Immunology Flashcards
What the Immune System Protects Against?
- Bacteria/Parasites
- Tumour Cells
- Toxins
- Virus’
- Fungi
- Foreign Cells/Particulates
Characteristics of the Immune System
- Highly specific
- Widespread
- Memory
- Pathogen species and strains
- It moves
- Extremely fluid, constantly changing
- Determines non self
- Every organ and system
Blood Composition
- 55% plasma - complements/coagulation proteins
- 0.1% buffy coat - white blood cells, platelets
- 45% red blood cells
Examples of Non-Specific Immunity
- Physical barrier
- Secretion eg tears, saliva
- Cellular eg phagocyte
Non-Specific Response
- No memory
- Non-specific
- 1st line of defence
3 Responses of Non-Specific Immunity
- Inflammation
- Phagocytosis - find non self and digest them
- Natural Killer Cells - Not B or T cells. Kill cancer, virus, bacteria, infected cells
The Purpose of Inflammation
Increase temperate for optimum activity. Increase dilation causing vessels to be leaky. Increases permeability for large white blood cells.
Stages of Inflammation
- Bacteria enters through barrier
- Platelets stop blood flow forming a clot
- Most cells secrete factors that cause vasodilation/vascular constriction. Delivering blood, plasma and white blood cells to area
- Neutrophils secrete factors that kill pathogens
- Macrophages remove pathogens
- They also secrete cytokines hormones, that trigger more immune response and repair process of mitosis
- Inflammatory response continues until materials gone and wound repaired
What is Chronic Inflammation?
Macrophage in injured tissue release toxins that injure/dmg tissue eg reactive oxygen species
Stages of Phagocytosis
- They’re attracted to chemical trails of pathogens
- The phagocyte has receptors at its surface that attach to the pathogen’s antigens
- Phagocytes engulfs pathogen turning it into a phagosome
- Lysosomes fuse with phagosome (vesicle)
- Lysosomes release lysozyme enzymes that hydrolyse and break down phagosome. Smaller soluble material absorbed into the cytoplasm of the phagocyte
Natural Killer Cells
- Identify “non-self” in the form of infected/corrupted cells
- Secrete enzymes such as proteases to destroy “non-self”
- Destroy both cell and the infection within
- Can also destroy cancerous cells
Cell-Mediated Response
- Phagocyte engulfs pathogen
- Phagocyte presents pathogens antigens on its surface membrane
- Receptors in helper T Cells fit to pathogens antigens
- T Cells rapidly divide into cytotoxic T Cells and;
- Either develop into memory cells or stimulate B Cells to divide and excrete their antibodies
Humoral/B Ceel Response
- Pathogens antigens taken into B Cell by endocytosis
- B-Cell processes and presents antigens
- Helper T Cells attach antigen to B Cell, activating it
- B Cell divides by mitosis into plasma and memory cells
Immunoglobins and What they are For
- IgG - direct neutralisation
- IgM - activates complement proteins
- IgP - unsure
- IgE - Anaphylaxis and parasites
What is Microbiology?
The study of organisms that cannot be seen by the naked eye
Types of Microbes
- Fungi
- Bacteria
- Virus
- Parasite
What is the Importance of Microbiology?
- Infection of the largest causes of morbidity and mortality
- About 30% of patients are there for infection are on antibiotics
- 10% of patients acquire infections in hospital
Common Bacterial Infections
- Bacterial Meningitis - Brain
- Otitis Media - ear
- Eye
- Gastritis - stomach
- Food Poisening - intestinal
- UTI
- STD - sexual organs
- Pneumonia (many bacterial causes) - lungs
Common Viral Infections
- Eye
- Parotitis - mumps in lymph throat
- Common cold
- Encephalitis/Meningitis - brain
- Pharyngitis - pharynx
- Pneumonia
- Myelitis - stomach
- Gastroenteritis - intestines or stomach
- Pancreatitis - pancreas
- STD
- Skin infections
- Hepatitis - liver
- Gingivostomatitis - throat/trachea
What is Sepesis?
Life threatening condition that arises when the body has an overreactive immune response causing its own tissues/organs to be dmg’d
Rare but serious complication of an infection
Cause of Sepesis and Septic Shock
- Triggered by minor infection such as UTI, cytisis, appendicitis, cellulitis, chest infections or serious infections
- Septic shock is life threatening and is characterised by low blood pressure and organ dysfunction or failure
Who’s at Risk of Sepsis? (8)
- Very young (under 1)
- Older people (75+) or very frail
- Impaired immune system
- Surgery in last 6 weeks
- Cuts, burns, blisters, skin infections
- Misuse of intravenous drugs
- Ppl with indwelling lines or catheters
- Medication - cancer/chemotherapy, diabetes, long term steroids, tumour suppressant drugs, splenectomy/sickle cell
Early Symptoms of Sepsis
- Increased temperature or decreased temperature
- Chills and shivering
- Rapid heartrate
- Rapid breathing
Late Symptoms of Sepsis
- Dizzy/faint/loss of consciousness
- Confusion/disorientation/slurred speech
- Diarrhoea
- Severe muscle pain
- Sever breathlessness
- Less than normal urine output
- Feeling of impending doom
- Cold, clammy, pale, mottled skin
