bio Final exam 3-from Ayden

followed by Guillain in Immunology

broad class of immunity

innate immunity

adaptive immunity

Innate immunity

present before any exposure to pathogens

does not have memory response

adaptive immunity

immune cell receptors recognize specific pathogens

innate immunity defense

skin

mucous

AMPs

skin and mucous defend with

Ph

oils

wax

Lysosome

AMP’s defend with

phagocytic cells

natural killer cells

antimicrobial proteins

inflammatory response

Lysosomes

are secreted in saliva

disrupt peptidoglycan in bacteria cell walls

peptidoglycan

is what bacterial cell walls are made of

AMP’s

protect against broad classes of pathogens

Antimicrobial peptides

defensin

Drosomycin

innate immunity

Drosomycin

Effective against fungi

AMP

defensin

effective against bacteria

AMP

Interferons

proteins that initiate signaling to block viral RNA and protein synthesis

innate immunity

Phagocytic cells

Hemocytes

Neutrophils

Macrophages

Neutrophils

secret proteolytic enzymes to break down structures between cells to search for invaders mobile phagocytes found in the bloodstream, attracted to inflammation

NETs

have rapid ameboid movement

innate immunity

Hemocytes

phagocytic cells in invertebrates

NETs

Neutrophil extracellular traps spew DNA nets that trap and kill microbes

the neutrophil dies after

Macrophages

ingest dying cells, microbes, debris, and neutrophils

they congregate in lymph nodes

release cytokines may form from granulomas innate immunity.

Cytokines

signaling molecules that induce fever when released to the hypothalamus

Mycobacterium tuberculosis

can resist digestion by lysozymes and can even grow inside macrophages

granulomas

a group of macrophages that surround and digest inanimate foreign bodies that are too large to be engulfed by a single macrophage

contains lymphocytes, macrophages, and fibroblasts

Natural killer cells

detect broad classes of non-self molecules and release chemicals to kill invaders, including infected self-cells

secretes perforins and granzymes

recognize self-MHC1

innate immunity

perforins

an enzyme that forms a hole in the enemy cell membrane

granzymes

enzymes that enter the hole in enemy cell membranes and degrade enemy cell enzymes.

natural killer cells do not attack

cell with self-MHC1 displaying epitomes on the surface

MHC1

Major histocompatibility complex

epitomes

self peptides

Lymphocytes

White blood cells that have receptors for specific pathogen antigens

B cells

T cells

adaptive immunity

B-cells

Mature in bone marrow

congregate in lymph nodes

has 2 antigen binding sites

Activated B cells

Make plasma cells, which secrete immunoglobulins the humoral immune response

Immunoglobulins

Antibodies

clonal selection

Proliferation of an activated lymphocyte

a lymphocyte with a matching receptor is produced to make memory cells

memory cells

are long-lived cells that respond to a pathogen in a second exposure

Aggregation

antibodies clump pathogens together to prevent infection

Blocked attachment

antibodies bind to a pathogen, preventing the pathogen from binding to a cell.

Blocked uncoating

antibodies inhibit the pathogen’s ability to uncoat its genome for replication

Antibodies can attract

macrophages to the pathogen

T cell

receptor has a single antigen binding site that binds to an antigen fragment (epitope) displayed on infected host cells

Cytotoxic T-cells kill

host cells that display the pathogen’s antigen

APCs

present antigens bound to MHC II on their cell surface, which attracts helper cells of the adaptive immune system

Helper T-cells

bind to antigens on APC cytokines stimulate self-republication and active cytotoxic T cells and B cells (release antibodies) they check if the B-cell found a pathogen

Circulating memory cells

allow a faster response upon second exposure to a pathogen.

Hormonal immune response

The branch of acquired immunity that involves the activation of B cells and that leads to the production of antibodies which defend against bacteria

cell meditated

The branch of adaptive immunity that involves the activation of cytotoxic T cells, which defend against infected cells

Edward Jenner’s controversial experiment

infecting a healthy boy with cowpox, and then exposing him to the small pox virus (1796)

demonstrated the principle of vaccination

Passive immunization

involves transferring antibodies, providing short-lived protection

can be naturally acquired or artificial

Naturally acquired passive immunity example

maternal antibodies are transferred to the fetus through the placenta or form breast milk to the gut of the infant

