Respiratory system function:
- Air passageway: moves air between external environment and the alveoli of the lungs
- Site of gas exchange: Thin barrier between alveoli and pulmonary capillaries
- Enables Oxygen and carbon dioxide to diffuse across barriers.
- Detects odors: olfactory receptors in the superior region of nasal cavity
- Sound protection: vocal cords of the larynx vibrate as air is passed between them.
Respiratory System Organization:
- Upper Respiratory tract includes the nose, nasal cavity, & pharynx
- Lower respiratory tract includes larynx, trachea, bronchi, bronchioles, alveoli
- Functional Organization:
- Conducting zone: nose to terminal bronchioles
- Respiratory zone: respiratory bronchioles, alveolar ducts, alveoli
Mucosal lining: lining of respiratory tract
- Is ciliated epithelium containing epithelium, basement membrane, & lamina propria
- Gets progressively thinner the deeper the structure
- Changes from pseudostratified ciliated columnar → simple columnar → simple cuboidal
→ simple squamous
- Exceptions:
- Pharynx – passageway for both air and food
- Larynx – includes vocal cords and immediate superior region
- Possess non-keratinized stratified squamous epithelium
Mucus:
- Produced by: Goblet cells and the Lamina propia
- Have mucous and Serous glands
- Compositio:n
- Mucin: a “sticky” protein that increases the viscosity of mucous and entraps dust, dirt,
micro-organisms, pollen, etc.
- Lysozyme: antibacterial enzyme
- Defensins: family of antimicrobial proteins and IgA: Antibodies
Nose: Main conducting passageway for inhaled air
- Formed by bone, hyaline cartilage, dense irregular CT, and covered with skin externally
Nostrils (nares):
- Open into the inferior surface of the nose leading into the nasal cavity
Nasal cavity Anatomy:
- Internal space formed by the nose (anterior) and skull (superior & posterior)
- Oblong-shaped; extends from nostrils to choanae
- Floor is the hard palate
- Roof composed of bones of the skull (nasal, frontal, ethmoid, sphenoid) and some nose cartilage
- Nasal septum
- Formed by nasal septal cartilage and bone (vomer and ethmoid)
- Divides the nose into two chambers
- Lateral walls possess the nasal conchae
- Three paired, bony projections (superior, middle, inferior) referred to as turbinate bones
- Produce turbulence in the inhaled air
, - Nasal meatus: Partitions formed by conchae, immediately inferior to its corresponding conchae
Nasal cavity Functions to Condition the Air:
- Warms the air to body temperature
- Due to extensive vascularization
- Cleanses the air
- Microbes, dust, etc. are trapped by in mucus
- Cilia sweeps “dirty” mucus to pharynx
- Humidifies: Enhanced by conchae which creates turbulence and exposes more air to the mucosal
lining
Pharynx (throat);
- Posterior to the nasal cavity, oral cavity, and larynx
- Conducts air along it’s entire length
- Air and food along the inferior portion
- Lateral walls composed of skeletal muscle
- Flexible and distensible
- Aids in swallowing and propelling food to the esophagus
- Three regions
Nasopharynx: superior region of the pharynx
- Posterior to the nasal cavity and superior to the soft palate
- Lined with pseudostratified ciliated columnar epithelium
- Lateral walls house the openings to the auditory tubes
- Serve to equalize pressure in the middle ear
- Also houses the tubal tonsils
- Posterior wall houses the pharyngeal tonsil, aka adenoids
Oropharynx: middle of pharynx
- Posterior to the oral cavity
- Lined with non-keratinized stratified squamous epithelium
- Lateral walls house the palantine tonsils
- Lingual tonsils located at the base of the tongue
Laryngopharynx: inferior of pharynx
- Posterior to the larynx
- Extends from hyoid bone to larynx and esophagus
- Lined with non-keratinized stratified squamous epithelium
- Serves as common passageway for food and air with oropharynx
Larynx: (voice box)
- Continuous with Laryngopharynx (superior) & trachea (inferior)
- Composed of cartilage and supported by muscle and ligaments
- Functions: Passageway for air
- Prevents ingested materials from entering the respiratory tract
- Epiglottis closes over the laryngeal inlet (opening) and glottis closes during
swallowing
- Produces sound for speech via the glottis
- Vibration of the vocal folds as air passes between them through the rima glottidis
- Air passageway: moves air between external environment and the alveoli of the lungs
- Site of gas exchange: Thin barrier between alveoli and pulmonary capillaries
- Enables Oxygen and carbon dioxide to diffuse across barriers.
