The Respiratory System

Overview  The main function of the system is to allow gas exchange  The Respiratory system is divided into an upper respiratory tract and a lower respiratory tract  The upper tract consists of the nasal passages, pharynx, and larynx  The lower tract includes: trachea, bronchi ( and their smaller branches), and the lungs.  The main function of the system is to allow gas exchange  The Respiratory system is divided into an upper respiratory tract and a lower respiratory tract  The upper tract consists of the nasal passages, pharynx, and larynx  The lower tract includes: trachea, bronchi ( and their smaller branches), and the lungs.

Upper Tract: The Nose  Only external part of the respiratory system  Air enters, passing through external nares (nostrils) and through the nasal cavity.  The air is warmed  Mucus helps to moisten the air and traps bacteria and other debris  Mucus is then pushed towards the throat (pharynx), where it is swallowed and digested in the stomach  Only external part of the respiratory system  Air enters, passing through external nares (nostrils) and through the nasal cavity.  The air is warmed  Mucus helps to moisten the air and traps bacteria and other debris  Mucus is then pushed towards the throat (pharynx), where it is swallowed and digested in the stomach

Upper Tract: The Nose (cont)  Unwanted Particles are also deflected through the conchae  Conchae swirls the air and deflects the particles into the mucus, preventing unwanted particles from entering the lungs.  The Nasal and Oral cavity is supported by the palate, some of which is supported by bone, (hard palate), and other with little support (soft palate)  Unwanted Particles are also deflected through the conchae  Conchae swirls the air and deflects the particles into the mucus, preventing unwanted particles from entering the lungs.  The Nasal and Oral cavity is supported by the palate, some of which is supported by bone, (hard palate), and other with little support (soft palate)

Upper Tract: Pharynx  Muscular passageway, commonly called the throat  Passage for both food and air  Air enters through nasopharynx, through oropharynx, to enter larynx below  Tonsils, are located high up in the nasopharynx.  Muscular passageway, commonly called the throat  Passage for both food and air  Air enters through nasopharynx, through oropharynx, to enter larynx below  Tonsils, are located high up in the nasopharynx.

Upper Tract: Larynx  The larynx or a.k.a. the voice box  Made up of eight hyaline cartilages, including the thyroid cartilage, commonly known as an Adam’s apple  The epiglottis only lets air enter the larynx, if anything else enters the larynx, the cough reflex is triggered and the debris is directed to the esophagus or out of mouth  The larynx or a.k.a. the voice box  Made up of eight hyaline cartilages, including the thyroid cartilage, commonly known as an Adam’s apple  The epiglottis only lets air enter the larynx, if anything else enters the larynx, the cough reflex is triggered and the debris is directed to the esophagus or out of mouth

Upper Tract: Larynx When there is no swallowing the passage stays open for air  The larynx also includes vocal folds, that vibrate the air when releasing it, helping us to speak.  The Larynx also has cilia to filter air When there is no swallowing the passage stays open for air  The larynx also includes vocal folds, that vibrate the air when releasing it, helping us to speak.  The Larynx also has cilia to filter air

Upper Tract

Lower Tract: Trachea  Wind pipe  Tracheal Tube: largest tube in respiratory system  Lined with ciliated mucosa, which act in the opposite direction of the traveling air  Repel mucus, filters air  Wind pipe  Tracheal Tube: largest tube in respiratory system  Lined with ciliated mucosa, which act in the opposite direction of the traveling air  Repel mucus, filters air

Lower Tract:Bronchi  Tracheal Tube leads to two branches of Bronchi  The right Bronchus is wider and shorter than the left, and is commonly where unwanted debris would enter  Air at this point is mostly warm and filtered  Smaller branches of bronchi (Bronchioles) lead directly to air sacs.  Tracheal Tube leads to two branches of Bronchi  The right Bronchus is wider and shorter than the left, and is commonly where unwanted debris would enter  Air at this point is mostly warm and filtered  Smaller branches of bronchi (Bronchioles) lead directly to air sacs.

