Immune System1. Innate, Nonspecific–– first two lines of defense

a. 1st line of defensei. Skin

1. is a barrierii. Mucus

1. lining of organs 2. Traps particles

iii. Oil and sweat 1. Lower pH2. causes an acidic environment on the skin, keeps bacterial cells

from attackingiv. Lysozyme in most bodily fluids

1. Goes across cell wall, lyses it2. In tears, saliva, perspiration

v. Ciliab. 2nd line of defense

i. Most effective for short term, mostly work on flu viruses and cold virusesii. White Blood Cells (WBC) (Leukocytes)

1. 5 diff kinds, 3 are nonspecific a. Neutrophil

i. Chemotaxisii. 70 percent of WBC countiii. Become activated by piercing of skin, breaking

apart of cellsiv. Release, migrate towards problem, phagocytoticv. Self destruct

b. Monocyte i. Matures into macrophage ii. Aemebo cell: can change shapeiii. Spend time going through interstitial fluidiv. Found in lymphatic system

1. Helps to clean bloodc. Eosinophil

i. Fight against large parasites, roundwormsd. Natural Killer Cells

i. Destroy virus-infected body cellsii. Specifically infected by virus, or cancerousiii. Cause cell to lyse

iii. Antimicrobial Proteins1. Help in 2nd line of defense

a. Lysozymeb. Rest are set of 20 serum proteins; known as complement

system

i. Help with lysis of microbesii. Function with chemokines in attracting phagocytic

cellsc. Interferon

i. Secreted by virus-infected cellsii. Interferes with virus’s ability to attach to host coats

of neighboring cellsiii. Inhibit viral reproduction

iv. Inflammatory Response1. Localized

a. Precapillary arterioles dilate, increasing local blood supply2. Triggered by

a. Physical injuryb. Entry of microorganisms

3. Initiated by chemical signalsa. Histamine is released by cells of the body in response to

tissue damageb. Produced by circulating WBC called basophils and mast

cells in connective tissue4. Blood vessel will vasodilate, increase blood flow, becomes more

permeable to WBCa. Enhances migration of neutrophils b. Prostaglandin discharged by damaged tissue

i. Promote blood flowc. Chemokines attract phagocytes as well

i. 50 diff proteins that bind to receptors of WBC5. Blood clotting occurs

a. Neutrophils arrive, then macrophages, pus accumulatesv. Systemic Response

1. Entire body respondsa. Hypothalamus changes body temperature to be higherb. Fever

i. Leukocytes can release pyrogens, which set body at higher temperature

ii. Inhibits growth of some microorganismsiii. Speeds up body reactions, speeds repair of tissue

c. Septic shocki. Certain bacterial infection inhibit inflammatory

responseii. High fever and low blood pressure

2. Meningitis and Appendicitis cause leukocytes to increase in blooda. Injured cells emit chemical signals that stimulate release of

neutrophils from bone marrow2. Adaptive, Specific–– production of antibodies specific for a certain kind of disease

a. Ability to respond to and eliminate specific diseaseb. Most bacterial cells have antigens

i. Antigen is a foreign moleculeii. Has particular shape that stimulates certain B cellsiii. Tip is called epitopeiv. Made from immunoglobulins (protein)

c. Lymphocytes i. Come from stem cells and located in bone marrowii. Differentiate into B and T cells: both have antigen receptors on plasma

membraneiii. Mature cells concentrated in spleen, lymph nodes, lymphatic tissueiv. Stem cells

1. Early cells, can be changed into diff types, like lymphocytesv. B cells

1. Made in bone marrow; mature in bone marrow2. Stimulated by antigens to make antibodies3. DIVERSE; can react to numerous invaders4. Can tell difference between safe and not safe

vi. T cells 1. Made in bone marrow; mature in thymus2. More responsible for mediated-response3. Helper T cells

a. Its receptor binds to MHC on APC cellb. Secretes cytokines (interleukin 2)

i. Activate B cell and cytotoxic cellsii. B cells make antibodies, which allow marking for

destruction

vii. Clonal Selection 1. Activation of the ‘correct’ lymphocyte

a. Predetermined specificity2. Stimulates it to divide into 2 clones of cells3. Effector cells are short lived and combat the same antigen

a. Include plasma cells, cytotoxic T cells, helper T cells4. Memory cells are long-lived cells that bear receptors for that

antigenviii. APC

1. Can be macrophage or B cellix. Special characteristics

1. Self tolerancea. can identify self from nonselfb. MHC: major histocompatibility complex

d. Reactions to diseasesi. Humoral

1. Stimulation of B cellsa. results in production of antibodies that circulate in blood

plasma and lymph, called humorsb. Also makes memory cells

2. Viruses free in the bodyii. Cell-mediated

1. T cells are active against fungi, protozoa, parasitic wormsa. Target already infected cells

2. Against transplant tissue and cancer cells3. Reacting to infected cell4. Stimulation of cytotoxic T cells

a. These release perforinb. Form pores in cell membrane, causing it to lyse

iii.

