Hereditary Spherocytosis
Epidemiology and Etiology Epidemiology Etiology In HS, gene mutations lead to cytoskeletal protein deficiency: Pathophysiology Clinical Presentation General features Categories Four clinical categories have been established based on hemoglobin (Hb), reticulocyte (retic) count, and bilirubin (bili) level. Diagnosis History and physical exam Initial tests Confirmatory tests Management and Complications Management Complications Differential Diagnosis The differential […]
Chalazion
Epidemiology and Etiology Epidemiology Etiology Occurs due to gland blockage, which can be associated with: Pathophysiology and Clinical Presentation Pathophysiology Clinical presentation Diagnosis and Management Diagnosis Diagnosis is clinical based on the history and physical exam. Management Differential Diagnosis References
Retinal Vessel Occlusion
Anatomy The internal carotid artery enters the skull through the carotid foramen and branches into the ophthalmic artery, which further divides into: The central retinal artery; supplies the inner ⅔ of the retina) The posterior ciliary arteries (branch retinal artery); supply the outer ⅓ of the retina The central retinal vein Drains either into the […]
Esophageal Cancer
Epidemiology and Etiology Epidemiology Etiology Table: Epidemiology of and risk factors for esophageal cancer Adenocarcinoma Squamous cell carcinoma Sex Male Male Race Caucasians African Americans, Asians Major risk factors Barrett’s esophagus, smoking, obesity Smoking, alcohol consumption, low vegetable and fruit intake, drinking hot liquids, caustic strictures, achalasia Clinical Presentation and Complications Clinical presentation Table: Esophageal […]
Cellular Adaptation
Definition Adaptation: Hypertrophy Overview Physiologic hypertrophy Pathologic hypertrophy Mechanism Hyperplasia Overview Physiologic hyperplasia Pathologic hyperplasia Mechanism Atrophy Overview Physiologic atrophy Pathologic atrophy Mechanism Metaplasia Overview Clinical correlation Mechanism Clinical Relevance References
Diabetes Insipidus
Epidemiology Pathophysiology Role of antidiuretic hormone (ADH) Antidiuretic hormone is also called vasopressin. Function: Antidiuretic hormone regulates serum osmolality and blood pressure. Production: Central DI Central diabetes insipidus is caused by the insufficient production of ADH from the hypothalamus or insufficient release from the posterior pituitary gland. Nephrogenic DI Nephrogenic diabetes insipidus is caused by an insufficient response […]
Retinal Detachment
Overview Definition Retinal detachment is the separation of the retina from the underlying retinal pigment epithelium and choroid. Anatomy Retina: Innermost layer, containing photoreceptors that convert light stimuli into nervous impulses Rods: black-and-white vision (function in dim light) Cones: color vision (function in bright light) Optic retina Neural or neurosensory layer Contains the photoreceptor cells […]
Vaccination
Overview Active and Passive Immunization Active immunization Passive immunization Types of Active Vaccines Table: Types of active vaccines Vaccine type Description Pros Cons Examples Live attenuated Microorganism loses its pathogenicity but retains capacity for transient growth within inoculated hosts. Induces cellular and humoral responses Induces strong, often lifelong immunity May revert to virulent form Often […]
Anal Fistula
Definition and Epidemiology Definition Epidemiology Etiology and Pathophysiology Etiology Pathophysiology Clinical Presentation History Physical exam Diagnosis and Management Diagnosis Types of fistula Management Mnemonic Why fistulas stay open: “FRIENDS” Differential Diagnosis References
Anal Fissure
Definition and Epidemiology Definition Epidemiology Etiology and Pathophysiology Etiology Pathophysiology Clinical Presentation Diagnosis and Management Diagnosis Management Mnemonic The “Ds” of anal fissures: Differential Diagnosis References