Systemic Biomedical Sciences 2 Review Exam 1 PDF

↳ abs 1 Systemic Biomedical Sciences 2 Review Exam 1 Neoplasia A neoplasm is defined as a mass that develops due to abnormal cell or tissue growth. It is an abnormal mass of autonomous cells. Its literal meaning is “new formation”. L plasma ( net Neoplasia refers to various types of growths including...

↳ abs 1 Systemic Biomedical Sciences 2 Review Exam 1 Neoplasia A neoplasm is defined as a mass that develops due to abnormal cell or tissue growth. It is an abnormal mass of autonomous cells. Its literal meaning is “new formation”. L plasma ( net Neoplasia refers to various types of growths including non-cancerous/benign tumors, precancerous growths, carcinoma in situ and malignant/cancerous tumors. The two basic components of neoplasms are: Neoplastic cells - the proliferating neoplastic cells that make up the main tumor. Reactive stroma - supportive stroma made up of blood vessels and connective tissue (silent collaborator). Vascularization growth - Benign tumors usually have the su Lipoma Hemangioma Adenoma Well differentiated - Resemble local cells ood) 19 x “-oma”. Lymphangioma Myoma Malignant tumors are usually dependent on the embryonic origin of the a ected tissue. Sarcomas - mesenchymal origin Carcinoma - epithelial origin Leukemia/lymphoma - Lymphoproliferative. tumors Classifications of neoplasms consists of: Behavior - benign or malignant cambianremente Degree of di erentiation - well di erentiated or poorly-di erentiated. Embryological origin - epithelial, lymphoproliferative or mesenchymal. Gross appearance - Well circumscribed (restrained) or infiltrative.-HasAffectedheene - se pueden demarcar n 7 Benign tumors grow slowly, have distinct borders, don't invade the surrounding tissue, don't invade other parts of the body, may cause compression without tissue invasion and its treatment mainly consists in surgical removal.(biopsy Malignant (cancerous) tumors can grow quickly, have irregular borders, often invade surrounding tissue and can spread to other parts of the body through a process called metastasis. Metastasis - cancerous cells travel to other parts of the body through the blood and lymphatic system. Treatment can consist of surgery, radiotherapy, chemotherapy, immunotherapy or a combination to prevent cancer spread. · y > e - ~ #X > 2 Comparison between benign and malignant tumors: Characteristic Benign Malignant Di erentiation/Anaplasia Well di erentiated; structure may be typical of tissue of origin. Some lack of di erentiation with anaplasia; structure is often atypical. Rate of growth Progressive and slow, may come to a standstill or regress, mitotic figures are rare and normal. Erratic and may be slow or rapid; mitotic figures may be numerous and abnormal. Local Invasion Usually cohesive and expansive well-demarcated masses that do not invade or infiltrate the surrounding normal tissue. Locally invasive, infiltrating the surrounding normal tissues; sometimes may be seemingly cohesive and expansile. Absent Frequently present, the larger and more undi erentiated the primary, the more likely metastasis is. Metastasis Dysplasia is the disordered proliferation (non-neoplastic) and abnormal growth of epithelial cells leading to loss of cellular uniformity and orientation. It can only be seen with a microscope. Pleomorphism involves the variation in size and shape; including hyperchromatic nuclei and mitosis. Dysplasia grading depends on the organ: Two levels: ○ Low grade - earlier form of a precancerous lesion. ○ High grade - carcinoma in situ, transformation into cancer is high but treatment is still e ective. Three levels: ○ Mild ○ Moderate ○ Severe 3 Higher grades are more likely to turn into cancer. Invasive carcinomas penetrate the basement membrane to invade the tissue. Anaplasia is There is increased mitotic activity, loss of cell orientation and lack of normal organization in the anaplastic tissue. In nonneoplastic tissue, anaplasia may represent the borderline between dysplasia and neoplasia. Malignant neoplasms are frequently composed of cells that are pleomorphic and anaplastic. Etiology of neoplasms: Genetic disease caused by DNA mutation - monoclonal in essence so all cells are similar. Inherited - include retinoblastoma and multiple poliposis coli. Acquired - can be due to environmental agents, exposure to physical-chemical agents or age. Factors which are responsible for change of normal cells into cancer cells are known as carcinogens. It is believed that all cells carry certain cancer producing oncogenes. Oncogenes are the genes that are responsible for induction of tumors which can be triggered by certain conditions to multiply rapidly into a malignant neoplasm. Etiological agents that induce cancer include: Environmental factors - tobacco, smoking, certain diets and environmental pollutants can cause lung cancer; heavy smoking can cause lung/oral cavity/esophagus cancer and excessive intake of alcohol can cause liver cancer. Chemical carcinogens - includes nickel compounds, cadmium, arsenic, nitrosamines, trichloroethylene, arylamines, benzopyrene, aflatoxins, reactive oxygen radicals, etc. Physical carcinogens - UV rays (ultraviolet), ionizing radiation (x-rays and gamma rays). Biological carcinogen ○ Viruses have been associated with various types of cancers; these cancers are known as oncoviruses. RSV is the first discovered treo-virus causing cancer; others include HPV, Epstein-Barr, Hep. B and HSV. ○ Bacterias - H. pylori can cause stomach cancer. Endogenous factors - include mutations, changes in DNA replication, metabolites of rx, reactive oxygen radicals, immune system defects and aging. The commonly accepted basis of the pathogenesis of cancer is the damage to the genetic cells through either mutation, disturbance of gene expression, activation of tumor promoter genes and/or inactivation of tumor suppressor genes. Oncogenes are mutated genes that have the potential to cause cancer. 