Bryce Hennings & Brooke Taylor Function To supply oxygen and remove carbon dioxide from the blood as it circulates through the body. Upper Respiratory Tract • Consists primarily of the nose (nostrils and nasal passages) • Mouth • Nasopharynx • Oropharynx • Laryngopharynx • Larynx • These structures filter, warm, and humidify inspired air. • Detects taste, smell, chewing and swallowing of food. Nostrils and Nasal Passages • Air enters through your nostrils where small hairs and mucus filter out dust and foreign particles. • Air passes into two nasal passageways, separated by what is called the septum. Nose Continued… • Sinuses and nasopharynx: located in the frontal, sphenoid, and maxillary bones • Sinuses provide speech resonance • Nasopharynx located behind nose and above throat. Oropharynx and Laryngopharynx • Oropharynx posterior wall of mouth • It connects nasopharynx and laryngopharynx • Laryngopharynx extends to the esophagus and larynx Larynx • Contains the vocal cords and connects the pharynx with the trachea. Lower Respiratory Tract • Consists of the trachea, bronchi, and lungs. • These structures contain a mucous membrane with hair like cilia which lines the lower tract. • Cilia cleans the tract. Trachea • Extends from the cricoid cartilage • C shaped cartilage rings that protect and prevent it from collapsing Bronchi • The primary bronchi begin at the carina. • Right mainstream delivers air to the right lung, left mainstream to the left. • Secondary bronchi enter the pleural cavities and the lungs at the hilum and located behind the heart. Alveoli • Respiratory bronchioles eventually become alveolar ducts, which terminate in clusters of capillary-swathed alveoli. Types: • Type 1 cells are the most abundant. They are thin, flat, squamous cells that gas exchange occurs. • Type 2 cells secrete surfactant, which is a substance that coats alveolus and promotes gas exchange by lowering surface tension. Lungs • Cone shaped, straddle the heart, anchored by root and pulmonary ligaments. • Right lung is shorter, broader and larger. • 3 lobes (right) & handles 55% of gas exchange • 2 lobes (left) Pleura and Pleural Cavities • Pleura – membrane that totally encloses lung & composed of a visceral layer and parietal layer. • Visceral pleura hugs entire lung surface. Serous Fluid & Functions • Pleural cavity - space between visceral and parietal layers contains a thin film of serous fluid which… • Lubricates pleural surfaces • Creates a bond between the layers that causes the lungs to move the chest wall when breathing. Thoracic Cavity • Area surrounded by diaphragm, the scalene muscles and fascia of the neck and ribs, intercostal muscles, vertebrae, sternum, and ligaments (around the circumference) Mediastinum • This is the space between the lungs which contains the… • Heart and pericardium • Thoracic aorta • Pulmonary artery and veins • Venae cavae and azygos veins • Thymus, lymph nodes and vessels • Trachea, esophagus and thoracic duct • Vagus, cardiac, and phrenic nerves Thoracic Cage • It is composed of bone and cartilage which supports and protects the lungs, allowing them to expand and contract • Posterior & anterior How You Breathe • http://youtu.be/NSEzg6TBheY Inspiration and Expiration • Breathing simply involves inspiration and expiration • Both actions rely on respiratory muscle functions and effects of pressure • Rising of the diaphragm and relaxation of the intercostal muscles causes and increase in intrapleural pressure, resulting in expiration Normal • External intercostal muscles aid the diaphragm • Diaphragm descends to lengthen the chest cavity while intercostal muscles contract • This causes a reduction in intrapleural pressure, resulting in inspiration What Affects Breathing? • Exercise is a major factor of determining breathing because when you exercise your body requires more oxygen Continued… • Forced inspiration: when all of your muscles involved in breathing contract while trying to let in more oxygen for the lungs Continued… • Active Expiration: internal intercostal muscles contract to shorten the chest’s diameter and depressing the ribs Nervous System • Involuntary breathing results from stimulation of the respiratory center in the medulla and the pons of the brain • Monitors amounts of carbon dioxide in the blood (involuntarily) • When carbon dioxide levels rise, the rate and depth of breathing increases to eliminate excess carbon dioxide • Medulla also controls the contraction of the diaphragm which produce intrapulmonary pressure which causes inspiration. • When the workload of your body is increased, efficiency is decreased. Gas Exchange • Occurs rapidly in millions of tiny alveoli. • Inside these air sacs, oxygen inhaled diffuses into the blood while carbon dioxide diffuses from the blood into the air (exhaled). • Then blood circulates throughout the body, delivering oxygen and picking up carbon dioxide. • Finally blood returns to lungs to be oxygenated again. Acid-Base Balance • Oxygen taken up into the lungs is transported to the tissues by circulatory system • Is then exchanged for carbon dioxide produced by metabolism in body cells • Carbon dioxide can dissolve in blood which forms bicarbonate (base) and smaller amounts of carbonic acid (acid). Most Common Forms of Lung Diseases… • Asthma. • Bronchitis. • Chronic obstructive pulmonary disease (COPD) • Emphysema. • Lung cancer. • Pneumonia. • Pulmonary edema. Respiration Changes With Aging • Structural – lungs become more rigid, alveoli number decreases as well as size. • 30% reduction in respiratory fluids which heightens the risk of pulmonary infection and mucus plugs. • Closes airways due to poor ventilation • Lung tissue degeneration Works Cited “Anatomy & Physiology made Incredibly Easy!” Fourth Edition. Google Images (Diagrams). Norris, Maggie and Siegfried Rae Donna. “Anatomy & Physiology for Dummies.” "Organs Involved in the Respiratory System." Organs Involved in the Respiratory System. Web. 29 Apr. 2015. "Respiratory System | MyVMC." MyVMC. 26 June 2006. Web. 29 Apr. 2015. "Respiratory System - Breathing; Inspiration (inhalation) and Expiration (exhalation)." YouTube. YouTube. Web. 29 Apr. 2015. "Structure of the Respiratory System." Structure of the Respiratory System. Web. 29 Apr. 2015. "What Controls Your Breathing?" - NHLBI, NIH. Web. 29 Apr. 2015.