You should be able to Lesson 13 1 Explain the function of the respiratory system The respiratory system supplies cells with oxygen and removes produced carbon dioxide The five functions of the respiratory system are Provides extensive gas exchange surface area between air and circulating blood Moves air to and from exchange surfaces of lungs Protects respiratory surfaces from outside environment Produces sounds Participates in olfactory sense 2 Describe the difference between the upper and lower respiratory system What type of cells lines each system The URS is above the larynx and the LRS is below the larynx The URS trachea and bronchi contains mucous glands that secrete onto epithelial surfaces The LRS conducting portion contains smooth muscle cells that encircle lumen of bronchioles 3 Describe the composition of the respiratory epithelium Why can it allow for efficient gas exchange The structure of the respiratory epithelium changes along the respiratory tract A pseudostratified ciliated columnar epithelium with numerous mucous cells lines the nasal cavity and the superior portion of the pharynx The epithelium lining inferior portions of the pharynx is a stratified squamous epithelium similar to that of the oral cavity These portions of the pharynx conduct air to the larynx and also convey food to the esophagus The pharyngeal epithelium must therefore protect against abrasion and chemical attack A pseudostratified ciliated columnar epithelium comparable to that of the nasal cavity lines the superior portion of the lower respiratory system The smaller bronchioles have a cuboidal epithelium with scattered cilia The exchange surfaces of the alveoli are lined by a very delicate simple squamous epithelium Other more specialized cells are scattered among the squamous cells and together they form the alveolar epithelium Gas exchange can take place quickly and efficiently because the distance between the blood in an alveolar capillary and the air inside 1 an alveolus is generally less than 1 um 4 Explain the respiratory defense system The Respiratory Defense System removes particles and pathogens and consists of a series of filtration mechanisms Mucous cells and mucous glands Produce mucus that bathes exposed surfaces Cilia Sweep debris trapped in mucus toward the pharynx Filtration in nasal cavity removes large particles Alveolar macrophages engulf small particles that reach lungs 5 Describe the components of the conducting portion of the respiratory system Consists of airways that deliver air to lungs Nose o Air enters the respiratory system Nasal hairs Are the first particle filtration system o The Nasal Cavity Provides sense of smell olfaction and mucous secretions and tears clean and moisten the nasal cavity Warms and humidifies air entering respiratory system Breathing through mouth bypasses this important step Pharynx o A chamber shared by digestive and respiratory systems o Extends from internal nares to entrances to larynx and esophagus o Divided into three parts The nasopharynx Superior portion of pharynx lined with pseudostratified ciliated columnar epithelium The oropharynx Middle portion of pharynx lining changes from pseudostratified columnar epithelium to stratified squamous epithelium The laryngopharynx Inferior portion of pharynx lied with a stratified squamous epithelium that resists abrasion chemical attack and invasion by pathogens Larynx o From the pharynx air enters the larynx 2 A cartilaginous structure that surrounds the glottis which is a narrow opening connecting the pharynx to larynx Cartilages of the Larynx Thyroid cartilage Anterior surface called laryngeal prominence or Adam s apple Hyaline cartilage U shaped Cricoid cartilage Hyaline cartilage Epiglottis Elastic cartilage Cartilage Functions Thyroid and cricoid cartilages support and protect The glottis The entrance to trachea During swallowing The larynx is elevated The epiglottis folds back over glottis Prevents entry of food and liquids into trachea Vestibular ligaments Lie within vestibular folds Trachea o Also called the windpipe o Extends from the cricoid cartilage into mediastinum Where it branches into right and left pulmonary bronchi o Esophagus is behind the trachea o The Tracheal Cartilages 15 20 tracheal cartilages Strengthen and protect airway Discontinuous where trachea contacts esophagus C shaped allows distortion of tracheal wall for food passage in esophagus o Ends of each tracheal cartilage are connected by An elastic ligament and trachealis muscle band of smooth muscle contraction of reduces diameter Connects the ends of each tracheal cartilage 3 Bronchi o The Primary Bronchi Normally regulated by sympathetic division sympathetic stimulation causes relaxation there is more air able to reach trachea of trachealis muscle because Right and Left Primary Bronchi Separated by an internal ridge the carina The Right Primary Bronchus Is larger in diameter than the left Descends at a steeper angle as a result most foreign objects that enter the trachea enter the right primary bronchus Bronchioles Alveoli 6 Where does the respiratory system diverge from the digestive system The epiglottis in the oral cavity 7 Explain how sounds are produced by the larynx Air passes through the glottis and vibrates vocal folds slender short folds higher pitch thicker longer folds lower pitch voice Vocal folds involved with sound are known as vocal cords They produce sound waves which are varied by tension on vocal folds that is controlled by voluntary muscles 8 Explain why the tracheal cartilages are C shaped along the region where the trachea contacts the esophagus Because these cartilages are not continuous the posterior tracheal wall can easily distort when you swallow allowing large masses of food to pass through the esophagus 9 Describe the bronchial structure of the lungs Bronchial Structure A Primary Bronchus branches to form secondary bronchi lobar bronchi One secondary bronchus goes to each lobe branches to form tertiary bronchi segmental bronchi o Each tertiary bronchus branches into multiple bronchioles o Bronchioles branch into terminal bronchioles One tertiary bronchus forms about 6500 terminal bronchioles 4 Bronchioles have NO cartilage and are dominated by smooth muscle The walls of primary secondary and tertiary bronchi o Contain progressively less cartilage and more smooth muscle increased smooth muscle tension affects airway constriction and resistance 10 Explain how airflow in the bronchioles
View Full Document
Unlocking...