THE RESPIRATORY SYSTEM

RESPIRATION The exchange of gases between the atmosphere, lungs, blood, and tissues

Respiration Pulmonary ventilation: “breathing” Pulmonary ventilation: “breathing” External respiration: occurs within the lungs External respiration: occurs within the lungs Transport of respiratory gases: via the blood Transport of respiratory gases: via the blood Internal respiration: occurs within the tissues Internal respiration: occurs within the tissues

REQUIREMENTS Gas exchange surfaces must be thin. Gas exchange surfaces must be thin. Gas exchange surfaces must remain moist. Gas exchange surfaces must remain moist. Gas exchange surfaces must be large in relation to the size of the organism. Gas exchange surfaces must be large in relation to the size of the organism.

FUNCTIONAL ANATOMY - Upper respiratory Nose Nose Pharynx Pharynx - Lower respiratory Larynx Larynx Trachea Trachea Bronchial tree Bronchial tree Lungs Lungs Diaphragm Diaphragm

Nose

Features of the Nose External Nares: External Nares: The nostrils where air enters the nasal cavity The nostrils where air enters the nasal cavity Nasal Septum: Nasal Septum: Divides the nasal cavity into two symmetrical halves Divides the nasal cavity into two symmetrical halves Olfactory/Respiratory Mucosa: Olfactory/Respiratory Mucosa: Contain smell receptors and goblet cells for mucus secretion Contain smell receptors and goblet cells for mucus secretion

Nose

Features of the Pharynx Nasopharynx: Nasopharynx: Acts only as an air passageway; when swallowing, uvula and soft palate close it off Acts only as an air passageway; when swallowing, uvula and soft palate close it off Location of pharyngeal tonsil Location of pharyngeal tonsil Eustachian tubes Eustachian tubes Oropharynx: (fauces) Oropharynx: (fauces) Common passageway for food and air Common passageway for food and air Location of palatine and lingual tonsils Location of palatine and lingual tonsils Laryngopharynx: (hypopharynx) Laryngopharynx: (hypopharynx) Common passageway for food and air Common passageway for food and air Intersects with trachea; location of epiglottis Intersects with trachea; location of epiglottis

Pharynx

Features of the Larynx Three functions Three functions Provides an open airway Provides an open airway Routes food and air into proper tubes (epiglottis) Routes food and air into proper tubes (epiglottis) Voice production (vocal folds) Voice production (vocal folds) Several cartilages located here (thyroid, cricoid, and arytenoid) Several cartilages located here (thyroid, cricoid, and arytenoid) Epiglottis: Epiglottis: Flap of elastic cartilage that shuts off larynx and trachea from incoming food (only works in conscious people) Flap of elastic cartilage that shuts off larynx and trachea from incoming food (only works in conscious people) Vocal Folds: Vocal Folds: True vocal cords that vibrate with air coming up from the lungs. Space between is called the rima glottidis True vocal cords that vibrate with air coming up from the lungs. Space between is called the rima glottidis Vestibular folds (false vocal cords) Vestibular folds (false vocal cords)

Larynx

Larynx

Vocal Folds and Ligaments

Features of the Trachea Contains mucosa Contains mucosa Goblet cells produce mucus Goblet cells produce mucus Cilia of pseudostratified columnar epithelium propel debris-laden mucus to pharynx Cilia of pseudostratified columnar epithelium propel debris-laden mucus to pharynx Contains C-shaped cartilage Contains C-shaped cartilage Helps the trachea to expand and recoil Helps the trachea to expand and recoil Prevents trachea from collapsing despite pressure changes that occur during breathing Prevents trachea from collapsing despite pressure changes that occur during breathing

Trachea

Tracheal Anatomy

Features of the Bronchial Tree Primary Bronchi: Primary Bronchi: Runs obliquely into mediastinum and enters lung at lung hilus; two primary bronchi emerge from trachea. Right bronchi is larger, shorter and oblique. Aspiration. Bifurcation is called the carina. Runs obliquely into mediastinum and enters lung at lung hilus; two primary bronchi emerge from trachea. Right bronchi is larger, shorter and oblique. Aspiration. Bifurcation is called the carina. Secondary Bronchi: Secondary Bronchi: Each primary divides into secondary (3 on right and 2 on left) bronchi that service each lung Each primary divides into secondary (3 on right and 2 on left) bronchi that service each lung Tertiary Bronchi: Tertiary Bronchi: Secondary bronchi branch into tertiary which branch into smaller and smaller tubes Secondary bronchi branch into tertiary which branch into smaller and smaller tubes Bronchioles: Bronchioles: Tiniest of tertiary bronchi, less than 0.5 mm in diameter; smallest are terminal bronchi Tiniest of tertiary bronchi, less than 0.5 mm in diameter; smallest are terminal bronchi

Bronchial Tree

Bronchoscope: illuminated, tubular instrument to view bronchi and trachea. Bronchoscope: illuminated, tubular instrument to view bronchi and trachea. Bronchography: technique used to examine the bronchial tree. A catheter (intratracheal) is passed through the nose or mouth and through the rima glottidis into the trachea. A contrast, usually containing iodine, is inhaled and an x-ray is taken called a bronchogram. Bronchography: technique used to examine the bronchial tree. A catheter (intratracheal) is passed through the nose or mouth and through the rima glottidis into the trachea. A contrast, usually containing iodine, is inhaled and an x-ray is taken called a bronchogram.

Features of the Lower Bronchial Tree Terminal Bronchioles: Terminal Bronchioles: The smallest bronchioles that feed directly into: The smallest bronchioles that feed directly into: Respiratory Bronchioles: Respiratory Bronchioles: Feed into each lung which lead into: Feed into each lung which lead into: Alveolar ducts: Alveolar ducts: Contain rings of smooth muscle and alveoli which is the structure gases are exchanged in. Contain rings of smooth muscle and alveoli which is the structure gases are exchanged in. Contain a chemical called surfactant which reduces surface tension Contain a chemical called surfactant which reduces surface tension

Lower Bronchial Tree

Alveoli and Respiratory Membrane

The Lungs and Pleural Coverings

Lungs - right and left - Lungs have lobes and fissures - 3 lobes in the rt. lung - superior - middle - inferior - 2 fissures: horizontal and oblique - 2 in the left lung - superior - inferior - cardiac notch for heart to rest in. - 1 fissure: oblique

- Lung has broad inferior surface called the base. - Lung has a pointed superior surface called the apex or the cupola