Respiratory Function
- Composed of upper & lower respiratory tracts, blood vessels, thoracic cage (spine,ribs,
sternum), respiratory muscles (diaphragm)
Ventilation: movement of air from the atmosphere to the alveoli
Diffusion: exchange of oxygen and carbon dioxide at the alveolar capillary membrane
Perfusion: blood flow
- Innervations of the respiratory system are controlled by the neurologic system
(medulla,pons,spinal nerves), muscular system (diaphragm, intercostal muscles), and
chemical regulation
Anatomy of Upper Respiratory Tract
- Nose, nasal passages, pharynx, tonsils, adenoids, larynx
Nose
- Internal nose divided into 2 vertical divider, septum (supplied w/ sensory nerves & blood
vessels)
- Nasal passage divided into 3 passageways by conchae
- Middle passageway (meatus) under the middles turbinate & contains ostia (openings),3
paranasal sinuses
- Mucus covers the surface of nasal mucosa and is secreted constantly by by goblet cells
Cilia- moves mucus back to nasopharynx (fine hairs)
Paranasal Sinuses
- Frontal (above eyebrows), ethmoidal (between eyes & behind nose), sphenoidal (behind
ethmoid sinuses), maxillary (on cheeks below eyes)
- Resonating chamber in speech & common site of infection
Pharynx, Tonsils, & Adenoids
- Pharynx (throat) connects nasal & oral cavities to larynx & is passageway for respiratory
& digestive tracts
- Nasopharynx posterior to nose & above soft palate
- Adenoids (pharyngeal tonsils) in roof of nasopharynx
- Nerves in nasopharynx detect odors & provoke sneezing
- Eustachian tubes drain mucus & equalize pressures
- Oropharynx houses faucial, tonsils, which encircle the throat
Larynx
- Major function is voice box & lower airway from foreign substances & promotes coughing
- Epiglottis: valve flap that covers entrance to larynx during swallowing (prevent
aspiration)
- Glottis: opening between vocal cords
- Thyroid Cartilage: largest cartilage structure (adams apple)
- Cricoid Cartilage: only complete cartilaginous ring in larynx
- Arytenoid cartilages: used in vocal cord movement w/ thyroid cartilage
- Vocal cords: ligaments controlled by muscular movements that create sounds
- Expiration, vocal cords vibrate to produce high/low sounds
- High sounds associated w/ taut glottis & low sounds more relaxed
Anatomy of Lower Respiratory Tract
- Trachea, right & left mainstem bronchi, secondary bronchi, bronchioles, & lungs
, - Subdivided into conducting airways & acinus, bronchioles & alveoli are located
Trachea
- Windpipe composed of smooth muscle w/ C shaped incomplete rings of cartilage
- Extends from cricoid cartilage of the larynx to the top of carina (trachea divides)
Lungs
- Separated into upper & lower lobes by oblique/major fissures
- Right middle lobe can only be auscultated one anteriorly
Bronchi & Bronchioles
- Right main bronchus provides air to right lung, is wider & shorter, more vertical
- Aspiration tends to occur in right lung
- Mainstream bronchi divide 5 lobar bronchi: 3 in right lung & 2 in left lung
- Bronchioles have no cartilage in walls
- Production of mucus, presence of serous glands that secrete watery substance
containing antibacterial enzymes, & surfaces are covered w/ cilia
Alveoli
- Lung made up of 300 million alveoli
- Type 1 alveolar cells are epithelial cells that form on alveolar walls
- Type 2 alveolar cells are metabolically active & secrete surfactant (prevents collapse)
- Type 3 alveolar cells macrophages are large phagocytes that ingest foreign matter
Pleura
- Serous membrane that line lungs & wall of the thorax
- Visceral pleura covers lungs & parietal pleura covers thorax (fibers for pain transmission)
- Intrapleural space, contains 20-25 cc that provides frictionless surface between 2 pleura
Respiratory Muscles
- Diaphragm dome shaped muscle
- Contracts (inspiration) pulls lungs in downward & forward direction, abdomen
enlarges
- Expiration diaphragm & intercostals recoil & increase intrapulmonary pressure
over atmospheric pressure so gasses are expelled from lungs
- Additional accessory muscles of inspiration are scalene (elevate first 2 ribs), alae nasi
(nostril faring)
Neuroanatomy Related to Respiration
- Rhythm of breathing controlled by medulla oblongata & pons
- Central chemoreceptors in medulla respond to changes in PCO2, & pH levels in
cerebrospinal fluid & alter the depth and rate the ventilation to correct imbalance
- Peripheral chemoreceptors are located in aortic arch & carotid arteries respond to PaO2
changes & to PaCO2 & pH by altering depth & rate of respiration
- Hering-Breuer reflex that prevents overinflation of the lung, is activated by stretch
receptors located within smooth muscle of large & small airways that inhibit inspiration
Respiration
- Requires gas exchange in lungs & in tissues
- 1. Ventilation: act of breathing (inspiration & expiration)
- 2. Perfusion: blood flow to alveoli so gasses can be exchanged
- 3. Diffusion: movement of gasses form higher area to lower area of concentration
