2RespirationThe exchange of gases between the atmosphere, blood, and cellsPulmonary Ventilation - the exchange of air between the atmosphere and lungsExternal (Pulmonary) Respiration - gas exchange between the lungs and bloodInternal (Tissue) Respiration - gas exchange between the blood and cells
3Functions of the Respiratory System Provides structures and mechanisms for gas exchangeIntake of O2Elimination of CO2Helps maintains body’s pHSense of smellSpeech and sound production
4Organs of the Respiratory System NosePharynxLarynxTracheaBronchiLungs
7Nose External Portion Internal Portion - large cavity within the skull Supporting bony frameworkCartilage - SkinMucous membranesNostrils or external naresInternal Portion - large cavity within the skullConnects the external nose to the pharynx through two openings (Internal Nares)
11Functions of the Nose Warming, moisturizing and filtering incoming air Smell (reception of olfactory stimulus)Resonating chamber for speech
12Pharynx Funnel-shaped tube about 13 cm long Extends from the internal nares down to the cricoid cartilage of the larynxWalls composed of skeletal muscle lined with a mucous membraneDivided into three areasNasopharynxOropharynxLaryngopharynx
14Functions of the Pharynx Passageway for food and airResonating chamber for speech
15Larynx (Voice Box)A short passageway that connects the pharynx with the tracheaWalls of the larynx is composed of 9 pieces if cartilageThree single pieces of cartilageepiglottic cartilage (Epiglottis)thyroid cartilage (Adam’s Apple)cricoid cartilage (attaches the Larynx to the Trachea)Three paired pieces of cartilagearytenoid - corniculate - cuneiform
17Trachea Tubular passageway about 12 cm long and 2.54 cm in diameter Anterior to the esophagusExtends from the larynx to about the 5th thoracic vertebraeComposed of C-shaped cartilage rings stacked upon one anotherHyaline cartilage ringsCovers the anterior and lateral walls
19TracheaNon-cartilaginous posterior softer portion of the trachea allows for expansion of the esophagus during swallowingLined with ciliated epitheliumThe point where the trachea bifurcates is called the carinaAbout the 5th thoracic vertebrae
20BronchiTubes that branch off of the trachea at the carina and extend into the lungsLeft Primary Bronchus (Left Mainstem Bronchus)Right Primary Bronchus (Right Mainstem Bronchus)Shorter and more verticalSwallowed objects more likely to lodge in the right primary bronchus than the left
21Bronchi Also composed of cartilaginous rings Continue branching as they enter the lungs into a structure called the bronchial treeTrachea Mainstem (Primary) Bronchi Secondary (Lobar) Bronchi Segmental (Tertiary) Bronchi Terminal Bronchioles Respiratory Bronchioles Alveolar Ducts
23BronchiolesBronchioles are smaller air passages which branch from the bronchi. Bronchioles are small, muscular tubes with a narrow diameter. Changes in the size of the bronchioles help direct the flow of air to various parts of the lungs.
24Alveolar DuctsAlveolar ducts are enlarged chambers found at the end of the bronchioles. These very fine passageways end at the alveolar sacs and connect to the alveoli.
25Alveoli A cup shaped out pouching of epithelial tissue Place where external respiration occurs (gas exchange between the lungs and the blood)Lungs contain million alveoliSurface area of about 750 sq. ft.The size of a Tennis Court
27Pharynx Funnel-shaped tube about 13 cm long Extends from the internal nares down to the cricoid cartilage of the larynxWalls composed of skeletal muscle lined with a mucous membraneDivided into three areasNasopharynxOropharynxLaryngopharynx
28Structures of the Larynx EpiglottisGlottisHyoid BoneThyroid CartilageCricoid CartilageTrue and False Vocal Cords
29EpiglottisLarge leaf-shaped piece of cartilage lying on top of the larynxThe stem of the epiglottic cartilage is attached to the thyroid cartilageLeaf portion of the cartilage is unattached and acts like a trap door covering the opening to the trachea which is called the glottis.Dependent upon breathing or swallowing
31GlottisThe opening from the pharynx to the larynx that contains the vocal cordsVocal Cords - mucous membrane folds that extend across the glottis in two layersupper layer or folds - false vocal foldslower layer or folds - true vocal foldsSounds originate from vibration of these true vocal cords
33Hyoid BoneIs located in the neck between the lower jaw and the larynx.It does not articulate with any other bones.It serves as the posterior attachment for the tongue and helps in swallowing.
34Thyroid CartilageThe thyroid cartilage is the largest cartilage of the larynx.It give the larynx its characteristic triangular shape.Nicknamed the Adam’s Apple because of its enlarged size due to the influence of testosterone.
35Cricoid Cartilage The most inferior cartilage of the larynx. Used as a landmark to perform a tracheotomy.
