immune system test Flashcards
2 parts of immune response
innate and adaptive
the innate immune system is
nonspecific, 2 parts
part 1 of innate immune system
physical/chemical barriers to keep contaminants out
part 2 of innate immune system
responses like macrophages, inflammation, and fever to keep microbes at bay
adaptive immune response
how the body learns to specifically target and eliminate contaminants
skin
(normally) solid barrier that stops bacteria from getting inside inside the body
the outer layer of the skin is coated in
protein keratin
function of keratin in the skin
works with other lipids and proteins to form a tight seal separating inside from out
The outer cells of the skin
is continuously shedding , this is called desquamstion
desquamation takes
attached microbes with them
the skin secretes waxy, oily
sebum
sebum gives the skin a pH of about what
5.5
pH of sebum is
acidic compared to body’s 7.4
change in pH due to sebum can cause
denature enzymes in bacteria, slows their function
95% of infections from
begin in the mucous membranes
5% of infections result from
vector bites
Other pH barriers to microbes
saliva
stomach
vagina
saliva pH
roughly neutral (7)
pH of stomach after a meal
2
pH of stomach at rest
3.5
inside of vagina pH
4
what are the OTHER physical barriers to microbes
mucus, urinations, defectation, vomitting, tears, hairs and cilia
where is MUCUS found
airway, esophagus, stomach, intestines, cervix (females)
how does mucus affect microbes
microbes stick to it and are broken down by protein and/or expelled from the body
what washes microbes out of the body
urination, defcetation, vomiting and tears
hairs in the nose and cilia in the windpipe can….
stop microbes from entering the lungs
because of cilia…. bacteria are pushed
up and away from the lungs through the mucociliary elevator
if a particle is detected in the airway
extremely sensitive nerves in the airway will force a cough reflex
lysozyme (a chemical barrier)
lysozyme is an enzyme in tears, mucus, breast milk, saliva
lysozyme function
breaks apart peptidoglycan, kills bacteria
what is peptidoglycan
main component of bacterial cell walls,
normal flora
bacteria living on it in a mutualistic relationship
instead of harming the body………
many benefits
benefits of normal flora
- nutrients that the body can’t normally provide (B12)
- competition for space and nutrients,
- create compounds that kill other bacteria
- modify the pH of an area to make it inhospitable to other bacteria
competition for space and nutrients causes
makes it hard for bad bacteria to survive
how much human cells in the body
10^13
how much symbiotic bacteria in the human body
10^14
first step of phagocytosis
- chemotaxis and adherence of microbes to phagocyte
second step of phagocytosis
- ingestion of microbe by phagocytosis
step 3 phagocytosis
formation of a phagosome
step 4 phagocytosis
fusion of the phagosome with a lysosome to form a phagolysosome
step 5 phagocytosis
digestion of ingested microbe by enzymes
step 6 phagocytosis
formation of residual body containing indigestible material
step 7 phagocytosis
discharge of waste materials
phagocytes
white blood cells that eat and destroy foreign contaminants through phagocytosis
types of phagocytes
neutrophils
macrophages
dendritic cells
neutrophils function
eat bacteria
macrophages function *
eat everything that dosen’t have a proper ID
dendritic cells function*
eat surroundings that show PAMPS
macrophages and dendritic cells
present digested guts to surrounding cells, especially T cells
what is PAMPs
micro-associated patterns
PAMPs
pathogen-associated molecular patterns
peptidoglycan (PAMPs)
main bacterial cell wall component, gram positive
peptidoglycan chemical surrounds
membranes of many bacteria
if a bacterial membrane contains a thick layer of peptidoglycan
gram positive
why is something gram positive
turns purple when dyed w/ Gram method
if it does NOT turn purple hen dyed with the gram method
gram negative… turns pink instead
LPS (PAMPs)
main bacterial membrane component, gram negative
LPS
lipopolysaccharides
what are LPS
long chains of sugars that attach to membranes of gram-negative bacteria with thin peptidoglycan layer
Flagellin (PAMPs)
a protein found in bacterial flagella
many bacteria have a flagellum
to help them move through the body
many flagellum
flagella
main protein in flagella
flagellin, is a PAMP
Double stranded RNA (PAMPs)
found in viruses
glucans (PAMPs)
major component of fungal cell walls
PRRs
Pattern Protein Receptors
where are PRRs found
they are proteins found on the plasma membrane of macrophages
job of PRRs
recognize PAMPs
2 main types of PRRs;
Phagocytosis receptors
TLRS
Phagocytosis receptors
binding to a PAMP causes the onset of phagocytosis..
phagocytosis receptors are only found in
phagocytes
TLRs
toll-like receptors
TLRs function
bidning to PAMP causes the activation of genes coding for cytokines
what are cytokines
signalling proteins
where are TLRs found
phagocytes, epithelial cells and MORE
there are many kinds of TLRs that each
recognize specific microbial compoents
each TLRs trigger the
release of some cytokines
cytokines are….
small proteins produced by various white blood cells
cytokines are produced in response to
PAMP binding to a TLR
cytokines can be
autocrine
paracrine
endocrine
autocrine (cytokine)
meaning they act on the red blood cell that secrets them
paracrine (cytokine)
they act on nearby cells
endocrine (cytokine)
travel longs distances in the body
3 things tat cytokines cause to happen
- vasodilation of blood vessels
- upregulation or downregulation of genes
- white blood cell hematopoiesis
3 OTHER THINGS that cytokines can cause
- production of antobodies
- apoptosis
- inhibition of viral replication
chemokines
are a type of cytokine, attract molecules through chemical signals
two categories of chemokines
homeostatic
inflammatory
homeostatic chemokines
attract various types of white blood cells to the area and invoke diapedesis