes the oral cavity off from pharynx in
order to clear upper respiratory passage). Laughing Crying
(involves release of air in # of short breaths, similar to
laughing) Yawn (formerly believed to be triggered by low O 2 )
Hiccup (sudden inspiration due to diaphragm spasms)
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Respiratory Volumes and Capacities Normal breathing moves about
500 ml of air with each breath (tidal volume [TV]) {normal quiet
breathing} Many factors that affect respiratory capacity A persons
size Sex Age Physical condition Residual volume of air after
exhalation, about 1200 ml of air remains in the lungs
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Respiratory Volumes and Capacities Inspiratory reserve volume
(IRV) Amount of air that can be taken in forcibly over the tidal
volume Usually between 2100 and 3200 ml Expiratory reserve volume
(ERV) Amount of air that can be forcibly exhaled Approximately 1200
ml
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Respiratory Volumes and Capacities Residual volume Air
remaining in lung after expiration About 1200 ml
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Respiratory Volumes and Capacities Vital capacity The total
amount of exchangeable air Vital capacity = TV + IRV + ERV Dead
space volume Air that remains in conducting zone and never reaches
alveoli About 150 ml
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Respiratory Volumes and Capacities Functional volume Air that
actually reaches the respiratory zone Usually about 350 ml
Respiratory capacities are measured with a spirometer
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54 This air-blood barrier is where gas exchange occurs. The
respiratory membrane is also called the air-blood barrier. Oxygen
diffuses from air in alveolus into pulmonary blood in capillary
Carbon dioxide diffuses from the pulmonary blood in the capillary
into the air in the alveolus
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Air Flow 1. Nose & Mouth 2. Pharynx (the 3 parts of the
pharynx) nasopharynx oropharynx laryngeopharynx 3. Larynx 4.
Trachea 5. Primary bronchi (right & left) 6. Secondary bronchi
(aka. Bronchiole) 7. Tertiary bronchi (aka. Bronchiole) 8.
Alveoli
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Respiratory Rate Changes Throughout Life Newborns (neo-6 wks)
30 60 breath/min Infants (6wk 6mo) 25-40 br/min Toddler (1- 3 yrs)
20-30 br/min Young Children (3 6 yrs) 20 25 br/min Older Children
(10 14yrs) 15 20 br/min Adults 15 & up 12 20 br/min Rate often
increases somewhat with old age
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Extra Credit Ideas 1.Create a 3-d model of the respiratory
system out of gummy life savers & other food items @ home.
Label each structures & indicate if it is part of the
conducting or respiratory zone. 2.Make a working lung model out of
a plastic bottle, balloons, & straws. Explain how it works.
3.Label the respiratory system on a turtle neck shirt.