Respiratory System Respiration Pulmonary respiration movement of air into and out of the respiratory system External respiration movement of O2 from the lungs into the blood and the exchange of CO2 from the blood into the lungs Gaseous transport materials are transported throughout the body transport between the lungs and the tissues Internal respiration exchange between blood and tissues O2 from lungs go to tissues and CO2 from tissues go to lungs Respiratory Apparatus the structures the air passes through to get to the lungs Nose only external structure in the resp pathway Passageway Warms and moistens superficial capillaries warm moistens because of watery secretions Filters Resonating chamber affects voice Olfactory receptors Anatomy Joke of the Day Nasal Cavity External nares openings nostrils Vestibule where air goes immediately after going through nares Vibrissae hairs lining vestibule Internal nares posterior nasal apertures Paranasal sinuses cavities that lighten the head increases surface area and amount of heat and moisture Nasal Mucosae Olfactory mucosa Smell receptors Respiratory mucosa Pseudostratified ciliated columnar epithelium PSCC starting in the nose Goblet cells produce mucous Mucous glands also produce mucous Serous glands produce enzymes function to kill bacteria Defensins function like antibodies Pharynx common pathway between oral and nasal cavity Nasopharynx typically only air passes through PSCC lining Uvula flips up when swallowing so food does not go up nasopharynx Pharyngotympanic tubes run from middle ear into the nasopharynx equalize equilibrium of the inner ear to keep at atmospheric pressure Oropharynx pharynx assoc with oral cavity change in epithelium because it carries both air and food stratified squamous epithelium Fauces then bend at the back Laryngopharynx food and air can pass through stratified squamous epithelium Larynx Provides open airway Directs food and air Produces voice Vocal Structures Vocal folds length and tension cause pitch Glottis the wider the glottis the deeper the sound Vestibular folds cause glottis to close when swallowing food Trachea Carina last tracheal cartilage C shaped cartilage reinforcements which are made of hyaline cartilage back of trachea where C is not connecting is smooth muscle immediately behind smooth muscle is esophagus Tracheal Layers Bronchial Tree Primary bronchi where it meets trachea Secondary and tertiary bronchi 3 tertiary on right side and 2 tertiary on left because diff of lobes on each side of body each lobe connected to one bronchi Bronchioles 1 mm in dia Terminal bronchioles 1 2 mm Respiratory bronchioles microscpic and lead to alveolar duct starts as PSCC then to columnar then to cuboidal no cilia or mucous production in the bronchiole tree also more smooth muscle Lungs Pleural cavities Cardiac notch space where the heart sits within the cavity Lobes each lung divided into lobes which are divided into segments 10 on R and 8 9 on L and are supplied by tertiary bronchus 3 on right and 2 on left Alveoli alveolar sacs functional part of lungs Alveolar Structure Type I cells simple squamous epithelium Pulmonary capillaries covers entire entire surface single layer of cells Respiratory membrane Type I cells and pulmonary capillaries together Type II cells cuboidal epithelium which functions mostly in secretion secretes surfactant which decreases surface tension of the tension of the alveoli which facilitates diffusion Alveolar pores connections between alveoli allow equalization of entire lung Alveolar macrophages phagocytic cells Pleurae double layer serosae Parietal pleura attached to thoracic wall Visceral pleura external covering of lung Pleural cavity space between 2 pleuras filled with pleural fluid Pleural fluids causes lung to basically adhere to thoracic wall as thoracic cavity expands it moves lungs with it as lungs change vol they change pressure Pulmonary Ventilation Consists of Inspiration Expiration Regulated by Pressure gas wants to move from high to low pressure Volume as you change vol you change pressure Resistance typically minimal friction due to passageway determined by dia Surface tension Compliance stretchiness of lung loss of compliance loss of ability to expand lung scarring of lungs causes less compliance Pressures Atmospheric pressure air exerts on our bodies 760 mm of mercury Intrapulmonary pressure inside alveoli changes when we breath Intrapleural pressure in pleural cavity also changes when we breath neg when compared to atmospheric or intrapulomary Transpulmonary diff between intrapulmonary and intrapleural keeps lungs from collapsing Boyle s Law Relationship between volume and pressure P1V1 P2V2 Breathing Anatomy Joke of the Day Respiratory Volumes movement of air into and out of lungs Tidal volume amount of air that moves in and out under normal circumstances 1 2 liter of air Inspiratory reserve volume amount of excess air that can be taken in with a deep breath roughly 6xs the tidal vol Expiratory reserve volume excess air forced out Residual volume amount of air that remains in the lungs after you exhale forcefully 1200ml of air Anatomical dead space air that s in the conducting zone not involved in gaseous exchange but is inside the resp system 1500 ml of air Respiratory Capacities Inspiratory capacity tidal vol plus inspiratory reserve vol all the air we can take in Functional residual capacity amount of air that remains inside the lungs expiratory reserve plus residual vol Vital capacity total amount of exchangeable air air that can contribute to gaseous exchange Total lung capacity total amount of air that could possibly go into the lung Nonrespiratory Air Movements Coughing Sneezing Crying Laughing Hiccuping Yawning Atmospheric Composition Nitrogen Oxygen Carbon dioxide Water 78 6 597mm Hg 20 9 159mm Hg 0 04 0 3mm Hg 0 46 3 7mm Hg 760mm Hg Alveolar Gas Composition Nitrogen Oxygen Carbon dioxide Water 74 9 569mm Hg 13 7 104mm Hg 5 2 40mm Hg 6 2 47mm Hg 760mm Hg Dalton s Law Pressure exerted by mixture of gasses is sum of pressures of each individual gas Partial pressure of any gas in a mixture is directly proportional to its percentage composition External Respiration of O2 Alveolar PO2 is 104mm Hg Pulmonary capillary PO2 is 40mm Hg Oxygen diffuses into blood until equilibrium of 104mm Hg reached Henry s Law When a mixture of gases contacts a liquid each gas dissolves in the liquid in proportion to its partial pressure Dissolved gases may reenter