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Lymph System

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lymphatic vessels, lymphoid tissues
2 semi-independent parts
lymphatic vessels
transport fluids that have escaped from the blood vessels back to the blood
lymphoid tissues and organs
scattered throughout the body; house phagocytic cells and lymphocytes
phagocytic cells,lymphocytes
play roles in body defense and resistance to disease
lymphatic vessels
pick up lymph and return it to bloodstream in a one-way system, flowing towards the heart
lymph
excess tissue/interstitial fluid
lymphatics
another name for lymphatic vessels
lymph capillaries
microscopic, blind-ended; spider-web between the tissue cells and blood capillaries in the loose connective tissue of the body that absorb the leaked fluid; very permeable
lymphatic collecting vessels
large lymphatic vessels through which lymph is transported from lymph capillaries
right lymphatic duct, thoracic duct
large ducts in thoracic region through which lymph is returned to the nervous system
right lymphatic duct
drains lymph from right arm, and right side of the head, and thorax
thoracic duct
receives lymph from areas where right lymphatic duct does not drain from
subclavian vein
right lymphatic duct and thoracic duct empty into this on their own side of the body
muscular and respiratory pumps
transport lymph
lymph nodes
help protects body by removing foreign material from the lymphatic stream and by producing lymphocytes; filters lymph
lymphocytes
function in immune response
inguinal, axillary, cervical
where large clusters of lymph nodes are found
macrophages
located within nodes; destroy and engulf bacteria viruses, and other foreign substances in the lymph before it is returned to blood
nodes
where lymphocytes are found
lymph nodes
become swollen during infection
afferent lymphatic vessels
where the lymph enters the convex side of the node
sinuses
lymph flows through here while in nodes
hilus
where lymph exits nodes
efferent lymphatic vessels
how lymph exits hilus
more afferent vessels than efferent
why flow of lymph is slow through node
spleen
located in left side of abdominal cavity and extends to curl around the anterior aspect of the stomach
spleen
blood-rich organ that filters and cleanses blood of bacteria, viruses, and other debris; destroys RBC's and returns some of their products to the liver; stores platelets and acts as blood reservoir; in fetus, it is an important hematopoictic site
lymphocytes
produced in adult spleen
thymus gland
functions at peak levels during youth
thymus gland
found low in throat, overlying heart
thymus gland
produces hormone thymosin and others that function in the programming of certain lymphocytes to carry out protective roles in the body
tonsils
small masses of lymphatic tissue that ring the pharynx, where they are found in the mucosa
tonsils
trap and remove any backteria or other foreign pathogens from entering the throat
tonsilitis
tonsils become congested with bacteria and become red, swollen, and sore
peyer's patches
resemble tonsils; formed in the wall of the small intestines
peyer's patches
prevents bacteria from penetrating intestinal walls
mucosa associated lymphatic tissue
tonsils and peyer's patches are part of this
mucosa-associated lymphatic tissue
collection of small lymphoid tissues
mucosa-associated lymphatic tissue
MALT
mucosa-associated lymphatic tissue
protects upper respirator and digestive tracts from attacks of foreign mattering entering those cavities
surface membrane barriers, cells and chemicals
nonspecific body defenses
non specific body defense
responds immediately to protect the body from all antigens
surface membrane chemicals
skin and mucous membrane line body cavities and produce protective chemicals
acid pH of skin secretions
inhibits bacterial growth
sebrum
contains chemicals that are toxic to bacteria
stomach mucosa
secretes HCl and protein-digesting enzymes
protein-digesting enzymes
kill pathogens
pathogens
disease-causing microorganisms
eysozyme
contained in saliva and lacrimal fluid
eysozyme
enzyme that destroys bacteria
cells and chemicals
second line of defense
phagocytes
macrophage and neutrophil
natural killer
attacks target cell's membrane and releases a lytic chemical, which causes the target cell's membrane and nucleus to disintegrate
inflammatory response
triggered whenever body tissues are injured
inflammatory response
redness, heat, swelling, pain
histamine and kinins
inflammatory chemicals that are released when cells are injured
inflammatory chemicals
cause blood vessels in the involved area to dilate and capillaries to become leaky
inflammatory chemicals
activate pain receptors
inflammatory chemicals
chemotaxis
chemotaxis
the attraction of white blood cells to the site of inflammation
complements and interferon
antimicrobial chemicals
complements
enhances the effectiveness of both nonspecific and specific responses
complements
refers to a group of at least 20 plasma proteins that circulate in the blood in an inactive state
complete fixation
the activation of when complement becomes attached to foreign cells
membrane attack complexes
MAC
membrane attack complexes
one result of complete fixation
