pediagenosis: Respiratory
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Showing posts with label Respiratory. Show all posts
Showing posts with label Respiratory. Show all posts

Tuesday, June 8, 2021

INTRODUCTION OF CHEST DRAINAGE TUBES

INTRODUCTION OF CHEST DRAINAGE TUBES

INTRODUCTION OF CHEST DRAINAGE TUBES

INTRODUCTION OF CHEST DRAINAGE TUBES


Pleural drainage tubes are inserted for evacuation of air or fluid from the pleural space in diseases such as pneumothorax, hemothorax, and empyema.

Placement of an intercostal tube or catheter for pneumothorax can be readily accomplished under local anesthesia, with or without an intercostal nerve block. Chest tube placement may be done at the bedside, but strict aseptic precautions should be observed. The second or third anterior intercostal space in the midclavicular line or the fourth or fifth intercostal space in the midaxillary line are the preferred sites for chest tube placement. To help select the optimal point of entry, chest radiographs should be reviewed unless the clinical situation is one of extreme urgency.

OXYGEN THERAPY IN CHRONIC RESPIRATORY FAILURE (AMBULATORY AND HOME USE

OXYGEN THERAPY IN CHRONIC RESPIRATORY FAILURE (AMBULATORY AND HOME USE

OXYGEN THERAPY IN CHRONIC RESPIRATORY FAILURE (AMBULATORY AND HOME USE

OXYGEN THERAPY IN CHRONIC RESPIRATORY FAILURE (AMBULATORY AND HOME USE


Supplemental oxygen was the first treatment shown to improve survival in patients with chronic obstructive pulmonary disease (COPD). A multicenter clinical trial published in 1980 demonstrated the benefit of oxygen used continuously compared with oxygen only administered nocturnally. The current recommendations for oxygen therapy in patients with COPD are (1) partial pressure of oxygen in arterial blood (Pao2) of 55 mm Hg or below (or pulse oxygen saturation [Spo2]  88%) or (2) Pao2 of 56 to 60 mm Hg (Spo2, 89%) with erythrocytosis (hematocrit >56 mL/dL) or cor pulmonale. Because of the benefits of oxygen, reimbursement is available from most medical insurance payers. The long-term benefit of oxygen in patients with less severe hypoxemia is unknown.

METHODS OF OXYGEN ADMINISTRATION

METHODS OF OXYGEN ADMINISTRATION

METHODS OF OXYGEN ADMINISTRATION

METHODS OF OXYGEN ADMINISTRATION


Various types of oxygen delivery devices are available. With a flow rate of 6 to 10 L/min of 100% oxygen, it is possible to achieve inspired oxygen concentrations (Fio2) of up to 95%. The actual Fio2 depends on the system used and the oxygen flow rate relative to the patient’s respiratory rate and tidal volume.

OXYGEN THERAPY IN ACUTE RESPIRATORY FAILURE

OXYGEN THERAPY IN ACUTE RESPIRATORY FAILURE

OXYGEN THERAPY IN ACUTE RESPIRATORY FAILURE

OXYGEN THERAPY IN ACUTE RESPIRATORY FAILURE


ARTERIAL BLOOD GAS COMPOSITION

Arterial blood gas (ABG) findings can be explained by the carbon dioxide: oxygen diagram shown at the top of the illustration. Because there is no uptake or excretion of nitrogen during respiration and the alveolar partial pressure of water vapor is a function of body temperature only, there is a reciprocal relationship between the alveolar Pco2   and Po2, as indicated by the alveolar gas composition line.  Because prolonged survival is not possible when the PaO2    is less than 20 mm Hg, the range of arterial gas tensions compatible with life is confined to the yellow triangle. Initial ABG values of air-breathing patients with decompensated chronic obstructive pulmonary disease (COPD) fall in the upper shaded blue area. With higher oxygen concentrations, the alveolar gas composition line is shifted to the right, and much higher PaCO2 values are possible.

