Transcript Document
Unit 4 (Chapter 14) The Respiratory System Presented by Dawn Duran, PT, MHS, CSCS Adjunct Professor, Kaplan University The Respiratory System What are the components of the Respiratory System? The Respiratory System Components/Organs of the Respiratory System Upper Respiratory Tract Nose Pharynx Larynx Lower Respiratory Tract Trachea Bronchi Lungs Air Flow The order in which oxygen passes from the environment through the respiratory system is: Nasal Cavities Pharynx Larynx Trachea Lungs The Respiratory System What are the functions of the Respiratory System? Functions of the Respiratory System *These are the two basic functions of the respiratory system Serve as an air distributor* Serves as a gas exchanger for the body* O2 and CO2 diffuse across the respiratory membrane, ie exchange of gases in the respiratory system is a passive process Ensures that oxygen is supplied to and carbon dioxide is removed from the body’s cells The respiratory system also warms, humidifies and filters the air we breathe. Transport of gases, gas exchange in the lungs and tissue, and pulmonary ventilation are all associated with the respiratory system. Gases in the Blood Most CO2 is transported as bicarbonate ions in the blood Chemoreceptors located in the carotid and aortic bodies sense changes to increases in blood CO2 levels and decreases in O2 levels Low levels of CO2 would stimulate ventilation, causing hyperventilation. Most of the O2 transported by the blood is bound to hemoglobin Respiratory Epithelium What are the structure and function of respiratory epithelium? Structure & Function of Respiratory Epithelium The respiratory mucosa is a specialized membrane that lines the air distribution tubes in the respiratory tree Lines most of the air distribution tubes of the respiratory system Cilia on mucosal cells beat in only one direction, moving mucus upward to pharynx for removal Cigarette smoking paralyzes the cilia in the respiratory mucosa causing a buildup of mucus that results in "smoker's cough". The Nose What are the structure and function of the Nose? Structure & Function of the Nose Air enters the respiratory tract through the external nares (aka nostrils) It then flows into the right and left nasal cavities A partition called the nasal septum separates these two cavities The nose is lined with a mucous membrane The nose warms and moistens inhaled air and it contains sense organs of smell There are three shelf-like bony structures that increase the surface area in the nose by protruding into the nasal cavity. They are called conchae. The lacrimal sacs/tear ducts collect tears that eventually drain into the nose Sinuses What are the structure and function of the Sinuses? Structure & Function of the Sinuses Sinus/paranasal sinus refers to a space or cavity located in some solid structure such as a bone They are spaces or cavities located inside the frontal, maxillary, sphenoidal and ethmoid bones These drain into the nasal cavities Sinus pressure: Sinus pressure refers to the pressure and pain that results from the sinus cavities becoming inflamed, infected, blocked and filled with mucus Pharynx What are the structure and function of the Pharynx? Structure & Function of the Pharynx Structure that many of us call the throat Can be divided into 3 portions The most superior part (just behind the nasal cavities) is called the nasopharynx The eustachian tube connects the middle ear with the nasopharynx and permits equalization of pressure between the middle and external ear The portion behind the mouth is called the oropharynx The last or lowest segment is called the laryngopharynx Air and food pass through the pharynx on their way to the lungs and stomach This makes the pharynx part of both the respiratory and digestive systems Larynx What are the structure and function of the Larynx? Structure & Function of the Larynx Commonly called the voicebox Located just below the pharynx Composed of several pieces of cartilage The largest of these is the thyroid cartilage Vocal cords stretch across the interior of the larynx The space between the vocal cords is the glottis The epiglottis partially covers the opening of the larynx Acts like a trapdoor, closing off the larynx during swallowing and preventing food from entering the trachea Trachea & Bronchi What are the structure and function of the Trachea and Bronchi? Structure & Function of the Trachea & Bronchi Trachea is commonly called the windpipe Extends from the larynx in the neck to the bronchi in the chest cavity 15-20 C-shaped rings of cartilage hold the trachea open and keep it from collapsing One of the most important roles is to furnish part of the open passageway through which air can reach the lungs from the outside Bronchi The first branches of the