Bronchi

Lower Tract:Lungs  Thoracic cavity  Apex: narrow, superior portion of lungs  Base: portion of lung resting on diaphragm  Thoracic cavity  Apex: narrow, superior portion of lungs  Base: portion of lung resting on diaphragm

Lower Tract: Lung  Left lung has two lobes, the right lung has three  Lungs are made up of Stroma, elastic tissue, easy to expand  The outer surface of the lungs is covered by the visceral pluera  The thoracic cavity is covered by parietal pleura  The lung can slide easily because of these surfaces during breathing  They resist being pulled apart from each other  Left lung has two lobes, the right lung has three  Lungs are made up of Stroma, elastic tissue, easy to expand  The outer surface of the lungs is covered by the visceral pluera  The thoracic cavity is covered by parietal pleura  The lung can slide easily because of these surfaces during breathing  They resist being pulled apart from each other

Lower Tract: Lung  Aveoli: air sacs  Bronchioles lead air into respiratory zone in the lungs and into the Aveoli, where there is gas exchange  Bronchi serve as conducting zone structures, leading into and out of the respiratory zone.  Aveolar pores connect to other air sacs, in case some of the Bronchioles become clogged  Aveoli contains “dust cells” or Macrophages that pick up bacteria and clean the air sac  Aveoli: air sacs  Bronchioles lead air into respiratory zone in the lungs and into the Aveoli, where there is gas exchange  Bronchi serve as conducting zone structures, leading into and out of the respiratory zone.  Aveolar pores connect to other air sacs, in case some of the Bronchioles become clogged  Aveoli contains “dust cells” or Macrophages that pick up bacteria and clean the air sac

Respiratory Membrane  Located in the lungs  Alveoli on 1 side, capillary on other  walls1 cell thick  Gas flows on one side, while blood flows on the other  The oxygen diffuses through the membrane to supply the blood and carbon dioxide enters the air sacs and is released from the body  Located in the lungs  Alveoli on 1 side, capillary on other  walls1 cell thick  Gas flows on one side, while blood flows on the other  The oxygen diffuses through the membrane to supply the blood and carbon dioxide enters the air sacs and is released from the body

Physiology  Pulmanary Venilation: gases in air sacs of lungs are continuously changed, commonly known as breathing  External Respiration: Gas exchange between blood and alveoli  Respiratory Gas Transport: Oxygen and carbon dioxide is pumped into and out of lungs by the bloodstream  Internal Respiration: Gas exchange between blood and tissue through capillaries  Pulmanary Venilation: gases in air sacs of lungs are continuously changed, commonly known as breathing  External Respiration: Gas exchange between blood and alveoli  Respiratory Gas Transport: Oxygen and carbon dioxide is pumped into and out of lungs by the bloodstream  Internal Respiration: Gas exchange between blood and tissue through capillaries

Inspiration  Diaphragm and intercostal muscles contract  Thoracic cavity enlarged – lung tissue stuck to sides by pluera - vacuum  Air sucked in  Diaphragm and intercostal muscles contract  Thoracic cavity enlarged – lung tissue stuck to sides by pluera - vacuum  Air sucked in

Expiration  Passive process: due to elasticity of lung tissue

Breathing  Triggered by CO2 level.

Air Volumes  Tidal volume: normal amount of air in and out of lungs  Inspiratory reserve: amount one can force in after normal breath  Expiratory reserve: amount one can force out after normal exhale  Residual volume: stays in lungs (more time for gas exchange)  Tidal volume: normal amount of air in and out of lungs  Inspiratory reserve: amount one can force in after normal breath  Expiratory reserve: amount one can force out after normal exhale  Residual volume: stays in lungs (more time for gas exchange)

Control breathing  Medulla sets basic rate  Pons smooths out the rhythm  Medulla sets basic rate  Pons smooths out the rhythm