Both regulated by lymphocytes, both B and Tiv. Effector cells

1. short lived cells that combat the same antigen2. In B cells

a. plasma cells : make antibodies3. In T cells

a. cytotoxic T-cells : destroy infected cellsb. Helper T-cells: both humoral and cell mediate

v. Primary immune response1. 10-17 days for maximum effector cell response2. Plasma cells made

vi. Secondary immune response1. 2-7 days faster2. Of greater magnitude; more prolonged

e. Self-tolerancei. Failure lease to multiple sclerosis

f. Cell surface markers

i. Glycoproteins encoded by genes called major histocompatibility complex (MHC)

ii. Class 1 MHC1. Show friendly cells2. On almost every cell of the body

iii. Class II MHC

1. In macrophages, B cells, activated T cellsg. Humoral response

i. Virus engulfed by APC cell (antigen presenting cell)ii. After it digests virus, all that is left is antigensiii. MHCII marker presents antigen to outsideiv. CD4 protein helps Helper T-cell attach to APC cellv. B-cell has also been exposed to some disease

1. Activated to activate plasma cell2. makes copies of antibodies

h. Antigensi. T- dependant

1. Respond to helper T cells and B cellsii. T- independant

1. Triggered without macrophages or T cellsi. How antibodies work

i. Do not directly destroy antigenii. Neutralization reaction

1. Blocks viral binding sites2. White blood cells recognizes markings, eats it

iii. Agglutination1. Diff shaped antibody2. Can attach to 5 antigens- clumping3. White cell comes, eats ‘em up

iv. Precipitate1. Some antigens can hide in interstitial fluid2. Antibodies get antigens to come out of fluid

v. Complement Proteins1. Proteins work with antibodies2. Help to lyse victim

j. Complement systemi. Component of both nonspecific and specific defenseii. Circulate in inactive formiii. Two pathways

1. Classicala. humoral//cell mediatedb. Made for specific antigens

2. Alternativea. Uses proteins and antibodiesb. Nonspecificc. Trigger release of histamine

k. Cell mediated responsei. APC can produce interleukinsii. CD8, not CD4iii. APC makes interleukin I once connected to T-celliv. Stimulates helper T-cell to make interleukin II

1. Stimulates continued production of Interleukin II2. Helps produce cytotoxic T-cell

a. Recognizes and destroys infected cell

b. These release perforinc. Form pores in cell membrane, causing it to lyse

3. Helps produce plasma cella. Cleans up when cyto t cell breaks openb. Makes antibodies ready to attach to viral antigens

v. T Cell also stimulates macrophages to come

l. Infected celli. Perforin attached to infected cell, makes it break openii. Water pressure causes cell to lyseiii. Antibodies attach, clean up mess

m. Monoclonal antibodiesi. Made in the lab from single called called hybridoma cellii. Produce certain kind of cell, make copiesiii. Made of 2 diff kinds of cells

1. Cancer cells2. Plasma cell

iv. Used for someone with certain diseases, can’t make certain antibodies3. Diseases and Immunity

a. Day 1: first exposure to antigen Ab. Day 15: maximum production of antibodies to antigen A in primary immune

response; individual will fight off infectionc. Day 28: second exposure to antigen A

d. Day 28-35: second immune response is more rapid and more intense than the primary immune response due to immunological memory (memory B cells)

e. Active Immunityi. Can naturally make antibodies, or artificially be vaccineii. Depends on a person's own immune system

f. Passive Immunityi. Transferred between individualsii. Usually from mom to babyiii. Can be found in breast milk or placentaiv. SHORT LIVED

g. Autoimmune diseasesi. Lupus

1. Attacks immune system2. Attacks skin

ii. Diabetes1. Attacks pancreatic cells

iii. Rheumatoid arthritis1. Attacks cartilage between bones

iv. MS ( multiple sclerosis)1. Attacks nervous system

h. Immunodeficiencyi. Deficient in defensesii. HIV

1. Attacks white blood cells, t cells, cd8, cd42. Body can't make antibodies3. Some medicines4. Can sit inactive for years5. Mutates quickly

i. Allergiesi. Immune system is hypersensitiveii. Body will react by producing histamine which makes you itchy and stuffiii. Anti Histones calms thisiv. Grass is flowering plant

4. Blood typesa. Presence of antigen stimulates production of antibodiesb. Blood type A has A antigens in bloodc. Blood type O has nond. rH Factor

i. Inheritedii. 85 percent positiveiii. Not that big of a problemiv. Sets off immune system when mixed with(-)

Nervous System1. A lot faster than endocrine system

a. Messenger is electrochemical: impulseb. Carried by special wiring, neurons, not blood

i. Only cells that can change charge from (+) to (-) and back2. CNS

a. Spinal cord and brain3. PNS

a. 12 pairs of cranial nervesb. 31 pairs of spinal nerves

4. Sequence of eventsa. Reflex arc-- body does w/out brain

interactingb. Receptor is neuron, alerts CNSc. CNS send interneurond. Responsee. Motor neuronf. effector: muscle that moves

