3.3: nervous system

CNS is responsible for

integration, processing, coordination, higher cognitive functions (thinking & memory)

PNS is responsible for _____

-sensation:

-integration:

-response:

delivering sensory info to CNS, carrying motor commands to body, monitor internal & external changes, processes sensory input & determine responses, activate effector organs

subcategories of peripheral nervous system

sensory PNS, motor PNS

types of sensory PNS

somatic & visceral

sensory PNS is responsible for ____

-made up of ___ signals

carrying info from receptors to CNS, afferent

somatic sensory PNS receives sensations from:___

receptors for: ___

skin, bones, muscles, etc,

touch, pressure, vibration & special senses like taste, smell, hearing

*visceral sensory PNS

sensation from organs, mainly touch, temp, etc (like drinking water and feeling its temperature go down the esophagus and stomach and bladder expanding)

motor PNS transmit info from ____ to ____

made up of ___ signals

CNS, body, efferent

somatic motor PNS

contraction of skeletal muscles, voluntary movement, somatic reflexes

autonomic, aka ___ motor PNS:

-regulates:

-used for ___ movement

-sympathetic & parasympathetic

visceral, smooth & cardiac muscles & glands, involuntary

glia function

cell support

types of glia for CNS

astrocytes, oligodendrocytes, microglia, ependymal cells

astrocytes:

-provides ___ ___

-regulate ____ environment

-regulation of substances in ___ & ___

-___ & ___ damaged tissue

structural support, extracellular, blood, brain, divide, replace

oligodendrocytes

wrap around axons to form myelin sheath

microglia

phagocytic defense cells; clean up debris & eliminate pathogens

ependymal cells

form & help circulate cerebral spinal fluid

glia of PNS

satalite & schwann cells

satelite cells

provide structural support, regulate extracellular environment

schwann cells

form myelin sheath & help repair damaged axons

neurons:

-excitability:

-conductivity:

-secretion:

-extremely long-lived

-amitotic:

-high metabolic rate

respond to stimuli, produce & transmit electrical signals, release neurotransmitters, don’t reproduce through mitosis

anatomy of neuron:

-soma:

-dendrites: 

-axon terminal: 

cell body, receive signals, communicate with target cell

anatomy of a nerve:

-axon:

-fascicle:

-nerve:

surrounded by myelin sheath, group of axons, group of fascicles & blood vessels

-myelin sheath:

-plasma membrane of schwann cells/ oligodendrocytes facilitate: 

-segmented:

insulation around axons, signal transmission, unmyelinated nodes & myelinated internodes

myelinated PNS: ____

begins prenatally or postnatally?

schwann cells spiral around axon, prenatally

myelinated CNS:

begins prenatally or postnatally?

oligodendrocyte process wrap around multiple axons, postnatally

categories of neurons:

sensory (afferent) neurons, motor (efferent) neurons

sensory (afferent) neurons:

-conduct ____ from ___ to ___

-CNS interneurons integrate ___ ___ & mediate ____

signals, receptors, CNS, incoming signals, responses

motor (efferent) neurons conduct ___ from ___ to ___

signals, CNS, effectors

types of neuron shapes

miltipolar, pseudounipolar, bipolar

multipolar neurons

typical motor neurons, interneurons

pseudounipolar neurons

sensory neurons

bipolar neurons are found in this type of neuron:

special sensory neuron

gray matter consists of:

soma, dendrites, unmyelinated axons

white matter is made up of

myelinated sheaths

synapes

connection point between neuron & adjacent cell (post synaptic cells)

electrical synapses: ___

-allowing for ____ ____

gap junctions join adjacent cells, rapid transmission

chemical synapses

neurotransmitters released from synaptic vessels to receptors on postsynaptic cell membrane on receiving cell

neurotransmitters: __

types: ___ & ___

-can vary based on ___ ___

chemical signals that alter postsynaptic cell physiology; excitatory, inhibitory, receptor type