not well understood

amoeboid cells in many species destroy foreign materials

earthworms have immunologic memory

recent advances have been made in bumblebee immunity research

2 types of bumblebee immunity

innate

induced

bumblebee immunity

innate

-more general defense

-faster

-usually against parasites

-phagocytes and granular hemocytes ingest pathogen parts

-they then produce melanin and other quinones

encapsulate the foreign body (parasite)

bumblebee immunity

induced

-fungus or bacterium recognized

-messenger molecules are produced

-stimulate fat body cells to produce peptides

peptides cause fungus or bacterium to rupture

all animals

innate immunity

nonspecific

-present before any exposure to pathogens

-effective from the time of birth

-nonspecific responses only

-consists of

*external barriers

*internal cellular and chmical defenses

~macrophages and other phagocytic cells

innate immunity consists of

external barriers

internal cellular and chemical defenses

-macrophages and other phagocytic cells

-adaptive immunity (=specific resistance)

-develops after exposure to agents (microbes, toxins, foreign substances)

-involves a very specific response to pathogens

-recognition is by white blood cells called lymphocytes

-lymphocytes produce antibodies (B) and destroy infected cells, cancer cells or foreign tissue (T)

-slower response

*skin and mucous membranes

-physical bariers to entry of microorganisms and viruses

-mucous membrane produce mucus

~viscous fluid that traps microbes and other partivles

~trachea (up and down resp system)

`ciliated epithelial cells sweep mucus and any entrapped microbes upward

`preventing microbes from entering the lungs

antimicrobial properties

skin sweat and oil, mucus

-hostile to microbes

-pH between 3 and 5

*prevent colonization of many microbes

-proteins such as lysozyme

*digests bacterial cell walls

nostril hairs

-trap pathogens

stomach HCL

-kiills pathogens

internal defenses

(1st line of defense, part b)

general

depend mainly on phagocytosis

phaocytes

-ingest microorganisms

*engulf them

*forming a vacuole that fuses with a lysosome

-initiate inflammation

-macrophages (type of phagocyte)

*migrate through the body

*found in organs of the lymphatic system

defends against pathogens

drains interstitial fluid

antimicrobial proteins

complement

*30 proteins (not a living cell)

* make up the complement system

-causes lysis of invading cells

-helps tirgger inflammation

*innate defense

*attacking microbes directly

*impeding their reproduction

antimicrobial protein

interferons

against viruses

help activate macrophages produced by virus-infected cells

infected cells die, but IF inhibits viral reproduction in neighboring cells

not strain specific

most effective agains short-term infections (cold flu)

used to treat some cancers

skin sweat and oil, mucus

hostile to microbes

pH between 3 and 5

prevent colonization of many microves

proteins such as lysozyme

digests bacterial cells walls

lymphatic system

my pp

defends against pathogens

drains interstitial fluid

transports lipids

internal defense: antimicrobial

protiens:complement

30 proteins

make up the complement system

lysis of invading cells

helps trigger inflammation

innate defens

attacking microbers directly

impeding their reproduction

local inflammation

-histamine and other chemicals released from injured cells promote changesin blood vessels

-allow more fluid, phagocytes, and antimicrobial proteins to enter tissues

-stimulated by

*tissue damage

*pathogen entry

-release hitamine and prostaglandis

~dialted vessles become leaky-->edema

*results from severe infections

-meningitis, appendicitis

*fever develops

-pathogen toxis

-pyrogens from WBCs

-moderate fever interferes with pathogen growth, increases phagocytosis and tissue repairs

internal defens

natural killer (NK) cells

attack virus-infected body cells and cancer cells

trigger apoptosis in the cells they attack

specific resistance

*key player:lymphocytes

*makes use antigens

-foreign molecules

0recognized by lymphocytes

-eleicts a response form them

-lymphocyte or antibody recognizes and binds to a small protion of the antigen called an epitope

B=bone

T=thymus

both originate in red bone marrow

about 100,000 identical antigen receptors each

all antigen receptors on a single cell recognize the same epitope

B cell receptors for antigens

receptors bind to specific intact antigens

produce anitbodies

-immunoglobulins

-structurally similar to B cell receptors

=not anchored to cell membrane-free floating

MHC major histocompatibillity complex

or HLA (human leukocyte antigens)

group of glycoproteins in cell membranes

20 genes, 100 alleles for each gene

only ID twins have id MHC markers

source of self/non-self recognition

T cells and MHC

t lymphocytes

t cells bind to antigen fragments-signalling other cells this thing could be attacked

infected cells produce MHC molecules

-bind to antigen fragments

-transported to the cell surface

-antigen presentation

*a nearby T cell can then detect the antigen fragment displayed on the cell's surface

located mainly on

*dendritic cells

*macrophages

*B cells

(antigen presenting cells)

-display antigens to helper T cells

cell mediated (CMI)

humoral AMI antibody mediate immunity

*cellular based

*T lymphocytes

*produced in response to

-intracellular bacteria and viruses

-fungi

-protists

-worms (paracitic)

-transplanted tissues

-cancer

*direct lymphocyte action, not anitbodies

cell-mediated immunity

APC (antigen preseinting cells)

