Respiratory System By: Mrs. Bailey Functions Air distributor and gas exchanger so that oxygen may be supplied to and carbon dioxide removed from the body s cells Filters, warms, and humidifies the air we breathe Influences sound production (speech) Makes the sense of smell possible Plays a role in regulation of ph in the body Structural Plan Upper Respiratory Tract ose, nasopharynx, oropharynx, laryngopharynx, and larynx Lower Respiratory Tract Trachea, bronchial tree, and lungs Upper Respiratory Tract ose Functions Passageway for air traveling to and from the lungs Filters air Aids speech Makes possible the sense of smell 1
ose ose Frontal sinus Sphenoid sinus asal Septum osebleeds Superior turbinate Middle turbinate Inferior turbinate The asal Cavity Maxilla Palatine bone page 686 Hard palate Soft palate Opening of auditory tube page 686 ose The movement of air through the nose to the pharynx: - Anterior nares - Vestibule - Inferior, middle, and superior meati - Posterior nares ose Paranasal Sinuses Air-containing spaces that open, or drain, into the nasal cavity and take their names from the skull bones in which they are located After passing over the vestibule, the air passes over the respiratory mucosa, a pseudostratified ciliated columnar epithelium rich in goblet cells! This later changes into yellowish mucosa and is referred to as the olfactory epithelium which helps with sense of smell. page 688 2
Common pathway for the respiratory and digestive tracts! Affects speech production Pharynx a.k.a. Throat Composed of muscle lined with mucous membrane asopharynx > located behind the nose > pharyngeal tonsils Oropharynx > behind the mouth > palatine tonsils & lingual tonsils Laryngopharynx > from the hyoid bone to the esophagus The Larynx Location Between the root of the tongue and the upper end of the trachea Function Functions in respiration Helps in the removal of dust particles and in the warming and humidification of inspired air Protects against entering of solids and liquids (epiglottis) Serves as the organ of voice production page 691 Structure Largely composed of cartilages attached together by muscles or fibrous & elastic tissue components. Lined with ciliated mucous membrane which divides the larynx into 3 parts: 1 - Vestibular fold (a.k.a. false vocal cords) 2 - True vocal cords 3 Rima glottidis Glottis = true vocal cords + rima glottidis 3
Cartilages of the Larynx 9 cartilages make up the larynx; but 3 are most important! 1) Thyroid cartilage - a.k.a. Adam s apple - puberty 2) Epiglottis - projects upward behind the tongue; moves up and down during swallowing to prevent food & liquid from entering the trachea 3) Arytenoid - most important, serve as points of attachment for the vocal cords 4
page 699 The Lungs Bronchial Tree Distributes air to the lung s interior Accomplishes gas exchange between the air and blood Cleanses, warms, humidifies inspired air page 695 2 primary bronchi divide from the trachea Incomplete cartilaginous rings which become complete when entering the lungs Ciliated mucosa Bronchial Tree Each primary bronchi branch into smaller, secondary bronchi and again into smaller bronchioles Bronchioles subdivide into alveolar ducts, which end in clusters of alveoli called alveolar sacs. Alveoli page 695 5
Structure/Function of the Alveoli Very effective in exchange of CO 2 and O 2 because each has extremely thin walls and is in contact with blood capillaries Thorax Structure Has 3 divisions each separated by pleura Parts of the cavity taken up by the lungs are the pleural divisions. Function Plays a large role in respiration The changes in thorax size bring about inspiration & expiration The barrier in which gases are exchanged between alveolar air and the blood is respiratory membrane page 696 page 699 Physiology of the Respiratory System Pulmonary Ventilation - technical term for breathing Mechanisms of Pulmonary Ventilation Pressure gradients allow for respiration. These gradients are established by changes in the size of the thoracic cavity Inspiration As the diaphragm contracts, it descends, which makes the thoracic cavity longer. page 712 6
Expiration The inspiratory muscles relax, causing a decrease in the size of the thorax and an increase in intrapleural pressure Boyle s Law explains pressure changes in the lungs: The volume of gas varies inversely with pressure at a constant temperature P 1 V 1 = P 2 V 2 page 711 Compliance, ability of the lungs & thorax to stretch, is essential to respiration page 712 Fick s Law of Diffusion Fick s Law of Diffusion states that the rate of diffusion across a membrane depends on surface area, concentration (partial pressure) difference, and distance. R = D x A ( p/d) R = rate of diffusion D = diffusion constant A = area over which the diffusion takes place p = difference in partial pressures d = distance across which diffusion takes place Alveoli provide each lung with an enormous surface area for gas exchange (A). Because alveolar air and capillary blood are separated by only 2 cell layers (d), diffusion is rapid. 7
How Blood Transports Gases Hemoglobin Upon entering blood, O 2 & CO 2 dissolve in the plasma. Since fluids can only hold so much gas, most of the O 2 & CO 2 forms a chemical union with some other molecule. Once gas molecules bind to another molecule, their plasma concentration decreases allowing more gas to diffuse into the plasma page 722 Red blood cells act as O 2 sponges Transport of Carbon Dioxide Bicarbonate Transport of Carbon Dioxide Dissolved Carbon Dioxide 2/3 + of the CO 2 carried by the blood is carried in the form of bicarbonate ions CO 2 molecules are constantly diffusing into the plasma and will continually be removed from the solution and converted into bicarbonate This allows room for even more CO 2 - carrying capacity of the blood Carbonic acid A small amount of CO 2 dissolves in plasma and is transported as a solute. Carbamino Compounds When carbon dioxide binds to H 2 (amine) groups, it forms carbamino compounds which are formed and transported in red blood cells. Carbaminohemoglobin is formed when carbon dioxide combines with hemoglobin. 8