- Composed of upper & lower respiratory tracts, blood vessels, thoracic cage (spine,ribs,
sternum), respiratory muscles (diaphragm)
Ventilation: movement of air from the atmosphere to the alveoli
Diffusion: exchange of oxygen and carbon dioxide at the alveolar capillary membrane
Perfusion: blood flow
- Innervations of the respiratory system are controlled by the neurologic system
(medulla,pons,spinal nerves), muscular system (diaphragm, intercostal muscles), and
chemical regulation
Anatomy of Upper Respiratory Tract
- Nose, nasal passages, pharynx, tonsils, adenoids, larynx
Nose
- Internal nose divided into 2 vertical divider, septum (supplied w/ sensory nerves & blood
vessels)
- Nasal passage divided into 3 passageways by conchae
- Middle passageway (meatus) under the middles turbinate & contains ostia (openings),3
paranasal sinuses
- Mucus covers the surface of nasal mucosa and is secreted constantly by by goblet cells
Cilia- moves mucus back to nasopharynx (fine hairs)
Paranasal Sinuses
- Frontal (above eyebrows), ethmoidal (between eyes & behind nose), sphenoidal (behind
ethmoid sinuses), maxillary (on cheeks below eyes)
- Resonating chamber in speech & common site of infection
Pharynx, Tonsils, & Adenoids
- Pharynx (throat) connects nasal & oral cavities to larynx & is passageway for respiratory
& digestive tracts
- Nasopharynx posterior to nose & above soft palate
- Adenoids (pharyngeal tonsils) in roof of nasopharynx
- Nerves in nasopharynx detect odors & provoke sneezing
- Eustachian tubes drain mucus & equalize pressures
- Oropharynx houses faucial, tonsils, which encircle the throat
Larynx
- Major function is voice box & lower airway from foreign substances & promotes coughing
- Epiglottis: valve flap that covers entrance to larynx during swallowing (prevent
aspiration)
- Glottis: opening between vocal cords
- Thyroid Cartilage: largest cartilage structure (adams apple)
- Cricoid Cartilage: only complete cartilaginous ring in larynx
- Arytenoid cartilages: used in vocal cord movement w/ thyroid cartilage
- Vocal cords: ligaments controlled by muscular movements that create sounds
- Expiration, vocal cords vibrate to produce high/low sounds
- High sounds associated w/ taut glottis & low sounds more relaxed
Anatomy of Lower Respiratory Tract
- Trachea, right & left mainstem bronchi, secondary bronchi, bronchioles, & lungs
, - Subdivided into conducting airways & acinus, bronchioles & alveoli are located
Trachea
- Windpipe composed of smooth muscle w/ C shaped incomplete rings of cartilage
- Extends from cricoid cartilage of the larynx to the top of carina (trachea divides)
Lungs
- Separated into upper & lower lobes by oblique/major fissures
- Right middle lobe can only be auscultated one anteriorly
Bronchi & Bronchioles
- Right main bronchus provides air to right lung, is wider & shorter, more vertical
- Aspiration tends to occur in right lung
- Mainstream bronchi divide 5 lobar bronchi: 3 in right lung & 2 in left lung
- Bronchioles have no cartilage in walls
- Production of mucus, presence of serous glands that secrete watery substance
containing antibacterial enzymes, & surfaces are covered w/ cilia
Alveoli
- Lung made up of 300 million alveoli
- Type 1 alveolar cells are epithelial cells that form on alveolar walls
- Type 2 alveolar cells are metabolically active & secrete surfactant (prevents collapse)
- Type 3 alveolar cells macrophages are large phagocytes that ingest foreign matter
Pleura
- Serous membrane that line lungs & wall of the thorax
- Visceral pleura covers lungs & parietal pleura covers thorax (fibers for pain transmission)
- Intrapleural space, contains 20-25 cc that provides frictionless surface between 2 pleura
Respiratory Muscles
- Diaphragm dome shaped muscle
- Contracts (inspiration) pulls lungs in downward & forward direction, abdomen
enlarges
- Expiration diaphragm & intercostals recoil & increase intrapulmonary pressure
over atmospheric pressure so gasses are expelled from lungs
- Additional accessory muscles of inspiration are scalene (elevate first 2 ribs), alae nasi
(nostril faring)
Neuroanatomy Related to Respiration
- Rhythm of breathing controlled by medulla oblongata & pons
- Central chemoreceptors in medulla respond to changes in PCO2, & pH levels in
cerebrospinal fluid & alter the depth and rate the ventilation to correct imbalance
- Peripheral chemoreceptors are located in aortic arch & carotid arteries respond to PaO2
changes & to PaCO2 & pH by altering depth & rate of respiration
- Hering-Breuer reflex that prevents overinflation of the lung, is activated by stretch
receptors located within smooth muscle of large & small airways that inhibit inspiration
Respiration
- Requires gas exchange in lungs & in tissues
- 1. Ventilation: act of breathing (inspiration & expiration)
- 2. Perfusion: blood flow to alveoli so gasses can be exchanged
- 3. Diffusion: movement of gasses form higher area to lower area of concentration