4 Before an oncogene becomes mutated, it is called a proto-oncogene and it plays a role in regulating normal cell division. ○ Cancer can arise when they become mutated since the cell divides and multiplies uncontrollably. A tumor suppressor gene encodes a protein that acts to regulate cell division by promoting apoptosis and preventing DNA damage. When a tumor suppressor gene is inactivated by a mutation, the protein it encodes is not produced/doesn't function properly and as a result, uncontrolled cell division may occur. A tumor marker is anything present in or produced by cancer cells or other cells of the body in response to cancer or certain benign tumors. They are proteins or other substances that are made at higher amounts by cancer cells than normal cells. The two main types of tumor markers are: Circulating tumor markers - can be found in the blood, urine, stool or other bodily fluids; they are used to estimate prognosis, determine the cancer stage, detect remaining cancer after treatment or returning cancer, assess how well a treatment is working and/or monitor whether the treatment has stopped working. Tumor tissue markers - found in the actual tumor themselves through biopsies; they are used to diagnose/stage/classify cancer, estimate prognosis and select and appropriate treatment. Respiratory System The respiratory system contributes to homeostasis by providing for the exchange of gasses (O2 and CO2) between the atmospheric air, blood and cells. It also helps adjust the pH of body fluids. Blood pH - 7.35-7.45; average: 7.4 Above 7.45 - Alkalemia Below 7.35 - Acidemia The body’s cells continually use oxygen for metabolic reactions that release energy from nutrient molecules and produce ATP. These reactions release CO2 which can produce acidity when in large amounts so it must be eliminated quickly and e ciently. The cardiovascular and respiratory systems cooperate to supply oxygen and eliminate CO2. Respiratory system - gas exchange Cardiovascular system - transports blood containing gasses between the lungs and body cells. The respiratory system consists of the nose, pharynx, larynx, trachea, bronchi and lungs. The respiratory system can also be classified according to function and structure: 5 Structurally - Upper respiratory system and Lower respiratory system. Functionally - Conducting zone and Respiratory zone. The upper respiratory system includes the nose, pharynx and associated structures. The lower respiratory system includes the larynx, trachea, bronchi and lungs. The conducting zone is a series of interconnecting cavities and tubes both outside and within the lungs. Include the nose, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles. Function to filter, warm and moisten air and conduct it into the lungs. The respiratory zone consists of the tissues within the lungs where gas exchange occurs. Include the respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli. They are the main sites of gas exchange between air and blood. The pharynx is a 5 in. (~13cm) funnel-shaped tube that starts at the internal nares and extends to the level of the cricoid cartilage; laying just posterior to the nasal and oral cavities, superior to the larynx and just anterior to the cervical vertebrae. Its walls are composed of skeletal muscle and lined with mucous membranes. Contraction of these muscles helps in deglutition. Functions as a passageway for air and food, provides a resonating chamber for speech sounds and houses the tonsils. The larynx (voice box) is a short passageway that connects the laryngopharynx with the trachea and lies in the midline of the neck, anterior to the esophagus and 4-6th cervical vertebrae. It is composed of 9 pieces of cartilages: 2 arytenoid cartilages, 2 cuneiform cartilages, 2 corniculate cartilages, a thyroid cartilage (Adam’s apple), a cricoid cartilage and the epiglottis. The epiglottis is a large, leaf-shaped piece of elastic cartilage covered in epithelium. The stem of the epiglottis is the tapered inferior portion attached to the anterior rim of the thyroid cartilage and hyoid bone. The leaf portion is unattached and free to move up and down. During swallowing, the pharynx and larynx rise, widening the pharynx to receive food and the larynx elevates causing the epiglottis to move down and form a lid over the glottis, preventing the food from entering the larynx. The trachea (windpipe) is a tubular passageway for air 5in. long and 2.5cm/1 in. in diameter which is located anterior to the esophagus and extends from the larynx to the superior border of T5, where it divides into the right and left primary bronchi. Has 16-20 incomplete C’s, stacked one above the other and connected by dense connective tissue. ○ The open part of the C faces the esophagus posteriorly and the semi-solid cartilage provides support to prevent the tracheal wall from collapsing inward and obstructing passage of air. 6 The trachea divides at the level T5 into the primary bronchi. At the point where the trachea divides into the right and left primary bronchi an internal ridge is formed called the carina. The right primary bronchus goes into the right lung and is shorter, wider and more vertical. The left primary bronchus goes into the left lung. After entering the lungs, the primary bronchi divide to form smaller bronchi. Secondary (lobar) bronchi - one for each lobe of the lungs (3 in the right and 2 in the left). Tertiary (segmental) bronchi Bronchioles Terminal bronchioles As the branching becomes more extensive, several structural changes can be noted such as: 1. Mucous membrane changes from pseudostratified ciliated columnar epithelium (primary, secondary and tertiary bronchi) to ciliated simple columnar epithelium with goblet cells (larger bronchioles) to ciliated simple cuboidal epithelium with no goblet cells (smaller bronchioles) to nonciliated simple cuboidal epithelium (terminal bronchioles) 2. Plates of cartilage gradually replace the incomplete rings of cartilage in primary bronchi and finally disappear in the distal bronchioles. 3. As the amount of cartilage decreases, the amount of smooth muscle increases. Since there is no supporting cartilage, muscle spasms can close o the airways. (asthma) The lungs are paired, cone-shaped organs in the thoracic cavity. Each lung is enclosed and protected by a double-layered serous membrane, known as the pleural membrane. ○ Parietal pleura - superficial layer, lines the walls of the thoracic cavity. ○ Visceral pleura - covers the lungs. The walls of the alveoli consist of two types of alveolar epithelial cells: Type I Alveolar cells - simple squamous epithelial cells that form a nearly continuous lining of the alveolar wall; it is considered the main site for gas exchange. Type II Alveolar cells - rounded cuboidal epithelial cells with free surface microvilli which secrete alveolar fluid and keep the surface between cells and air moist. Alveolar macrophages are associated with alveolar walls; these are phagocytes that remove fine dust particles and other debris from the alveolar space. The exchange of O2 and CO2 between air spaces in the lungs and the blood takes place by di usion across the alveolar and capillary walls which form the respiratory membrane. The respiratory membrane is very thin (0.5µm thick) and consists of 4 layers: 7 Alveolar walls - a layer of type I and II alveolar cells and associated alveolar macrophages. Epithelial basement membrane - underlying the alveolar wall. Capillary basement membrane - fused to the epithelial basement membrane. Capillary endothelium The lungs contain ~300 million alveoli for gas exchange. Deoxygenated blood enters the pulmonary trunk, which divides into the left and right pulmonary articles, the only arteries to carry deoxygenated blood. The bronchial arteries are a branch from the aorta which delivers oxygenated blood to the lungs; it is mainly used to perfuse the muscular walls of the bronchi and bronchioles. The veins return oxygenated blood to the heart; the 4 pulmonary veins drain into the left atrium. The process of gas exchange is called respiration and consists of 3 basic steps: 1. Pulmonary ventilation (breathing) - the inhalation (inflow) and exhalation (outflow) of air and involves the exchange of air between the atmosphere and the alveoli of the lungs. 