Objectives

Be able to discuss the generalized functions of the respiratory system.

Be able to identify the major organs of the respiratory system and describe the function of each.

Be able to describe the major respiratory disorders.

Be able to identify structures in the sagittal section of the head and neck.

Functions

Air distributor and gas exchanger – supply oxygen and remove carbon dioxide

Filter, warm, and humidify air we breathe

Associated organs:

Influence speech or sound production

Make sense of smell (olfaction) possible

Respiratory Tracts

Upper – nose, pharynx, and larynx

Pharynx-throat

Larynx-voice box (la,la,la)

URI-head cold

Lower – trachea, bronchial tree, lungs

Trachea-windpipe

Infections-pneumonia(inflammation of lungs)

Respiratory Mucosa

Membrane that lines most of the air distribution tubes in the system

Protective mucous blanket (over 125 ml)

Air purification (traps inspired irritants, such as dust, pollen, and bacteria)

Cilia on mucosal cells beat in only one direction, moving mucus upward to pharynx

Nose

External nares – nostrilsNasal septum – separates nasal cavitiesOlfactory nerve endings – smellFrontal, maxillary, sphenoidal, and ethmoidal paranasal sinuses drain into the nasal cavityWarms and moistens inhaled air, smell

Lacrimal sacs- collect tears from corner of each eye and drain into nasal cavity

Conchae-three shelf-like structures that increase surface area for warming and humidifying air

Pharynx

About 12.5 cm long (5 inches)

Divided into

Nasopharynx (behind nasal cavities)

Oropharynx (behind mouth)

Laryngopharynx (lowest segment)

Nasal cavities, mouth, esophagus(foodpipe), larynx, and auditory tubes (eustachian) have openings into pharynx

Pharyngeal tonsils and auditory tubes open into nasopharynxAuditory tube connection permits equalization of air pressure between the middle and exterior earInflammation of the nasopharynx can result in a middle ear infectionTonsils (mass of lymph tissue) found in oropharynx

Tonsillitis-inflammation of tonsils

Tonsillectomy-removal of pharyngeal and palatine tonsils; now performed only after other options are exhausted

Larynx

Thyroid cartilage (Adam’s apple)

Epiglottis (trap door) partially covers opening into larynx

Vocal cords stretch across interior

Glottis-space between vocal cords

Air distribution (to and from lungs)

Voice production

Upper Respiratory Infections

Rhinitis (coryza) – nasal inflammation, as in a cold, influenza, or allergy

Pharyngitis (sore throat) – inflammation or infection of the pharynx, as in strep throat

Laryngitis – inflammation of the larynx resulting from infection or irritation

Croup-acute laryngitis in children under 5 years of age; may cause difficulty in breathing

URT Anatomical Disorders

Deviated septum-septum that is abnormally far from the midsaggital plane (congenital or acquired)

Epistaxis (bloody nose) – can result from mechanical injuries, hypertension, severe inflammation, or even brain injury