membrane attack complexes
produces lesions/holes in the foreign cell's surface, which allows water to rush into the cell, causing it to burst
opsonization
activated complement amplifies the inflammatory response and causes the foreign cells to become sticky so they are easier to phagocytizie
interferon
small proteins secreted by virus-infected cells
interferon
help defend cells that are not yet invaded, by binding to their membrane receptors, hindering the ability of viruses to multiply within these cells
fever
systemic response to invading microorganisms; WBs release pyrogens
pyrogens
resets the internal thermostat in the hypothalamus during a fever
mild/moderate fever
beneficial because they cause the liver and spleen to gather up iron and zinc and increase the metabolic rate of tissue cells in general, speeding up the repair process
high fever
dangerous because excess heat denatures enzymes and proteins
immune system
specific body defense
immune system
mounts an attack against particular foreign substances; results in immunity
immunity
a highly specific resistance to disease
antigen-specific, systemic, has memory
three important aspects of the immune system
antigen
any substance capable of provoking an immune response
antigen
are considered non-self
non-self
our own cells have antigenic markers on them, but as we developed, our bodies took inventory of them, so they are recognized as "self"
lymphocytes, macrophages
cells of the immune system
b-lymphocytes and t-lymphocytes
two types of lymphocytes
b cells
b-lymphocytes
t cells
t-lymphocytes
b cells and t cells
both start out as the same immature lymphocyte, differentiate depending where in the body they receive immunocompetence
immunocompetence
capable of responding to a specific antigen by binding to it
t cells
arise from lymphocytes that migrate to the thymus, where they undergo a maturation process of 2-3 days, directed by thymic hormones
t cells
only those with the sharpest ability to identify foreign antigens survive. The ones capable of binding strongly with self-antigens are weeded out and destroyed
b cells
develop immunocompetence in bone marrow
genes
determine what specific foreign substances our immune system will be able to recognize and resist
lymph nodes, spleen, and loose connective tissue
where t and b cells migrate after becoming immunocompetent where their encounters with antigens occur
macrophages
arise from monocytes formed in the bone marrow
macrophages
become widely distributed in lymphoid organs and connective tissue
macrophages
not only engulf particles, but also "present" fragments of those antigens on the surface, so immunocompetent t cells can recognize the antigen
macrophages
act as antigen presenters
killer macrophages
activated t cells release chemicals that cause macrophages to become insatiable phagocytes
macrophages
tend to remain fixed in the lymphoid organs; whereas t cells circulate the body
humoral immune response
provided by antibodies present in the body's fluids
clonal selection
after an antigen binds to a b cell's surface receptors, it becomes fully mature, by becoming sensitize/activated and undergoing this
clone
the lymphocyte begins to grow and then multiplies rapidly to form an army of cells identical to itself and bearing the same antigen specific receptors, the resulting family of identical cells descended from the same ancestor cell called this
plasma cells
most clones become these
plasma cells
produce antibodies
memory cells
the b cells that do not become plasma cells become these
memory cells
capable of responding to the same antigen at later meetings with it
active immunity
naturally acquired during bacterial and viral infections, during which you may develop symptoms of the disease
active immunity
artificially acquired when you receive vaccines
vaccines
most contain dead or attenuated pathogens
attenuated
living but extremely weakened
passive immunity
antibodies are not made by your plasma cells, they are required from an immune human or animal donor; since your b cells were never challenged, memory does not get made and protection ceases when the antibodies break down
passive immunity
conferred naturally on fetus when mother's antibodies cross the placenta and enter the fetal circulation, and after birth through breastfeeding; baby is protected from all antigens to which the mother is currently being exposed to
passive immunity
conferred artificially when one receives immune serum or gamma globolin
passive immunity
conferred artificially when scientists use monoclonal antibodies for research, clinical testing for diagnostic purposes, and treating certain cancers
immune serum
poisonous snake bites, botulism, rabies, tetanus-because these diseases will kill a person before active immunity will be established
gamma globolin
given after exposure to hepatitis
monoclonal antibodies
produced by descendants of a single cell and exhibiting specificity for one antigen
antibodies
aka immunoglobuuns
immunoglobuuns
produced by plasma cells; specific for a particular antigen
MADGE
antibody classes
IgM
can fix complement; first one released to plasma from plasma cells; potent agglutinating agent
IGA
aka secretory IgA
Iga
found mainly in mucus and other secretions that bathe the body surfaces