PULMONARY REHABILITATION

PULMONARY REHABILITATION

PULMONARY REHABILITATION

PULMONARY REHABILITATION


Pulmonary rehabilitation is an evidence-based, multi-disciplinary, and comprehensive intervention for patients with chronic respiratory diseases who are symptomatic and often have decreased daily life activities. Integrated into the individualized treatment of the patient, pulmonary rehabilitation is designed to reduce symptoms, optimize functional status, and reduce health care costs through stabilizing or reversing the manifestations of the disease.

PULMONARY PHARMACOLOGY

PULMONARY PHARMACOLOGY

PULMONARY PHARMACOLOGY

BRONCHODILATORS
BRONCHODILATORS


Pulmonary pharmacology concerns the effects of drugs on the lungs and understanding how drugs used to treat patients with pulmonary diseases work. Much of this pharmacology concerns drugs used to treat obstructive airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD).

Wednesday, May 5, 2021

INNERVATION OF THE LUNGS AND TRACHEOBRONCHIAL TREE

INNERVATION OF THE LUNGS AND TRACHEOBRONCHIAL TREE


INNERVATION OF THE LUNGS AND TRACHEOBRONCHIAL TREE
The tracheobronchial tree and lungs are innervated by the autonomic nervous system. Three types of pathways are involved: autonomic afferent, parasympathetic efferent, and sympathetic efferent. Each type of fiber is discussed here; the neurochemical control of respiration is covered later in the section on physiology (see Plates 2-25 and 2-26).
 
INNERVATION OF TRACHEOBRONCHIAL TREE: SCHEMA
INNERVATION OF TRACHEOBRONCHIAL TREE: SCHEMA
Autonomic Afferent Fibers
Afferent fibers from stretch receptors in the alveoli and from irritant receptors in the airways travel via the pulmonary plexus (located around the tracheal bifurcation and hila of the lungs) to the vagus nerve. Similarly, fibers from irritant receptors in the trachea and from cough receptors in the larynx reach the central nervous system via the vagus nerve. Chemoreceptors in the carotid and aortic bodies and pressor receptors in the carotid sinus and aortic arch also give rise to afferent autonomic fibers. Whereas the fibers from the carotid sinus and carotid body travel via the glossopharyngeal nerve, those from the aortic body and aortic arch travel via the vagus nerve. Other receptors in the nose and nasal sinuses give rise to afferent fibers that form parts of the trigeminal and glossopharyngeal nerves. In addition, the respiratory centers are controlled to some extent by impulses from the hypothalamus and higher centers as well as from the reticular activating system.
STRUCTURE OF THE TRACHEA AND MAJOR BRONCHI

STRUCTURE OF THE TRACHEA AND MAJOR BRONCHI


STRUCTURE OF THE TRACHEA AND MAJOR BRONCHI
The trachea or windpipe passes from the larynx to the level of the upper border of the fifth thoracic vertebra, where it divides into the two main bronchi that enter the right and left lungs. About 20 C-shaped plates of cartilage support the anterior and lateral walls of the trachea and main bronchi. The posterior wall, or membranous trachea, is free of cartilage but does have interlacing bundles of muscle fibers that insert into the posterior ends of the cartilage plates. The external diameter of the trachea is approximately 2.0 cm in men and 1.5 cm in women. The tracheal length is approxi- mately 10 to 11 cm.

STRUCTURE OF THE TRACHEA AND MAJOR BRONCHI

Mucous glands are particularly numerous in the posterior aspect of the tracheal mucosa. Throughout the trachea and large airways, some of these glands lie between the cartilage plates, and others are external to the muscle layers with ducts that penetrate this layer to open on the mucosal surface. Posteriorly, elastic fibers are grouped in longitudinal bundles immediately beneath the basement membrane of the tracheal epithelium, and these appear to the naked eye as broad, flat bands that give a rigid effect to the inner lining of the trachea; they are not so obvious anteriorly. More distally, the bands of elastic fibers are thinner and surround the entire circumference of the airways.

