Respiratory System PDF

Good morning. So for today, we will going to discuss your respiratory system. So when we say respiration, it is a term used to describe 2 different but interrelated processes. So we have cellular respiration and mechanical respiration. So cellular respiration, this one is the series of intracellular...

Good morning. So for today, we will going to discuss your respiratory system. So when we say respiration, it is a term used to describe 2 different but interrelated processes. So we have cellular respiration and mechanical respiration. So cellular respiration, this one is the series of intracellular biochemical processes by which the cell produces energy by metabolism of your organic molecules. Mechanical respiration it involves, different steps like your inhalation. So inhale. So the air is being drawn into our body, going to our lungs from the atmosphere. So before it reaches the furthest part of our lungs, the air is being cleaned by removal of particulate matter. And, also, it is being warm so that its temperature is equals that of the body and is also moistened. So in the, oxygen is being extracted from the air and transferred into the blood vascular system where it pans tightly with your hemoglobin in the red cells for transport in the systemic arterial circulation. So at the same time, that oxygen is passing from air into the blood. Your carbon dioxide is also transferred from the blood to the air. So after your gaseous exchange, the air is returned to the atmosphere by exhalation. So as I recall, in your anatomy, inhalation and exhalation are achieved by expanding and also by contracting the thoracic cavity using your intercostal muscles and as well as your diaphragm. So drawing air in when the thoracic cavity expand and driving air out when it contracts. So we have 2 divisions in your, respiratory system. We have anatomic or structural division and functional division. So under anatomic division, we have your upper and lower respiratory tract. So upper respiratory tract includes your sphenoid sinus, your frontal sinus, your nasal cavity, and as well as your firings. Again, for upper respiratory tract, it includes your sphenoid, your fontal sinus, your nasal cavity, and your pharynx. While your lower respiratory tract includes your larynx, trachea, and bronchi, as well as your lungs. So histologically and functionally, the respiratory system has conducting portion, which consists of all the components that condition air and bring it into our lungs and a respiratory portion where your gas exchange actually occurs. So it consists of your respiratory bronchioles, your alveolar duct, and as well as your alveoli in your lungs. So just to differentiate your conducting zone versus your respiratory zone. So conducting zone, consists of large airways, including your nose, your pharynx, your larynx, and your trachea. Noteworthy to remember here is that airway resistance, airway resistance, is highest in your large to medium size bronchyle. So conducting zone. Conducting zones, warms. Also, it humidifies and filters air. But please remember that conducting zone does not participate in gas exchange. So participate in the gas exchange. Atomic dead space. Okay. So as you can see here, we have your, cartilage and goblet cells that extend to the end of your bronchial. So so the stratified ciliated columnar cell primarily make up epithelium of your bronchus and extend to the beginning of your terminal bronchioles. So then, it will translate into cuboidal cell, clear mucus and debris from the lungs, and your airway muscle cells extend to the end of your terminal bronchioles. So in contrast with your respiratory zone, so it includes your lung parenchyma consisting of respiratory bronchioles, your alveolar ducts, and as well as your alveolar sacs, and your alveoli. So it participates in gas exchange. So, mostly, cuboidal cells in respiratory bronchioles, then simple squamous cells up to your alveoli, and your cilia terminate in your respiratory bronchioles, and your alveolar macrophage, clear your debris, and participate in immune response. For nasal cavities, so please remember that our nose is subdivided into 2 nasal cavities. Septum. Okay. So the nasal cavities and your paranesal sinuses are lined by respiratory mucosa, and the major function of which is to adjust the temperature and for humidity of inspired air. So particulate matter entering the Nares is usually trapped by the hairs at that site, but some smaller particles are caught on the respiratory mucosa. So these functions are enhanced by a large surface area provided by your turbinic bones. So these are your turbinic bones, which project into the nasal cavity. So part of the nasal mucosa, the olfactory mucosa, the olfactory mucosa, which contains receptors for the sense of our smell. And olfactory mucosa is an extensive in the lower mammals, but in man, it is confined to small area in the roof of the nasal cavity. So note the close proximity of your nasal cavities to the