3-THE RESPIRATORY SYSTEM.pdf

THE RESPIRATORY SYSTEM CHIRADEE MAY P. MARQUEZ, RN, MAN FUNCTIONS Oversees gas exchanges between the blood and external environment. Exchange of gasses takes place within the lungs in the alveoli. Passageway of air to the lungs by purifying, warming, humidifying the incoming air...

THE RESPIRATORY SYSTEM CHIRADEE MAY P. MARQUEZ, RN, MAN FUNCTIONS Oversees gas exchanges between the blood and external environment. Exchange of gasses takes place within the lungs in the alveoli. Passageway of air to the lungs by purifying, warming, humidifying the incoming air. FUNCTIONAL ANATOMY OF THE RESPIRATORY SYSTEM ORGANS OF THE RESPIRATORY SYSTEM INCLUDE: NOSE PHARYNX LARYNX TRACHEA BRONCHI (and their smaller branches) LUNGS (which contains the alveoli or terminal sacs) DIAPHRAGM Gas exchanges happen only in the alveoli - thus other respiratory system structures are just passageways that allow air to reach the lungs. THE NOSE NOSE -is the only externally visible part of the respiratory system. -air enters the nose by passing through the nostrils or nares. -the interior of the nose consists of the nasal cavity divided by a midline nasal septum. -the olfactory receptors for the sense of smell are located in the mucosa in the slitlike superior part of the nasal cavity, just beneath the ethmoid bone. THE NOSE NOSE -the rest of the mucosa lining the nasal cavity, which is the respiratory mucosa, rests on a rich network of thin-walled veins that warms the air as it flows past. -the sticky mucus produced by the mucosa's glands moistens the air and traps incoming bacteria and other foreign debris and lyzosome enzymes in the mucus destroy bacteria chemically. -the lateral walls of the nasal cavity are uneven owing to three mucosa- covered projections or lobes called conchae. THE NOSE NOSE CONCHAE -increases the surface area of the mucosa exposed to the air. -increases the air turbulence in the nasal cavity. NASAL CAVITY -is separated from the oral cavity below by a partition, called the palate. -hard palate - anteriorly, supported by a bone -soft palate - posteriorly, unsupported  HOMEOSTATIC IMBALANCE CLEFT PALATE -a genetic defect. -failure of the bones forming the palate to fuse medially. -results in breathing difficulty as well as problems with oral cavity functions such as chewing and speaking. THE NOSE NASAL CAVITY -is surrounded by a ring of paranasal sinuses located in the frontal, sphenoidal, ethmoid, and maxillary bones. -sinuses lightens the skull and act as resonance chambers for speech. -they also produce mucus which drains into the nasal cavities. -the suctioning effect created by nose blowing helps to drain the sinuses. -the nasolacrimal ducts, which drains tears from the eyes, also empty in the nasal cavities. THE NOSE PARANASAL SINUSES  HOMEOSTATIC IMBALANCE RHINITIS -inflammation of the nasal mucosa. -caused by cold viruses and various allergens. -excessive mucus produced results in nasal congestion and postnasal drip.  HOMEOSTATIC IMBALANCE SINUSITIS -inflammation of the sinus. -difficult to treat and can cause changes in voice quality. -when passageways connecting the sinuses to the nasal cavity are blocked with mucus or infectious matters, the air in the sinus cavities is absorbed. The result is a partial vacuum and a sinus headache over the inflamed area. HOMEOSTATIC IMBALANCE THE PHARYNX PHARYNX -is a muscular passageway about 13 cm (5 inches) long that vaguely resembles a shorth length of red garden hose. -commonly called as the throat. It serves as a passageway for food and air. THE PHARYNX PHARYNX -air enters the superior portion, the nasopharynx, from the nasal cavity and then descends through the oropharynx and laryngopharynx to enter the larynx below. -food enters the mouth and then travels along with air through the oropharynx and laryngopharynx. But instead of entering the pharynx, food is directed into the esophagus posteriorly. THE PHARYNX PHARYNX -clusters of lymphatic tissue called tonsils are also found in the pharynx. -the pharyngeal tonsil often called adenoid, is located high in the nasopharynx. -the palatine tonsils are in the oropharynx at the end of the soft palate, as are the lingual tonsils, which lie at the base of the tongue. THE PHARYNX TONSILS  HOMEOSTATIC IMBALANCE TONSILITIS -inflammation of the