Artificially acquired passive immunity example

Convalescent plasma therapy

injection of purified antibodies

Convalescent plasma therapy

transferring antiserum from a person who recovered after pathogen exposure

plasma

antiserum

injection of purified antibodies

is commonly applied in emergencies, or for patients with a compromised immune system

antivenom

Receptor variation is created

during lymphocyte maturation by lymphocyte-specific RAG enzymes that cut and splice DNA

In autoimmune diseases

failure due to various mechanisms leads to the activation of self-reactive B or T cells

Mast cells

cells that bind to antibodies will bind to the allergen, triggering the release of histamine

Anaphylactic shock

rapid and severe swelling to an allergen, leading to a drop in blood pressure

histamine

inflammatory mediator

commonly associated with allergic reactions, promoting vascular and tissue changes, and processing high chemoattractant activity

antigenic variation

Antigenic variation is the process by which pathogens modify their surface antigens to evade detection by the host’s immune system, enabling prolonged infection and transmission.

Latency

A pathogen may hide inside host cells in an asymptomatic form, preventing detection by the immune system

ex: Herpes simplex virus

Cancer Immunotherapy

was practiced by William B. Coley in 1891

injected streptococcal organism into a patient with inoperable cancer. He thought that the infection he produced would have the side effect of shrinking the malignant tumor. He was successful

Cancerous cells may express

unique antigens, allowing them to be targeted by the immune system

Erysipelas

a hospital infection caused by Streptococcus bacteria

Kaposi sarcoma appears

due to a compromised immune system

a type of cancer

Nervous system process information in three stages

Sensory input, interaction and motor input

Sensory neurons

carry signals from the outer parts of the body (periphery) into the central nervous system

Interneurons

neurons within the brain and spinal cord that communicate internally with other neurons

Motor neurons

carry signals to your muscles or glands to help you move and function.

electrical potential of a resting neuron

~70 mV

An electrical potential is caused by

inorganic gradients across the semi-permeable cell plasma membrane

Na+ outside the neuron

150 mM

Na+ inside the neuron

15 mM

K+ outside the neuron

5mM

K+ inside the neuron

140 mM

Cl- inside the neuron

10 mM

Cl- outside the neuron

120 mM

Cation concentrations differ on each side of the cell plasma membrane

Ion pumps generate concentration differentials using ATP

Ion movement through channels (passive and active transport)

create electrical potential

K+

is the main determinant of resting potential (-70 Mv)

Depolarization

A shift towards a more positive membrane potential by increased permeability of sodium channels

Hyperpolarization

a shift towards a more negative membrane potential caused by increased permeability of potassium channels

graded potential

A change in membrane potential that fails to reach the threshold

An action potential is triggered

when depolarization exceeds the threshold (around -55mV)

The threshold of excitation is reached

voltage-gated sodium channels open rapidly letting in more Na+ making the change more positive (all or noting action potential

When peak action potential is reached

voltage-gated sodium channels close while voltage-gated potassium channels are opened, making the change more negative.

during Hyperlactation

temporarily deactivates voltage-gated sodium channels a refractory period.

refractory period

preventing initiation of action potential unidirectional flow of action potentials

Active transport of sodium and potassium

restores resting potential

(5)

Action potential originate

at the axon hillock in response to depolarization initiated at the dendrites

Axon

the part of a neuron where the action potential (AP) is propagated.

Dendrites

the receiving of input portions of a neuron

Axon hillock

the region of a neuron that controls the initiation of an electrical impulse based on the inputs from other neurons or environment

Synaptic terminals

release neurotransmitters when stimulated by an electrical signal carried by the axon.

Schwann cells

glial cells that form the myelin sheath on axons for insulation which seeps up the propagation of the AP via saltatory conduction.

Multiple sclerosis (MS)

the immune system attacks the myelin, which becomes destroyed in many areas.

This loss of myelin forms scar tissue called sclerosis

Synapses

a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter

may be electrical or chemical

Postsynaptic Neuron

integrates all the signals it receives to determine what it does next with chemical signals

Presynaptic Neuron

at the end of an axon and is placed where the electrical signal (the action potential) is converted into a chemical signal (neurotransmitter release)

PSPa

Postsynaptic potentials

excitatory (depolarizing) and inhibitory (hyperpolarizing), which are summed in the axon hillock

When an action potential reaches a chemical synapse

neurotransmitters are released into the synaptic cleft

Ca2+ triggers synaptic vesicle exocytosis, thereby releasing the neurotransmitters contained in the vesicles

adrenaline

a neurotransmitter and a hormone flight or fight response

dopamine

pleasure neurotransmitter

glutamate

memory neurotransmitter

most common type of neurotransmitter