5. Neurona. Dendrite

i. Bring impulse from neighboring neuronb. Cell body

i. Nucleus, cytoplasmc. Axon hillock

i. Where action potential generatedd. Axon

i. Myelin sheath helps to protect spinal nerveii. Helps impulse move

e. Terminal branchi. Sends message to next one

f. Synapsei. Gap btwn neurons

6. Types of neuronsa. Sensory

i. Bring message from peripheral to nervous systemb. Interneuron

i. Integrated as reflex at spinal cordii. Or, helps you lean, gives to brain

c. Motor neuroni. Brings message from CNS--PNS

7. Other types of cells support nervous systema. Do not conduct impulseb. More supporting cells than neuronsc. Supporting cells (Glial)

i. Support NCSii. Astrocyte

1. Encircle capillaries, which coat the brain2. Create a blood-brain barrier3. This helps create ionic flux

iii. Oligodendrocytes 1. Form myelin sheath2. Insulates neurons3. Helps increase speed of impulse4. Provides electrical insulation

iv. Schwann cells1. In PNS2. Form myelin sheath

v. MS causes disruption of myelin sheath; lose coordination

8. Membrane potentiala. Membrane potential is the difference in charges on sides of the wallb. -70 mV is the resting potential for neuron; no action potentialc. Neurons contain gated ion channels

i. At rest, both sodium and potassium are closedii. Are excitableiii. Hyperpolarizediv. depolarized

d. Action potentiali. All or nothingii. More (-) inside cell because of DNA and proteinsiii. Stimulus opens some Na+ channels

1. If threshold is reached, additional channels open2. Interior becomes more positive

iv. Bring pulse from beginning to end of neuronv. -55 mV

e. Hyperpolarizationi. Occurs when stimulus open potassium gate, potassium leave the cell

f. Depolarizationi. Opens up sodium channels, sodium influxes

9. Stimulating an Action Potentiala. 1) Resting: all gates closedb. 2) Threshold stage

i. Stimulus has occurred1. Neurotransmitters

ii. Some sodium gates openiii. Sodium come in

c. 3) Depolarizationi. All sodium gates openii. Beginning of action potential

d. 4) Repolarizationi. End of 1st action potentialii. Sodium gates close; potassium gates openiii. Potassium effluxes, leaves, the cell

e. 5) Undershoot phasei. K gates closeii. Refractory period: neuron is insensitive to stimuli

~~positive inside action potential~~10. Synapse Jump

a. Presynaptic celli. Action potential opens Ca+ gates (impulse makes walls more permeable

to Ca+)ii. Vesicles release neurotransmitters

b. Synaptic vessels are nonmotilei. Neurotransmitter inside= ex: acetylcholineii. When it comes in contact with Ca+ move to end

c. Neurotransmitters released through exocytosisi. Binds to postsynaptic cell

d. Post synaptici. Membrane is either

1. Excited (EPSP)– Na+ gates open2. Inhibited (IPSP)– K+ gates open

e. Neurotransmitter is degraded

11. Neurotransmitters a. Acetylcholine

i. Excitatory to muscle cellsb. Biogenic amines

i. Dopamine1. Generally excitatory

ii. Serotonin1. Generally inhibitory

iii. Epinephrineiv. Amino acidsv. Endorphins

1. Generally inhibitory12. Vertebrate Nervous System

a. PNS

i. Regulates internal environmentii. can be divided into different sections

➔ Sensory◆ Afferent◆ Makes sure internal and external environment at homeostasis

◆ To the brain (CNS): one way➔ Motor

◆ Efferent◆ Autonomic

● Involuntary● Sympathetic

○ “Fight or flight”○ Epinephrine○ Pupils dilate, blood pressure goes up○ Directs resources from non-urgent resources

● Parasympathetic○ Send opp signals to same signals○ Reorient resources to non-urgent things○ Blood pressure goes down

◆ Somatic ● Takes care of voluntary actions● Sitting in a chair

b. CNSi. spinal cord

1. Conveys info to and from brainii. Brain

1. Covered by meninges, 3 layers2. Cerebrospinal Fluid keeps from drying out3. 1.5 kg, one of largest organs

● Hindbrain○ Medulla oblongata

■ Attached from spinal cord to brain■ Controls autonomic, homeostatic functions: breathing, heart rate, blood

pressure○ Pons ○ Cerebellum

■ Coordinates muscle coordination and balance● Midbrain

○ Receipt and integration of sensory information● Forebrain

○ Cerebrum■ Voluntary■ 5 lobes, specialized for different functions

● Insula is inside■ Speech, senses, vision ■ Controls thought, speech, learning, memory, language■ Covered by thin, convoluted layer - cerebral cortex

○ Thalamus and Hypothalamus ■ Pituitary gland■ Thermostat■ FSH+LH