Intro to Biovet Flashcards
Define DISEASE
A disease is an alteration of the state of the body or some of its organs that interrupts proper performance of bodily functions. It may be manifested by physical signs. clinical signs or it may be subclinical.
Define SUBCLINICAL
Subclinical is where a disease does not show any outwards signs. It is the stage of development of a disease before symptoms have developed.
Define AETIOLOGY
Aetiology is the cause of a disease.
Define PATHOGENESIS
Pathogenesis is the origin and development of a disease.
Define PATHOLOGY
Pathology is the study of the cause, origin, nature and the effect of a disease.
Define a PATHOGENIC ORGANISM
A pathogenic organism is an organism capable of causing a disease in its host.
What are some features of pathogenic organisms?
- can be passed from one person/horse to another
- reaches susceptible host/tissue
- multiplies to infective level numbers
- produce toxins/enzymes
- able to survive outside the host
What are some methods of host resistance?
- primary defences (e.g. skin)
- phagocytosis
- inflammation
- fever
- general good health
- immunity
What factors may cause disease in a horse?
- grazing/pasture management
- stabling
- companions and social contact
- infection, injury and parasites
- exercise
What are some visual parameters that must be monitored?
- eating/drinking habits
- level of alertness
- number/consistency of droppings and urine
- coat condition - is it shiny or dull?
- breathing rate
- level of sweating
- body condition
- colour of mucous membrane in the gums
What are some non-visual parameters that must be monitored?
- heart rate
- temperature (+sudden changes in temp).
What is the role of the immune system?
The immune system is the body’s defence against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease.
Define IMMUNITY
Immunity is the state of a body having adequate biological defences to fight off disease and infection
Define INNATE IMMUNITY
Innate immunity is non-specific and present from birth. It does not increase with subsequent exposure. Includes:
- anatomical barriers
- antibacterial secretions
- prevention of stasis (stoppage of slowdown of bodily fluid, e.g. blood or lymph).
Define ACQUIRED IMMUNITY
Acquired immunity develops in response to antigen exposure and creates an immune memory. e.g. chicken pox.
What are some physical barriers to disease?
- skin - secretes sebum (fatty acid) that inhibits fungal/bacterial growth
- mucous membrane - release lysozyme (an enzyme that can break down the outer cell walls of bacteria) and controls mucous in the respiratory tract
What are the different types of epithelial tissue?
- squamous - blood vessels
- cuboidal - digestive tract
- columnar - stomach lining
- ciliated - respiratory tract
What are the components of the immune system?
The tonsils and thymus, which make antibodies.
The lymph nodes and vessels (the lymphatic system)
Bone marrow - produces all blood cells
The spleen, which filters the blood by removing old or damaged blood cells and platelets and helps the immune system by destroying bacteria and other foreign substances.
White blood cells.
What is the non-specific inflammatory response?
- inflammatory cells bind to bacterial receptor sites and induce two mechanisms: macrophage and neutrophils
- damaged tissues release histamines. This increases blood flow to the area
- histamines cause capillaries to leak, releasing phagocytes and clotting factors into the wound
- phagocytes engulf bacteria, dead cells and cellular debris
- platelets move out of the capillary to seal the wounded area
Define PHAGOCYTOSIS
Phagocytosis is where an inflammatory cell englufs the pathogen
Define PHAGOCYTES
A phagocyte is a type of cell within the body capable of engulfing and absorbing bacteria and other small cells and particles.
How does the immune system work?
- first line of non-specific defence (e.g skin)
- second line of non-specific defence (e.g. white blood cell general attack of a foreign body).
- a specific, targeted defence
The targeted defence may be faster if the pathogen has invaded before, as WBC will have a memory of how to fight them.
Define a MACROPHAGE
A macrophage is a large phagocytic cell found in stationary form in the tissues or as a mobile white blood cell, especially at sites of infection.
Define a NEUTROPHIL
Neutrophils are the most abundant type of granulocytes and the most abundant (60% to 70%) type of white blood cells in most mammals. They form an essential part of the innate immune system.