tonsils. -if the pharyngeal tonsils becomes inflamed and swollen, it obstructs the nasopharynx and forces the person to breath through the mouth. -in mouth breathing, air is not properly moistened, warmed, or filtired before reaching the lungs. THE LARYNX LARYNX -or the voice box routes air and food into the proper channels and plays a role in speech. Located inferior to the pharynx. -formed by eight rigid hyaline cartilages and a spoon-shaped flap of elastic cartilage called epiglottis. -the largest of the hyaline cartilages is the shield-shaped thyroid cartilage, which protrudes anteriorly and is commonly called as the Adam's apple. THE LARYNX LARYNX THE TRACHEA TRACHEA -or the windpipe. Air entering the trachea from the larynx travels down the its length (10-12 cm or about 4 in) to the level of the fifth thoracic vertebra, which is approximately mid chest. -it is fairly rigid because its walls are reinforced with C-shaped rings of hyaline cartilage. THE TRACHEA TRACHEA 2 purposes of the rings: -open parts of the rings abut the esophagus and allows it to expand when we swallow a large piece of food. -the solid portions supports the trachea walls and keep it patent in spite of the pressure changes that occur during breathing. -the trachealis muscle abuts the esophagus and completes the wall of the trachea posteriorly. THE TRACHEA TRACHEA  HOMEOSTATIC IMBALANCE CHOKING/ SUFFOCATION -because the trachea is the only way air can enter the lungs, tracheal obstruction is life- threatening. -many people have suffocated after chocking on a piece of food that suddenly closed-off the trachea.  HOMEOSTATIC IMBALANCE HEIMLICH MANEUVER -a procedure in which the air in a person's own lungs is used to "pop- out", or expel an obstructing piece of food, has saved many lives.  HOMEOSTATIC IMBALANCE HEIMLICH MANEUVER  HOMEOSTATIC IMBALANCE TRACHEOSTOMY -surgical opening of the trachea to provide an alternative route for air to reach the lungs. THE TRACHEA TRACHEA -the trachea is lined with ciliated mucosa. The cilia beat continuously and in a direction opposite to the of incoming air. -they propel mucus, loaded with dust particles and other debris, away from the throat and lungs, where it can be swallowed or spat out. STRUCTURAL RELATIONSHIP OF TRACHEA AND ESOPHAGUS THE MAIN BRONCHI MAIN BRONCHI -the right and left main (primary) bronchi are formed by the division of the trachea. -each main bronchus runs obliquely before it plunges into medial depression (hilum). -the right main bronchus is wider, shorter and straighter than the left. THE MAIN BRONCHI THE LUNGS LUNGS -the lungs are fairly large organs. They occupy the entire thoracic cavity except for the most central area, the mediastinum, which houses the heart, the great blood vessels, bronchi, esophagus, and other organs. -the apex, is the narrow superior portion of each lung is just deep to the clavicle. -the broad lung area resting on the diaphragm is the base. -Each lung is divided into lobes by fissures: the left lung has 2 lobes, the right lung has 3 lobes. THE LUNGS LUNGS THE LUNGS LUNGS -the surface of each lung is covered with a visceral serosa called the pulmonary or visceral pleura and the walls of the thoracic cavity are lined up by the parietal pleura. -the pleural membranes produce pleural fluid. -the lungs are mostly air spaces. -the lungs relatively weigh only about 2 1/2 pounds, and they are soft and spongy. THE LUNGS BRONCHIOLES -after air enters the lungs, the main bronchi subdivide into smaller and smaller branches (secondary and tertiary bronchi, and so on), finally ending in the smallest of the conducting passageways called the bronchioles. -because of this branching and re-branching of the respiratory passageways within the lungs, the network formed is referred to as the bronchial or respiratory tree. THE LUNGS BRONCHIOLES THE LUNGS ALVEOLI -the terminal bronchioles lead into respiratory zone structures, even smaller conduits that eventually terminate in alveoli. -the respiratory zone which includes the respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli is the only site for gas exchange. THE LUNGS THE RESPIRATORY MEMBRANE -the walls of the alveoli are composed largely of a single, thin layer of squamous epithelial cells. -Alveolar pores connect neighboring air sacs and provide alternative