Neuroscience Unit 2

What did anton von leeuwenhoek do? 

invented the microscope 

waht did matthias schleiden and theodore schwann propose?

cell theory

What is cell theory?

The idea that everything is made out of cells

what did Camillo Gogli do?

developed a staining method to see neurons

what did santiago ramòn do?

refined goglis method and discovered that neurons don’t actually touch.

the fundamental structre and functional unit of the nervous system is the 

neuron 

neurons have 3 parts;

dendrites, axons, and cell bodies

Johannes müller proposed

the law of specific nerve energies

what does the law of specific nerve energies say?

the origin of sensation doesn’t determine our sensation, the pathway it is carried on does.

Cajal proposed the _______ of neurons

dynamic poloarizaiton of neurons 

what is the dynamic polarization of neurons

the idea that information only flows one way ( today. we know that’s not true)

Charles sherrington was the first to describe the spaces between neurons called

synapses

Molecules are defined as

2 or more atoms held together by a chemical bond

4 types of molecules 

simple sugars, fatty acids, amio acids and neucleo tides 

simples sugars give you

energy

fatty acids give the cell

strength

Glial cells are

astrocytes, satellite cells, oligodendroglia, schwan cells and microglia

astrocytes are in the _____ and do what? 

CNS, and maintain the neural environment, repair/ feed the neurons, modulate neural transmission and modulate breathing 

Satellite cells are in the ____ and do what?

PNS and maintain the neural environment, repair/ feed the neurons, modulate neural transmission and modulate breathing.

Oligodendroglia is in the _____ and do what?

CNS, produce myelin and coat neurons in segments

Schwan Cells is in the ___ and does what?

PNS and produce the myelin and coat neurons in segments

Microglia is in the ____ and does what? 

CNS and scavenges debries, defends and repairs

The sender of the message is the

axon

the reciever of the message is the

dendrite

Unipolar neurons

touch/ pain sensory neurons; only one axon coming off the cell body

bipolar neurons 

specialized sensory neurons; has 2 axons coming from the cell body 

the cell body is also known as the

soma

multiplar neurons

all kinds of functions; has multiple stems of dedrites coming out of the cell body

Axaxonic neurons

one soma with no axons but multiple dendrites

neurons can be classified by 

function, axon length, shape or neuron transmitter. 

Neuron similarities compared to other cells

have a membrane, nucleus, cytoplasm, mitochondria and other organelles

Neuron differences compared to other cells

specialized projections, communication with each other with electricity, and can be multiple feet long

the synapse is defined as

the space between one neurons axon terminals and anouthers dendrites

Axodendritic 

axons to dendrites; usually excitatory

Axosomatic

axons to cell body; usually inhibites

Axoxonic 

axon to axon; usually regulating 

Neurotransmitters are either

inhibitory, excitatory or regulatory

neurotransmitters

chemicals housed in the terminal buttons; a chemical messenger that tranmites messages from pre to post neurons through the synaptic cleft.

Acetylocholine

muslce contraction in PNS; loss of memory assoc with degeneration of this neurotransmitter

what was the first neurotransmitter discovered? 

acetylcholine in 1951

cholinergic neurons release what neurotransmitter

acetylcholine

Glutmate causes

the excitation of the CNS

increased levels of ___ can lead to seizures, while an imbalance can lead to schizophrenia

glutamate

GABA does what? 

inhibits the CNS

Gabanergic neurons release

the neurotransmitter GABA

GABA plays roles in

circadian rhythm, depression and insomnia

Decreased levels of ___ are assoc. with depression, while increased levels are associated with insomnia

GABA

Dopamine helps 

motor control and brain reward system 

Dopamine is found in 3 pathways called

mesotriatal, mesolimbic, and mesocortical

mesotriatial is the

motor pathoway; damage can result in parkinsons

mesolimbic is the

emotional pathway; damage here can cause addictions. Causes the positive signs/ symptoms of schizophrenia. 

mesocortical is the 

cognitive pathway; controls the negative signs/ symptoms of schizophrenia. 

Epinephrine does what?

excites the heart, and enacts a fight or flight response

too much ___ results in anxiety while too little results in fatigue.

Epinephrine

NorEpeniphrine controls

Attention, alertness and mood

Too little ____ is implicated in ADHD, depression and narcolepsy 

Norepinehprine 

Serotonin does what?

excites/ inhabits the the nervous system

Serotinergic neurons produce what?

the neurotransmitter seretonin

To little of ___ is associated with depression, anxiety and OCD. Too much is associated with dysregulated circadian rythem

Seretonion

Substance P

sensitized to pain; causes inflammation

too much of ____ can cause Exzema; too little can cause Alzheimers and type one diabetes

the neurotransmitter Substance P

axotomy

when the axon gets cut torn or damaged

Wallerian degeneration 

if an axon is cut or crushed the axon enters a degeneration process. The distal part of the axon form the soma and intergrade from the cut, pulls away and breaks apart. 

In the _____ after wallerian degeneration schwan cells can regrow an axon

PNS

neurons primary purpose is

communication

efferent communication

motor signals from top down ( CNS to PNS)

afferent communication 

sensory signals form bottom up (PNS to CNS)

2 phases of communication 

electrial phase and communication phase 

the electrical phase uses what parts of the neuros?

dendrites and axons

the chemical phases uses what parts of the neuron?

the neurotransmitters and synaptic cleft

two types of transport

active and passive

Gradient 

the two sides want to be equal to high potential flows to low potential 

resting membrane potential is about

-70 mv

ionotrophic receptors

the neurotransmitter key opens the channels and quickly everything blows through

metabolic receptors

a neurotransmitter is accepted and then must go through like “customs” to open.

absolute refractory period 

sodium channels inactivated, so new simulation has no effect on the neuron 

relative refractory period

neuron will respond to neurotransmitters but only very strong simulations

Intellectual disability could be caused by

genetics, viruses or pre-natal alcohol

Brain tumors can be

begnin or malignant

Begnin tumors are 

slow growing, and don’t metastasize

malignant brain tumors are

fast growing and metastasize

brain tumors are named after

the part of the brain they impact

Grade 1

slow growing, rare metastis, possible to totally remove. 

Grade 2

slow, likely metastis, removal is dependent on size and location 

Grade 3

quick, likely metastis, chemo/radiation with possible surgery

Grade 4

quick, sure metastis, chemo/radiation are only options.

ALS stands for

amyotrphoic lateral sclerosis.

ALS is a

motor neuron disorder that involves the withering of upper and lower motor neurons; onsets between 40-60 years old and most pass btwn 3-5 years after onset. No cure, but a drug can slow down symptoms 

Limb onset ( for ALS)

starts in the periphery

Bulber onset ( for ALS)

starts in the “trunk”/ face area.

MS ( multiple sclerosis) means 

multiple scarring 

MS is 

an autoimmune disorder of unknown cause in which the myelin around the axon is damaged. No cure, but meds can supress symptoms. 

Symptoms of MS include

“pins and needles”, numbness, weakness, balance and motor issues.

Myasthenia Gravis (MG) means

grave muscle weakness

MG is

a neurological disease of a neurological junction. ACh receptors are blocked by the body’s antibodies. 

Symptoms of MG include 

weakness and fatigue( weakness increases with muscle use, and then with rest can return to baseline)

Guillain Barré Syndrome is

a rapid. progressive demyelinating PNS disease

Symptoms of Guillain Barre Syndrome are

progressive paralysis followed by recovery.

How many sections is the vertebral column divided into? 

5

The Spinal Cord is an

Information superhighway conveying motor ( efferent) and sensory (afferent) information between brain and body