chapter 22 Lymphatic
Susceptibility
lack of resistance or being vulnerable to disease
Innate (Nonspecific) Immunity
present at birth
includes defense mechanisms that provide general protection against invasion by a wide range of pathogens
Innate (Nonspecific) Immunity
Adaptive (Specific) Immunity
involves activation of specific lymphocytes that combat a specific pathogen or other foreign substance
Drain excess interstitial fluid and return it to the blood; transport dietary lipids, carry out immune repsonses
Lymphatic System functions
where lymphatic vessels begin
lymphatic capillaries
located between cells of many tissues
lymphatic capillaries
merge to form lymphatic vessels
lymphatic capillaries
one-way structure that allows interstitial fluid to flow in-not out
lymphatic capillaries
Minivalves
the closed ends of lymphatic capillaries
lymphatic vessels
merge from lymphatic capillaries
resembles small veins but have thinner walls and more valves
lymphatic vessels
lymph nodes
flows through lymphatic vessels
contains lymphocytes B and T cells
lymph nodes
when pressure in interstitial fluid increases, fluid can flow in but when pressure inside of capillary is greater, cells adhere closer and fluid cannot flow back out
lymphatic capillary overlap
forms the wall of lymphatic capillary overlap
endothelial cells
thoracic (left lymphatic) duct
largest lymphatic vessel
main duct to return lymph to blood
thoracic (left lymphatic) duct
Lacitials
specialized lymphatic capillaries in small intestine
carry dietary lipids into lymphatic vessels
lactials
chyle
white lymph
lipids the lacteal that causes lymph draining the sm intestines
chyle
Respiratory pump
helps lymph return to blood
lymph flow maintained by pressure changes during breathing
respiratory pump
skeletal muscle pump
contraction of skeletal muscles compresses the lymphatic vessels and pushes the blood toward the junction of internal jugular and subclavian veins
primary lymphatic organs
red bone marrow and thymus
stem cells divide and become immunocompetent
red bone marrow
where most immune response occur (secondary lymphatic organs/tissue)
lymph nodes, spleen, lymphatic nodules (follicles)
afferent lymphatic vessels
carry lymph toward the center of node then enter sinuses in the lymph node
subcapsular sinuses-->trabecular sinuses-->medullary sinuses
afferent lymphatic vessels
efferent lymphatic vessels
where the medullary sinuses drain into
wider and fewer in number than afferent vessels
efferent vessels
exit the lymph node at the hilum along w/ blood vessels
efferent lymphatic vessels
lymph nodes
main function is filtration
foreign substances get destroyed by macrophages by phagocytosis and lymphocytes by immune response
lymph nodes
how filtered lymph extis the node...
through efferent lymphatic vessels
foreign substances gets trapped in reticular fibers in the sinuses
when lymph enters the node
spleen
largest mass of lymphatic tissue
parenchyma
white pulp and red pulp
white pulp
contains mostly lymphocytes and macrophanges
located in spleen
white pulp
removal by macrophages of ruptured, worn out or defective blood cells and platelets
red pulp
red pulp
consists of venous sinuses and splenic cords (Billrotins cords)
located in spleen; storage of platelets; productions of RBC during fetal life
red pulp
The first line of defense...
skin and mucous membrane
Second line of defense...