2. External (pulmonary) respiration - the exchange of gasses between the alveoli of the lungs and the blood in pulmonary capillaries across the respiratory membrane. It is the process in which capillaries gain oxygen and lose CO2. 3. Internal (tissue) respiration - the exchange of gasses between blood in systemic capillaries and tissue cells. The blood loses O2 and gains CO2. Air moves into the lungs when the air pressure inside the lungs is less than the air pressure in the atmosphere and out when the air pressure inside the lungs is greater than the air pressure in the atmosphere. Just before inhalation, the air pressure inside the lungs is equal to the air pressure of the atmosphere. For air to flow into the lungs, the pressure inside the alveoli must become lower than the atmospheric pressure (760mmHg). The di erence in pressure in respiration is caused by changes in lung volume; they expand to increase in volume and decrease air pressure. Lung expansion consists of the contraction of the main muscles of inhalation, the diaphragm and the external intercostals. Inhalation is considered an active process since this muscle contraction is involved. During exhalation, the pressure in the lungs is greater than the pressure in the atmosphere. Normal quiet exhalation is considered a passive process since no muscle contraction is involved because it results from the elastic recoil of the chest wall and lungs. It becomes active only during forceful breathing. 8 The muscles of exhalation include the abdominals and internal intercostals. The tidal volume (𝑉𝑇 ) is the volume of one breath, the amount of air that moves in and out of the airways during normal quiet breathing. 70% reaches the respiratory bronchioles while 30% remains in the anatomic dead space (nose, larynx, pharynx, etc). The minute ventilation (MV) is the total volume of air inhaled and exhaled each minute. MV = Respiratory rate x Tidal volume A decreased MV is usually a sign of pulmonary malfunction. The alveolar ventilation rate is the volume of air per minute that actually reaches the respiratory zone. The inspiratory reserve volume (IRV) is the additional amount of air taken by a deep breath. Avg adult male - 3,100mL Avg adult female - 1,900mL The expiratory reserve volume (ERV) is the additional amount of air exhaled after a normal inspiration. Avg adult male - 1,200mL Avd adult female - 700mL The forced expiratory volume in 1 second (FEV1) is the volume of air that can be exhaled from the lung in 1 second with maximal e ort following a maximal inhalation. The residual volume is the volume of air remaining in the lungs that cannot be measured. Avg adult male - 1,200mL Avg adult female - 1,100mL The inspiratory capacity is the sum of tidal volume and inspiratory reserve volume. Avg adult male - 3,600mL Avg adult female - 2,400mL The functional residual capacity is the sum of residual volume and expiratory reserve volume. Avg adult male - 2,400mL Avg adult female - 1,800mL The vital capacity is the sum of inspiratory reserve volume, tidal volume and expiratory reserve volume. Avg adult male - 4,800mL Avg adult female - 3,100mL The total lung capacity is the sum of vital capacity and residual volume. Avg adult male - 6,000mL Avg adult female - 4,200mL 9 Dalton’s law states that each gas in a mixture of gasses exerts its own pressure as if no other gasses are present. Atmospheric air consists of 78.6% nitrogen, 20.9% oxygen, 0.04% carbon dioxide and 0.06% other gasses in addition to water vapor. Compared to inhaled air, alveolar air has less O2 (13.6%) and more CO2 (5.25%). Henry’s law states that the quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility. In body fluids, the ability of gas to stay in solution is greater when its partial pressure is higher and when it has a high solubility in water. Internal respiration (systemic gas exchange) consists of the exchange of O2 and CO2 between systemic capillaries and tissue cells. The left ventricle pumps oxygenated blood into the aorta and through the systemic arteries to systemic capillaries. Some factors a ecting pulmonary and systemic gas exchange include: Partial pressure di erences of the gasses - the rate of di usion is faster when the di erence between PO2 in alveolar air and pulmonary capillary blood is larger and the di usion is slower when the di erence is smaller. Surface area available for gas exchange - any pulmonary disorder that decreases the functional surface area of the respiratory membranes, decreases the rate of external respiration. Di usion distance - increase in di usion distance can slow the rate of gas exchange. Molecular weight and solubility of the gasses - when di usion is slower than normal, O2 insu ciency (hypoxia) typically occurs before there is significant retention of Co2 (hypercapnia). Oxygen doesn’t dissolve easily in water. 1.5% of inhaled O2 is dissolved in blood plasma while 98.5% is bound to hemoglobin in RBC. Hemoglobin consists of 2 chains (2 alpha chains and 2 beta chains) and an heme ring. Fully saturated - when reduced hemoglobin is completely converted to oxyhemoglobin (Hb-O2). Partially saturated - when hemoglobin consists of a mix of Hb-O2 and Hb. O2 and Hemoglobin bind to form oxyhemoglobin in a reversible reaction. The most important factor that determines how much O2 binds to hemoglobin is the partial pressure of O2 (PO2). ○ Higher PO2 = more O2 combines with hemoglobin. The factors a ecting the a nity of hemoglobin for O2 are: Acidity - as acidity is increased the a nity of hemoglobin for O2 decreases and O2 dissociates more readily from hemoglobin. ○ This creates a shift to the right so Hb is less saturated; this is known as the Bohr e ect. 10 Partial pressure of carbon dioxide (PCO2) - as CO2 enters the blood, much of it is temporarily converted to carbonic acid (H2CO3) in a reaction catalyzed by carbonic anhydrase. ○ This reaction produces hydrogen and bicarbonate ions. Thus, an increase in PCO2 creates an increase in H+ which decreases pH (more acidity) leading to more O2 being released (curve shifts right). Temperature - as temperature increases, the amount of O2 release from hemoglobin also increases (curve shifts to the right). ○ Metabolically active cells require more O2 and liberate more heat and acids which in turn promotes the release of O2 from oxyhemoglobin. 