AP -Lymphatic/Immune

lymph

a fluid similar to plasma

does NOT have plasma proteins

when interstitual fluid enters the system

lymphatic vessels (lymphatics)

network that carries lymph from peripheral tissues to the venous system

lympoid tissues & lympoid organs

found throughout the body

drain excess interstitial fluid

3 liters of interstitual fluid needs to be reabsorbed

NOT for exchange → just collected

lymph system uses WBC to “clean” fluid & return it to blood stream

transport dietary lipids

when fat is absorbed in GI tract & fat soluble vitamins are transported in the lymph system

carry out immune response

immune system is contained in the lymphatic system

lymphatic capillaries

are for collection ONLY → NOT exchange

closed at one end→containing one way flow into capillary & back to the heart

large diameters & thinner walls

located between spaces of cells, run with blood vessels/stream

endothelial cells

important in maintaining one way flow into lymphatic capillaries

anchoring filament

used to keep lymphatic capillaries open

prevents collapse

lacteals

specialized lymphatic capillaries in small intestine to carry lipids from diet

chyle

specialized whit lymph (contains fat) from lacteals

lympathic flow

blood capillaries→ interstitial space (fluid)→ lymphatic capillaries→ lymphatic vessels→ lymphatic ducts→ subclavian veins

primary organs & tissue

where stem cells divide & develop (factory)

red bone marrow

produces hemocytoblasts → produces B cells & pre-T cells

thymus gland

matures (educates) T cells

secondary organs & tissue

where the immune system response occurs (battle field)

lymph nodes

lymph will flow from one node to another

capsule

outer covering

outer cortex

contains mostly B cells & marcophages

inner cortex

contains mostly T cells

medulla

B cells

antibodies from plasma cells

macrophages

lymph node flow

afferent lymphatic vessel → subcapsular sinus→ trabecular sinus→ medullary sinus→ efferent lymphatic vessel

metastasis

secondary tumor sites can be predicted according to the direction of lymph flow from the primary tumor site

spleen

largest single mass of lymphatic tissue

located left side, inbetween stomach & kidney

parenchyma

center of spleen, two tissues

white pulp

lymphatic tissue

lymphocytes & macrophages are located around a central artery

red pulp

blood filled venous sinuses

contains RBCs, leukocytes & plasma cells

remove worn out RBCs

store platelets → 1/3 of body total

produce blood cells when fetus

functions of red pulp

cortex of thymus gland

pre T cells ( immature cells) collect here from red bone marrow

where they will mature

helps “education) T cells by “positive selction”

only 20% make it

T cells leave thymus to collect in spleen

epithelial cells function

lymphatic nodules

spread through different areas of the body

egg-shaped masses of lymphatic tissue NOT covered by a capsule

tonsils

lymphatic bodules in the oral cavity

pharyngeal

posterior wall of nasopharynx

palatine

back side of oral cavity

lingual

back base of tongue

malt (mucosa associated lymphatic tissue

spread throughout out connective tissue of GI tract

urinary & repoductive systems

appendix

mass of fused lymphoid nodules

present at brith

offers immediate protection against a variety of pathogens

functions the same way regardless of the type of invader

innate defense

skin (epidermis)

provides a tough physical barrier

mucous membrane

traps many microbes & foreign substances

lacrimal apparatus

provides tears to wash away irritants to the eyes

saliva

reduces growth of microbes in the mouth

urine flow

cleanes the urethra

gastric juice

strong acidity destroys many pathogens

internal antimmicrobial proteins

found in blood & intersitial fliud

discourages growth in microbes

interferons

prevent virus from replicating

complement system

found in blood plasma membranes

when activated enhances immune reactions→ stimulating inflammation, attraction phagocytes

