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 – nostrils Nasal septum – separates nasal cavities Olfactory nerve endings – smell Frontal, maxillary, sphenoidal, and ethmoidal paranasal sinuses drain into the nasal cavity Warms 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 nasopharynx Auditory tube connection permits equalization of air pressure between the middle and exterior ear Inflammation of the nasopharynx can result in a middle ear infection Tonsils (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