3-biphosphoglycerate (BPG) - a substrate formed by RBC during glycolysis which decreases the a nity of hemoglobin for O2 and helps unload O2. ○ Can be increased by certain hormones and higher altitudes. CO2 is transported in blood in 3 main forms: 1. Dissolved CO2 - 7% is dissolved in blood plasma. 2. Carbamino compounds - 23% combines with hemoglobin to form carbaminohemoglobin (Hb-CO2). 3. Bicarbonate ions - 70% is transported in blood plasma as bicarbonate ions. Deoxygenated blood returning to the pulmonary capillaries contains: CO2 dissolved in plasma, carbaminohemoglobin and CO2 incorporated into HCO2 within RBCs. The size of the thorax is altered by the action of the respiratory muscles, which contract due to nerve impulses transmitted from the centers in the brain and relax in the absence of nerve impulses. These impulses are sent from clusters of neurons located bilaterally in the medulla oblongata and pons of the brain stem. The respiratory center is divided into 3 areas: Medullary rhythmicity area located in the medulla oblongata - in control of the basic rhythm of respiration with inspiratory and expiratory areas. Pneumotaxic area located in the upper pons - helps in rhythm regulation of the inspiratory area. Apneuristic area located in the pons - stimulates the inspiratory area to activate and prolong inhalation. The respiratory center is regulated by: Cortical influences - voluntary control of respiratory pattern. Chemoreceptor regulation - chemical stimuli to regulate breathing with chemoreceptors to monitor levels of CO2, O2 and H+. ○ Central chemoreceptors - central nervous system ○ Peripheral chemoreceptors - aortic bodies and carotid bodies. Proprioceptor stimulation of respiration Inflation (Hering-Breuer) reflex - protective mechanism Respiratory System: Pathology Diagnostic testing involves: Radiographic imaging ○ Chest X-ray 11 ○ CT ○ MRI/MRA Spirometry Arterial blood glasses Sputum analysis Spirometry is the simplest and most commonly performed pulmonary function test which measures Forced Vital Capacity (FVC) and can also measure Forced Expiratory Volume. Ratios can be performed, which if below the normal limit can be indicative of obstructive lung disease. Arterial blood gas is a diagnostic tool used to evaluate the partial pressure of a gas in blood and acid/base content; it measures the PaO2, PaCO2 in arterial blood and PH. Blood gas analysis can use blood from anywhere but arterial blood gas (ABG) needs arterial blood. Expected values: ○ pH: 7.35 - 7.45 ○ PaCO2: 35-45mmH ○ PaO2: 75-100mmHg Pleural biopsies are performed when suspecting lung neoplasms or to determine the cause of exudative pleural e usion. Respiratory symptoms include cough, hemoptysis, dyspnea and abnormal sounds on auscultation. Obstructive diseases include asthma, chronic bronchitis, emphysema and cystic fibrosis. Asthma Epidemiology - more common in males pre-puberty and females post-puberty, a ects 8% of US population, a ects 340m people worldwide and causes 420,000 deaths yearly. Signs and symptoms - commonly present before 25 y/o but can develop at any given time and include: shortness of breath, cough, wheezing, increased respiratory rate (tachypnea) and tachycardia. Pathophysiology - Clinical syndrome of unknown etiology characterized by recurrent episodes of airway obstruction that resolve spontaneously or with treatment. ○ Physiological hallmarks - resistance to airflow due to airway obstruction resulting from smooth muscle constriction, thickening of the airway epithelium and secretions. Diagnosis - Abnormal pulmonary function tests, altered ABG’s (in moderate/severe cases). CXR is normal, except in severe cases. Treatment - aimed at controlling symptoms and preventing exacerbations with rescue and controller treatments including: inhaled glucocorticoids combined with beta-agonists, short/long-acting B2 adrenergic agonists, inhaled antimuscarinic agents, oral antileukotrienes and systemic glucocorticoids. Inhaled common glucocorticoids include budesonide (pulmicort), fluticasone propionate (Flovent) and fluticasone furoate (Arnuity ellipta). 12 Inhaled common short acting B-adrenergic agonists include albuterol (Proventil HFA, Ventolin HFA) and Levalbuterol (Xopenex HFA). Common combination inhalers include: Symbicort, Breo Ellipta and Advair Diskus/ Advair HFA/Wixela Inhub. Chronic obstructive pulmonary diseases (COPD) include chronic bronchitis, emphysema and cystic fibrosis. Emphysema Epidemiology - adult presentation (typically 60+), 175m a ected worldwide, causing 3.2m deaths/year (3rd leading cause of death). Signs and symptoms - Breathlessness with exertion, chronic shortness of breath, cough with or without sputum production and some present wheezing. Pathophysiology - Progressive lung disease due to damage to airways distal to terminal bronchioles (acinus) causing abnormal and permanent dilatation of the airspaces and destruction of the walls resulting in a decreased surface area, thus decreasing gas exchange. ○ Risk factors include smoking, occupational exposure to chemicals/dust, rarely AR alpha-1 antitrypsin deficiency. Diagnosis - Abnormal pulmonary function tests, abnormal CXR (if severe). If young, recommended to test for alpha-1 antitrypsin deficiency. Treatment - No intervention (except a lung transplant) can reverse or cure it so treatment is aimed at risk-factor modification and managing symptoms through use of bronchodilators (as monotherapy or combination with anti-inflam.) and inhaled corticosteroids. ○ Supportive therapy includes oxygen therapy and ventilatory support to maintain oxygen saturation above 90%. Chronic bronchitis Epidemiology - 3-7% of healthy adults with elderly patients and smokers at higher risk. 74% of those diagnosed with COPD. Signs and symptoms - characterized by a productive cough lasting 3 months or more and occurring within a span of 2 years. Color of the sputum may vary, fever is uncommon (may suggest infection) and wheezing. Pathophysiology - Caused by smoking and inhaled pollutants; acute bronchitis is caused by bacterial/viral infections. Caused by the overproduction and hypersecretion of mucus from goblet cells causing airways to become clogged, impending airflow. Diagnosis - CXR if suspected pneumonia, CBC w/di to rule out infectious origin (if infection is suspected, sputum culture), altered pulmonary function tests. Treatment - Bronchodilators (SABA/LABA, anticholinergic and glucocorticoids), antibiotics therapy is not indicated and smoking cessation. Cystic fibrosis Epidemiology - Prevalence in the US - 1/10,000, 1 in 2,000 white live births; Autosomal recessive 13 Signs and symptoms - Median age of diagnosis is around 6 months old, chronic productive cough, crackles on auscultation and chronic wheezing. Pathophysiology - Caused by a deficient or absent cystic fibrosis transmembrane conductance regulator (CFTR) protein which causes dehydration of mucosal surfaces and visceral secretions that obstruct luminal compartments and