Nervous System

Four primary tissues of the body

epithelial, connective, nervous, muscle

Central Nervous System Organs

Brain, spinal cord

Peripheral nervous systems

controls everything besides brain and spinal cord

Two major cell types of the nervous 

neurons, supporting cells 

main function of the neurons

generate and conduct impulses, responds to stimuli, transmit electrical chemicals over distance

main function of supporting cells

support, insulate, and protect delicate neurons

3 functions of nervous system

sensory inout, integration, motor output 

divisions of the nervous system

central and peripheral

subdivisions of the PNS

sensory/afferent, motor/efferent

sensory or afferent division carries impulses away or towards

towards

somatic sensory fibers

impulses from the skin, skeletal muscles and joints

visceral sensory fibers

transmits impulses from the visceral organs

motor/efferent carries impulses towards or away

away

subdivisions of motor division

somatic/ voluntary, autonomic

somatic nervous system is also referred to as

voluntary nervous system

autonomic nervous system is known as 

involuntary nervous system

subdivisions of the autonomic nervous system

sympathetic, parasympathetic

What does the sympathetic division of the PNS do?

mobilizes body systems during activity

Parasympathetic division of the ANS in the PNS function

conserves energy, promotes house-keeping functions during rest

What is another name for supporting cells?

neuroglia

What are the 6 types of neuroglia/supporting cells

astrocytes, microglial cells, ependymal cells, oligodendrocytes, schwann cells, satellite cells

Which neuroglia make up the CNS

astrocytes, microglial cells, ependymal cells, oligodendrocytes

Where are astrocytes found

in the CNS

What is the function of astrocytes

exchanges between capillaries and neurons, guide migration/synapse formation, recycle ions/neurotransmitters, control the chemical environment, respond to nerve impulses and released neurotransmitters

microglial cells 

transform into a special macrophage that phagocytizes when invading microorganisms or dead neurons are present 

Ependmyal cells

ciliated, line central cavities, between cerebral spinal fluid

Oligiodendrocytes

produce myelin sheath, line-up along thicker nerve fibers

optic neuritis 

inflammation of optic nerve 

Symptoms of optic neuritis

pain, vision loss in one eye, VF loss

neuroglia in the PNS

satellite cells, schwann cells

Satellite cells

surround neuron cell bodies 

Schwann Cells

form myelin sheaths

Guillain-Barre Syndrome

acute autoimmune attack of PNS

1st Sx of Guillan-Barre Syndrome

parethesia and/or loss of sensation

2nd Sx of Guillan-Barre Syndrome

muscle weakness

3rd Sx of Guillan-Barre Syndrome

paralysis including respiratory failure

Plasmapharesis and IV IgG (immunoglobulins are the treatment for 

Guillan-Barre 

Neurons have extreme what?

longevity

Are neurons mitotic or a-mitotic?

a-mitotic (can’t regrow)

Neurons have an extremely high _____, which contributes to why they cannot survive for more than a few minutes without oxygen

metabolic rate

what is is another name for the neuron cell body?

perikaryon 

What is another name for the Rough ER

chromatophilic substance or Nissl bodies

what are used to maintain cell shape in the neuron cell body?

microtubules, neurofibrils

What is lipofuscin?

a harmless by product of lysosomal activity 

clusters of cell bodies in the CNS

nuclei

clusters of cell bodies that lie along nerves in the PNS

ganglia 

Clumping of tau proteins causes what?

neurodegenerative disorders (alzheimers)

cell transport system is made of microtubules which are held together by what?

Tau proteins

what are neuron processes 

armlike

Two types of neuron proceses

dendrites, axons

dendrites are present where

virtually all organelles

dendrites bristle with what?

dendritic spines

do dendrites convey incoming messages toward or away from the cell body?

towards

dendrites convey action potentials or graded potentials?

graded potentials

Each neurons has 1 ___

axon

cone shaped area of cell body, where the impulse begins

axon hillock

knob-like distal endings of the terminal branches, where the cell meets another cell 

axon terminals or terminal boutons

function of the axon

generates nerve impulses and transmits them

whats another name for plasma membrane? 

axolemma 

what is the trigger zone

where the nerve impulse is generated

when the impulse reaches the axon terminal they are called

neurotransmitters

an axon lacks what compared to the dendrites

rough ER, golgi apparatus

an axon depends on what 

its cell body to renew necessary proteins, efficient transport mechanisms 

Retrograde

movement back towards the cell body

anterograde

movement away from the cell body

Rabies uses what type of movement and what is the rate at which it travels?

retrograde, 1 cell/day

what diseases use retrograde as their transport mechanism?

polio, rabies, and HSV

myelinated fibers conduct nerve impulses very rapidly or slowly?

rapidly

non-myelinated fibers conduct nerve impulses more rapidly or slowly?

slowly

dendrites are always myelinated or non-myelinated?

non-myelinated

myelin sheaths are formed by Schwann cells in the CNS or PNS

PNS

how does polio enter the body?

contaminated water, food, dirty fingers

in 99.5% of polio cases, the virus causes what symptoms?

no symptoms or mild flu-like symptoms 

less than 0.5% of polio cases attacks which system?

CNS

Polio mostly affects which part of the body?

legs

gaps in myelin sheath are called 

nodes of ranvier 

do schwann cells touch each other?

no

gray matter contains mostly

nerve cell bodies and non-myelinated fibers

white matter

dense collections of myelinated fibers 

3 major neuron groups

multipolar, bipolar, and unipolar

Which class of neurons makes up the majority?

mutlipolar

where are bipolar cells found 

retina 

what is another name for unipolar neurons?

pseudounipolar neurons

facts to classify something as an axon

generates and conducts an impulse, heavily myelinated

in dendrites, unipolar nuerons have what?

receptive endings

functional classification of neurons

sensory, motor, interneurons

sensory or afferent neurons

toward or into the CNS

What are all sensory neurons, and where are their cell bodies located?

unipolar, outside the CNS 

some sensory neurons are naked meaning

they function as sensory receptors

motor/efferent neurons carry impulses

away

motor neurons are 

multipolar

interneurons are also called

association neurons

which neurons make up 99% of neurons in the body

interneurons 

almost all interneurons are also considered

multipolar

response to an adequately stimulated neuron

action potential or nerve impulse

what is the electrical charge of the body

neutral 

measure of potential energy

voltage

flow of electrical current

current

hinderance to charge flow

resistance 

high electrical resistance

insulators