Monday, May 3, 2021

INTRAPULMONARY AIRWAYS

INTRAPULMONARY AIRWAYS


INTRAPULMONARY AIRWAYS
According to the distribution of cartilage, airways are divided into bronchi and bronchioles. Bronchi have cartilage plates as discussed earlier. Bronchioles are distal to the bronchi beyond the last plate of cartilage and proximal to the alveolar region. Cartilage plates become sparser toward the periphery of the lung, and in the last generations of bronchi, plates are found only at the points of branching. The large bronchi have enough inherent rigidity to sustain patency even during massive lung collapse; the small bronchi collapse along with the bronchioles and alveoli. Small and large bronchi have submucosal mucous glands within their walls.

INTRAPULMONARY AIRWAYS

When any airway is pursued to its distal limit, the terminal bronchiole is reached. Three to five terminal bronchioles make up a lobule. The acinus, or respiratory unit, of the lung is defined as the lung tissue supplied by a terminal bronchiole. Acini vary in size and shape. In adults, the acinus may be up to 1 cm in diameter. Within the acinus, three to eight generations of respiratory bronchioles may be found. Respiratory bronchioles have the structure of bronchioles in part of their walls but have alveoli opening directly to their lumina as well. Beyond these lie the alveolar ducts and alveolar sacs before the alveoli proper are reached.
STRUCTURE OF BRONCHI AND BRONCHIOLES LIGHT MICROSCOPY

STRUCTURE OF BRONCHI AND BRONCHIOLES LIGHT MICROSCOPY


STRUCTURE OF BRONCHI AND BRONCHIOLES LIGHT MICROSCOPY
The airways are the hollow tubes that conduct air to the respiratory regions of the lung. They are lined throughout their length by pseudostratified, ciliated, columnar epithelium (also referred to as respiratory epithelium) supported by a basement membrane (see Plate 1-24 for details of cell types and their arrangement). The remainder of the wall includes a muscle coat and accessory structures such as submucosal glands, together with connective tissue. In the bronchi, cartilage provides additional support.
In adults, the diameter of the main bronchus is similar to that of the trachea (-2 cm), and the diameter of a terminal bronchiole is about 1 mm. These measurements vary with age and the size of the individual and with the functional state of the airway. For reference purposes, it is helpful to designate airways by their order or generation along an axial pathway. The epithelium is thicker in the larger airways and gradually thins toward the periphery of the lung.
Immediately beneath the basement membrane, elastic  fibers are collected into fine  bands that form longitudinal ridges. In cross-section, the fiber bundles are at the apices of the bronchial folds. The rest of the wall is made up of loose connective tissue containing blood vessels, nerves, capillaries, and lymphatics.

STRUCTURE OF BRONCHI AND BRONCHIOLES LIGHT MICROSCOPY

Blood Supply
The bronchial arteries supply the capillary bed in the airway wall, forming one plexus internal and another external to the muscle layer (see also Plate 1-26).
ULTRASTRUCTURE OF THE TRACHEAL, BRONCHIAL, AND BRONCHIOLAR EPITHELIUM

ULTRASTRUCTURE OF THE TRACHEAL, BRONCHIAL, AND BRONCHIOLAR EPITHELIUM


ULTRASTRUCTURE OF THE TRACHEAL, BRONCHIAL, AND BRONCHIOLAR EPITHELIUM
The lining of the respiratory airways is predominantly a pseudostratified, ciliated, columnar epithelium in which all cells are attached to the basement membrane but not all reach the lumen. In the smaller peripheral airways, the epithelium may be only a single layer thick and cuboidal rather than columnar because basal cells are absent at this level.
Ciliated cells are present in even the smallest airways and respiratory bronchioles, where they are adjacent to alveolar lining cells. The “ciliary escalator” starts at the most distal point of the airway epithelium. In smaller airways, the cilia are not as tall as in the more central airways. Eight epithelial cell types can be identified in humans, although ultrastructural features and cell kinetics have been studied mainly in animals. The following classification is based on studies in the rat: the (1) basal and (2) pulmonary neuroendocrine cells are attached to the basement membrane but do not reach the lumen; (3) the intermediate cell is probably the precursor that differentiates into (4) the ciliated cell, (5) the brush cell, or one of the secretory cells (6) the mucous (goblet) cell, (7) the serous cell, or (8) the Clara cell.
The Clara cell, The mucous (goblet) cell, The brush cell,  The ciliated cell, The basal cell