natural killer cells

5-10% of lymphocytes

attacks cells that display abnormal plasma membrane proteins

phagocytes

specialized cells that ingest microbes & other cellular debris

neutrophils & macrophages

examples of phagocytes

chemotaxis

chemically stimluated movement of phagocytes

adherence

attachment of phagocytes to microbe

ingestion

process of engulfing the microbe

digestion

uses digestice enzymes & strong oxidates

killing

digestion & oxidation kills microbe

inflammation

defensive response to tissue damage

redness, pain, heat, swelling

charateristics of inflammation

necrosis

local tissue destruction in area of injury

pus

misture of debris & necrotic tissue

abscess

pus accumulated in an enclosed space

fever

abnormal high body temperature that occurs because hypothalamic thermostat reset

pyrogens

any material that causes the hyothalamas to raise body temperature including circulating pathgoens, toxins, or antibody complexes

immunity

ability to mount a specific resistance against specific antigens

specifc

ability to singal out foregin substances for destruction

also recognize self

memory

to be able to rememeber an antigen & kill it faster next time

systemic

affects the whole body

not restricted to the area of infection

antigens

anything that is perceived as foreign due to surface proteins

viruses, bacteria, cancers, bacterial toxins, pollen, incompatible blood cells

examples of antigens

pathways to lymphatic tissue

enter bloodstream & are trapped as they flow through the spleen

penetrate the skin enter lymphatic vessels & get lodged in lymph nodes

penetrate mucous membranes & become entrapped by MALT

antigens receptors

before T cells leave the thymus & B cells leave red bone marrow they insert specific proteins into the plasma membrane capable of recognizing specific antigens.

T-Cells

kill other cells

B Cells

produce plasma cells that produce antibodies

major histocompatibility complex (MHC)

the body’s self anitgens

a protein on the surface of all cells

how the body recognizes it owns cells (EXCEPT RBC)

class 1 MHC

appear on all body cells

EXCEPT RBC

class 2 MHC

appear only on activated T cells & cells of the thymus

antigen presented

antigen gets noticed/discovered

bumps into WBC

antigen presenting cell → mirgrates to lymphatic tissue to present antigen to T cell

activation of T cells

antigen causes a small number of T cells to activate

costimulation

activation is complete after a second chemical confrimation

prevents unneeded immune responses

proliferate

makes coppies of itself from a few to thousand

differentiate

forms different more specialized copies

helper (CD4)

scretes interluken 2

cytoxic (CD8)

recognizes antigens combined with MHC 1

cells that have gone bad

perforin

punches holes in plasma membrane of target cell

lymphotoxin

activates enzymes in target cell that destroys cells DNA

binding & activation B cells

B cells can bind directly to antigen but are much more efficient when antigen is presented to B cells

anitbody structure

2 parellal pairs of polypeptide chains

1 pair of heavy chains

1 pair of light chains

chains contatin constan segments & variable segments

IgG

most abundant

protects against bacteria, viruses, toxins & triggers complement system

can cross placenta from mom to fetus

IgA

found in secretions

tears, mucus, salvia, breat milk

protects mucus membranes from bacteria & viruses

IgM

first secretion to plasma cells

activates complement system

are antigen receptors on B cells

anti-A & anti-B antibodies in blood plasma

IgD

rare act as B cells antigen receptors

activation of B cells

IgE

act as receptors on mast cells & basophils

involved with allergic & hypersensitivity reactions

help aganist parasitic worms

neutralizing

stop reactivity

cross link clumping

makes antigens stick together

activating complement

sequences of reactions that lead to → inflammation & increased phagocytosis

memory

primary response = days

secondary response = hours

naturally acquired active immunity

antigen is recognized by T cells & B cells → memory cells for sytotoxic T cells & antibody producing plasma B cells are produces

naturall acquired passive immunity

transfer of IgG (pregnancy) or IgA (breastmilk)

artificiatly acquired active immunity

introduction of weakened or dead antigens to riiger body into making cytotoxic T memory cells & antibody plasma B cells (vaccinations)

artificially acquired passive immunity

injection of antibodyies (serums)

AIDS

kills CD4 T cells

retrovirus