orbital cavity. So these are your orbital cavities and the anterior cranial, fossa. So these are your anterior cranial fossa. Please remember that the epithelium on the middle and inferior country is respiratory epithelium, while the roof of your nasal cavities and the superior country is specialized olfactory epithelium. So for respiratory epithelium, we have 5 major, cell types. We have ciliated columnar cells, your goblet cells, your brush cells, your small granule cells, and B cell cells. So please remember that the most abundant is your, ciliated columnar cells. And your goblet cells are composed of b cell nuclei and apical domains filled with granules of mucin glycoproteins. Brash border cells are responsible for chemosensory receptors. Small granule cells are also known as your, Kulchitski cells. So they are part of your diffuse neuroendocrine system. And for basal cells, they are mitotically active stem cells and progenitor cells that give rise to other epithelial cell types. So, also, noteworthy to remember that ciliated columnar cells are composed of 250 to 300 cilia. So smoking can destroy the cilia or the tiny hairs in your airway that keep dirt and mucus out of your lungs. So when these cilia are destroyed, you would develop what is known as smoker's cough. So smoker's cough is a chronic cough that is often seen in long term or daily smokers. So toxins presence in your, cigarette will going to paralyze the cilia. And, eventually, no, shortening of the cilia leading to the destruction of your, cilia, removing an important protection from our respiratory system. So, again, there is immobilization of the cilia that causes failure to clear mucus containing filtered material and exacerbates the problem, leading, eventually, to the likelihood of your squamous metaplasia of the epithelium. So a change from your pseudostratified saluted columnar to stratified squamous epithelium can also occur, and particularly in the mucosa of your bronchi. This can produce precancerous cell dysplasia in this tissue. But please remember, if a smoker quits before cancer actually starts, even if the cells are in a precancerous state, the process is highly, okay, highly reversible Okay? So cilia regeneration starts in about 3 days. Again, your regeneration of your cilia start 3 days once smoking stops. So even if the cilia has been destroyed and not present for years, the lining tissue of the windpipe will start to repair. So even the precancerous cells will be sloughed off over time, reversing the cellular process to the point where your lining tissues go back to normal. But if a smoker waits too long and cancer starts, it may be too late to save his or her life. So irreversible Okay? Progression of your cancer. Again, start cancer reversible. So common morphologic findings, so we have what we call your smoker's macrophage. So these are your dusty brown pigment laden macrophages and may contain surfactant derived bodies due to phagocytosis of your necrotic type 2 pneumocytes. So parison type 2 pneumocytes. Type 2 pneumocytes are important for the secretion of your surfactant. From your lamellar bodies. So surfactant is it decreases your alveolar surface tension. Also, it decreases alveolar collapse and decreases lung recoil and increase your compliance. So your, type 2 pneumocytes are very important. Okay? Under smoking related interstitial diseases, we have 2, your DIP and your respiratory bronchiolitis associated interstitial lung disease. So in DIP, you will going to see your smoker's macrophage in your alveolar spaces, while in your respiratory bronchiolitis, the macrophage is seen in your bronchioles and as well as your alveolar ducts. So you have chronic inflammation in peribronchular fibrosis in your respiratory bronchiolitis associated interstitial lung disease. So for olfactory epithelium, olfactory epithelium houses your olfactory chemoreceptors that are responsible for the sense of smell. So this is a specialized region of your mucous membrane covering the superior country at the roof of your nasal cavity. So in adults, it is about 10 centimeters squared in area up to 100 micrometer in thickness. So this tick so this stratified, columnar epithelium has 3 major cell types. First is your olfactory neurons. So olfactory neurons are bipolar neurons that are present throughout this epithelium, and their nuclei form an irregular row near the middle of the thick epithelium. So the apical or luminal pole of each olfactory cell is its dendrite end and has an oblique swelling with about dozen basal bodies from which long cilia project into the overlying aqueous layer. So these cilia have nonmotile axonemes and collectively provide a large surface for transmembrane chemoreceptors. So these are your olfactory neurons. So it lie in the middle of your pseudostratified olfactory epithelium with a zone of supporting cell nuclei above it. So at the apical end of the cells are your nonmotile cilia. So these are your nonmotile cilia or olfactory hairs and a layer