The basal cell divides and daughter cells pass to the superficial layer.
The pulmonary neuroendocrine cell (PNEC), previously referred to as the Kulchitsky cell, contains numerous neurosecretory granules and is a rare, but likely important, functional cell of the airway epithelium. The PNEC neurosecretory granules contain serotonin and other bioactive peptides such as gastrin-releasing peptide (GRP). PNECs are more numerous before birth and may play a role in the innate immune system. The intermediate cell is columnar. It has electronlucent cytoplasm and no special features. It is probably the cell that differentiates into the others.
BRONCHIAL SUBMUCOSAL GLANDS

BRONCHIAL SUBMUCOSAL GLANDS


BRONCHIAL SUBMUCOSAL GLANDS
The submucosal glands of the human airways are of the branched tubuloacinar type: tubulo refers to the main part of the secretory tubule and acinar to the blind end of such a tubule.
Three-dimensional reconstruction of the gland reveals its various zones:
1.  The origin is referred to as the ciliated duct and is lined by bronchial epithelium with its mixed population of cells. With the naked eye, the origin of the gland is seen as a hole of pinpoint size in the surface epithelium of the bronchus.
2.  The second part of the duct expands to form the collecting duct and is lined by a columnar epithelium in which the cells are eosinophilic after staining with hematoxylin and eosin. Ultrastructural examination shows these cells to be packed with mitochondria, resembling the cells of the striated duct of the salivary gland (except that they lack the folds of membrane responsible for the appearance of striation). The collecting duct may be up to 0.25 mm in diameter and 1 mm long. It passes obliquely from the airway lumen, so the usual macroscopic section does not include the full length of the duct. It is usually seen as a rather large “acinus” composed of cells without secretory granules.
3.  About 13 tubules rise from each collecting duct. These may branch several times and are closely intertwined with each other. The secretory cells lining these tubules are of two types: mucous and serous. Mucous cells line the central or proximal part of a tubule; serous cells line the distal part. Outpouchings or short-sided tubules may arise from the sides of the mucous tubules, and these are lined by serous cells. The peripheral portion of a tubule usually branches several times, and each of the final blind endings is lined with serous cells.

BRONCHIAL SUBMUCOSAL GLANDS

The gland tissue is internal to a basement membrane. In addition to the cell types described above, the following are found: (1) myoepithelial cells; (2) “clear” cells; and (3) nerve fibers, including motor fibers. Outside the basement membrane, there are rich vascular and lymphatic networks and the nerve plexus.

Tuesday, April 20, 2021

INTRAPULMONARY BLOOD CIRCULATION

INTRAPULMONARY BLOOD CIRCULATION


INTRAPULMONARY BLOOD CIRCULATION
The human lung is supplied by two arterial systems referred to as pulmonary and bronchial, each originating from a different side of the heart. Blood from the lungs is drained by two venous systems, pulmonary and true bronchial. The pulmonary veins drain oxygenated blood from the regions supplied by the pulmonary artery and deoxygenated blood from the airways within the lung that are supplied by the  bronchial  artery. The true bronchial veins serve only the perihilar region, supplied mainly by the bronchial artery, and this blood drains to the azygous system and right atrium.