36True Vocal CordsThe most inferior of the horizontal folds in the larynx.Contain elastic fiber which vibrate to create sound.
37False Vocal Cords The most superior of the folds in the larynx. Help the glottis close during swallowing to prevent food from entering the lower respiratory passages.
38LungsPaired - cone shaped organs that occupy most of the thoracic cavitySeparated from each other by the heart and other structures of the mediastinumSurrounded by a double layered serous membrane called the pleural membrane
39Features of the LungsApex - the pointed, superior portion of the lungs.Base – the broad, inferior surface of the lungs which rests on the diaphragm.
42Pleural Membrane Parietal Pleura - outer layer of the pleural membrane Attached to the thoracic wallVisceral Pleura - inner layer of the pleural membraneAttached to the lungs themselvesBetween the parietal pleura and the visceral pleura is a potential space called the pleural cavityContains pleural (serous) fluid (reduces friction)
43Gross Anatomy of the Lungs Extend from the diaphragm to an area about 2.54 cm above the clavicles on both sides of the thoracic cavityBaseApexHilusLobes
44Lobes and FissuresEach lung is divided into lobes by one or more fissuresThere are three lobes in the right lung and two lobes in the left lung.
45Pleural CavityThe mediastinum divides the thoracic cavity into two pleural cavities, each of which contains one lung.
46Gas ExchangeGas exchange occurs in the alveoli due to the difference in the partial pressures of oxygen and carbon dioxide in the capillary blood and the alveoli.Since the concentration of oxygen is greater in the alveoli, it diffuses into the capillary blood.
47Since the level of carbon dioxide is higher in the capillary blood than in the alveoli, carbon dioxide diffuses out of the blood and into the alveoli.
48Lung ParametersTidal Volume (TV) ml - volume of air moved in and out of the lungs during breathingVital Capacity (VC) ml - maximum volume of air that can be exhaled after taking the deepest possible inhalation VC - TV + IRV + ERV
50Physiology of Ventilation Ventilation - the process of inhaling and exhaling air in and out of the lungsPulmonary Ventilation - the process by which air flows between the lungs and the external environmentDue to a change in pressure between the atmosphere and the air in the lungs
52Inspiration (Inhalation) Bringing air into the lungs from the external environmentThe lungs themselves contain no muscles and thus depend upon the relationship with the muscles of the walls of the thoracic cavity to alter lung volumes
55Expiration (Exhalation) Movement of air from the lungs to the external environmentNormally a passive process (no energy or muscular contractions required)Dependent upon muscle and lung elasticityMay become active during high levels of physical activityMost people require ventilation rates above % - 65% of their vital capacity for expiration to become active
58Chemical StimuliDetermines how fast and how deeply an individual breathesVery sensitive to the levels of CO2 and H+ ion concentration in the bloodMonitored by chemoreceptors at:carotid arteries, aorta, and the medulla oblongata.
60RESPIRATORY DISORDERS AND HOMEOSTATIC IMBALANCES
61Bronchiogenic Carcinoma (Lung Cancer) Most fatal cancer in the U.S.Highly metastaticUsually linked with cigarette smokingStarts in the walls of the bronchi due to irritation of the bronchiole epitheliumCommon irritants include smoking, pollution, dust particles20 times more prevalent in smokers than non- smokers
62Emphysema “Blown up or full of air” A condition where the alveolar walls lose their elasticity and remain filled with air during expirationAlveoli become damaged and eventually merge together to form large air sacs with reduced overall volumePatients often develop a barrel chestGenerally caused by cigarettes, pollution, industrial dust particles
63Influenza •Caused by one of many viruses Antibiotics cannot help Medications used to treat the symptomssneezing - coughingcongestion - rhinorrheaMay result in rhinitis: inflammation of the nasal mucosaCommonly known as the flu
64Pneumonia Acute infection or inflammation of the alveoli of the lungs Most common infectious cause of death in the U.S.Alveolar sacs fill with fluid and dead white blood cells reducing the amount of functional surface area of the lungsMost commonly caused by bacteriumStreptococcus pneumoniaeAffects those in poor health or compromised immune system
65Sudden Infant Death Syndrome (SIDS) 10,000 infant deaths per year in the U.S.Cause is not known but thought to be caused by an infectious agent or compressed carotid arteryMost deaths occur in the fall or winterOver 50% of SIDS death children had an upper respiratory infection within the past two weeksMay also be caused by improper positioning for sleeping in the crib
66Tuberculosis (Tb) Caused by a bacterium Mycobacterium tuberculosisAn infectious communicable disease that destroys the lung tissue and pleuraReplaced by fibrous connective tissue called tuberclesDisease is spread by inhalation of the bacterium