of your mucus. So supporting cells. Supporting cells are columnar with narrow bases and broad cylindrical apexes containing nuclei and extending microvilli into the fluid layer. For basal cells these are small, spherical, cone shaped cells near the basal lamina, and stem cells for the other two types replacing the olfactory neurons every 2 to 3 months and support cells less frequently. For nasal mucosa, so the mucosa of the nasal cavities and as well as your paranasal sinuses consists of your pseudostratified ciliated columnar epithelium containing numerous mucin secreting goblet cells. So this is called your respiratory epithelium. So this one, and is found elsewhere in the conducting part of your respiratory tract. So the respiratory epithelium has an unusually thick basement membrane. So it is supported by a lamina propria reached in your blood vessels and your mucus glands. So the secretions of these glands and epithelial goblet cells trap small particles in the inspired air in a thin layer of surface mucus. So this mucus layer is propelled towards the parynx by coordinated movement of your cilia. This is sometimes described as your mucociliary escalator. So from the pharynx, most of the mucus is swallowed, and your gastric acid will going to destroy any trapped bacteria. I also mentioned a while ago that the temperature of the inspired air is being adjusted close to that of the body as a result of warming by the rich plexus of blood vessel. So the air is also humidified by contact with the gland secretions, particularly those of your serous glands. Paranesal sinuses. So paranesal sinuses are bilateral cavities in the frontal, maxillary, ethmoid, and spinoid bones of the skull. So they are named after the bones they are housed. So it decreases skull bone weight and communicate with the nasal cavities through small openings or ducts. So next is your nasal firings. So nasal firings is lined with pseudostratified ciliated columnar epithelium. And you can also see here patches of squamous epithelium that occur with increasing age, particularly near the lower end and extensively in your smokers. So the lamina propria of your nasal parynx contains some serous and mucous gland, But the dominant feature of the mucosa at the site is the presence of large masses of your lymphoid tissue, which forms a component of your wildyielding of your lymphoid tissue. So protecting the entry portals of the respiratory and as well as your gastrointestinal system. So this lymphoid tissue is particularly prominent in children and as well as young adults and usually bulge outwards into the lumen of your nasopharynx, producing an appearance similar to that seen in your lingual tonsil. So this is a low power photomicrograph shows the constituent of one half of the larynx. So it comprises 2 folds which protrude into the airway. So the upper fold is the false vocal cord. So this is your false vocal cord, which is covered by columnar ciliated respiratory type epithelium. Again, columnar ciliated respiratory type of epithelium and contains serous glands. So these are your serous glands. So the lower fold is the true vocal cord. So this is your true vocal cord. In the surgically removed human larynx, the sharp tip of the true cord has been removed. So the true cord contains the vocalis muscle. So this is your vocalis muscle and your vocalis ligaments, which are responsible for moving the true cord so that it moves towards or away from the true cord on the other side. Thus, controlling the pitch of the sound made and the true cords are covered by stratified squamous. So this is the epithelium, stratified squamous epithelium, which is more resistant to the effects of physical trauma caused by the free margins of the true cords contacting each other during your speech. So between the true and false cords, there is a narrow cleft, your ventricle. So this is your ventricle, which terminates in the blind ending sacule, which is not shown here. And the ventricle and saccule are lined by respiratory type columnar epithelium and also contains seromucous glands. So, again, your nasopharynx is lined with pseudostratified ciliated columnar, epithelium with goblet cell, and the mucosa contains the medial pharyngeal tonsil and the opening of the 2 auditory tubes. For oropharynx, it contains 2 pairs of muscular arches, palatine, and your lingual tonsils. For laryngopharynx, it is the inferior narrowed region. So your larynx is composed of your mucosa, vestibular folds, and vocal folds, or your cords. Your mucosa are 2 pairs of folds separated by a ventricle. Vestibular folds are the upper pair, which is immovable, and the vocal folds or cords is the lower pair important for phonation or sound production. So the inflammation of the larynx or what we call your laryngitis is typically due to viral infection and is usually accompanied by edema or the swelling of the organs, lamina propria. So this change the shape of your vocal folds or the other parts of the larynx, producing hoarseness or