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What is the nasal mucosa?
- The nasal mucosa:
- -Lines the nasal cavities
- -Lined with Goblet Cells
- -Heats and moisturizes the incoming air
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Goblet Cells?
Produce mucus: which traps bacteria and air pollution
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3 parts of the Pharynx?
- Nasopharynx
- Oropharynx
- Laryngopharynx
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The Nasopharynx
- The uppermost portion, located about the soft palate
- It is a passageway for air only
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Soft Palate
Elevates during swallowing to block the nasopharynx and prevent food and saliva from going up rather than down
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Oropharynx
- Located behind the mouth
- Passageway for air and food
- Lateral walls contain the palatine tonsils
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Laryngopharynx
- Passageway for air and food
- opens anteriorly to the larynx and posterior to the esophagus
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Larynx
"Voice box"
- Functions:
- -Speaking
- -air passageway btwn the pharynx and the trachea
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Epiglottis
- The uppermost cartilage
- -During swallowing the epiglottis closes over the top, to prevent entry of saliva or food into the larynx
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Pathway for the bronchial tree
Primary bronchi --> Secondary Bronchi --> bronchioles --> alveoli
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Primary Bronchi
- Right and left
- The branches of the trachea that enter the lungs
- Right is shorter than the left
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Secondary Bronchi
- to the lobes of each lung
- 2 in the right lung
- 3 in the left lung
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Bronchioles
- Have no cartilage in their walls
- Smaller branches
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Alveoli
Smallest bronchioles that terminate into clusters of alveoli
Air sacs of the lungs
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Parietal pleura
lines the chest wall
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Visceral pleura
is on the surface of the lungs
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Serous fluid
- Between the parietal and visceral pleura that prevents friction
- keeps the membranes together during breathing
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Alveoli
- Air Sacs
- Sight of gas exchange in the lungs
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Within the alveoli are ___ that phagocytize pathogens
Macrophages
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Each alveolus is lined with a thin layer of what and why?
- Tissue fluid
- it is essential for the diffusion of gases
- (because a gas must dissolve in a liquid in order to enter or leave a cell)
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Alveolar type 2 cells
a secretes a lipidprotein (pulmonary surfactant) -- that mixes with the tissue fluid and decreases its surface tension, permitting inflation
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Venilation
Movement of air to and from the alveoli/lungs
- 2 Aspects:
- Inhalation
- Exhalation
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Respiratory Centers
Medulla and Pons
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Domed shaped muscle made of skeletal muscle (separates the thoracic and abdominal cavities) and is below the lungs that is
Diaphragm
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Respiratory muscles
- Diaphragm
- external and internal intercostals
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The pressure of the air around us? At sea level it is 760 mmHg
Atmospheric Pressure
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The pressure within the potential pleural space between the parietal and visceral pleura
-usually slightly below atmospheric pressure
"Negative Pressure"
Intrapleural Pressure
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the pressure within the bronchial tree and alveoli; fluctuates during breathing
Interpulmonic pressure
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Motor impulses from the medulla travel along the phrenic nerves to the diaphragm, which contracts and moves down.
Impulses are sent along intercostal nerves to external intercostal muscles, which pull ribs up and out
Process of Inhalation
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As the lungs expand, intrapulmonic pressure ___ (inc/dec) and air enters the ____?
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Tidal volume
the amount of air in one normal inhale and exhale
average = 500 mL
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Minute respiratory volume (MRV)
the amount of air inhaled and exhaled in 1 minute
MRV = Tidal vol X # of respiration's/min
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Residual air volume
the amount of air that remains in the lungs after the most forceful exhalation
average =1000-1500 mL
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What test is used to diagnose emphysema?
Forced Expiratory Volume (FEV)
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2 Sites of gas exchange
- 1) Between air in alveoli and blood
- 2) Between blood and tissue fluid
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The exchange of gases between the air in the alveoli and the blood in the pulmonary capillaries
External respirations
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The exchange of gases between blood in the systemic capillaries and the tissue fluid
Internal respirations
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Partial Pressure
- concentration of each gas in a particular site
- measured in mmHg
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Hemoglobin
Carries O2 in the blood
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Factors that increase the release of more O2?
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The O2 - Hemoglobin bond is formed by the lungs when PO2 is ___ (high/low), when the blood passess through the tissues with a low PO2 the bond breaks and the ___ is released into the tissue
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The lower the O2 concentration the ___ (+/-) O2 the hemoglobin will release?
more
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The higher the PO2 the ___ (+/-) the SaO2
- the higher
- the are related
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Carbon dioxide is carried by what in the blood?
Hemogloboin - Carbaminohemoglobin
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Most carbon in the plasma is carried in the form of?
bicarbonate ions
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Where does the CO2 diffuse when it enters the blood?
Red blood cells
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Two types of mechanisms that regulate breathing
- Nervous mechanisms
- Chemical Mechanisms
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The Medulla contains which centers?
the inspiration and expiration centers
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The respiratory centers in the pons work with the with inspiration centers to produce what?
normal rhythms of breathing
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This center prolongs inhalation and then interrupted
Apneustic center
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Interrupts the apneustic center, and contributes to exhalation
pneumaotaxic center
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Refers to the effect on breathing of blood pH and blood levels of O2 and CO2
Chemical Regulation
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Chemoreceptors
- detect changes in blood gases and pH
- located in the carotid and aortic bodies
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Hypoxia
decrease in blood oxygen levels
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hypercapnia
- excess of CO2
- makes the blood more acidic
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Major regulator of respiration
Carbon dioxide (b/c it affects the pH of blood)
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Reasons why O2 would be the major regulator of respirations
People with severe chronic pulmonary diseases: emphysema
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Respiratory Acidosis
- Occurs when respiration rate decreaes
- CO2 increases
- pH decreases
Examples: pneumonia,emphysema,severe asthma
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Respiratory Alkalosis
- occurs when respiratory rate increases
- CO2 decreases
- increases pH
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Examples of Respiratory Alkalosis
- Hyperventilation
- Crying for long periods
- Traveling to high altitudes
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