RESPIRATORY SYSTEMFUNCTIONS: Bring oxygen-rich air into the body for delivery to the blood cells. Expel waste products (CO2 & H2O) that have been returned to the lungs by the blood. Produce the air flow through the larynx that makes speech possible.
STRUCTURES OF THE RESPIRATORY SYSTEMUPPER RESPIRATORY TRACT: Nose Mouth Pharynx LarynxLOWER RESPIRATORY TRACT: Trachea
NOSE NOSE AND NASAL CAVITIES Mucous membrane is the specialized form of epithelial tissue that lines the nose and respiratory system. Mucus, which is secreted by the mucous membranes, helps to moisten, warm, and filter the air as it enters the nose. Cilia, the thin hairs located just inside the nostrils, filter incoming air to remove debris.
SINUSESSINUSIt is an air-filled cavitywithin a bone that is linedwith mucous membrane.(Paranasal sinus)Functions:To make the bones of theskull lighter.To help produce sound bygiving resonance to thevoice.To produce mucus thatdrains into the nasal cavity.
PHARYNX (THROAT)Three Divisions:Nasopharynx – posterior to the nasal cavity andcontinues downward to behind the mouth.Oropharynx – portion that is visible when looking intothe mouth; shared by respiratory and digestivesystems.Laryngopharynx –continues downward tothe openings of theesophagus and trachea.
LARYNX / VOICE BOX / GLOTTISTriangular chamber located between the pharynx andtrachea.Thyroid cartilage is the largest and its prominentprojection is commonly known as Adam’s Apple.It contains the vocal cords.During sound production, the vocal cords close togetherand vibrate as air expelled from the lungs.Epiglottis acts like a trapdoor to keep food and otherparticles from entering the larynx.
TRACHEA / WINDPIPE It is the main airway to the lungs. It extends from the neck into the chest directly in front of the esophagus and is held open by a series of C-shaped cartilage rings. It divides into the right and left bronchi at the level of the T5, channeling air to the right or left lung.
BRONCHI AND BRONCHIAL TREE At T5, trachea divides into Right and Left Primary Bronchi and goes to each lung. The Bronchus divides and subdivides into increasingly smaller bronchi. Bronchioles are the smallest branches of the bronchi. Because of the similarity of these branching structures to a tree, this is referred to as the Bronchial Tree.
ALVEOLI / AIR SACSAlveoli are very smallgrapelike clusters found at theend of each bronchiole.The thin flexible walls of thealveoli are surrounded by anetwork of microscopicpulmonary capillaries.During respiration, the gasexchange between the alveolarair and the pulmonary capillaryblood occurs through the wallsof the alveoli.Alveolar ducts and alveolipermit rapid diffusion of oxygenand carbon dioxide
LUNGSLungs are soft and spongybecause they are mostly airspaces surrounded by the alveolarcells and elastic connective tissue.A LOBE is a division of the lungs:Right Lung – shorter, broader andhas a greater volume than the leftlung: Superior lobe Middle lobe Inferior lobeLeft lung – longer and narrower. Ithas an indentation called theCardiac Notch, on its medialsurface for the apex of the heart: Superior lobe Inferior lobe
MEDIASTINUM AND PLEURAMEDIASTINUM a.k.aINTERPLEURAL SPACELocated between the lungs.This space contains the thoracicviscera including the heart, aorta,esophagus, trachea, bronchialtubes, and thymus gland.PLEURAMultilayered membrane thatsurrounds each lung with its bloodvessels and nerves..
DIAPHRAGMMuscle that separates thethoracic cavity from theabdomen.It is the contraction andrelaxation of this musclethat makes breathingpossible.Phrenic Nerve stimulatesthe diaphragm and causesit to contract.
EMPHYSEMAProgressive loss of lung functiondue to a decrease in the totalnumber of alveoli, enlargement ofthe remaining alveoli, and thenprogressive destruction of theirwalls.CHRONIC BRONCHITISOngoing inflammation of thebreathing tubes. It is almostalways the result of long termsmoking (Smoker’s Cough).The official definition of chronicbronchitis requires coughing upphlegm most days for at least 3months of the year for at least 2years in a row.
ACUTE RESPIRATORY DISTRESSSYNDROME (ARDS)Type of lung failure resulting from manydifferent disorders that cause pulmonaryedema. Causes include severe infection, shock,pneumonia, burns,and injuries.PULMONARY EDEMAAccumulation of fluid inlung tissues.PNEUMORRHAGIABleeding from the lungs.ATELECTASIS(Collapsed Lung)Lungs fail to expand becauseair cannot pass beyondthe bronchioles that areblocked by secretions.
TUBERCULOSIS (TB)Infectious disease caused byMycobacterium tuberculosis.PNEUMONIAInflammation of the lungs inwhich the air sacs fill with pusand other liquid.Main causes of pneumonia arebacteria, viruses, fungi orinhaled substances such aschemical irritants.Lobar – affects one or morelobes of a lungBronchopneumonia – affectsbronchioles
PULMONARY FIBROSISFormation of scar tissue thatreplaces the pulmonary alveolarwalls. This destruction of lungtissue results in decreased lungcapacity and increased difficulty inbreathing.CYSTIC FIBROSISGenetic disorder in which thelungs are clogged with largequantities of abnormally thickmucus. In CF, the digestivesystem is also impaired by thickgluelike mucus that interferes withdigestive juices.