respiratory tree to come off the trachea are called primary bronchi The bronchioles terminate in alveolar ducts that end with the alveolar air sacs and alveoli. Bronchioles and alveoli are different structures. The Respiratory System Lungs What are the structure and function of the Lungs? Structure & Function of the Lungs Upper/superior part of each lung is called the apex The broad lower part of each lung is the base. It rests on the diaphragm The right side has 3 lobes and the left side has 2 lobes Why only 2 on the left? The right lung is larger and has more lobes than the left lung (3 vs 2) because the heart is normally located on the left side, and takes up space where the lung would have been. The function of the lungs is breathing (pulmonary ventilation) Pleura it covers the outer surface of the lungs and lines the inner surface of the rib cage it is a thin moist membrane it is divided into a visceral and parietal pleura inflammation of the pleura is called pleurisy Alveoli Surfactant reduces the surface tension and allows alveoli to inflate with ease after expiration and prevents them from collapsing. Surfactant, therefore, allows the lungs to expand The respiratory membrane separates the air in the alveoli from the blood in surrounding capillaries. The alveolus is the functioning unit of the respiratory system, and it is here that gas exchange occurs. Pulmonary Ventilation Pulmonary Ventilation is commonly called breathing Normal breathing is called eupnea Dyspnea refers to difficulty breathing Absence of breathing is called apnea Respiratory Conditions Pneumothorax Refers to the presence of air in the intrapleural space. It is also called a collapsed lung. A collapsed lung is a buildup of air in the space between the lung and the chest wall. As the amount of air in this space increases, the pressure against the lung causes the lung to collapse. This prevents your lung from expanding properly when you try to breathe in, causing shortness of breath and chest pain. A pneumothorax may become life-threatening if the pressure in your chest prevents the lungs from getting enough oxygen into the blood. A pneumothorax is usually caused by an injury to the chest, such as a broken rib or puncture wound. Respiratory Conditions Pleurisy Pleurisy is inflammation of the thin layers of tissue (pleura) covering the lungs and the chest wall Pleurisy is sometimes called pleuritis. Respiratory Conditions Hemothorax is a collection of blood in the space between the chest wall and the lung (the pleural cavity). The most common cause of hemothorax is chest trauma Treatment: The goal of treatment is to stabilize the patient, stop the bleeding, and remove the blood and air in the pleural space. A chest tube is inserted through the chest wall to drain the blood and air. It is left in place for several days to re-expand the lung. Respiration What are the mechanical aspects of respiration? Mechanical Aspects of Respiration Inspiration Inspiration occurs when there is a decrease in air pressure within the thoracic cavity Normal inspiration is an active process The diaphragm is the major muscle of respiration. It is innervated by the phrenic nerve. Other muscles of inspiration include the internal and external intercostals. With inspiration the diaphragm contracts and flattens Expiration When alveolar pressure becomes greater than atmospheric pressure expiration occurs and air flows out of the alveoli Quiet expiration is a passive process Respiration When the diaphragm relaxes it returns to a domelike shape When the diaphragm contracts it pulls the floor of the thoracic cavity downward Changes in thorax size bring about inspiration and expiration Raising the ribs increases the depth and width of the thorax Internal Respiration How are gases exchanged in the tissues during internal respiration? Gases Exchanged in the Lungs during Internal Respiration Internal respiration is the exchange of gases that occurs between the blood and the cells of the body Hemoglobin is the protein that oxygen combines with for transport through the blood Most of the oxygen in the blood is transported combined with hemoglobin Carbon dioxide is removed and oxygen is moved into the blood Oxygenated blood is found in systemic arteries and pulmonary veins Pulmonary Ventilation What are the volumes of air exchanged during pulmonary ventilation? VC IRV TV ERV RV Volumes of Air Exchanged during Pulmonary Ventilation VC = TV + IRV + ERV A spirometer is a special device used to measure the amount of air exchanged in breathing VC – vital capacity The amount of air maximally exhaled following maximal inhalation Greatest amount of air that one can breathe out in one expiration TV – tidal volume Amount normally breathed in or out with each breath RV – residual volume Amt of