Arteries
The bronchial arteries arise from the aorta and supply the capillary plexus of the airway walls from the hilum to the respiratory bronchiole.
The pulmonary artery branches run with airways and their accompanying bronchial arteries in a single connective tissue sheath referred to as the bronchoarterial or bronchovascular bundle. The pulmonary artery transforms into a capillary bed only when it reaches the alveoli of the respiratory bronchiole. It supplies all capillaries in the alveolar walls that constitute the respiratory surface of the lung.
FINE STRUCTURE OF ALVEOLAR CAPILLARY UNIT

FINE STRUCTURE OF ALVEOLAR CAPILLARY UNIT


FINE STRUCTURE OF ALVEOLAR CAPILLARY UNIT
The cellular composition of the alveolar capillary unit was not recognized until the era of electron microscopy. Before that time, it was thought that a single membrane separated blood and air at the level of the terminal airspace. We now know that, even at its narrowest, the boundary between blood and air is composed of at least two cell types (the type I alveolar epithelial cell and the endothelial cell) and extracellular material, namely, the surfactant lining of the alveolar surface, the basement membranes, and the so-called “endothelial fuzz.” The last is composed of mucopolysaccharides and proteoglycans (or glycocalyx) that may be involved in signal transduction, including mechanotransduction or shear stress at the endothelial surface. Plate 1-27 shows part of a terminal airspace and cross sections of surrounding capillaries. In humans, the diameter of the alveoli varies from 100 to 300 μm. The capillary segments are much smaller in diameter (10-14 μm) and may be separated from each other by even smaller distances. Each alveolus (there are 300 million alveoli in the adult human lungs) may be associated with as many as 1000 capillary segments.
The thinness of the cellular boundary between the blood and the air presents enormous surface area to air on one side and to blood on the other (  ̴70 m2 for both lungs). Given the paucity of organelles, the cells at this location likely play mainly passive roles in physiologic and metabolic events involved in the management of airborne or bloodborne substrates.
Ninety-five percent of the alveolus is lined by epithelial type I cells. The remaining cells are larger polygonal type II cells. These two cell types form a complete epithelial layer sealed by tight junctions. The cellular layer lining the alveoli is remarkably impermeable to salt-containing solutions, but little is known about specific metabolic activities of type I alveolar cells. Growing evidence suggests a more important role in the maintenance of alveolar homeostasis than previously thought, evidenced by the expression a large number of proteins such as aquaporin (AQP-5), T1α, functional ion channels, caveolins, adenosine receptors, and multidrug-resistant genes. Type II cells and endothelial cells have long been known to play active roles in the metabolic function of the lung by producing surfactant and processing circulating vasoactive substances, respectively. In addition, recent research suggests more complex roles for both of these cell types.
ULTRASTRUCTURE OF PULMONARY ALVEOLI AND CAPILLARIES
ULTRASTRUCTURE OF PULMONARY ALVEOLI AND CAPILLARIES

Alveolar Cells And Surface-Active Layer
As illustrated in Plate 1-28, in addition to being larger, the type II alveolar cell is distinguished from the type I alveolar cell by having short, blunt projections on the free alveolar surface and lamellar inclusion bodies. The intracellular origins of the lamellar bodies (LBs) and the exact mechanism for lipid transport into them are not known with certainty, although lipid translocation across the LB membrane is facilitated by the ABCA subfamily of adenosine triphosphate binding cassette transporters. The LB contains the phospholipid component of surfactant and two small hydrophobic surfactant polypeptide proteins (SP-B and SP-C) that are coreleased from the type II cell by a process similar to exocytosis. Two additional components of surfactant (large hydrophilic proteins SP-A and SP-D) are synthesized and released independent of LBs.
LYMPHATIC DRAINAGE OF THE LUNGS AND PLEURA