routes for air to reach alveoli whose feeder bronchioles have been clogged by mucus or otherwise blocked. -the external surfaces of the alveoli are covered with "cobweb" of pulmonary capillaries. -together, the alveolar and capillary walls, their fused basement membranes, and occasional elastic fibers construct the respiratory membrane (air-blood barriers). THE RESPIRATORY MEMBRANE THE RESPIRATORY MEMBRANE -the gas exchange occur by simple diffusion through the respiratory membrane. Oxygen passing from the alveolar air into the capillary blood and carbon dioxide leaving the blood to enter the gas-filled alveoli. -the final line of defense for the respiratory system is in the alveoli. Alveolar macrophages or called "dust cells", wander in and out of the alveoli picking up bacteria, carbon particles, and other debris. -also scattered epithelial cells that form most pf the alveolar walls are chunky cuboidal cells that look very different from the squamous epithelial cells - these cells produce a lipid (fat) molecule called surfactant - which coats the gas exposed alveolar surfaces and is very important in lung function. THE RESPIRATORY PHYSIOLOGY THE RESPIRATORY PHYSIOLOGY The major function of the respiratory system is to supply the body with oxygen and to disposed of carbon dioxide. -to do this, at least four distinct events, called respiration, must occur: 1. Pulmonary ventilation - the air must move into and out of the lungs so that the gases in the air sacs (alveoli) of the lungs are continuously refreshed. This process of ventilation is commonly called breathing. 2. External respiration - gas exchange between the pulmonary blood and alveoli must take place. In external respiration, gas exchanges are being made between the blood and the body exterior. THE RESPIRATORY PHYSIOLOGY 3. Respiratory gas transport - oxygen and carbon dioxide must be transported to and from the lungs and tissue cells of the body via the bloodstream. 4. Internal respiration - at systemic capillaries, gas exchange must be made between the blood and tissue cells. In internal respiration, gas exchanges are occurring between the blood and cells inside the body. -the actual use of oxygen and production of carbon dioxide by tissue cells, that is cellular respiration, is the cornerstone of all energy- producing chemical reactions in the body. MECHANICS OF BREATHING Breathing, or pulmonary ventilation, is a completely mechanical process that depends on volume changes occurring in the thoracic cavity. RULE: Volume changes leads to pressure changes, which lead to the flow of gases to equalize the pressure. INSPIRATION - when air is flowing into the lungs EXPIRATION - when air is leaving the lungs MECHANICS OF BREATHING MECHANICS OF BREATHING MECHANICS OF BREATHING https://www.youtube.com/watch?v=NM3PK5qy9uA RESPIRATORY SOUNDS As air flows into and out of the respiratory tree, it produces two recognizable sounds that can be picked with a stethoscope. BRONCHIAL SOUNDS - are produced by air rushing through the large respiratory passageways (trachea and bronchi). VESICULAR BREATHING SOUNDS - occur as air fills the alveoli. The vesicular sounds are soft murmurs that resemble a muffled breeze.  HOMEOSTATIC IMBALANCE CRACKLE -a bubbling sound WHEEZING -a whistling sound RALES -are abnormal bronchial sounds produced by the presence of mucus or exudate in the lung passages or by thickening of the bronchial walls. RESPIRATORY SOUNDS https://www.youtube.com/watch?v=2NvBk61ngDY GAS TRANSPORT IN THE BLOOD GAS TRANSPORT IN THE BLOOD https://www.youtube.com/watch?v=pFQVq6ArdSw  HOMEOSTATIC IMBALANCE HYPOXIA -an inadequate oxygen delivery to the blood that causes cyanosis (bluish discoloration of the skin or mucosae). CONTROL OF RESPIRATION NEURAL REGULATION: SETTING THE BASIC RHYTHM -the activity of the respiratory muscles, the diaphragm and external intercostals, is regulated by nerve impulses transmitted to them from the brain by the phrenic and intercostal nerves. -the neural centers that control respiratory rhythm and depth are located mainly in the medulla and pons. -the medulla which sets the basic rhythm of breathing contains a pacemaker or self-exciting inspiratory center, called the ventral respiratory group or VRG. CONTROL OF RESPIRATION NEURAL REGULATION: SETTING THE BASIC RHYTHM -impulses going