complete loss of your voice. Common disorders of the nose, nasopharynx, and larynx. So first one is your viral infections, including choriza, which is the common cold, and allergic inflammation, including allergic rhinitis, hay fever, which is very commonly affect the nose, nasal sinuses, and nasopharynx. So we also have nasal polyps. Nasal polyps are edematous protrusions of the respiratory mucosa and are common consequence of prolonged or recurrent inflammation, particularly allergic inflammation. So patients typically complain of nasal blockage or snoring because this lesion can occupy much of the space in your nasal cavity. You also have malignant tumors of the nasal passages and sinuses. These are very rare, but nasopharyngeal carcinoma is of special interest because it is associated with a viral infection, specifically your EBV or your Epstein Barr virus. So this virus is also linked to some other malignant tumors, including your lymphoma. So please remember that the stratified squamous epithelium of the larynx may undergo hyperplastic or dysplastic change to form benign squamous papillomas or invasive squamous cell carcinoma. Again, cigarette smoking and alcohol consumption predisposed to the development of the carcinoma of the larynx. So meaning to say, cigarette smoking, including exposure to cigarette smoke and chronic alcohol consumption, cause carcinoma in our respiratory system, including larynx, lungs, and also our nose, nasal carcinoma. For trachea, trachea is 10 to 12 centimeter long in adults, and it is lined with typical respiratory mucosa in which the lamina propria contains numerous serum mucous glands producing watery mucus. This is a series with about a dozen c shaped rings of hyaline cartilage between the submucosa and adventitia. So at the level of your external angle, just a recall in your anatomy, it bifurcates into the right and left primary bronchi. So you can see here a specimen from a newborn child, and it shows the general structure of urticula. So this is a flexible tube of fibroelastic tissue and cartilage, which permits expansion in diameter and as well as extension in the length during your expiration. And also, passive recoil during expiration. Again, this is a series of C shaped rings of hyaline cartilage that support the tracheal mucosa and prevent its collapse during inspiration. So bands of smooth muscle called your trachealis muscle, join the free end of the ring posteriorly. And contraction of the trachealis reduces your tracheal diameter and thereby assist in raising your intrathoracic pressure during coughing. So a few strands of longitudinal muscle can be seen disposed behind your trachealis muscles. So these are your longitudinal muscle. Again, the trachea is lined by typical respiratory epithelium underlain by connective tissue of the lamina propria and ceramucose glands in the lamina propria and your submucosa. Going into your bronchial tree and lungs, so we have your right and left primary bronchi. So under which we have your extrapulmonary and intrapulmonary. Extrapulmonary outside the lungs, intrapulmonary inside the lungs or within the lungs. We also have your secondary bronchi or your lobar. So in the right, we have 3, and in the left, we have 2 secondary bronchi. So just a comparison about your right and left main bronchus. So your right mean bronchus is wider, shorter, and more vertical, while your left main bronchus is narrower, longer, and more horizontal. So how many bronchopulmonary segments? Bronchopulmonary segments. Again, how many bronchopulmonary segments are there on each lung? So in the right, we have 10 bronchopulmonary segments, while in the left, we have 8 to 10 bronchopulmonary segments. So what vessel carry the oxygenated blood to the lungs? The oxygenated the oxygenated pulmonary arteries. Oxygenated blood to the lung and your bronchial tree, we have your bronchial arteries. So important anatomy and the histology of the lungs. So, because if we have aspiration or foreign object, so foreign object or aspiration supine So foreign object in the superior supine superior segment of your lower lobe. Upright position? Segment of your lower lobe. Okay? Just, recall from your anatomy. Okay. Please do memorize and remember this table. So we have here the region of airway, the epithelium, and the muscle and the skeletal support of that region of airway, and other features and major functions. For bronchi, the epithelium is respiratory. For bronchioles, It is simple ciliated cuboidal to columnar with exocrine with exocrine club cells. For terminal bronchioles, we have simple cuboidal ciliated, ciliated cell, and club cell. For respiratory bronchioles, it is simple cuboidal, ciliated cells, and clubbed cells with scattered alveoli. So for alveolar ducts and sacs, it is simple cuboidal between many alveoli. And for your alveoli, it is composed of type 1 and type 2 alveolar cells or pneumocytes. So please remember this table. So we have here your primary bronchus, which is sustained in your