Download The Respiratory System

The Respiratory System
Week 25
Vocabulary to Know
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Respiration
Alveolus (alveoli)
Atelectasis
Cyanosis
Hypoxia
Apnea
Bradypnea
Eupnea
Nares
pharynx
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Rhinorrhea
Rhinitis
Bronchus
Bronchiole
Dyspnea
Tachypnea
Diaphragm
Inspiration
Exhalation
Pleural effusion
More Vocabulary
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Vital capacity
Intercostal
Residual
Chest cavity space
Tidal air
Tidal volume
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Plural effusion
Epistaxis
Epiglottis
empyema
Divisions of the Respiratory System
• Upper Respiratory
System
• Lower Respiratory
System
Nose and Nasal Cavities
• Structure and function
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Nasal cavities
Conchae
Olfactory receptors
Paranasal sinuses
• The nasal cavity___________ the air we
breathe.
– Warms
– Humidifies
– Filters
Pharynx
• Muscular tube
• Between nasal cavity and cervical
vertebrae
• Divided into nasopharynx and oropharynx
and laryngopharynx
Larynx
• Also know as the
voice box
• Air passageway
between pharynx and
trachea
• Hyoid bone
• Thyroid cartilage
• Epiglottis
• Vocal cords
• Another name for the larynx is:
– Middle ear
– Voice box
– Pharynx
– Eustachian tube
Trachea and Bronchial Tree
• Trachea
• Right and left
mainstem bronchi
• Bronchioles
Lungs and Pleural Membrane
• Protected by ribcage
• Base rests on diaphragm
• Hilus
Pleural Membranes
Alveoli
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Functional unit of the lung
Millions in each lung
700 to 800 square feet
Simple squamous epithelium
Mechanism of Breathing
• Ventilation: movement of air into and out
of lungs
• Inhalation and exhalation
• Respiratory centers: medulla and pons
• Muscles: diaphragm and intercostal
Pulmonary Volumes
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Vary with age and size of the individual
Capacity and elasticity diminish with age
Tidal volume: 500mL
Minute respiratory volume
Inspiratory reserve: 2000-3000mL
Expiratory reserve: 1000-1500mL
Vital capacity: 3500- 5000mL
Residual air: 1000-1500mL
Alveolar ventilation: 350- 400mL
• Anatomic dead space 100-150mL
• Physiologic dead space
• Compliance
Gas Exchange
• Two exchange sites
– Lungs
– Body tissues
• Respiration
– Internal
– External
Diffusion of Gases and Partial
Pressures
• Gases diffuse from areas of higher
concentration to areas of lower
concentration
• Gases are mixed
• Each gas in a mixture exerts part of the
pressure that the mixture as a whole
exerts.
• Partial pressure is the pressure exerted by
a particular gas in the mixture
• Partial pressure of Oxygen (PO2)
• Partial pressure of carbon dioxide (PCO2)
– PO2> PCO2 in alveoli
– PO2< PCO2 in pulmonary capillaries
– Oxygen diffuses into capillaries, CO2 diffuses
into alveoli
• In the body
– PO2 > PCO2 in systemic capillaries
– PO2< PCO2 in tissue fluid and cells
– O2 diffuses into cells, CO2 diffuses into
capillaries
Conditions that Impair Gas
Exchange
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Pneumonia
Pulmonary fibrosis
Pulmonary edema
Bronchitis
Transport of Gases in the Blood
• Little oxygen is carried dissolved in blood
plasma
• Oxygen binds to hemoglobin in RBCs
• Iron in hemoglobin gives oxygen binding
capacity
• Unstable oxygen-hemoglobin bond
• SaO2
• CO2 is carried as HCO3
Regulation of Respiration
• Brain stem: medulla and pons
• Medulla generates impulses that cause
the respiratory muscles to contract
• Inflated lungs stimulate baroreceptors
• Baroreceptors generate sensory receptors
to depress inspiration center
• Relaxation follows
Normal Respiratory Pattern
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Inspiration 1-2 seconds
Exhalation 2-3 seconds
Normal rate 12-20 breaths per minute
Tachypnea > 20
Bradypnea < 12
Apnea = 0
Abnormal Respiratory patterns
Respiration and Acid-Base Balance
• Respiratory Acidosis
– Due to decrease in efficiency or rate
– CO2 build up
– Relationship to respiratory disease
• Respiratory alkalosis
– Due to increase in respiratory rate
– Decrease H+ formation
– Not common
– Relationship to anxiety
The Aging Respiratory System
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Muscles weaken with age
Lung tissue loses elasticity
Ossification of cartilage
Cilia deteriorate
Alveolar macrophages less efficient