Week 2- Immune System Flashcards
Describe innate immunity (3)
First line of defence against invading pathogens
Fast acting
Non-specific, no memory
Doesn’t improve after exposure to antigen
Always present
Activates adaptive immune system
Specific when particular to the pathogen
Non-spec when indicates a degree of resistance to infections
List physical barriers
Skin and mucous membrane
List chemical barriers
Gastric acid
Lysosome
Lactoferin
Nitric acid
List cell barriers
Phagocyte and natural killer
List protein defence barriers
Complement, acute phase proteins and interferons
List mechanical removals
Sneezing
Coughing
Secretions
Urine
Perisatalsis
Ciliary escalator
Respiratory mucosa
List colonisation resistance barrier
Skin
Gut micro biome
List types of host defence mechanisms
Physical barrier
Chemical barriers
Cell
Protein
Mechanical removal
Colonisation resistance
List certain factors which reduce the effectiveness of this protection
• Breach of physical barrier (i.e. trauma, burns, eczema)
• Loss of chemical barriers (i.e. drugs which inhibit gastric secretion)
• Suppression of the cough reflex (i.e. opiates, neurological disease)
• Failure of respiratory mucus clearance (i.e. smoking, asthma, cystic fibrosis)
• Failure of washing mechanism (i.e. urinary stasis)
• Loss of colonization resistance (i.e. broad spectrum antibiotic use
List factors that influence the level of innate immunity
Age
• Very old or very young are more susceptible to infectious disease
Hormones
• Endocrine disorders such as Diabetes Mellitus, hypothyroidism and adrenal dysfunctions create
enhanced susceptibility to infection.
• Increased corticosteroid - decreased anti-inflammatory effect.
Nutrition
• Immune response is reduced in malnourished patient
Medications
Detox immune system
Diet
Stress
In recombination, what protein is called upon to alter dna
Major histamine compatibility
MCH2
Why does recombinbantion occur
In order for an antigen to be presented on the phagosomes cell surface
Why do monocytes undergo exocytosis
Monocytes are not antigen presenting cells
Instead they transport the pathogen out of the cell by vesicle docking at plasma membrane, fusing with the cel membrane and are released outside the cell in apoptic bodies
Once exocytosis is undergpon, an antigen is also released from the cell
What are apoptotic bodies
A controlled for of cell death
Small fragments contain cellular components and are packaged by cuytosplasm of ‘monocyte’ type cell to ensure safely packaged cells.
Doesn’t cause inflammatory response of cause damage
List the 4 functions of complement system
- Lysis of infectious organisms
- Activation of inflammation
- Opsonisation
- Immune clearance
Once antigens are presented/ floating where do they move to
Lymph nodes
Once antigens are presented/ floating where do they move to
Lymph nodes
In lymph nodes what occurs to the antigen involving a B-cell
B-cell rejectors on a b-cell binds to the antigen.
Recombination occurs
The MCH2 molecule presents the antigen
In lymph nodes what occurs with the antigen and a t-cell
Antigen contacts t-cell receptor which activates cd4. T-cell locks on to the antigen on the macrophage’s presented antigen.
T-cell needs to be activated to stimulate the b-cell
Cell turns from naive to mature and active via interlukin cell 2,4,5,6. Undergoes colonial expansion by creating other b-cells presenting this antigen (Memory cells)
Differentiation occurs where some cells are plasma cells and some are antibodies, memory cells.
T-cells create t helper cells