Chapter 22 Study Guide 1 2 3 4 5 Respiratory System Main learning outcomes Know the seven main functions of the respiratory system Provides O2 and CO2 exchange between blood and air Serves for speech and other vocalizations Provides the sense of smell Affects pH of body fluids by eliminating CO2 Affects blood pressure by synthesis of vasoconstrictor angiotensin II Breathing creates pressure gradients between thorax and abdomen that promote the flow of lymph and venous blood Breath holding helps expel abdominal contents during urination defecation and childbirth valsalva maneuver Name the main organs of this system as detailed in the notes Nose Pharynx Larynx Trachea Bronchi Lungs Trace the flow of air from the nose to alveoli Conducting Division 1 Nasal Cavity 2 Pharynx 3 Larynx 4 Trachea 5 Main bronchi R L 6 Lobar secondary bronchi 7 Segmental tertiary bronchi 8 Bronchioles 9 Terminal bronchioles Respiratory division 10 Respiratory bronchioles 11 Alveolar ducts 12 Alveolar sacs Describe the Nasal cavity Nasal cavity Functions of the nose warms cleanses and humidifies inhaled air detects odors in the airstream and serves as a resonating chamber that amplifies the voice The nose extends from nostrils nares to a pair of posterior openings called the posterior nasal apertures choanae Nasal fossae right and left halves of the nasal cavity Nasal septum divides the nasal cavtity Tissues in the Nasal Cavity 3 folds of tissues nasal conchae superior middle and inferior nasal conchae turbinates Meatus narrow air passage beneath each concha The narrowness and turbulence ensures that most air contacts mucous membranes Cleans warms and moistens air Olfactory epithelium detects odors Covers a small area of the roof of the nasal fossa and adjacent parts of the septum and superior concha Ciliated pseudostratified columnar epithelium with goblet cells Immobile cilia to bind odorant molecules that is involved in smelling Respiratory epithelium lines the rest of the nasal cavity except the vestibule Ciliated pseudostratified columnar epithelium with goblet cells Cilia are motile Goblet cells secrete mucus and cilia propel the mucus posteriorly toward the pharynx Swallowed into digestive tract 6 Why does one of my nostrils always seem more open than the other Erectile tissues extensive venous plexus in inferior concha Every 30 to 60 minutes erectile tissue on the side swells with blood Restricts airflow through that fossa Most air directed through other nostril and fossa allowing engorged side time to recover from drying Preponderant flow of air shifts between the right and left nostrils once or twice an hour 7 What is the pharynx and the three regions of it Pharynx throat a muscular funnel extending about 13 cm from the choanae to the larynx Three regions of the pharynx Nasopharynx 1 Only passes air 2 Receives auditory tubes and contains pharyngeal tonsil Oropharynx 1 Passes air food and fluid 2 Contains palatine tonsils Laryngopharynx 1 Passes air food and fluid 2 Esophagus begins where this ends 8 What is the larynx Larynx voice box cartilaginous chamber about 4cm long Primary function to keep food and drink out of the airway Has evolved to additional role now called phonation the production of sound Epiglottis flap of tissue that guards the superior opening of the larynx During swallowing extrinsic muscles of the larynx pulls the larynx upwards and the tongue pushes the epiglottis down to meet it then the airway closes and directs the food to the esophagus behind it Vestibular folds keep food and drink out of the airway 9 What is the trachea Trachea windpipe a rigid tube about 12 cm long and 2 5 cm in diameter Supported by 16 to 20 C shaped rings of hyaline cartilage that reinforce the trachea and keeps it from collapsing when you inhale The trachealis muscle spans opening in rings 1 The gap in the C allows for the esophagus to expand as swallowed food passes by 2 Contracts or relaxes to adjust airflow Inner lining of trachea is a ciliated pseudostratified columnar epithelium which is composed mainly of mucus secreting cells ciliated cells and stem cells 1 Mucociliary escalator mechanism for debris removal a The mucus traps inhaled particles an the upward beating cilia drives mucus toward pharynx where it is swallowed 10 What is a tracheostomy To make a temporary opening in the trachea inferior to the larynx and insert a tube to allow airflow ex throat cancer patients that need to be on a ventilator longer than a week 11 Major divisions of the respiratory system Conducting Division Those passages that serve only for airflow No gas exchange it gets air to the respiratory division Nostrils through bronchioles Respiratory division Consists of alveoli and other gas exchange regions 12 General Divisions of the respiratory divison Upper Respiratory tract in head and neck neck up Nose through larynx Lower respiratory tract organs of the thorax Trachea through the lungs Again as detailed as given in the notes Describe the function of the following muscles of respiration 13 Diaphragm and intercostal muscles Diaphragm Prime mover of respiration contraction flattens diaphragm enlarging the thoracic cavity and pulling air into lungs moves down relaxation allows diaphragm to bulge upward again compressing the lungs and expelling air moves up accounts for 2 3 of airflow Intercostal muscles between ribs and stiffen the thoracic cage during respiration synergist to the diaphragm prevents it from caving inward when diaphragm descends and contributes to the enlargement and contraction of the thoracic cage 1 3 air that ventilates the lungs swing ribs upward like to door handle of a car and then opens it up with the diaphragm 14 Describe the brainstem centers that control breathing and the inputs they receive from other levels of the nervous system Neural control of breathing is the unconscious cycle of breathing that is controlled by three pairs of respiratory centers in the medulla oblongata and pons Inspiratory neurons fire during inspiration Expiratory neurons fire during expiration Innervation o Fibers of the phrenic nerve supple diaphragm o Intercostal nerves supply intercostal muscles Medulla Oblongata 1 Ventral respiratory organs VRG a primary generator of the respiratory rhythm b inspiratory neurons in quiet breathing fire for about 2 seconds signal is sent down phrenic and intercostal nerves inspiration c expiratory neurons in eupnea fire for about 3 seconds allowing inspiratory muscles to relax