ducts. This can a ect the lungs, pancreas, sweat glands, the liver and other organs. Major abnormality in calcium ion channels. ○ Lung disease results from mucus plugging the bronchioles leading to poor ventilation. ○ Prone to infections (Staph and Pseudomon.) Diagnosis - Altered pulmonary function tests, some may have radiographic evidence of sinusitis. In the US, newborns are tested for CF by measuring immunoreactive trypsinogen. Chest X-ray and/or CT are typically abnormal with evidence of cystic bronchiectasis. Treatment - Airway clearance, mucolytics, osmotic drugs, bronchodilators (Beta-adrenergics and anticholinergics), anti-inflammatory agents (Macrolide antibiotics, glucocorticoids and ibuprofen) and lung transplantation. Obstructive sleep apnea Epidemiology - A ects 1 billion people globally (25-30% of men and 9-17% of women) with higher prevalence in hispanic, black and asian people. Signs and symptoms - Loud/chronic snoring, excessive daytime somnolence (50% of patients) and witness sleep-related choking or gasping. Pathophysiology - Characterized by episodes of absent (apnea) or attenuated (hypopnea) upper airway flow for at least 10 seconds followed by arousal and resumption of ventilation. Risk factors include obesity, chest wall movement restrictions and upper airway narrowing. ○ Physiological hallmark: Repetitive cycle of asphyxia and sleep fragmentation. Diagnosis - Nighttime in-laboratory polysomnography Treatment - Lifestyle changes and managing of underlying medical conditions along with Positive Airway Pressure (PAP) therapy. ○ C-PAP - Continuous ○ BPAP - Bilevel Infectious diseases of the lungs include viral/bacterial/fungal pneumonia and upper respiratory infections (URI). Pneumonia Epidemiology - Community-acquired pneumonia is the most common infectious cause of hospitalization/death in the US; it is more common in elders. Signs and Symptoms - Cough, dyspnea, tachypnea, chest pain, can present with or without fever, may present severely ill (depends on infecting pathogen) and crackles over a ected area. Pathophysiology - Acute infection of the lung parenchyma associated with at least one respiratory symptom and abnormal chest imaging. Pneumonia can be viewed as an alteration of homeostasis, leading to a dominant pathogen. Categorized by the etiology of the infecting organism. ○ Hospital acquired or Community acquired (Typical or atypical) 14 Diagnosis - Abnormal opacities in the lungs on CXR or imaging. Lab work demonstrates elevated WBC count (Neutropenia = Bacterial, Leukopenia = Viral), sputum culture and PCR viral testing. Treatment - According to infectious etiology. Community-acquired bacterial organisms include: Typical - Strep. pneumoniae (15-30%), Staph. Aureus, H. influenzae, P. aeruginosa, E. coli, K.pneumoniae, M. catarrhalis Atypical - Mycoplasma pneumoniae, Chlamydia pneumonia, Chlamydia psittaci, Chlamydia trachomatis, Legionella spp. Hospital acquired bacterial organisms include: Gram negative bacteria, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas spp, MRSA. Community acquired viral organisms include: human rhinoviruses, Influenza A/B, Human metapneumovirus, RSV, Parainfluenza 1-3. Coronaviruses. Fungi/parasites capable of causing pneumonia include: Fungi - Pneumocystis jiroveci, Aspergillus spp, Mucorales spp, Histoplasma spp, Cryptococcus spp, Blastomyces spp, Coccidioides spp., Talaromycosis spp. Parasites - Toxoplasma gondii, Strongyloides stercoralis. Upper respiratory tract infection / Epidemiology - Top 3 diagnosis in outpatient setting, adult experience 3-4/year while children experience up to 8/year. The fall season has higher incidence. Catario Signs and Symptoms - Cough, sore throat, runny nose/congestion, headache, low-grade fever,sneezing, malaise, myalgias, can present with concurrent viral conjunctivitis. Pathophysiology - Involves the nose, sinuses pharynx, larynx and larger airways. Common cold. ○ Most common etiology are rhinoviruses but it can also be caused by influenza, adenovirus, enterovirus, RSV, S.pyogenes, and group A streptococcus. ○ Organism is usually acquired by inhalation of infected droplets. Diagnosis - Clinical diagnosis, nasopharynx swab for viral PCR testing, strep swabs can be used to rule out bacterial pharyngitis. Treatment - Symptom relief via decongestants/cough relievers. Tuberculosis (TB) Epidemiology - Present worldwide but developing countries have a higher incidence; WHO estimates there at 1.7m latent infections. Signs and symptoms - Chronic cough, hemoptysis, weight-loss, low-grade fever, night sweats. ○ Ocular manifestations include anterior/posterior uveitis and vitritis. Pathophysiology - Granulomatous disease caused by Mycobacterium tuberculosis caused by infection from inhaling aerosol droplets from infected. It is a multisystemic disease, with primarily a ection for the lungs. For most people, initial contact with the pathogen leads to a latent stage. ○ Physiological hallmark - Caseating granulomas 15 Diagnosis - Tuberculin skin testing: Mantoux test, Interferon release assays (IGRA, more specific) and abnormal CXR. Treatment - First line treatment includes Isoniazid, rifampicin, Rifabutin, Rifapentine, Pyrazinamide, Ethambutol and other microbials. Interstitial diseases of the lungs include: interstitial lung disease and sarcoidosis. Interstitial lung disease Epidemiology - 80/100,000 men and 70/100,000 women. Signs and symptoms - Most frequently reported symptom is dyspnea of gradual onset; also cough, hemoptysis or maybe asymptomatic. Pathophysiology - Collection of distinctive lung disorder characterized by acute and chronic lower respiratory tract disorder with many potential causes. May a ect gas exchange units (alveolar walls, capillaries, alveolar space and acini), bronchiolar lime, terminal bronchioles and pulmonary parenchyma. ○ Etiology can include environmental/occupational exposure, auto-immune disease, idiopathic disease, drug-induced. Diagnosis - Abnormal pulmonary function tests, abnormal imaging. Important to inquire about exposure risk factors. Treatment - Depending on the etiology. Sarcoidosis Epidemiology - 11/100,000 whites, 34/100,000 in african americans; typically, before 50 YO. Signs and symptoms - Persistent dry cough, fatigue, shortness of breath, skin lesions, problems, etc. ○ Ocular manifestations include Anterior/Intermediate/Posterior/ Pan-uveitis and most commonly, bilateral anterior uveitis. Pathophysiology - Multisystem disorder of unknown etiology that presents with noncaseating granulomas in various organs. Can a ect the lungs, skin, eyes, and joints. Diagnosis - CBC with di (Elevated ESR and C-reactive protein), lamba/panda sign on gallium scans, elevated serum lysozyme and elevated ACE. Treatment - In some cases, it can be asymptomatic and require no treatment. If treatment is required, glucocorticoids are used. Lung Neoplasms Lung cancers grow from a single abnormal cell or a small group of abnormal cells that develop into large macroscopic masses that may be several centimeters in diameter. Most lung cancers originate in the bronchial epithelium. Non-carcinoma lung cancers are less common and may include: Carcinoid Pulmonary blastomas (common in younger patients) Sarcomas Lung neoplasm Epidemiology - Most common cancer worldwide. 