hematoxylin and aosine, and the other one is sustained with your toluidine blue. So the basic structure of the wall of amine bronchus is similar to that of your trachea but differs in several details. So first, their respiratory epithelium is less tall and contains fewer goblet cells, and the upper lamina propria contains more elastin. So the lamina propria is separated from your submucosa by a layer of smooth muscle, which becomes more prominent in more distal bronchi. So, also, the contains fewer serum mucinous glands, and these are your serum mucinous glands. And the cartilage support is flattened, interconnected plates rather than in distinct ring. So in here the micrograph shows the epithelial layer at a very high magnification. So the cells are pseudostratified, as you can see here, in the basis of all the cells contacting the basement membrane, but not all the cells reaching the luminal surface. So the ciliated and your goblet cells, so these are your ciliated. And as you can see here, cilia. And your goblet cells can be easily distinguished. So the underlying lamina propria contains your elastic fibers and occasional mast cell. So these are your mast cell. So we have here your tertiary or segmental bronchus, and the epithelium is just visible in this image, and it is tall and columnar with little pseudostratification. The lamina propia is thin, elastic, and completely encircled by smooth muscle, which is disposed in a spiral manner. So this arrangement permits contraction of your bronchi in both length and also in diameter during your expiration. Your serum mucinous glands are sparse in your submucosa. So these are your serum mucinous glands. So these glands are rarely found within your smaller sir smaller airways, and the cartilage framework is reduced to a few irregular pleats. So these are your cartilage. And cartilage does not usually extend beyond your tertiary bronchi. So please take note that the submucosa, these are your submucosa, merges with the surrounding adventitia and then with the lung parenchyma. So small aggregates of your lymphocytes, part of your mucosa associated lymphoid tissue are seen in the adventitia. So for bronchiol, so bronchiol is an airway of less than 1 millimeter in diameter, which has neither cartilage or submucosal glands in its wall. So the epithelium is composed of ciliated columnar cells and few goblet cells. No? So in the terminal and the respiratory bronchioles, your goblet cells are replaced by your clara cells. So clarasaanclaria cells. Claria cells have several lung protective function, so they detoxify, different synobiotics and also oxidant gases. They also control the extent of your inflammation and participate in your mucociliary clearance of environmental agents. Also, they proliferate or differentiate to maintain the ciliated cell population. So in here this micrograph shows your neuroendocrine cells. So these cells form part of the diffuse neuroendocrine system secreting number of peptide hormones, including your, serotonin or your 5 HT and also a number of bombasin. So bombasin regulate muscle tone in your bronchial and vessel walls. Again, please do not forget your neuroendocrine cells that secretes your serotonin and your brombocin that regulates muscle tone in your bronchial and vessel wall. Also, don't forget your clara cells that have several functions, like, again, they produce one of the component of your surfactant. They act as your stem cell, meaning to say they are able to divide, differentiate, and replace other damaged cell types. And lastly, no, they contain enzyme systems which can detoxify different noxious substances. So for alveoli, so the alveolar wall is consists of 3 tissue components, like your surface epithelium, supporting tissue, and blood vessels. So the epithelium provides a continuous lining to itch your alveolus and consists of cells of 2 types. So most of your alveolar surface area is covered by a large squamous cell called your type 1 pneumocytes or your alveolar lining cell. Type 1 pneumocyte. Again, type 1 pneumocyte is also called as your alveolar lining cells. So type 1, pneumocytes. So, again, they are squamous, and they meet up 97% of your alveolar surface. Type 1 pneumocytes line the alveoli for optimal gas exchange. So type 1 pneumocyte. So for type 2 pneumocytes, so they represent some 60% of cells in the lining of epithelium, type 2, again, another type 2. And they are rounded in shape and thus occupies a much smaller portion of your alveolar surface area. So type 2 pneumocytes secrete, surface active materials called your surfactant, surfactant, which reduces your alveolar surface tension, preventing your alveolar collapse during expiration. So, again, clarastoles of the respiratory bronchioles probably synthesize other components of surfactant. So type 2 pneumocyte 13, the capacity of cell division and can differentiate into type 1 pneumocytes if required. Again, type 2 can differentiate into type 1 if So micrograph shows the light microscopic