- Detects odors: olfactory receptors in the superior region of nasal cavity
- Sound protection: vocal cords of the larynx vibrate as air is passed between them.
Respiratory System Organization:
- Upper Respiratory tract includes the nose, nasal cavity, & pharynx
- Lower respiratory tract includes larynx, trachea, bronchi, bronchioles, alveoli
- Functional Organization:
- Conducting zone: nose to terminal bronchioles
- Respiratory zone: respiratory bronchioles, alveolar ducts, alveoli
Mucosal lining: lining of respiratory tract
- Is ciliated epithelium containing epithelium, basement membrane, & lamina propria
- Gets progressively thinner the deeper the structure
- Changes from pseudostratified ciliated columnar → simple columnar → simple cuboidal
→ simple squamous
- Exceptions:
- Pharynx – passageway for both air and food
- Larynx – includes vocal cords and immediate superior region
- Possess non-keratinized stratified squamous epithelium
Mucus:
- Produced by: Goblet cells and the Lamina propia
- Have mucous and Serous glands
- Compositio:n
- Mucin: a “sticky” protein that increases the viscosity of mucous and entraps dust, dirt,
micro-organisms, pollen, etc.
- Lysozyme: antibacterial enzyme
- Defensins: family of antimicrobial proteins and IgA: Antibodies
Nose: Main conducting passageway for inhaled air
- Formed by bone, hyaline cartilage, dense irregular CT, and covered with skin externally
Nostrils (nares):
- Open into the inferior surface of the nose leading into the nasal cavity
Nasal cavity Anatomy:
- Internal space formed by the nose (anterior) and skull (superior & posterior)
- Oblong-shaped; extends from nostrils to choanae
- Floor is the hard palate
- Roof composed of bones of the skull (nasal, frontal, ethmoid, sphenoid) and some nose cartilage
- Nasal septum
- Formed by nasal septal cartilage and bone (vomer and ethmoid)
- Divides the nose into two chambers
- Lateral walls possess the nasal conchae
- Three paired, bony projections (superior, middle, inferior) referred to as turbinate bones
- Produce turbulence in the inhaled air
, - Nasal meatus: Partitions formed by conchae, immediately inferior to its corresponding conchae
Nasal cavity Functions to Condition the Air:
- Warms the air to body temperature
- Due to extensive vascularization
- Cleanses the air
- Microbes, dust, etc. are trapped by in mucus
- Cilia sweeps “dirty” mucus to pharynx
- Humidifies: Enhanced by conchae which creates turbulence and exposes more air to the mucosal
lining
Pharynx (throat);
- Posterior to the nasal cavity, oral cavity, and larynx
- Conducts air along it’s entire length
- Air and food along the inferior portion
- Lateral walls composed of skeletal muscle
- Flexible and distensible
- Aids in swallowing and propelling food to the esophagus
- Three regions
Nasopharynx: superior region of the pharynx
- Posterior to the nasal cavity and superior to the soft palate
- Lined with pseudostratified ciliated columnar epithelium
- Lateral walls house the openings to the auditory tubes
- Serve to equalize pressure in the middle ear
- Also houses the tubal tonsils
- Posterior wall houses the pharyngeal tonsil, aka adenoids
Oropharynx: middle of pharynx
- Posterior to the oral cavity
- Lined with non-keratinized stratified squamous epithelium
- Lateral walls house the palantine tonsils
- Lingual tonsils located at the base of the tongue
Laryngopharynx: inferior of pharynx
- Posterior to the larynx
- Extends from hyoid bone to larynx and esophagus
- Lined with non-keratinized stratified squamous epithelium
- Serves as common passageway for food and air with oropharynx
Larynx: (voice box)
- Continuous with Laryngopharynx (superior) & trachea (inferior)
- Composed of cartilage and supported by muscle and ligaments
- Functions: Passageway for air
- Prevents ingested materials from entering the respiratory tract
- Epiglottis closes over the laryngeal inlet (opening) and glottis closes during
swallowing
- Produces sound for speech via the glottis
- Vibration of the vocal folds as air passes between them through the rima glottidis