16 Signs and symptoms - No specific symptoms but can include: cough (50-75%), hemoptysis (15-30%), chest pain (20-40%) dyspnea (25-40%), weight loss and fatigue. ○ 15% can be asymptomatic at time of diagnosis. Pathophysiology - Hypothesized that repeated exposure to carcinogens leads to lung epithelium dysplasia, eventually leading to genetic mutations and a ected protein synthesis ○ Risk factors include smoking (80-90%), occupational exposure to carcinogens (asbestos) and radon. Diagnosis - Pulmonary nodule or mass seen in CXR or CT; bronchoscopy endobronchial ultrasound transbronchial needle aspiration. Treatment - According to lung cancer type and staging: surgical intervention, radiation therapy and systemic (chemotherapy) therapy. The histologic classifications of the primary lung malignancies include: Non-small lung carcinoma - 70-75% Adenocarcinoma - 30-35% Squamous cell carcinoma - 25-30% Large cell carcinoma - 10-15% Small cell carcinoma - 20-25% Combined pattern - 2-10% ○ Mixed squamous and adenocarcinoma ○ Mixed squamous and small cell lung carcinoma. Ocular manifestations of lung neoplasms consist o : Lung Pancoast tumor - wide range of tumors invading the apical chest wall producing a Pancoast-Tobias syndrome. ○ Pancoast-Tobias syndrome - severe shoulder/arm pain along C8-T2, Horner’s syndrome (miosis, anhidrosis, ptosis) and atrophy of intrinsic hand muscles. These tumors account for 3.5% of lung cancers; out of those, 95% are non-small cell lung cancer. Immunopathology In order to maintain homeostasis, there is a need for constant combat against harmful agents; both internal and external. Immunity is the ability to ward o damage or disease through our defense system. The absence of immunity is known as susceptibility. The e cacy of the immune system is determined by the ability to distinguish between foreign and dangerous invaders versus self-components. The two main types of immunity are: Innate (non-specific) immunity - it is the first line of defense against pathogens, made up of physical and chemical barriers (skin, mucous membranes). Its defenses are present at birth and always present; they provide a fast nonspecific response to antigens since it does not have memory. ○ Its cells include monocytes, macrophages, dendritic cells, NK cells, neutrophils, eosinophils, basophils and mast cells. 17 Adaptive (specific) immunity - presents once the antigen has been identified and mounts a specific response to said microbe; it is slow to respond and has a memory component. ○ Its cells include T-cells and B-lymphocytes. Antibodies can combine specifically with the epitope on the antigen; they belong to a group of proteins called globulins (immunoglobulins). Antibodies are composed of a four peptide chain containing: 2 identical heavy (H) chains 2 identical light (L) chains Connected to each other by sulfur bridges. The variable regions of antigens which change depending on the antigen and attach to them are known as antigen-binding site. Constant regions are nearly the same in all antibodies of the same class; they are the distinguishing mechanism between the 5 types of antibodies. Immunoglobulin A (IgA) make up 10-15% of the antibodies present in the body; provide antibodies to newborns; provide localized protection of mucous membrane against bacteria and viruses; can be decreased due to stress; produced by glandular epithelium (nasal mucosa, breast milk, GI secretions, sweat, tears). Immunoglobulin G makes up 75-80% of all antibodies; present in all body fluids; smallest antibody; most common antibody; provides memory immunity; provides passive immunity to the fetus since it crosses the placenta; protects by enhancing phagocytosis, neutralizing toxins and triggering the complement system. Immunoglobulin M (IgM) makes up 5-10% of all antibodies; present in blood and lymph; largest antibody; induces other immune system cells to destroy foreign substances (activates complement system and creates agglutination and eventual lysis of microbes); first antibody to respond to infections. In blood plasma, the anti-A and anti-B antibodies of the ABO group, which bind to A and B antigens during incompatible blood transfusions are IgM. Immunoglobulin D (IgD) is produced in small quantities (0.2%), its functions are unknown but they can activate B-cells; present in the digestive tract and lining tissue of the chest cavity. Immunoglobulin E (IgE) makes up less than 0.1% of antibodies; located on mast cells and basophils; present in the skin, lung and mucous membranes; involved in allergic and hypersensitivity reactions. Also responds to parasites, fungus and animal dander. The methods to acquire adaptive immunity include: Naturally acquired active immunity - following exposure to a microbe Naturally acquired passive immunity - transfer of IgG across the placenta and IgA from breastfeeding. 18 Artificially acquired active immunity - antigens induced during vaccination, they are immunogenic but not pathogenic. Artificially acquired passive immunity - IV injections of immunoglobulins. Hypersensitivity occurs when a foreign substance that is common in the environment and innocuous, triggers an immune response. Commonly known as an allergic reaction. Hypersensitivity reactions can range from minor manifestations (atopic dermatitis. rhinitis) to severe manifestations (anaphylaxis). Hypersensitivities are divided into 4 types of presentations according to their mechanism. Types 1-3 - Antibody mediated Type 4 - T-cell mediated Hypersensitivity Type I reactions are anaphylactic type reactions. Mechanism - IgE mediated release of antibodies against a soluble antigen. ○ IgE binds to mast cells, causing activation which leads to histamine release and other inflammatory mediators. Causes an increase in vascular permeability which leads to edema, constriction of smooth muscle leading to bronchoconstriction and stimulation of mucus secretion. Acute phase is evident within 5-30 minutes after exposure and typically subsides after 60 minutes. ○ Presents with vasodilation, vascular leakage and smooth muscle spasms. Late phase presents in ~50% of individuals, 4-12 hours after initial exposure without additional stimulation. ○ Causes intense infiltration and destruction. Examples of type 1 reactions include: asthma, allergic rhinitis, urticaria, angioedema, food allergies (peanuts, shellfish), allergic conjunctivitis, anaphylaxis. Anaphylaxis - medical emergency leading to acute, life threatening respiratory failure. It is the most severe allergic reaction. Causes bronchospasm, laryngeal edema, cyanosis, hypotension and shock. Hypersensitivity Type II reactions are IgG or IgM mediated cytotoxic-mediated against cell surface and extracellular matrix proteins leading to cellular destruction. Happens in response to cell surface modifications or matrix-associated antigens generating antigenic epitopes. 