back and forth between the medulla centers maintain a rate of 12-15 respirations/ minute. -this normal respiratory rate is called eupnea. -Pons centers appear to smooth out the basic rhythm of inspiration and expiration set by the medulla. -during exercise, we breathe more vigorously and deeply because the brain centers send more impulses to the respiratory muscles. The respiratory pattern is called hyperpnea. CONTROL OF RESPIRATION NON-NEURAL FACTORS INFLUENCING RESPIRATORY RATE AND DEPTH PHYSICAL FACTORS -talking, coughing and exercising can modify both the rate and depth of breathing. VOLITION (CONSCIOUS CONTROL) -during singing or swallowing and swimming, breath control is extremely important. CONTROL OF RESPIRATION NON-NEURAL FACTORS INFLUENCING RESPIRATORY RATE AND DEPTH EMOTIONAL FACTORS -watching horror movies, touched something cold or hot and gasped. All of these result from reflexes initiated by emotional stimuli acting through centers in the hypothalamus. CHEMICAL FACTORS -increased levels of carbon dioxide and decreased blood pH level are the most important stimuli leading to an increase in the rate and depth of breathing. CONTROL OF RESPIRATION HYPERVENTILATION -carbon monoxide or other sources of acids begin to accumulate in blood and blood pH level starts to drop - resulting to breathing more deeply and rapidly. -Hyperventilation blows off more carbon dioxide and decreases the amount of carbonic acid, which returns blood pH to the normal range.  HOMEOSTATIC IMBALANCE APNEA -cessation of breathing. Often brought on by anxiety attacks. -if breathing stops for an extended time, cyanosis may occur as a result of insufficient oxygen in the blood. THE RESPIRATORY DISORDERS COPD CHRONIC OBSTRUCTIVE PULMONARY DISORDER -exemplified by chronic bronchitis and emphysema, are a major cause of death and disability in the US. -certain features that are common: patients have a history of smoking dyspnea or labored breathing, "air hunger" coughing and frequent pulmonary infections COPD patients are hypoxic, retain carbon dioxide and have respiratory acidosis, and ultimately develop respiratory failure COPD CHRONIC BRONCHITIS -the mucosa of the lower respiratory passages becomes severely inflamed and produces excessive amount of mucus. -the excessive mucus impairs ventilation and gas exchange and dramatically increases the risk of lung infections, including pneumonia. -often referred to as "blue bloaters" because hypoxia and carbon dioxide retention occur early in the disease and cyanosis is common. COPD EMPHYSEMA -in emphysema, the alveoli enlarge as the walls of adjacent chambers break through, and chronic inflammation promotes fibrosis (scarring) of the lungs. -consequently, emphysema sufferers are sometimes referred to as "pink puffers". -overinflation of the lungs leads to a permanently expanded barrel chest. LUNG CANCER -is the leading cause of cancer death for both men and women in North America causing more deaths than breast, prostate, and colorectal cancer combined. -nearly 90% of lung cancers are the result of smoking. -the cure rate of lung cancer is low, most victims die within 1 year of diagnosis. The overall 5-year survival of those with lung cancer is about 17%. -because lung cancer is aggressive and metastasizes rapidly and widely, most cases are not diagnosed until they are well advanced. LUNG CANCER LUNG CANCER 3 most common types of lung cancer: SQUAMOUS CELL CARCINOMA - 25-30% of cases, which arises in the epithelium of the larger bronchi and tends to form masses that hollow out and bleed. ADENOCARCINOMA - 40%, which originates as solitary nodules that develop from bronchial glands and alveolar cells. SMALL CELL CARCINOMA - 20%, which contains lymphocyte-like cells that originate in the main bronchi and grow aggressively in small grapelike clusters within the mediastinum, a site from which metastasis is especially rapid. LUNG CANCER LUNG CANCER LUNG CANCER LUNG CANCER -the most effective treatment for lung cancer is the complete removal of the diseased lung lobes in an attempt to halt metastasis. -in most cases, radiation therapy and chemotherapy are the only options, but most lung cancers are resistant to these treatments. -remember that prevention is worth a pound of cure. DEVELOPMENTAL ASPECTS Developmental Aspects of the Respiratory