-macrophages

-t lymphocytes

-engulf antigen

-antigen binds to MHC on cell surface

*MHC-antigen recognized by helper t lymphocyte

-helper t cell activates Tc cells

-produces more

*acitvated helper t cells

*memory helper t cells

cytotoxic t lymphocytes

Tc cells

cell mediated response only

defend against intracellular pathogens

infeced host cells display antigens on cell membrane

Tc cells bind to these antigens

-releases perforin-punctures cell membrane

-cell lysis

-exposes antigens to antibodies, prevents further pathogen reproduction

*Tc cells attack other cells, attack tumor cells that present tumor surface antigen

production of antibodies

by b lymphocytes

in response to

-toxins, free bacteria, free viruses

antigen

a foreign substance that elicits a specif antibody response

*proteins or large polysaccarides (cell membrane)

*on surface of or produced by

-bacteria, viruses, fungi, protists, parasitic worms, pollen, insect venom, transplanted organs, worn out cells

a protein (immunoglobulin)

binds to a specific antigen

produced by plasma cell

forund on B and T cells

transmembrane antibodies (bound to cell membrane)

sometimes released from B cells--free antibodies

antigen enters body

binds to specific receptor on B-lymphocyte

b cell becomes activated

produces large number of

plasma cells-antibodies

memory B cells

stimulated B lymphocyte produces antibodies to destroy original antigen

two clones result

-effector cells (produce antibodies) short lived

-memory cell (memory) long lived

clonal selection after the body's first exposure to an antigen

10-17 day lag time

acquired immunity

body exposed to previous antigen

faster response 2-7 days

more prolonged

more numerous antibodies

=immunological memory

immunological memory

memory B lymphocytes

survive for long periods

not active during primary responses

second exposure stimulates memory B cells--new clone of effector and memory cells

new clones=secondary immune response

ability of the immune system to distinguish between a bod's won molecules and antigens

-during early development

-self-tolerance:lack of an immune respose against a body's own cells

-failure=autoimmune disorders

cell surface markers

MHC (major histocompatibility complex) or HLA(human leukocyte antignes)

-group of glycoproteisn in cell membranes

-20 genes, 100 alleles for each gene

-only ID twins have identical MHC markers

*source of slef/non self recognition

-1 plasma cell produces 2000 antibodies/sec

-last 4-5 days

-help eliminate antigen

antibodies recognize epitopes (regions of antigen

-epitopes=antigenic determinants

-antibodies are immuniglobulins (lgs) (proteins)

-y shaped, four polypeptide chains

-2 light, 2 heavy

-tips of Y = variable regions (vary from one antibody to the next) , regions that attach to epitopes

-lgM pentamer

-lgG monomer

-lgA dimer

-lgE monomer

-lgD monomer

most abundant

only lg class that crosses placenta, thus conferring passive immunity on fetus

first lg produced after initial exposure

promomtes neutralization and cross-linking of antigens

very effective in complement(group of protiens that attack pathogen) system activation

breast milk

passive immunity

contains lots of antibodies

colostrum

present in blood at low concentrations

allergic reactions

B cells have not been exposed to antigens

colonal selection

1 neutralization

2 opsonization

3 agglutination

4 precipitation

5 complement fixation

simplest

antibodies cover viruses or bacteria

prevents their binding to host cells

eventually detected and destroyed by phagocytes

opsoniation

antibodies and complement bind to antigen

->enhanced macrophage attachment and phagocytosis

cross linking of antibodies that are attached to viruses or bacteria

forms clump

easier for phagocytes to engulf the mass

2 bacteria w/antibody that stick together

similar to agglutination

joining of small soluble antigens attached to antibodies rather than larger bacteria easily enguled by phagocytes

not whole bacteria, just peices

complement bind to antigens

stick to BV walls ->destroyed by phagocytes

based on recovery from an infectious disease (memory B lymphocytes)

natural or artificial (immunization or vaccination)

vaccine:

-inactive bacterial toxins

-killed microbes

-parts of microbes

-alive, but weakend

-microbes

transfer of antibodies from one individual to another

naturally ;lgG form mother baby across placenta, breast milk (lgA)

-artificial: rabies (antibodies form people already vaccinated)

-temporary protection (weeks-->months)

-blood group antigens

-blood group antibodies

-ABO (lgM), Rh (lgG), others

-ABO group antibodies from due to exposure to symbiotic bacteria with very similar epitopes

-transfusion problems; RBC hemolysis, kidney damage

blood grouping

antigen a and b determine group

universal recipient

normally lacking

if Rh- peron receives Rh+ transfusion, produces anti-Rh antibodies (remain)

-subsequent transfusions dangerous beause Rh antibodies attack Rh+ new blood cell lysis kidney failure

genetics: + dominant

Rh- mom

Rh+ child

mother makes anti-Rh antibodies

during development, maternal antibodes cross placenta and harm a second Rh+child

to prevent it, rogam surpreses production of Rh antibodies if Rh- becaue Rh+ doesn't have antibodies