3 mechanisms: ○ Antibody binding to cell surface receptor, altering cellular activity. ○ Activation of complement pathway. ○ Antibody dependent cellular toxicity. Most common causes include: medications (penicillin, thiazides, cephalosporins, and methyldopa), against organ functions (Grave’s disease, Myasthenia gravis) and hemolytic disease of the newborn. Type II: Cell destruction without inflammation Can occur in 3 main mechanisms: 19 ○ Antibodies (IgG) bind to the target cell’s surface and to macrophages via the Fcy receptor. ○ They can also bind the antibody to the target cell and activate the complement pathway. ○ Antibodies can bind to the target cell and activate the complement pathway and activate the membrane attack complex. (Creates a channel to induce lysis). Both mechanisms act as an opsonin. Seen in hemolytic anemia, autoimmune thrombocytopenia and erythroblastosis fetalis. Type II: Inflammation mediated by complement Antibodies (IgM or IgG) can activate the complement pathway by binding to self-antigens resulting in the formation of complement C3a and C5a. These act as chemotactic factors, recruiting and activating neutrophils. ○ Neutrophils release enzymes and reactive oxygen species, causing lysis on target cells. Type II: Cellular dysfunction by antibodies Autoantibodies bind to the receptors on target cells, causing dysfunction without causing inflammation or destruction. In Hypersensitivity Type III reactions, the Ag-Ab complex initiates an acute inflammatory reaction. The antigen-antibody aggregates act as immune complexes. They can accumulate in multiple tissue locations (skin, vessels, joints), be circulating or fixed (in situ). The accumulation of Ag-Ag aggregates leads to complement activation, leading to recruitment of inflammatory cells which release lysosome enzymes and free radicals at the site, causing tissue damage. Can present as serum sickness or arthus reaction. Serum sickness - caused by drugs containing proteins of other species (antivenom, vaccines, antitoxins, and synthetic monoclonal antibodies). The proteins act as an antigen triggering an immune response. Medium/large complexes are removed from circulation by mononuclear cells, but small/intermediate size complexes are harder to remove and continue circulating. After deposition, an inflammatory reaction begins (~10 days after exposure) with non-specific symptoms like fever, urticaria, arthralgias, proteinuria and adenopathy. After deposition there is activation of the complements (C3a and C5a) which recruit macrophages and neutrophils causing inflammatory damage to tissues. Arthus reaction - localized inflammatory response, typically seen after vaccination at the site of injection after 24 hours. Causes swelling as the injected antigens create antigen-antibody complexes and activate the complement cascade, leading to vasculitis near the injection site. Vasculitis - inflammation of small blood vessels. 20 Hypersensitivity Type IV reactions are delayed reactions mediated by cellular response (T-cells). T-cells mount an inflammatory reaction against endogenous or exogenous antigens. Antigen presenting cells phagocytose the antigen and present it to the T-cells which then become sensitized and activate by releasing cytokines and chemokines to cause tissue damage. These reactions are important in fighting pathogens such as mycobacteria and fungi and play a role in tumor immunity and transplant rejection. Can cause transplant rejection, contact dermatitis (poison ivy), drug hypersensitivity, and tb test (Mantoux/PPD). Transplant rejection - acute transplant rejection occurs due to pre-formed anti-donor antibodies present in the recipient's circulation and can be activated within minutes to a few hours Characterized by widespread acute arteritis, arteriolitis, thrombosis of vessels and necrosis. Some tests for immunodeficiency and autoimmune related diseases include: C reactive protein (CRP) - increased by inflammation and infection. Erythrocyte sedimentation rate (ESR) - for active phase inflammation, measures time for blood cells to sediment, depends on age and gender. Rheumatoid factor (RF) Antinuclear antibody (ANA) test - used for connective tissue disorders. Human leukocyte antigen (HLA-B27) Anti-nuclear cytoplasmic antibodies (ANCA) - can be positive in lupus patients. Antibodies for H. pylori - GI conditions. Diseases of the Immune System Acquired diseases of the immune system include: HIV/AIDS. Congenital diseases of the immune system include: DiGeorge syndrome, Wiskott-Aldrich syndrome and deficiency of IgA. HIV/AIDS Epidemiology - a ected 36.7 million people as of 2016. Signs and symptoms - Primary infection presents 2-4 weeks with non-specific symptoms such as fever, fatigue, adenopathy, myalgia, arthralgia and sore throat. ○ Chronic infection without AIDS - AIDS is defined as a CD4 cell count less than 200 cells/µL. Severe/advanced AIDS is defined as 50 cells/µL. ○ AIDS predisposes the patient to more frequent and severe opportunistic infections like cytomegalovirus (retinitis) and Kaposi sarcoma. Pathophysiology - HIV infection is caused by an enveloped retrovirus that causes AIDS (AIDS is a late-stage HIV infection). HIV attaches to CD4 cells and CCR5 receptors, binding with the cell membrane and entering the T-helper lymphocytes causing DNA changes to produce proteins. Diagnosis - Rapid tests, ELISA test, Western blot, PCR test. Treatment -Highly active antiretroviral therapy (HAART) ○ Prevention - Pre-exposure Prophylaxis (PReP) 21 Di George syndrome Epidemiology - a ects 1/4,000 people since it is the most common immune defect. It a ects both sexes equally. Signs and symptoms - learning/behavior problems (developmental delays), speech/hearing problems, facial abnormalities, congenital heart disease, underdeveloped parathyroid glands, immunodeficiency and absent/hypoplastic thymus. Pathophysiology - Autosomal dominant e ect caused by a deletion on 22q11.2 causing a lack or decrease of T-cells for cellular immunity. Diagnosis - Genetic testing at birth. Treatment - No cure or treatment. Wiskott Aldrich syndrome Epidemiology - rare disease a ecting 1-10/million males. Signs and symptoms - Eczema, thrombocytopenia, immune deficiency, prone to autoimmunity/inflammatory disease (autoimmune hemolytic anemia/vasculitis/IBS) and increased risk of lymphoma. Pathophysiology - X-linked autosomal recessive genetic disease caused by mutations in the WAS gene. Diagnosis - In the first year of life; testing in males with eczema and thrombocytopenia; decreased