BIOH 113 1st Edition Lecture 15Outline of Last Lecture I. Capillary ExchangeII. Net Filtration PressureIII. Circulatory PressureIV. Hepatic Portal SystemsOutline of Current Lecture I. Respiratory SystemII. Nasal CavityIII. Pharynx IV. LarynxCurrent LectureI. Respiratory Systema. Major Functions:i. Supply body with oxygen and dispose of carbon dioxideii. Respiration—four distinct processes must happen1. Pulmonary ventilation: moving air in/out of lungs—breathing2. External respiration: gas exchange between lungs and blood3. Transport: transport of oxygen and carbon dioxide between lungs and tissues4. Internal respiration: gas exchange between systemic blood vessels and tissuesb. The respiratory system can be classified either structurally or functionallyi. Structural classification:1. Upper respiratory tract2. Lower respiratory tractii. Functional classification:1. Conducting zone2. Respiratory zonec. Upper respiratory structures:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. Mouth, nose, nasal cavity, pharynx and larynx—all structures above the vocal foldsii. Nasal cavities and nasopharynx are lined with stratified squamous epitheliumiii. Once you get past vocal folds, the larynx is lined with PCCEd. Lower respiratory structures: i. Trachea, bronchi, bronchioles, lungsii. Trachea:1. Tracheal cartilage—hyaline cartilage2. Trachealis muscle3. Lined with PCCE4. Has goblet cells that secrete mucuse. Respiratory Zone—site of gas exchangei. Consists of bronchioles, alveolar ducts and alveolif. Conducting zonei. Provides rigid conduits for air to reach the sites of gas exchange ii. Includes all other respiratory structuresg. Important transitions within the airways as they get smaller:i. Cartilage support structures change—amount of cartilage gets lesser as airways get smallerii. Epithelium type changes—going from PCCE toa simple columnar to simple cuboidal to simple squamous mucosal tissueiii. Amount of smooth muscle increases as airways get smallerII. Nasal cavitya. Lies in and posterior to the external noseb. Divided by the nasal septumc. Cranial bones form the roofd. Floor formed by hard and soft palatese. Function of the nose:i. Only externally visible part of the respiratory system—functions by:1. Providing an airway for respiration2. Moistening and warming entering air3. Filtering air and cleaning it of foreign particles4. Serves as a resonating chamber for speech5. Houses olfactory receptors—smell f. Respiratory mucosa lines the balance of the nasal cavityi. Glands secrete mucus containing lysozyme and defensins to help destroy bacteriag. Incoming air is:i. Humidified by the high water content in the nasal cavityii. Warmed by the rich plexus of capillariesiii. Ciliated mucosal cells remove contaminated mucush. Superior, medial, and inferior conchae:i. Protrude medially from the lateral wallsii. Increase mucosal areaiii. Enhance air turbulence and help filter airiv. Sensitive mucosa triggers sneezing when stimulated by irritating particlesi. Paranasal sinuses:i. Sinuses in bones that surround the nasal cavityii. Sinuses lighten the skull and help to warm and moisten airIII. Pharynxa. Funnel shaped tube of skeletal muscle that connects to thei. Nasal cavity and mouth superiorlyii. Larynx and esophagus inferiorlyb. Divided into 3 regions:i. Nasopharynxii. Oropharynxiii. Laryngopharyxc. Nasopharynx: lies posterior to nasal cavity, inferior to sphenoid, and superior to level of the soft palatei. Strictly an air passagewayii. Closes during swallowing to prevent food from entering the nasal cavityiii. The pharyngeal tonsils lie high on the posterior walliv. Pharyngotympanic tubes open into the lateral wallsd. Oropharynx: extends inferiorly from the level of the soft palate to the epiglottisi. Serves as a common passageway for food and airii. Epithelial lining is protective stratified squamous epitheliumiii. Palatine tonsils lie in the lateral wallsiv. Lingual tonsil covers the base of the tonguee. Laryngopharynxi. Serves as a common passageway for food and airii. Lies posterior to the upright epiglottisiii. Extends to larynx, where the respiratory and digestive pathways divergeIV. Larynx—voice boxa. Attached to the hyoid bone and opens into the laryngopharynx superiorlyb. Continuous with the trachea posteriorlyc. Three functions of the larynx:i. To provide a patent airwayii. Act as a switching mechanism to route air and food into proper channelsiii. Function in voice