LYMPHATIC DRAINAGE OF THE LUNGS AND PLEURA


LYMPHATIC DRAINAGE OF THE LUNGS AND PLEURA
The lymphatic drainage of the lung plays critical roles in the removal of excess interstitial fluid and particulate matter (free or within macrophages) deposited in the airspaces and in lymphocyte trafficking and immune surveillance. Discrepancies exist between the terminology of the Nomina Anatomica adopted by anatomists for lung lymphatic routes and the terms commonly and conveniently used by clinicians, surgeons, and radiologists. For this reason, in the illustrations, the terms in common usage are included in parentheses after the official Nomina Anatomica designations.
As the lymphatic channels approach the hilum, lymph nodes are present in the following distributions:
1.   The pulmonary (intrapulmonary nodes) within the lung, located chiefly at bifurcations of the large bronchi
2.   The bronchopulmonary (hilar) nodes situated in the pulmonary hilum at the site of entry of the main bronchi and vessels
3.   The tracheobronchial nodes, which anatomists subdivide into two groups: a superior group situated in the obtuse angles between the trachea and bronchi and an inferior (carinal) group situated below or at the carina (i.e., at the junction of the two main bronchi)
4. The tracheal (paratracheal) group situated alongside and to some extent in front of the trachea throughout its course; these are sometimes subdivided into lower tracheal (paratracheal) nodes and an upper group in accordance with their relative positions
5.   The inferior deep cervical (scalene) nodes situated in relation to the lower part of the internal jugular vein, usually under cover of the scalenus anterior muscle
6.   The aortic arch nodes situated under the arch of the aorta
LYMPHATIC DRAINAGE OF THE LUNGS AND PLEURA

Beginning centrally, the major lymph channels on the right side are (1) the bronchomediastinal lymph trunk, which collects lymph from the mediastinum, and (2) the jugular lymph trunk. The latter commonly unites with (3) the subclavian trunk to form a right lymphatic duct, which in turn joins the origin of the right brachiocephalic vein. In some cases, however, these three major lymphatic channels join the brachiocephalic vein independently. On the left side, the thoracic duct curves behind the internal jugular vein to enter the right brachiocephalic vein at the junction of the subclavian vein and internal jugular veins. There may or may not be a separate right bronchomediastinal lymph trunk; if present, it may join the thoracic duct or enter the brachiocephalic vein independently.
PULMONARY IMMUNOLOGY LYMPHOCYTES, MAST CELLS, EOSINOPHILS, AND NEUTROPHILS

PULMONARY IMMUNOLOGY LYMPHOCYTES, MAST CELLS, EOSINOPHILS, AND NEUTROPHILS


PULMONARY IMMUNOLOGY LYMPHOCYTES, MAST CELLS, EOSINOPHILS, AND NEUTROPHILS
The respiratory system is in intimate contact with the environment through the inhalation of large volumes of air every day (  ̴10,000 L). Protecting the respiratory system from pathogens and toxins while avoiding unnecessary inflammation when harmless proteins are inhaled is a challenge. Physical barriers such as the filtration of air by the nose and upper airways and the mucociliary apparatus, which moves inhaled particles, organisms, and cells toward the pharynx, where they can be swallowed, provide the first line of defense. Ingestion of organisms and particulate material by macrophages resident within the lung is another important line of defense. Ingestion of silica particles or asbestos fibers by macrophages may fail to clear these particles and may lead to persistence of inflammation and ultimately lung tissue damage.
PULMONARY IMMUNOLOGY: LYMPHOCYTES, MAST CELLS, EOSINOPHILS, AND NEUTROPHILS
        The airway epithelial cells have the capacity to ingest bacteria and have a variety of receptors, such as Toll like receptors, on their surface that may lead to activation of the epithelium on exposure to bacterial or viral products (e.g., DNA, RNA, lipopolysaccharide). Activated epithelium secretes chemoattractant molecules that will attract neutrophils, eosinophils, and lymphocytes, depending on the particular need. Cytokines secreted by the epithelium may also promote inflammation. Defensins are proteins that are secreted by epithelial cells that may bind to microbial cell membranes and create pores that assist in killing organisms. Epithelial cells also produce surfactant proteins that may assist in the elimination of pathogenic organisms.
DEVELOPMENT OF THE LOWER RESPIRATORY SYSTEM