appearance of type 2 pneumocytes or your surfactant cells, which are responsible for, again, surfactant production. So their nuclei are large and plump with dispersed chromatin and prominent nucleoli, and the plentiful eosinophilic cytoplasm is filled with fine and stained vacuoles representing your laminar body. So the phospholipid of which is dissolved out during tissue preparation. In comparison to the nuclei of your type 1 pneumocyte, again, type 1 pneumocyte is also called your alveolar lining cells, and the capillary endothelial cells are small, dense, and flattened. If we have deficiency in your surfactant, so surfactant deficiency. So surfactant deficiency specifically, surfactant is being produced by your type 2 pneumocyte. So again, increased surface tension causing alveolar collapse. So x-ray surfactant deficiency. Mgakarang yong ng ground glass appearance. So risk factor. No. Surfactant deficiency. By the way, surfactant deficiency is called your neonatal respiratory distress syndrome or neonatal RDS. Okay? Again, risk factors. First, we have prematurity, diabetes during pregnancy due to high fetal insulin. Also, cesarean section, mode of delivery is a high risk for having neonatal respiratory distress syndrome due to decreased disease of fetal glucocorticoids and less stressful than your vaginal delivery. So treatment, we give, maternal glucocorticoids before birth. Showing you here cancer cytology from fine needle aspiration sample and stained with gimzastin. So the micrograph demonstrate the difference between your normal epithelial cells, so these are your normal epithelial cells, and your adenocarcinoma cells. So the malignant cells are much larger, with prominent nuclei, larger nucleoli, and scantycytoplasm in contrast with the normal epithelial cells that exhibit the expected columnar shape. So cilia can just be discerned on the luminal surface of the normal cells in this image. So the diagnosis of lung carcinoma is usually first suspected patient signs and symptoms like weight loss, or breathlessness, and presence of your hemoptysis. Meaning to say blood. And, but the last suspect carcinoma for those patients smokers. So initial investigation typically involves obtaining a chest x-ray followed by more detailed imaging, such as your CT scan or your computed tomography. So if a lung mass is identified, formal diagnosis is usually made on the basis of small amounts of material obtained by a minimally invasive technique, such as bronchoscopic biopsy or radiology guided needle biopsy for peripherally situated lung masses. So this is necessary because management of your lung carcinoma is highly dependent upon the initial classification of small cell carcinoma or non small cell carcinoma. So most lung cancers actually arise within the epithelium of your bronchi and spread from there into the surroundings of your lung tissue. Thus, they are often accessible by bronchoscopy where cytological samples may be taken either by washing or brushing of the lesion. So more peripheral lesions may be accessed by technique of fine needle aspiration or FNA by passing a long needle into the tumor through the chest wall. So this invasive procedure for the examination of your lung carcinoma, we can do sputum smear for, those patients undergo invasive procedure. All of these specimens may be examined by ascitological techniques. So the 2 cavities in the thorax, which house the right and left lungs, the pleural cavities are lined internally by a thin smooth layer, which is called your pleura. So which is also reflected over the external surfaces of the lungs. So the part of the pleura that forms the internal lining of the chest cavity, Again, internal lining of your chest cavity is your parietal pleura while, externally. No? Coat externally is your visceral pleura. So the parietal and visceral pleura are normally in contact but separated by a potential space containing a small amount of serous fluid that lubricates the movement of your visceral upon parietal pleura during your breathing. So pleural cavity is between the parietal and visceral layers. So, again, visceral pleura, externally coats the lung, and serous membrane attached to the lung tissue, parietal pleura. So parietal pleura forms the internal lining of the chest cavity and serous membrane lining the thoracic, cavity. So this micrograph illustrates visceral pleura. So the outer surface is lined by a layer of flattened mesothelium supported by a thin basement membrane, and the underlying fibrous supporting tissue consists primarily of collagen and elastic fibers. So the fibrous layer of visceral pleura extend into the long as fibrous septa, which are continuous with the fibroelastic framework of the lung parenchyma. So the visceral pleura contains a superficial plexus of lymph vessels which drain via your septa into a deep plexus surrounding the pulmonary blood vessels and your airway. So the lymph from the deep plexuses drains into your thoracic duct via your lymph nodes in the hilar region.