MHC unique to each individual

Tc cells attack non-self MHC cells

cyclosporin A and FK506

-suppress cell-mediated

-not humoral immunity

-used in grafts/transplants

graft vs. host diseas

-bone marrow grafts are rejection by marrow lymphocytes of host (opposite of above)

allergies-disfunction

hypersensitivity to envronmental agent

lgE antibody

when lgE contact pollen

-stimulates mast cells to release histamine

causes allergy symptoms

treat with antihistaines

life threatening reaction to injected or ingested antigens

sudden vasodilation, BP drops

death in minutes

airway constriction

peanuts fish formic acid (bee sting)

immune system reacting against itself

-lupus erythromatosus: antibodies attack nucleic acids

-rheumatoid arthritis; joints

-IDD mellitus; pancreas

-multiple sclerosis; peripheral nerves

-repeated strep infections-heart valve

immunodeficiency diseases

-deficiency in humoral or cell-mediated immunity

-SCID severe combind immunodeficiency

*both fail to function

*congenital -around birth

*gene therapy has helped some

-AIDS

-hodgkins disease: cancer lymphatic sysem

-strss lowers immune resistance

*adrenal hormones suppress WBCs

*strong conection between NS and thyme

*lymphocytes possess neurotransmitter receptors

AIDS

acquired immunodeficiency syndrome

-Pneumocystic pneumonia

-kaposi's sarcoma

caused by HIV-1 and 2

susceptible to opportunistic infections, cancers

nearly 100% mortality rate

handfull of ppl immune

helper T lymphocytes macrophages

directs formation of new virus particles

invisible (hides in cells)

rapid mutational chanes of antigens

causes destruction of helper T lymphocytes--immune system collapse

late stage of infection

reduced T cells, secondary infections

transmitted through body fluids

-blood, semen, vaginal secretion

male homosexual sex

shared IV needles

heterosexual sex (africa, asia)

25% babies infected mothers contract infection

blood transfusions

AIDS treatments

AZT, ddl: DNA replication inhibitors, reverse transcriptase inhibitors, protease inhibitors

others to fight opportunistic infections

cost of treatment excludes most poor people

education best treatment

osmoregulation

eliminationg metabolic wastes

usually involve kidneys, intestines, lungs, sweat glands

adaptations that reduce water uptake

conserve solutes

mkost marine inverts

isoosmotic with their surroundings

do not regulate their osmolarity

adv, solute levels need to be a particular level for optimal preformance

most marine vertebrates and freshwater animal

expend energy to control water uptake and loss

a hyperosmotic or hypoosmotic environments

stenohalin

most animals

cannot tolerate substantial changes in external osmolarity

can survive large fluctuations in external osmolarity

aquatic invertebrates (water bear)

temporary ponds

lose almost all their body water and survive in dormant state

water bear

euryhaline animal

manage water budgets

-drinking and eating moist foods

-use metabolic water

specialized cells

eg salt glands of marine birds

transport epithelia

specialized cells

regulate solute movement

essential components of osmotic regulation and metabolic waste disposal

transport epithelia

salt glands of marine birds

-derived from metabolism of proteins and nucleic acids

-ammonia-toxic

-urea, uric acid (less toxic, takes ATP to make)

most aquatic animals

very water soluble

exits through skin or gills

-freshwater fishes exchange ammonia for sodium across gills

mamals and most adult amphibians

100,000 X less toxic than ammonia

reduces water loss

produced by combining ammonia and CO2

land snails, insects, birds, reptiles,

much less water soluble than urea or ammonia

secreted as a dry paste, mixed with feces

necessary in hard shelled eggs to avoid toxicity

excretory processe

excretory processes

key functions

filtration

reabsorption

secretion

excretion

filtration

reabsorption

protonephridia

flame bulb system

network of deadend tubules lacking internal openings

-smallest branches are capped by a cellular unit called a flame bulb

-tubules excrete a dilute fluid and function in osmoregulation

each segment has a pair of open-ended metanephridia

-consist of tubules that collect coelomic fluid and produce dilute urine from excreation

malpighian tubules

-insects and other terrestrial arthropods

-remove nigrogenous wastes from hemolymph

-fucntion in osmoregulation

-insects produce a relatively dry waste matter, and importnat adaptation to terrestrial life

-excretory organs of vertebrates

-both excreation and osmoregulation

-nephrons:functional unit of the mammalian kidney

-each kidney is supplied with blood by a renal artery and drained by a renal vein

-urin exits each kidney through the ureter

-ureter dreain into a common urinary bladder - ouside via urethra

formation of urine

*blood filtration

-blood pressuer forces fluid from the blood-glomerulus-lumen of bownan's capsule

-non-selective of small molecules

-filtratie in bowman's capsule mirrors concentration of solutes in blood plasma

from bwoman's capsule

fluid from several nephrons flow into a collecting duct

*filtrate-proximal tubule-loop of henle-the distal tubule

regulation of kidney function

nervous

hormonal

atrial natriuretic factor

opposes RAAS

antidiruetic hormone

increases water reabosorption in the distal tubules and collecting ducts of kidney

renin-angiotensin-aldosterone system

part of a complex feedback circuit