deck_16456568 Flashcards
Is innate immune system present at birth
Yes
Does innate imune system distinguish one threat type from another?
No it is non-specific
Physical barriers and chemical barriers
Components of innate immunity
skin and mucous membranes
phagocytes
Components of innate immunity
cells that engulf pathogens
immune surveilance
Components of innate immunity
destruction of abnormal cells by NK cells
Interferons
Components of innate immunity
Chemicals against viral infections
Complement
Components of innate immunity
Circulating proteins that assist antibodies
Inflammation
Components of innate immunity
Localized tissue-level response to limit spread of infection
Fever
Components of innate immunity
elevation of body temperature
First line of defence
innate immunity
External physical and chemical barriers
stop from entering body
Second line of defence
innate immunity
Internal defences, nk cells, interferons, etc…
used if things get in body
Integumentary system
1st line of defence
- Stratified squamous epithelium
- secretions
- hair
Mucous membranes
1st line of defence: physical barriers
- Mucous
- Hairs
- Cilia - move from lungs to throat
Lysozyme
chemical barriers
enzyme that break down cell walls of certain bacteria
Lacrimal apparatus
chemical barriers
found in eyes
saliva
chemical barriers
washes microbes from teeth and mouth
urine, vaginal secretions
move microbes out of body
types of Phagocytes
second line of defence
monocytes and macrophages
neutrophils
dentritic cells
Neutrophils
phagocytes
most abundant, fast acting
Monocyte-macrophage system
phagocytes
macrophages function as APC’s
Dendritic cells
phagocytes
found in tissue that has contact with outside environment
Eosinophils
phagocytes
less abundant
destroy antibody coated pathogens/foregin compounds
- Chemotaxis
5 steps of phagocytosis
movement of phagocyte due to attraction of chemicals
- Adherance
5 steps of phagocytosis
attachment of phagocyte to target
- Ingestion
5 steps of phagocytosis
“false feet” are formed and engulf target cell
- Digestion
5 steps of phagocytosis
Lysozomes, proteosomes bind with phagosome
- Killing
5 steps of phagocytosis
death of target cell and release of debris
What is immune surveillance?
constant monitoring of tissues by NK cells
What are tumour specific antigens
immune surveillance
often in cancer cells that NK cells recognize/destroy
Presense of unusual plasma membrane activate NK cell leading to
Steps of NK recognition and destruction
NK cell adhering to target
Golgi apparatus moves within NK cell to target cell
Steps of NK recognition and destruction
Produces vesicles containing perforins
What happens to perforins released from NK cell
Steps of NK recognition and destruction
They arrive at target cell
What do perforins do at once they rech target cell?
Steps of NK recognition and destruction
Create pores in target cell membranes
What are interferons
second line of defence
Small proteins released by activated lymphocytes
What do interferons do?
second line of defense
trigger production of antiviral proteins (cytokines)
What is complement system?
second line of defense
system that complements action of antibodies
What is the classical pathway?
Complement system
most rapid/effective
attach to antibody molecules
MAC complex
what is the lectin pathway?
complement system
activated by mannose-binding lectin protein
activate inflammatory response
enhances opsonization
What is alternative pathway
complement system
Several complement proteins interact in plasma
attachment of activated protein
What are the effects of complement system
- pore formation/cell lysis
- enhanced phagocytosis
- histamine release
What are iron binding proteins
Inhibit growth of bacteria by reducing availble iron
What are antimicrobial proteins
short peptides that have broad spectrum of antimicrobial activity
Which substances contribute to vasodilation and increased permeability
Histamine
Kinins
What are 3 stages of inflammatory response
- Vasodilation/increased permeability
- emigration of phagocytes from blood to IF
- Tissue repair
What does emigration of phagocytes depend on?
Chemotaxis
What substance helps with tissue repair
Fibroblasts
What is a pyrogen?
fever-inducing protein
what are benefits of fevers
- inhibit bacteria/virus
- accelerate tissue defense and repair process
