Download Respiratory lecture

Respiratory System
Anatomy and Physiology
Turk
Respiration
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Pulmonary Ventilation
External Respiration
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gas exchange between blood and alveoli
Transport of Respiratory Gases
Internal Respiration
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gas exchange is made between the blood
and cells
cellular respiration
Anatomy of the Respiratory System
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nose and nasal cavity,
pharynx, larynx, trachea,
bronchi, lungs, alveoli
respiratory zone
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site of gas exchange
bronchioles, alveolar
ducts, and alveoli
conducting zone
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somewhat rigid
cleanse, humidify, and
warm incoming air
Nose
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external nares to the nasal
cavity
nasal septum
 hyaline cartilage - vomer
& ethmoid bones
Pharynx
ethmoid and sphenoid bones
hard palate and soft palate
Paranasal Sinuses
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frontal, sphenoid, ethmoid, and
maxillary bones
sinusitis is inflamed sinuses
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partial vacuum leads to a sinus headache
Pharynx
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Nasopharynx
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above the level of food entry
Uvula
pharyngeal tonsil (adenoids)
auditory tubes
tubal tonsils
Pharynx
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Oropharynx
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soft palate to the
epiglottis
palatine tonsils and
linguinal tonsil
Laryngopharynx
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posterior to epiglottis extends to larynx
Larynx
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thyroid cartilage
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Epiglottis
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fusion of two cartilage plates
laryngeal prominence
laryngeal inlet
glottis
Voice Production
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opening and closing of the glottis
length and tension = pitch
loudness = forcefulness the air
Laryngitis
vestibular folds
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act as a sphincter when we cough, sneeze,
or strain
Trachea
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larynx - divides into 2
primary bronchi
Mucosa
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Submucosa
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pseudostratified
epithelium with goblet
cells
seromucous glands
Adventitia
Heimlich maneuver
Bronchial Tree
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secondary (lobar) bronchi
tertiary (segmental) bronchi
terminal bronchioles
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cartilage support changes
epithelium type changes
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pseudostratified columnar to
columnar to cuboidal
amount of smooth muscle
increases
Respiratory Zone
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respiratory bronchioles to alveolar
ducts to clusters of alveolar sacs
squamous epithelial cells, type I cells
alveolar and capillary walls =
respiratory membrane
cuboidal type II cells secrete
surfactant
alveolar macrophages
Pleural Coverings
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Mediastinum
hilus
cardiac notch
bronchopulmonary
segments
lobules
Blood Supply and Innervation
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bronchiole arteries
provide systemic
blood to lung tissue
parasympathetic
(constrict air tubes)
sympathetic (dilate
air tubes)
The Pleura
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parietal pleura
visceral
(pulmonary) pleura
pleural fluid
Pleurisy
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less pleural fluid
Mechanics of Breathing
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pulmonary ventilation
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inspiration – expiration
atmospheric pressure
intrapulmonary pressure = pressure in
the alveoli
intrapleural pressure = pressure in the
pleural cavity
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remains about 4 mm Hg below the alveolar
Mechanics of Breathing
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lungs naturally recoil
suface tension of alveolar fluid
elasticity of the chest wall
negative pleural pressure
transpulmonary pressure
atelectasis – lung collapse
pneumothorax – air in intrapleural
space
Pulmonary Ventilation
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Inspiration
 volume of the lungs is increased so
pressure lowers and air rushes in
 inspiratory muscles – diaphram and
external intercostals
volume increases by half a liter
 intrapulmonary pressure was less than
atmospheric
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Pulmonary Ventilation
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Expiration
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passive process based on the elasticity of
the lungs
pressure higher then atmospheric so air is
forced out of the lungs
forced expiration produced by contraction
of abdominal wall muscles
Physical Factors Influencing
Pulmonary Ventilation
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Airway Resistance
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diameters of the conducting tubes
Bronchioconstriction
Alveolar Surface Tension Forces
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Surfactant
infant respiratory distress syndrome (IRDS)
Lung Compliance
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based on the elasticity of the lungs and
