INNATE AND ADAPTIVE IMMUNITY Flashcards
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PRIMARY LYMPHOID ORGANS
Bone marrow
Thymus
SECONDARY LYMPHOID ORGANS
Spleen
Lymph nodes
Mucosal-associated lymphoid tissues (MALT)
Cutaneous-associated lymphoid tissue (CALT)
maturation of B lymphocytes and NK cells
Bone marrow
maturation of T lymphocytes
Thymus
One of the largest tissues in the body
bone marrow
function of bone marrow
source of hematopoietic stem cells
B cells is named after
bursa of Fabricius in birds
Immature T cells appear as early as
8 weeks in gestation
Site of T-cell maturation and
differentiation
thymus
Largest secondary lymphoid organ, Acts as a large discriminating filter, Removes old and damaged cells and
foreign antigens from the blood
spleen
Makes up over half the spleen’s volume
Destroys old and damaged red blood cells
red pulp
Only 20% of the spleen’s total weight
Contains lymphoid tissue arranged around
arterioles in the periarteriolar lymphoid sheath
(PALS)
PALS contains mainly T cells
White Pulp
Central collecting points for lymph fluid from adjacent tissues
Filtration of interstitial fluid allows contact between lymphocytes and foreign antigens
lymph nodes
Filtrate of blood from water and lowmolecular-weight solutes
Lymph fluid
Mucosal-Associated Lymphoid Tissues
Tonsils
Appendix
Peyer’s patches
small masses of macrophage lining oral and pharyngeal cavities
Tonsils
near the junction of the small intestine and the large intestine and has abundant infection-fighting lymphoid cells
Appendix
specialized type of MALT located at the lower ileum of the intestinal tract
Peyer’s patches
Resistance through normally
present body functions, nonspecific, and no prior exposure required
INNATE (NATURAL) IMMUNITY
Specific resistance for each
pathogen
Memory and specificity, increased
response upon repeated exposure
ADAPTIVE IMMUNITY
what line of defense does innate immunity belong
first and second line of defense
what line of defense does adaptive immunity belong
third line of defense
components of innate immunity
External Defense System
Internal Defense System
Anatomical barriers (e.g., skin, mucous membranes) that prevent pathogen entry.
External Defense System
Activated if external barriers are breached; includes cellular responses and phagocytosis.
Internal Defense System
external defense systems
Physical
Chemical
Biological
chemicals in:
skin
respiratory tract
stomach
vagina
found in tears and saliva
lactic acid, fatty acids, psoriasin
mucus, cilia
gastric acid, hydrochloric acid
lactic acid
lysozyme
physical barriers in unbroken skin
epidermis
dermis
Consists of tightly packed epithelial cells coated with keratin, making it impermeable to most infectious agents.
Epidermis
Contains connective tissue, blood
vessels, hair follicles, sebaceous
glands, sweat glands, and white
blood cells (WBCs) such as macrophages, dendritic cells, and
mast cells.
Dermis
protein in epidermis that it makes the skin impermeable to most infectious agents.
keratin
helps maintain an acidic skin pH of approximately
5.6
Block bacterial adherence and
contain surfactants that bind
to and help remove microorganisms.
Mucous Secretions
Cilia in the nasopharyngeal
passages move approximately
90% of deposited material out
of the respiratory tract.
Ciliary Action
Mechanisms to expel pathogens.
Coughing and Sneezing
Flushing action and slight
acidity help remove pathogens.
Urine
production maintains a vaginal pH of about (), preventing
pathogen invasion.
Lactic acid; 5
pH of digestive tract
pH 1
Found in tears and saliva, this enzyme attacks the cell walls of microorganisms, particularly gram-positive bacteria.
lysozyme
Resident microorganisms that inhabit specific body sites and help prevent pathogen establishment by competing for
resources and producing antimicrobial substances.
normal flora
proteins in the gut that disrupt the membranes of certain bacteria.
colicins
consists of cells and soluble
factors that perform specific
and crucial functions in
combating infections.
INTERNAL DEFENSE
serve as sensors for
extracellular infections. they activate phagocytic cells, enhancing their ability to engulf and destroy invaders.
PATHOGEN RECOGNITION
RECEPTORS (PRRs)
distinguish self from non-self
by recognizing PAMPs, which are
specific to microorganisms
PATHOGEN-ASSOCIATED
MOLECULAR PATTERNS
TLRs that are found on cell surfaces
TLR1
TLR2
TLR4
TLR5
TLR6
TLRs that are found in the
endosomal compartment of a cell
TLR3
TLR7
TLR8
TLR9