Resp (introduction-1).pdf

THE RESPIRATOTRY SYSTEM Introduction ANATOMY  The respiratory tract is divided into: 1- Conducting system: nasal cavity, sinuses, larynx, trachea, bronchi, and bronchioles 2- Exchange system: Lung (alveoli) Nasal Cavity  Longi...

THE RESPIRATOTRY SYSTEM Introduction ANATOMY  The respiratory tract is divided into: 1- Conducting system: nasal cavity, sinuses, larynx, trachea, bronchi, and bronchioles 2- Exchange system: Lung (alveoli) Nasal Cavity  Longitudinal section (sheep) D E V LT Dorsal concha (Turbinate) (D) Ethmoidal conchae (E) ventral concha (V) LT = lymphoid tissue meatuses narrow spaces (arrows) Longitudinal section (Horse) Cross section Histology 1- mucosa: lined by pseudo-stratified ciliated epithelium with goblet cells (arrows) 2- Submucosa : Connective tissue containing glands (arrow heads) , blood vessels (BV) Physiology  Oxygenation  Temperature regulation  Olfaction  Acid-base  Blood Pressure  Detoxification  Normal population of bacterial  Harmless except under stresses (viruses)  Example: Mannheimia haemolytica (Shipping Fever" in cattle ) General Pathology Escape of blood from the cardiovascular system may be external or internal bleeding into the intestinal lumen According to location According to Size Reaction of living tissue against local injury to eliminate it and prepare for repair It accompanied by: 1- Vascular changes 2- Cellular changes (inflammatory cells) Gross finding (acute)  EXUDATE  Fluid that leaks out of blood vessels into tissues.  The fluid is made of cells, proteins, and solid materials.  Dermatitis, vesicular Fluid rich in protein, few cells Causes Mild injuries (trauma, cold, blisters, sunburn) Grosslly yellow or clear fluid  CATARRHAL EXUDATE (MUCOID EXUDATE )  Exudate is mostly MUCUS with few inflammatory cells  Mucous is produced by goblet cells  Inflammation of a mucous membrane (GIT, Respiratory, Urogential) Grosslly Enteritis, mucoid Thick, sticky, semi-translucent  Exudate is mostly FIBRIN with inflammatory cells  Leakage of fibrinogen from blood vessels Fibrinogen turns into fibrin  Inflammation of mucous & serous membrane  Acute &severe Grossly Yellow sheet adhere to the surface Histo: Thread-like eosinophilic meshwork Fibrous Chronic Fibrous connective tissue lead to adhesion Origin: fibroblast Fibrinous Acute Origin: Fibrinogen (Plasma protein)  purulent exudate  Exudate is mostly PUS (Dead neutrophils release proteolytic enzymes liquefies the tissue)  Abscess is localized form  Cellulitis is diffuse form Grossly Opaque, thick, colored fluid (white, brown , green) May be of bad odor Histo: Many Dead and live NEUTROPHILS  Type of CHRONIC INFLAMMATION  Cause: irritant resist phagocytosis (Fungus, Mycobacteria, Plant material,….) Grossly Nodules contain cheesy-like material (caesous necrosis) Histo: Macrophages Predominate + Some Lymphocytes & Plasma Cells Giant Cells (circled)  Exudate is mostly bloody (RBCs) + inflammatory cells Distribution  Duration  Peracute  Acute  Subacute  Chronic Chronic-Active Agranulocytes Granulocytes Neutrophils Eosinophils lymphocytes plasma cells  Macrophages Giant Cells large vesiculate nuclei, eosinophilic cytoplasm