IgA
plays major role in preventing pathogens from gaining entry into the body
IgD
important in activation of B cells
IgG
most abundant Ig in blood plasma
IgG
only one that can cross the placental barrier; can fix complement
IgE
binds to basophils, triggering release of histamine, mediating inflammation and certain allergic responses
antibody function
inactive antigens by complement fixation, neutralization, agglutination, and precipitation
neutralization
occurs when antibodies bind to specific cites on bacterial exotoxins or on viruses that can cause cell injury, thus blocking the harmful effects of the exotoxin or virus
bacterial exotoxin
toxic chemicals secreted by bacteria
precipitation
occurs when so much agglutination/clumping occurs that the antigen-antibody complex settles out of solution
cellular immune response
provided by t-lymphocytes
cellular immune response
activated to form clones by binding with a recognized antigen; however unlike B cells, t cells cannot bind with free antigens, they must be presented by a macrophage
cytoxic, helper, suppressor, memory
four types of clones (t cells)
cytoxic
killer t cell
cytoxic
t cells that specialize in killing virus-infected, cancer, or foreign graft cells; one way is by binding to them and inserting a toxic chemical into the foreign cell's plasma membrane, rupturing the target cells
helper
t cells that act as the directors or managers of the immune system
helper
t cells that once activated, circulate through the body, recruiting other cells to fight invaders
helper
t cells that release cytokine chemicals that act indirectly to rid the body of antigens by stimulating cytotoxic t cells and b cells to grow and divide, attracting other types of protective white blood cells to the area, and enhancing the ability of macrophages to engulf and destroy microorganisms
suppressor
t cells that release chemicals that suppress the activity of t and b cells
suppressor
t cells that are vital for winding down and finally stopping the immune response after an antigen has been destroyed
suppressor
t cell that helps prevent uncontrolled or unnecessary immune system activity
memory
t cells that remain behind to provide the immunological memory for each antigen encountered and enable to body to respond quickly to its subsequent invasions
organ transplant and rejection
after transplant, patient needs to take immunosuppressant drugs so t hey won't reject transplanted tissue; this could cause lethal bacterial or viral infections
allergies, immunodeficiencies, autoimmune disorders
disorders of immunity
allergies
aka hypersensitivities
allergies
abnormally vigorous immune response in which the immune system causes tissue damage as it fights of a perceived "threat" that would otherwise be harmless to the body
immediate hypersensitivity
usually occurs within seconds of exposure and lasts about half an hour; histamine released
immediate hypersensitivity
can cause runny nose, watery eyes, hives, asthma
immediate hypersensitivity
rarely body-wide systemic allergic response
hives
itching, reddened skin
anaphylactic shock
occurs when allergen gets directly into blood stream, histamine causes vasodilation of systemic blood vessels, decrease blood pressure, shock, death
anaphylactic shock
immediate treatment is epinephrine
delayed hypersensitivities
takes about 1-3 days
delayed hypersensitivities
lymphokines are released instead of histamine, so corticosteroid drugs are used to proved relief, instead of antihistamines
allergic contact dermatitis
follows skin contact with poison ivy, some heavy metals, and certain cosmetic and deodorant chemicals
immunodeficiences
includes both congenial and acquired conditions in which the production or function of immune cells or complement is abnormal
severe combined immunodeficiency
marked deficit of both b and t cells; afflicted children have no protection against pathogens of any type
severe combined immunodeficiency
treatments include bone marrow transplants and umbilical cord blood for stem cells; without treatment, must live behind protective barriers
acquired immune deficiency syndrome
cripples immune system by interfering with activity of helper t cells
autoimmune disorders
when immune system loses ability to tolerate self-antigens; attacks self
multiple sclerosis
destroys white matter of brain and spinal cord
myasthenia gravis
impairs communication between nerves and skeletal muscles
graves disease
thyroid gland produces excessive amounts of thyroxine
type I diabetes mellitus
destroys pancreatic beta cells, resulting in deficient production of insulin
systemic lypusery thematosus
a systemic disease that occurs mainly in young females and particularly affects the kidneys, heart, lungs, and skin
glomerulonephritis
severe impairment of kidney function
rheumatoid arthritis
systemically destroys joints
developmental aspects
humans are born very immature; they need antibodies and certain chemicals to fight off diseases and to finish maturing; they get this from breastfeeding; the function of breast milk is analogous to the placenta, in that it provides for the same functions when a baby is no longer attached to the mom after birth; humans reach full immunocompetence around 6 years old