System -in the fetus, the lungs are filled with fluid, and all respiratory exchanges are made by the placenta. -at birth, the fluid-filled pathway is drained, and the respiratory passageways fill with air. The alveoli inflate and begin to function in gas exchange, but the lungs are not fully inflated for 2 weeks. -the success of this change - that is, from nonfunctional to functional respiration depends on the presence of surfactant - a fatty molecule made by the cuboidal alveolar cells. DEVELOPMENTAL ASPECTS SURFACTANT -surfactant lowers the surface tension of the film of water lining the alveolar sac so that the alveoli do not collapse between each breath. -surfactant is not usually present in large enough amounts to accomplish this function until late in pregnancy - 28-30 weeks.  HOMEOSTATIC IMBALANCE INFANT RESPIRATORY DISTRESS SYNDROME (IRDS) -infants who are born prematurely (before week 28) or in whom surfactant production is inadequate for other reasons usually have IRDS. -these infants have dyspnea within a few hours after birth and use tremendous amount of energy just to keep reinflating their alveoli, which collapse after each breath.  HOMEOSTATIC IMBALANCE CYSTIC FIBROSIS IN INFANT -Cystic fibrosis (also called CF) is a condition that causes thick mucus to build up in the body. This causes problems with breathing and digestion. -CF is passed from parents to children through genes. A baby has to inherit a CF gene from both parents to have CF. All babies have a newborn screening test for CF so it can be found and treated early. -Treatment can include medicines and chest therapy to help with your baby’s breathing and digestion. HOMEOSTATIC IMBALANCE  HOMEOSTATIC IMBALANCE SUDDEN INFANT DEATH SYNDROME (SIDS) -also called crib death, claims many newborn infants. -apparently, healthy infants stop breathing and die in their sleep. -believed to be a problem of the neural control of respiration, most cases occur in infants placed in a prone position to sleep.  HOMEOSTATIC IMBALANCE ASTHMA -Asthma causes wheezing, breathlessness, chest tightness, and coughing at night or early in the morning. -Being exposed to things in the environment, like mold or dampness, some allergens such as dust mites, and secondhand tobacco smoke have been linked to developing asthma. Air pollution and viral lung infection may also lead to asthma. HOMEOSTATIC RELATIONSHIPS BETWEEN THE RESPIRATORY SYSTEM AND OTHER BODY SYSTEMS NERVOUS SYSTEM Respiratory system provides oxygen needed for normal neural activity; disposes of carbon dioxide. Medullary and pons centers regulate respiratory rate/ depth; stretch receptors in lungs and chemoreceptors in large arteries provide feedback CARDIOVASCULAR SYSTEM Respiratory system provides oxygen; disposes carbon dioxide; tonsils in pharynx house immune cells. Maintain blood volume required for respiratory gas transport. Immune system protects respiratory organs from pathogens and cancer. REPRODUCTIVE SYSTEM Respiratory system provides oxygen; disposes of carbon dioxide. INTEGUMENTARY SYSTEM Respiratory system provides oxygen; disposes carbon dioxide. Skin protects respiratory system organs by forming surface barriers. SKELETAL SYSTEM Respiratory system provides oxygen; disposes carbon dioxide. Bones enclose and protect lungs and bronchi.  ENDOCRINE SYSTEM Respiratory system provides oxygen; dispose of carbon dioxide Epinephrine dilates the bronchioles; testosterone promotes laryngeal enlargement in pubertal males LYMPHATIC SYSTEM/ IMMUNITY Respiratory system provides oxygen; disposes carbon dioxide; tonsils in pharynx house immune cells. Maintain blood volume required for respiratory gas transport. Immune system protects respiratory organs from pathogens and cancer  DIGESTIVE SYSTEM Respiratory system provides oxygen; disposes carbon dioxide; tonsils in pharynx house immune cells. Digestive system provides nutrients needed by respiratory system. URINARY SYSTEM Respiratory system provides oxygen; disposes carbon dioxide. Kidneys dispose of metabolic wastes of respiratory system organs (other than carbon dioxide).  MUSCULAR SYSTEM Respiratory system provides oxygen; disposes carbon dioxide. The diaphragm and intercostal muscles produce volume changes necessary for breathing; regular exercise increases respiratory efficiency.  END OF LESSON 3