DEVELOPMENT OF THE LOWER RESPIRATORY SYSTEM


DEVELOPMENT OF THE LOWER RESPIRATORY SYSTEM
The development of the respiratory system in humans is an interesting demonstration of ontogeny recapitulating phylogeny. The embryology of the system goes through the fish, amphibian, reptilian, and mammalian evolutionary stages of humans’ ancestry. In the change from an aqueous to an aerobic environment, many basic structures were modified but retained as parts of the respiratory system, and others became nonrespiratory structures. At the same time, entirely new respiratory structures evolved. The olfactory organ of aqueous forms was incorporated into the respiratory system of terrestrial forms, and the simple sphincter mechanism of the swim bladder of fish became the larynx of air breathers, which also took on the function of phonation. In contrast, the part of the respiratory system involved in the gas exchange vital to life has essentially not changed throughout vertebrate evolution. Exchange of oxygen and carbon dioxide between the external environment and the circulating bloodstream occurs through a wet epithelium in both gills and lungs.
The respiratory system in humans differs from the other major body systems in that it is not operational until birth. Therefore, development of the antenatal respiratory system is genetically determined independently of the functional demands of the growing embryo and fetus. The system’s physiologic development is mainly one of preparation for instant action at birth, a feat unmatched by any other system. When the fetus passes from the uterine aquatic environment, the partially collapsed, fluid filled lungs immediately function efficiently to sustain life. The chief cause of perinatal death of human infants is failure of the respiratory system to work properly. In the majority of perinatal deaths, all other body systems are functioning normally.
 
DEVELOPING RESPIRATORY TRACT AND PHARYNX
DEVELOPING RESPIRATORY TRACT AND PHARYNX

Primitive Respiratory Tube
During the fourth gestational week, the first indication of the future respiratory tree is a groove that runs lengthwise in the floor of the pharynx just caudal to the pharyngeal pouches. From the outside, this laryngotracheal groove appears as a ridge. The ridge grows caudally to become a tube, the lung bud, and the cranial or upper part of the tube becomes the larynx. The caudal part becomes the future trachea, which soon develops two knoblike enlargements at its distal end, the bronchial buds (Plate 1-33).

Sunday, March 7, 2021

BENIGN TUMORS OF THE STOMACH

BENIGN TUMORS OF THE STOMACH

BENIGN TUMORS OF THE STOMACH

Benign tumors, compared with carcinomas, are relatively rare. They are small and typically do not cause symptoms. With the increasing use of endoscopy and radiologic imaging, small tumors are now more frequently detected incidentally.

DERMATOMYOSITIS AND POLYMYOSITIS

DERMATOMYOSITIS AND POLYMYOSITIS

DERMATOMYOSITIS AND POLYMYOSITIS

Polymyositis and dermatomyositis are two of the idiopathic inflammatory myopathies, a group of rare systemic autoinflammatory disorders of unknown cause. They are characterized by proximal muscle weakness (most patients present with the subacute onset of weakness and myalgias), increased serum skeletal muscle enzymes, characteristic electromyography abnormalities, and the presence of inflammatory cell infiltrates in muscle tissue. Patients with dermatomyositis are defined by the additional presence of an exanthem, most commonly a purple discoloration of the eyelids (heliotrope rash) or a symmetric, palpable, erythematous rash over the extensor surfaces of the metacarpophalangeal and proximal interphalangeal joints of the fingers (Gottron papules). Extramuscular organ involvement is common, particularly the skin, joints, and lungs. Pulmonary complications are a major cause of morbidity and mortality. These can be either primarily associated with the underlying autoinflammatory disorder or secondary to the muscle weakness. As with all autoimmune disorders, drug-induced disease and infection should always be an early consideration. Myositis specific findings include hypoventilation, aspiration pneumonia, and interstitial lung disease (ILD).

SYSTEMIC LUPUS ERYTHEMATOSUS

SYSTEMIC LUPUS ERYTHEMATOSUS

SYSTEMIC LUPUS ERYTHEMATOSUS

Systemic lupus erythematosus (SLE) is a systemic autoinflammatory disorder that most commonly affects women of childbearing age. Hispanics and African Americans present earlier and with more active and aggressive disease than whites. When SLE is diagnosed after age 50 years, there is a lower female : male ratio; a higher incidence of neurologic, serosal, and pulmonary involvement; greater accumulated organ damage; and higher mortality.

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