air that remains in the lungs after the most forceful expiration IRV – inspiratory reserve volume Accounts for about 1200 mL of air Amt of air that can be forcibly inhaled after a normal inspiration ERV – expiratory reserve volume Amount of air that can be forcibly exhaled after expiring the tidal volume Normal Range of Respiratory Rates 12-18 breaths per minute in an adult Infant (birth–1 year) 30–60 Toddler (1–3 years) 24–40 Preschooler (3–6 years) 22–34 School-age (6–12 years) 18–30 Regulation of Respiration What are the mechanisms that regulate respiration? Mechanisms that Regulate Respiration Respiratory control centers are found in the medulla and pons of the brain Cerebral cortex is responsible for voluntary control of respiratory activity Chemoreceptors respond to changes in carbon dioxide, oxygen and blood acid levels Pulmonary stretch receptors protect respiratory organs from overinflation Upper Respiratory Tract Disorders Rhinitis Pharyngitis Laryngitis is an inflammation of the voice box, or larynx, that causes your voice to become raspy or hoarse Deviated Septum Painful inflammation of the pharynx most often referred to as a sore throat Laryngitis Allergic rhinitis, often called allergies or hay fever, occurs when your immune system overreacts to particles in the air that you breathe-you are allergic to them. Your immune system attacks the particles in your body, causing symptoms such as sneezing and a runny nose. The particles are called allergens, which simply means they can cause an allergic reaction Displacement of the nasal septum, which separates right and left nasal passages, from the midline Epistaxis Fancy word for nosebleed Lower Respiratory Tract Disorders Acute Bronchitis, also called Tracheobronchitis Bronchitis means that the tubes that carry air to the lungs (the bronchial tubes) are inflamed and irritated. When this happens, the tubes swell and produce mucus. This makes you cough. Lower Respiratory Tract Disorders Pneumonia Pneumonia involves the lower respiratory tract Pneumonia is a lung infection that can make you very sick. You may cough, run a fever, and have a hard time breathing. For most people, pneumonia can be treated at home. It often clears up in 2 to 3 weeks. But older adults, babies, and people with other diseases can become very ill. They may need to be in the hospital. Tuberculosis Tuberculosis (TB) is a bacterial infection that is most often found in the lungs TB in the lungs is easily spread to other people through coughing or laughing. Treatment is often successful, though the process is long. Treatment time averages between 6 and 9 months. Obstructive Disorders Obstructive Disorders Chronic Bronchitis Chronic bronchitis keeps coming back and can last a long time, especially in people who smoke. Chronic bronchitis means you have a cough with mucus most days of the month for 3 months of the year for at least 2 years in a row Asthma Asthma is a chronic disease of the airways that makes breathing difficult. With asthma, there is inflammation of the air passages that result in a temporary narrowing of the airways that carry oxygen to the lungs. This results in asthma symptoms, including coughing, wheezing, shortness of breath, and chest tightness Asthma affects 22 million Americans. Asthma in children occurs in approximately 10%-12% of kids. Asthma may occur at any age, although it's more common in younger individuals (under age 40). Obstructive Disorders Emphysema Emphysema is a long-term, progressive disease of the lung that primarily causes shortness of breath. In people with emphysema, the lung tissues necessary to support the physical shape and function of the lung are destroyed Emphysema is called an obstructive lung disease because the destruction of lung tissue around smaller airways, called bronchioles, makes these airways unable to hold their shape properly when you exhale Asthma & Emphysema Lung Cancer Lung Cancer Although lung cancer is the leading cause of cancer death in the U.S. in both men and women, it is also one of the most preventable kinds of cancer. At least four out of five cases are associated with cigarette smoking Most lung tumors are malignant. This means that they invade and destroy the healthy tissues around them. How does the respiratory system interact with other body systems? In other words, what are the functional relationships between the body systems? A system with which the respiratory system interacts on a regular basis is the Circulatory System How do they interact? Can you think of any more? How does the Respiratory System contribute to homeostasis? Along the same lines as the previous question: what systems does this system interact with to accomplish this? How does this interaction occur? Questions??? Ask ME or ask your classmates!!