Friday, November 12, 2010

Respiratory system


Respiratory System
            2 main functions
                        make oxygen constantly available
                        Carry carbon dioxide away
                        By exchanging gasses between atmosphere and blood and cells
            Accessory function
                        Vocalization
            Protective devices
                        Coughing
                        Sneezing
            Contracts diaphragm
                        & external intercostals under normal breathing conditions
           
General path oxygen from nose to lungs
1.      nasal cavity
2.      pharynx
3.      larynx
4.      trachea
5.      bronchi
6.      lungs

            External Nares
                        The opening of the nose to the outside atmosphere
            Nasal Cavity
                        Large air filled space above and behind the nose in the middle of the face
                        Contains Olefactory Region, Inferior, Middle & superior Nasal Meatus
                                    Olefactory Region
                                                Mucous membrane line
                                                Ciliated Pseudo stratified columnar epithelium
                                                            For filtering the air
                                    Nasal meatus
                                                Add more area to allow for more filtering
            Internal Nares (Choana)
                        The opening between the nasal cavity and the nasopharynx
                        Has sebaceous glands just as skin does
            Nasopharynx
                        Always Open
            Oropharynx
            Laryngopharynx
            Larynx
                        Valved to prevent food from going down wrong tube
                        Glottis opens when swallowing
                        Epiglottis guards the entrance of the glottis, the opening between the vocal folds. It is normally pointed upward during breathing
                        Anterior wall
                                    Thyroid cartilage
                        Inferior wall
                                    Cricoid
                                    Fuses with trachea
                        Posterior wall
                                    Corniculate
                        Superior ventricular folds
                                    False vocal cords
                        Inferior ventricular folds
                                    True vocal cords
                                   
                                    Tension on these cords controls pitch
                                    Air volume moving past them controls volume
                                    Males are thicker & longer
           
            Trachea
                        Fibroelastic tube
                        11 cm long
                        2.5 cm diameter
                        C6 ~ T5
                        Divides into Right and Left Prime Bronchi
                        C shaped Cartilage supports
                        Trachealis muscle is a smooth muscle. It bridges the gap between free ends of C-shaped cartilages at the posterior border of the trachea,                                                 adjacent to the esophagus.
                        Lies Anterior to esophagus
                        Ciliated Pseudo stratified columnar epithelium
                                    For more filtering of air
                        Carina
                                    Most sensitive area
                                    Causes cough reflex to protect the lungs
                                    Lowest point of trachea

Respiratory Tree
                        2 branches
                        Right Prime Bronchi
                                    Shorter
                                    Broader
                                    3 subsidiary braches
                                                For the right 3 lobes
                        Left Prime Bronchi
                                    Longer
                                    2 subsidiary Branches
                                                for the left 2 lobes
                        smooth muscles replaces the C shaped cartilage of trachea

           
            Lungs
                        Extensive epithelial surface
                        Extensive capillary network
                        Elastic & spongy
                        Thin respiratory membrane (alveolar capillary Membrane)
                        Fills chest
                        Rest of diaphragm
                        Apex of either lung is ~ 2.5 cm above clavicle
                        Liver pushes right lung up slightly
                        Right Lung is shorter and broader & has a greater volume than the left side
                        Left lung is longer and has less volume avaible
                        Changes color over lifetime
                                    Changes depend on environment and lifestyle
                                    Red for fetus
                                    Pink for kids
                                    Grey ~ black for adults
                        Has a hylus for nerves and vessels to enter
                       
                        Visceral Pleura
                        Parietal Pluera
                        Plueral Caivty
                                    To keep lungs from rubbing on ribs

                        Both lungs have oblique fissures that divide superior and inferior lobes
                                    Right lobe has added transvers fissure for 3 lobe
                                    Inferior lobes are largest
                                    Lobes are highly elastic
                       
                        Arteries appear blue
                        Veins appear red
                        Lymph still green
                       
            Prime bronchii divide into bronchioles
                        (terminal) Bronchioles are barely a mm in diameter
                                    No cartilage
                        Alveolar duct
                        Alveolus


Type 1 alveolar
            Macrophages & monocytes
            To filter air and get rid of any bacteria that made it that far
Type 2 septal
            Produces phospholipid called surfactin
                        Surfactin keeps the walls of alveoli from sticking together
           
           

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