surrounding thoracic cage as well as the
surface tension of the alveoli
reduced by scar tissue, anything that
blocks respiratory passages, a reduction
in surfactant, or a decrease of the
thoracic cage expansion
Respiratory Volumes
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air moving in and out during breathing = tidal
volume
inspiratory volume = air which can be
inspired beyond the tidal volume
expiratory reserve volume = air which can be
expelled after tidal expiration
residual volume = air which remains in the
lungs even after strenuous expiration
Respiratory Capacities
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inspiratory capacity
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functional residual capacity
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sum of residual and expiratory reserve
vital capacity
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sum of tidal and inspiratory reserve
sum of tidal, inspiratory, and expiratory
reserve
total lung capacity
Dead Space
Pulmonary Function Tests
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Spirometer
Distinguish between obstructive pulmonary disease
and restrictive disorders
 increases in TLC, FRC, and RV during obstructive
diseases
 reductions in VC, TLC, FRC, and RV are due to
limited lung expansion
Alveolar Ventilation
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AVR= frequency of breaths x TV-dead
space
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measures the flow of fresh gases in and
out of alveoli over time
increasing the volume of each inspiration
raises the AV more than raising the
respiratory rate
Gas Exchanges in the Body
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hyperbaric oxygen chambers force
oxygen into a patients blood
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CO poisoning, circulatory shock,
asphyxiation, gas gangrene, or tetanus
atmosphere is almost all oxygen and
nitrogen while the air in the alveoli has
more carbon dioxide and water vapor
Gas Exchanges in the Body
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External Respiration
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respiratory membrane is about .5 – 1
micromillameters thick
the greater the surface area the more gas
which can be exchanged
Internal Respiration
Transport of Respiratory
Gases by Blood
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Oxygen
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bound to hemoglobin (98.5%) or
dissolved in the plasma (about 1.5%)
oxyhemoglobin- deoxyhemoglobin
only 20-25% of bound oxygen is
unloaded during one systemic circuit
BPG, temperature, or acidity
Transport of Respiratory
Gases by Blood
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Oxygen
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Hypoxia
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hemoglobin saturation is
below 75%
anemic hypoxia
ischemic (stagnant)
hypoxia
histotoxic hypoxia
hypoxemic (hypoxic)
hypoxia
Transport of Respiratory
Gases by Blood
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Carbon Dioxide
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dissolved in the plasma - 7-10%
bound to hemoglobin - 20-30% - called
carbaminohemoglobin
bicarbonate ion (HCO3-) in the plasma - 6070%
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slow shallow breathing - carbon dioxide accumulates
in the blood – carbonic acid level increases - blood
pH drops
rapid deep breathing flushes out carbon dioxide reduces the carbonic acid level - increases blood pH
Control of Respiration
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Neural Mechanisms and the
Breathing Rhythm
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dorsal respiratory group (DRG) – ventral
respiratory group (VRG)
DRG is also called the inspiratory center
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sends impulses along the phrenic and
intercostal nerves to excite the diaphram
and external intercostal muscles
Eupnea
pneumotaxic center in the pons
Respiratory Adjustments
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Exercise
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respiratory changes occur before there are
any chemical changes
High Altitudes
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acute mountain sickness
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headaches, shortness of breath, nausea,
dizziness
Homeostatic Imbalances
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Chronic Obtructive Pulmonary Disease
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obstructive emphysema
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permanant enlargement of the alveoli and
deterioration of the alveoli walls
Barrel chest - pink puffers
chronic bronchitis
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excessive mucus production in the lower
respiratory passageways
cyanosis is common and carbon dioxide
retention happens early in the disease
Homeostatic Imbalances
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Asthma
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coughing, wheezing, and chest tightness
inflammation of the airways
Tuberculosis
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Mycobacterium tuberculosis
fever, night sweats, weight loss, cough,
spitting up blood
antibiotic therapy requires 12 months
Homeostatic Imbalances
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Lung Cancer
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5 year survival is 7%
squamous cell carcinoma
Adenocarcinoma
small cell carcinoma
Cystic Fibrosis
Decompression Sickness
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Nitrogen bubbles in blood act as an emboli