HBS- The Neuron RETAKE

what are neurons

• primary signaling cells of the nervous system

• send and receive electrical and chemical signals to communicate with each other and with other types of cells in body

what are glial cells

cells in the nervous system that provide protectiona nd maintain homeostasis for neurons

what are the three essential parts of the neuron (picture)

• dendrite

• cell body

• axon

what is the soma (cell body)

• core section of neuron containing genetic information

• maintains the neuron’s structure

• provides energy to drive activities

what is the axon terminal

• any of the button-like endings of axons that change electrical impulses or action potentials within a neuron into chemical messages in the form of neurotransmiters

what is a dendrite

• designed to receive communications by bringing electrical signals to the cell body

• resemble tree like structure

what is the nucleus

• contains genetic material for cell development

• synthesis of proteins necessary for cell maintenance and survival

what is the node of ranvier

• periodic gaps in the myelin sheaths

• allow ions to diffuse in and out of neuron

• pushes electrical signal down the axon

what is myelin sheath

• insulating layer forming around the nerves

• made of protein and fatty substances

• allows electrical impulses to transmit quickly and efficiently along the nerve cells

ependymal cells

• central nervous system

• moves cerebral spinal fluid around neurons

oligodendrocytes

• central nervous system

• blanket (produces myelin that wraps around axon)

astrocytes

• central nervous system

• cook

• monitors chemical environment of neuron

• nourishment for neuron

microglia

• central nervous system

• body guard

• immune cell

satelite cells

• peripheral nervous system

• protects cell body

schwann cells

• peripheral nervous system

• produces myelin sheath

what is a unipolar neuron

• cell body splits to axon and/or dendrite

what is a multipolar neuron

1 axon and many dendrites

what is a pseudounipolar neuron

splits into 2 aons or 2 dendrites

what is a bipolar neuron

1 axon and 1 dendrite

what are sensory neurons

pns sends signals to the CNS directly from stimuli

(usually unipolar)

what are interneurons

relay signals from sensory to motor neurons in cns

(usually multipolar)

what are motor neurons

send signals from interneurons to muscles to signal needed movement

(usually multipolar)

what is acetylcholine

• neurotransmitter

• muscle contraction

• learning

• memory

what is dopamine

• neurotransmitter

• motivation

• mood

• attention

• memory

• movement

what is GABA

• neurotransmitter

• inhibitory neurotransmitter

• slows release of dopamine

• shuts down neurological function

• decreases likelihood of action potential

what is glutamate

• neurotransmitter

• excitory in neurotransmitter

• more than 90% of synapses

what is epinephrine

• neurotransmitter

• fight or flight (adrenaline)

what is serotonin

• neurotransmitter

• gets you up and going

• regulation of mood

• digestion

• slows amigdola for sleep

what is an agonist

• binds to a receptor and activates it to produce a response

ex: morphine

what is an antagonist

• binds to a receptor blocking agonist and preventing a response

• returns a receptor to baseline

ex: caffiene

what is an inverse agonist

• binds to a receptor

• produces opposite agonist

• reduces to baseline

ex: diphenhydramine (benadryl)

what is a reuptake inhibitor

• blocks the reuptake of neurotransmitter from synapse

ex: cocaine

what is devic’s disease

optic nerve and spinal chord attack (permanent blindness in both eyes)

what is epilepsy

seizures (more common in kids)

what is fibromyalgia

perceive sensation differently; normal sense feel painful

what is alzheimer’s

inner-neuron death

what is mutiple sclerosis

• fatigue

• pins and needles

• vision probems

• speech difficulties

• 1 eye blindness

• myelin sheath destruction

what is parkinson’s

• low dopamine

• tremors and jerky motions

• visible

what is Charcot Marie tooth disease

• genetic

• high arch in feeth

• foot pain

• low muscle mass

• die 5-10 years after daignosis

what is huntington’s disease

• genetic

• causes mood swings

• odd muscle movements

• degrading muscle

• starved inner neurons

what is lou gehrigs disease (ALS)

• causes speech problems

• coordination issues

• nerve pain

what is the reward pathway in the brain

it motivates survival behaviors by sending in dopamine to reinforce doing the action again in the future

what is a reflex

• involuntary

• automatic movement

• signal gets sent from the spinal chord so it never gets processed in brain

what is a reaction

• concious and voluntary action

• isn’t immediate because it requires processing in the brain

what happens in a sodium potassium pump

3 sodium goes out and 2 potassium go in

what is action potential

spike in electrical impulse to communicate

action potential: resting

occurs: high concentration of potassium inside and sodium outside and K+ leaks through channels

charges: - in; + out

action potential: depolarization

occurring: Na+ ions rush in action potential rapidly increases

more sodium = stronger signal

charges: + in; - out

action potential: repolarization

occurring: K+ channels open allowing ions out of cell, lowering action potential

charge: decreases membrane potential so it depends

action potential: hyperpolarization

occurring: more K+ rushes out than needed making it more negative than normal; sodium potassium pump works to restore normal levels

charge: - inside: + out

action potential: returning to resting

occurring: sodium potassium pump eventually keeps working continuously forever as long as it has ATP to open the pump

charge: - in; + out

what is the concentration flow for a sodium potassium pump

low to high