Transport of Carbon Dioxide Carbon Dioxide and ph Increasing the carbon dioxide content of the blood also increases the H + concentration. page 724 Therefore, an increase of carbon dioxide in the blood causes an increase in the acidity, or drop of ph, in the blood Regulation of Breathing Homeostasis of blood gases is controlled primarily by changes in ventilation the rate and depth of breathing. Respiratory centers located in the brainstem main integrators that control the nerves which affect the inspiratory & expiratory muscles. egative Feedback! page 730 Major Factors that Influence Breathing page 728 9
Reflexes that Indirectly affect Breathing Reflexes that Indirectly affect Breathing Cough reflex stimulated by foreign matter in the trachea or bronchi. Epiglottis & glottis close and contraction of the expiratory muscles causes air pressure in the lungs to increase. The epiglottis & glottis then suddenly open, which results in an upward burst of air that removes the foreign contaminant! Hiccup an involuntary, spasmodic contraction of the diaphragm. The characteristic sound is produced by the glottis suddenly closing. Sneeze reflex stimulated by foreign matter in the nasal cavity. The burst of air is directed through the nose and mouth, forcing the contaminants and mucus out of the respiratory tract. Droplets from a sneeze can travel >100 mph and travel 12 feet! Yawn slow, deep inspiration through an unusually widened mouth. A current hypothesis suggests that we yawn to prepare our muscles and our circulatory system for action. Scientists, however, still do not know the actual physiological mechanism for yawning. Heimlich Maneuver Diseases of the Respiratory System COPD Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. It makes it difficult to breathe. There are two main forms of COPD: Chronic bronchitis Emphysema page 733 Most people with COPD have a combination of both conditions. 10
Diseases of the Respiratory System Bronchitis is an inflammation of the bronchi. What are the Symptoms? Cough, wheezing, fever, and soreness in the chest. Is Bronchitis contagious? Yes. It can be spread by direct or indirect contact. What causes Bronchitis? Bronchitis may be caused by a virus, bacteria, smoking or the inhalation of chemical pollutants or dust. When the cells of the bronchial-lining tissue are irritated beyond a certain point, the cilia within them, which normally trap and eliminate pollutants, stop functioning. Consequently, the air passages become clogged by debris and irritation increases. In response, a heavy secretion of mucus develops, which causes the characteristic cough of bronchitis. Treatment: Acute bronchitis can be treated with antibiotics, bed rest, drinking plenty of fluids and staying indoors in damp, cold weather. If you smoke, you should cut down on the number of cigarettes you smoke, or stop smoking altogether. Diseases of the Respiratory System Emphysema doesn t develop suddenly. Patient has probably had several very bad colds each winter for the past few years, each accompanied by a heavy cough, and often with chronic bronchitis. The cough usually persists between colds and becomes chronic. What brings the patient to the doctor is that he or she has begun to experience shortness of breath on exertion in morning or evening or both. Causes of Emphysema Often a late effect of chronic infection or irritation of the bronchial tubes. Walls of the alveoli may tear. Capillaries in the walls disappear. If infection or irritation continues or is repeated for a long time and the stretching and destruction of the alveoli goes on, the lungs as a whole may become enlarged and gas exchange is now less efficient. Enlarged lungs is what gives the disease its name, emphysema (which is a Greek word meaning "Inflation"). Diseases of the Respiratory System Asthma - a chronic lung condition, characterized by difficulty breathing. People with asthma have extra sensitive or hyper responsive airways. The airways react by narrowing or obstructing when they become irritated. This makes it difficult for the air to move in and out. This narrowing or obstruction can cause one or a combination of the following symptoms: Wheezing Coughing Shortness of breath Chest tightness This narrowing or obstruction is caused by: Airway inflammation airways in the lungs become red, swollen and narrow Bronchoconstriction muscles that encircle the airways tighten or spasm) Diseases of the Respiratory System Pneumonia an inflammatory lung infection (bacterial or viral) that affects alveoli and can make you very sick. You may cough, run a fever, and have a hard time breathing. When you have mild symptoms, your doctor may call this "walking pneumonia. Diagnostic tools include x-rays and culture of the sputum. 11
Diseases of the Respiratory System Cystic fibrosis an autosomal recessive genetic disease that causes thick, sticky mucus to build up in the lungs, digestive tract, and other areas of the body. The secretions plug up tubes, ducts and passageways, especially in the lungs and pancreas. It is one of the most common chronic lung diseases in children and young adults. It is a lifethreatening disorder. Lung Cancer Bronchial Carcinoma Lung cancer is cancer that starts in the lungs. Most lung cancer begins in the cells that line bronchi. Lung cancer is the deadliest type of cancer for both men and women. Cigarette smoking is the leading cause of lung cancer. Secondhand smoke increases your risk for lung cancer. The following may also increase your risk for lung cancer: Asbestos Exposure to cancer-causing chemicals such as coal products, mustard gas, gasoline, and diesel exhaust Family history of lung cancer High levels of air pollution High levels of arsenic in drinking water Radiation therapy to the lungs Radon gas Many times, lung cancer is found when an x-ray or CT scan is done for another reason... Treatment Options: http://smartimagebase.com/view-item?itemid=70883 12