Disease Development Lesson 3 PDF

DEVELOPMENTAL ANOMALIES ======================= These are malformations that occur during the growth and development of a tissue or organ. Developmental anomalies, also called congenital diseases, are present at birth. Some are classified as genetic diseases, such as brachycephalic obstructive airw...

DEVELOPMENTAL ANOMALIES ======================= These are malformations that occur during the growth and development of a tissue or organ. Developmental anomalies, also called congenital diseases, are present at birth. Some are classified as genetic diseases, such as brachycephalic obstructive airway syndrome (BOAS) or von Willebrand Disease (vWD), while others, such as cerebellar hypoplasia in kittens exposed to panleukopenia in utero, are not based in genetics. Examples include polydactyly, palatoschisis, progressive renal atrophy, renal hypoplasia, or cardiac defects. Pictures of some disorders are provided below. 1. 2. 3. 4. Developmental Anomaly Definitions --------------------------------- ### Agenesis ### Aplasia  ### Hypoplasia ADAPTIVE LESIONS ================ Adaptive lesions are acquired by an organism in response to a change in homeostasis. They are characterized by adaptive responses of cells to the changes in physiologic demands made upon them. A lesion is a circumscribed area of pathologic tissue. Hyperplasia ----------- Physiologic hyperplasia -----------------------  Metaplasia ---------- Pictures of a cow ovary with metaplastic replacement of normal ovarian cells with squamous epithelial cells. Dysplasia ---------  Hypertrophy -----------  NEOPLASIA ========= The term neoplasia means "new growth". A neoplasm is an abnormal mass of tissue, the growth of which exceeds that of normal tissues, is haphazard in organization, and persists in the same manner after the cessation of the growth stimulus which evoked the change. If allowed to continue, growth may cause death of the animal. TERMINOLOGY ----------- ### Neoplasia  Picture of a cat with a neoplasia on its nose and face ### Tumor  #### *[Benign]* tumor Image of a benign lipoma- gross on the left and histopathology on the right #### Malignant tumor  ##### [Cancer] https://images.slideplayer.com/36/10580971/slides/slide\_4.jpg METASTASIS ---------- This is the greatest threat to a patient with malignant neoplasia, it is a very complex process. To occur, tumor cells must detach from the primary mass, gain entrance to the bloodstream or lymphatics, penetrate a vessel wall, escape the vessel, and invade tissue. Or cells are physically carried to other locations, such as by surgical instruments. If a tumor cell enters the lymphatic system, it will be carried to a lymph node.  CLASSIFICATION OF TUMORS ------------------------ Tumors are either mesenchymal or epithelial origin. Mesenchymal tissue is a term describing connective tissue and muscles. It is a component of all organs except the central nervous tissue. Epithelial tissue is that which covers or lines structures, or makes up the secreting portions of glands and their ducts. Most neoplasms are of one tissue type, so they fit into one of these groups. Some are a mixture of more than one neoplastic cell type, called mixed neoplasms. For example, mixed mammary tumors of dogs are tumors containing epithelial and mesenchymal tissues, including bone, cartilage, and muscle. Mixed mammary tumors can be either benign or malignant, although most are benign. https://slideplayer.com/slide/12800697/77/images/8/Classification+of+Tumours+According+to.jpg ### Benign versus malignant nomenclature  ETIOLOGY OF NEOPLASIA --------------------- In most cases, the cause of a specific tumor is unknown. Certain factors have been identified as causing cancer. These substances are called carcinogens. THE THREE CATEGORIES OF CARCINOGENS ----------------------------------- ### Chemicals ### Physical agents ### Viruses The diagram below shows the most common causes of cancer in humans. ZOONOTIC DISEASE ================ These are diseases that transmit from animals to humans and cause disease. Some cause minor problems, such as diarrhea caused by *Salmonella*, while others are severe and cause large numbers of fatalities, like some strains of Ebola. Many zoonotic diseases are infectious diseases, but not all are caused by pathogens such as bacteria and viruses. Some are caused by transmissible proteins called prions. Scrapie, mad cow disease, and chronic wasting disease are examples of this. As we go through the different types of pathogens, diseases, and parasites, we will discuss which ones are zoonotic. Some zoonotic diseases have such high public health or economic impact they are categorized as reportable diseases. This means once they are suspected or diagnosed, the veterinarian must report them to the State Department of Public Health. The speed of such reporting varies depending upon the impact of the disease. The current reportable disease list for Georgia is shown here.  NECROPSY ======== A necropsy is a thorough post-mortem evaluation of an animal to determine or confirm cause of death. It is performed in two stages: the gross necropsy and the microscopic necropsy. Necropsies should always be performed in a set manner to ensure no portions of the process are forgotten. The steps are described below, but might vary between individual veterinarians and pathologists. From the terms necro- dead, and --opsy- denoting medical examination or inspection. In humans, they are called post-mortem exams or autopsies- from auto- meaning self (i.e. same species). It's good to have a guide in your clinic.  Gross Necropsy -------------- ### External evaluation ### Head and oral cavity evaluation  ### Musculoskeletal evaluation ### Body cavity approach #### Overall abdominal evaluation  #### Gastrointestinal tract evaluation #### Splenic evaluation  #### Hepatic evaluation #### Adrenal gland evaluation  #### Urinary tract evaluation #### Reproductive tract evaluation Mare Reproductive Tract - ppt video online download #### Overall thoracic evaluation  #### Removing the pluck #### Respiratory system evaluation  #### Cardiovascular system evaluation #### Musculoskeletal system evaluation  #### Neurologic system evaluation