chapter 19 – respiratory system pharynx and larynx
TRANSCRIPT
Pharynx
• Throat– Located posterior to oral cavity, between the nasal
cavity and the larynx– Has 3 divisions• nasopharynx, oropharynxx, and laryngopharynx
Pharynx
• Functions:– Serves as a passageway for food moving from the
oral cavity to the esophagus – Serves as a passageway for air passing between
the nasal cavity and the larynx– Aids in producing sounds for speech
Larynx
• Functions– Serves as a passageway for air moving into and
out of the trachea– Prevents foreign objects from entering the trachea– Houses the vocal cords
Larynx
• Structure– Composed of muscles and cartilages that are
bound by elastic tissue• Single cartilages (largest):
– Thyroid, cricoid, and epiglottic cartilages
• Paired cartilages:– Arytentoid, corniculate, and cuneiform cartilages
Larynx• Structure– Thyroid cartilage• Lower portion is covered by the thyroid gland• Commonly called the Adam’s apple • Is more prominent in males due to differences in
hormones
Larynx
• Structure– Cricoid cartilage• Inferior to the thyroid cartilage• Marks the lowest portion of the larynx
Larynx
• Structure– Epiglottic cartilage• Attached to the upper border of the thyroid cartilage• Supports the epiglottis
Larynx• Structure– Corniculate cartilages• Attached to the tips of the arytenoid cartilages• Serve as attachments for muscles that help regulate
tension on the vocal cords during speech and aid in closing the larynx during swallowing
Larynx
• Structure– Cuneiform cartilages• Located in the mucous membrane between the
epiglottic and arytenoid cartilages• Stiffen soft tissues
Larynx
• Structure– False vocal cords (vestibular folds)• Horizontal folds of muscle and connective
tissue covered by mucous membrane that extend inward from the lateral walls of the larynx• Help to close the larynx during swallowing
– During swallowing, muscles close the triangular shaped opening (called the glottis) between the vocal cords
Larynx• Structure– True vocal cords• Horizontal folds of muscle and connective tissue
covered by mucous membrane that extend inward from the lateral walls of the larynx• Located below the false vocal cords• Contain elastic fibers that vibrate from side to side
when air is forced between the folds– The vibration produces sound waves that can be formed
into words through changes in shape and position of the pharynx, oral cavity, tongue, and lips
Larynx
• Structure– True vocal cords• Pitch (musical tone)
– Controlled by the amount of tension placed on the vocal cords by laryngeal muscles (ncreased tension causes higher pitch)
• Intensity (loudness)– Depends on the force of the air passing over the vocal cords
(stronger force creates greater vibrations and louder voice)