IgM, and in some cases IgA and IgE; genetic testing. Treatment - No treatment, just symptom management. Selective IgA deficiency Epidemiology - most common of the primary immunodeficiency disorders. Signs and symptoms - most a ected individuals are asymptomatic but they have higher propensity for asthma, rheumatoid arthritis, gluten intolerance and IBS. Pathophysiology - Deficiency of IgA (less than 7mg/dL). Lack of infections due to overlapping and compensation of other immune functions. Diagnosis - Serum IgA levels Acquired autoimmune conditions include: Rheumatic disease - Systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Ankylosing spondylitis and Sjogren’s syndrome. Pernicious anemia Grave’s disease Multiple sclerosis Rheumatic diseases are connective tissue diseases in which general or localized inflammation is associated with pain, weakness or loss of function; many of them tend to be associated with ocular inflammations. Tend to a ect females more than males. The 6 most common rheumatic diseases include: Rheumatoid arthritis, Systemic lupus erythematosus, Systemic sclerosis, Spondyloarthropathies (Ankylosing spondylitis and psoriatic arthritis), Sjogren’s syndrome and vasculitis. Rheumatoid arthritis is a chronic systemic inflammatory disease of unknown etiology that primarily targets synovial tissue. 22 The primary target of rheumatoid arthritis is the joints, but it can also have systemic manifestations. Caused by strong genetic and environmental factors like smoking, asbestos, silica. Epidemiology - global prevalence of 0.24% (2010), a ects 40/100,000 people in the USA, higher prevalence in women. ○ Risk factors include obesity and smoking. Mechanisms - presence of antibodies against citrullinated proteins which produces an inflammatory cascade. Signs and symptoms - joint pain, swelling (first in small joints and then large joints); hallmark signs include morning sti ness. ○ Ophthalmic manifestations include secondary Sjogren’s, episcleritis and scleritis. Diagnosis - + RF (80-90%) and elevated CRP/ESR. Treatment - NSAIDS, corticosteroids, methotrexate and hydroxychloroquine. Systemic Lupus erythematosus is a systemic autoimmune disease with multisystemic involvement (skin, kidneys, heart, eyes) and unknown etiology. Epidemiology - 10x more common in women, more probable in women of childbearing age, highest incidence in african americans (even presenting younger). Mechanism - a breakdown in tolerance in genetically susceptible individuals which leads to the activation of autoimmunity. Signs and symptoms - fatigue, malaise, fever, anorexia and weight loss, musculoskeletal involvement, cardiac involvement, pulmonary involvement, lupus nephritis and GI manifestations. ○ Mucocutaneous manifestations include malar/butterfly rash. ○ Ophthalmic manifestations include keratoconjunctivitis sicca, retinal vasculitis, optic neuritis, uveitis, scleritis and episcleritis with higher incidence of drug-induced damage (Plaquenil/Steroids). Diagnosis - + ANA test. Treatment - According to the presentation: plaquenil, corticosteroids (oral/topical) and NSAIDS. Sjogren’s syndrome is a systemic autoimmune disorder of unknown etiology presenting with severe dryness (sicca) due to inflammation and damage to lacrimal and salivary glands. ⅓ of the patients also develop extra-glandular involvement of the joints,skin, lungs, GI, nervous system and/or kidneys. Frequently occurs in conjunction with other immune conditions like Rheumatoid arthritis and Systemic lupus erythematosus where it is known as Secondary Sjogren’s. Epidemiology - a ects 0.5-1% of the population (400,000-1,000,000 adults) of which 50% also have Rheumatoid arthritis. Typically a ects more females than males. Diagnosis - mainly clinical diagnosis but confirmed via a biopsy of the salivary glands. Relevant lab tests include ANA, RF, SS-A and SS tests as well as tear and salivary functions tests. Treatment - management of dry eye via lubricant drops, punctal plugs, cyclosporine drops and serum tears. 23 Grave’s disease is an autoimmune disease that primarily a ects the thyroid gland but can also a ect the eyes and skin; it is the most common cause of hyperthyroidism (60-80%). Epidemiology - higher incidence with positive family history, 1.2% USA prevalence, more common in females (aged 20-50). Mechanism - caused by thyroid stimulating immunoglobulin (TSI) synthesized by B-cells within the thyroid; they bind to the TSH-receptor to stimulate production of TSH which stimulates thyroid hormone synthesis and thyroid gland growth. Signs and symptoms - heat intolerance, sweating, fatigue, weight loss, palpitations, nervousness, anxiety and goiter. ○ The inflammation can also cause: exophthalmos, eyelid retraction, periorbital edema, chemosis, injection and exposure keratitis. Diagnosis - TSH, free T4, free T3, total T4 and total T3. ○ Typically TSH is decreased while free T3 and free T4 are increased. Treatment - antithyroid drugs, radioactive iodine and total/partial thyroidectomy. Pernicious anemia is a rare autosomal disorder (less than 1%) which causes a decrease in vitamin B12 absorption resulting in megaloblastic anemia. Epidemiology - a ects people of all ages but is more common in people over 60. More common in patients of autoimmune gastritis (a ects 25%), diabetes type 1, autoimmune thyroid disease and vitiligo. Mechanism - intrinsic factor that facilitates B12 transport is inhibited and anti-IF antibody prevents intestinal absorption. Vasculitis Giant cell (temporal) arteritis is a systemic inflammatory vasculitis of medium and large arteries. Epidemiology - typically a ects elders and rare in patients younger than 50; a ects 20/100,000 people making it the most common vasculitis; a ects females more than males. Mechanism - immune-mediated inflammatory changes in vessel walls. ○ Risk factors include smoking. Diagnosis - temporal artery biopsy as well as elevated ESR and CRP. Signs and symptoms - constitutional symptoms like weight loss, malaise and fever; headache; scalp tenderness; jaw claudication; enlargement of the temporal artery (unilateral or bilateral). ○ Ophthalmic manifestations include anterior ischemic optic neuropathy (AION) and transient vision loss/amaurosis fugax. Treatment - anti-inflammatories. Takayasu arteritis aka “pulseless disease” is a systemic inflammatory condition that creates damage to large and medium arteries that lead to stenosis, occlusion or aneurysmal damage. Mechanism - abnormality in cell-mediated immunity but etiology is unknown. Epidemiology - more common in females, a ects young patients (40-50 y/o), rare in North America; most common in Asian or Mexican countries. Diagnosis - by arterial imaging abnormalities using CTA or MRA. Signs and symptoms - are nonspecific: fever, malaise, weight loss, anorexia. ○ Ophthalmic manifestations include visual defects, retinal hemorrhages and total blindness.