anitmicrobial substances, phagocytes, nautral killer cells, inflammaton, fever
inerferons, iron-binding proteins, complement system, antimicrobial proteins
antimicrobial substances
virus infected cells release IFNs that travel to uninfected neighbor cells and induce the production of antiviral proteins that prevent the virus from replicating
Interferons
Iron-binding proteins
inhibit growth of certain bacteria by reducing the available amount of iron needed for various processes
complement system
proteins in blood plasma and plasma membrance thatenhance certain immune reactions
causes cytolysis of microbes, promote phagotytosis, contribute to inflammation
compliment system
Antimicrobial Proteins (AMPs)
short peptides with a broad spectrum of antimicrobial function
Attract dendrito cells and mast cells that participate in immune activity
antimicrobial proteins (AMPs)
Natural Killer Cells (Nk)
attack any body cells that contain unusual or abnormal plasma proteins
releases chemicals perforin adn grandzymes
Natural Killer Cells (NK)
Granzymes
chemical released by natural killer cells and cytotoxic T cells
protein digesting enzymes that induce the target cell to self destruct (apoptosis)
Granzymes
kills infected cells, not microbe
Granzyme
phagocytes
ingestion of microbes and other particles
neutrophiles and macrophages
phagocytes
wandering macrophages
moves around the body through blood stream and lymph nodes searching and engulfing foreign particles
fixed macrophages
remain in a specifi area of the body such as brain, lungs, liver, kidneys or bones
pain, redness, immoblility, swelling, heat
s/s of inflammation
epitopes
small parts of an antigens molecule that acts a trigger for immune repsonse; recognized by B and T cells
Antigen-presenting cells (APCs)
a special class of cells tha process and present the antigens to T cells, triggering the adaptive immune response
dendrites, macrophages, and B cells
Antigen-presenting cells (APCs)
Exogenous Antigen Processing
antigens that are present in fluids outside the cell
Enodgenous Antigen Processing
antigens that are present inside the cell
Costimulation
a process whre theT cells only beome activated when they bind antigens and at the same time receives a second signal
neutralizing antigens, immobilizing bacteria, agglutinating antigens, activates compliment system, enchances phagocyosis
Antibody actions
Antigens
substances recognized as foreign that provoke immune responses
Specificity and memory
properties of adaptive immunity
Adaptive Immunity
refers to the body's ability to defend itself against specific invading agents
cell-mediated (adaptive immunity)
cytotoxic T cells directly attack invading antigens
antibody-mediated (humoral) (adaptive immunity)
b cells turn into plasma cells that form antibodies
B cells
capable of secreting an antibody that is identical to the antigen receptor displayed by the B cell that first responded
Active helper T cells
vital part of adaptive immunity by helping to activate other immune cells to fight infection and disease
Active helper T cells activated...
when their CD4 protein receptors interact with MHC II molecules on the surface of antigen presenting cells
goes under colonal selection-results in clone of active helper T cell and memory helper T cells
Active helper T cells
signals by releasing cytokines which send messages to other immune cells to start immune response
Active Helper T cells
B cell colonal selection
once activated, it undergoes clonal selection resulting in formation of plasma cell and memory B cells
MHC I Endogenous Antigen Processing
antigen to peptide fragments-synthesis of MHC-I molecules in endoplasmic-fragments bind to MHC I molecule-package of anitgen- MCH 1 molecule into vesicle-vesicle undergoes exotcytosis and antigen-MHC I are inserted into membrane
Exogenous Antigen Processing
phago or endocytosis of antigen-antigen to peptide fragement-synthesis of MGC II molecules-packaging of MHC II into a vesicle-vesicle containging antigen-peptide fragments and MCH II fuse-peptide fragments bind to MHC II molecules-vesicle undergoes exocytosis adn antigen- MHC II complexed are inserted into membrane
CD4 protein and T cells
inactive helper T cells recognize exogenous fragements assoc with MCH II molecules on APC- C4 proteins aids in interaction between helper T cell and APC-the helper T cells becomes activated
CD 8 and T cells
turn into cyotoxic T cells which recognize foreign antigens with MHC I molecules
Activation of cytotoxic T cells
maximal activation requires presentation to both MCH I and MCH II
compliment system
defensive system made of proteins
destroys microbes, cytolysis, inflammation and prevents excessive damage to tissues
compliment system
opsonization
increase phagocytosis by coating a microbe promoting attachment of the phagocyte to microbe
formed by C8 and C9 molecules and other compliment proteins that is inserted into membane which the complex then creates channels in membrane causing cytolysis
Membrane attack complex
Naturally acquired active immunity
formation of anti-secreting plasma cells, cytotoxic T cells, and T and B memory cells following exposure to a microbe
Naturally aquired passive immunity
large antibodies are transferred from mother to fetus across the placenta, or transferred from mother to baby via breastfeeding
Artificially acquired active immunity
antigen introduced during vaccination
Artificially acquired passive immunity
intravenous injection of antibodies
vasodilation and increase in premeability of blood vessels
inflammatory response
emigration of phagocytes from blood into interstitial fluid
inflammatory response
mphatic sac in the abdomen that serves as a reservoir for lymph fluid and is the origin of the thoracic duct
cisterna chyli
receives lymph from the abdominal and pelvic viscera and lower limbs, and drains it into the thoracic duct
cisterna chyli