CH 12: Nervous tissue and Nervous system

nervous system functions

communication

control

learning

communication

receive information about env

creating response to inf

integrating sensory inf with memory prior knowledge

control

modulating body processes

maintaining homeostasis

learning

storing knowledge of past stimuli plus responses and results

comparing new stimuli to past inf

CNS

central nervous system

brain, spinal cord

PNS

peripheral nervous system

outside spinal cord and brain

nervous tissue cells

neurons

neuroglia

neurons

functional unit

• send/receive stimuli

• generate electrical signal

neuroglia

cell that support neurons

neuroglia CNS

microglia

astrocyte

oligodendrocyte

ependymal cell

neuroglia PNS

schwann cell

satellite cell

microglia

perform immune function

astrocyte

blood-brain-barrier

take oxygen/nutrition from vessels and deliver to neuron and cellular waste

oligodendrocyte

provide myelination CNS

ependymal cell

special epithelium; choroid plexus

line ventricle of brain

produce CSF

swhann cell

provide myelin PNS

satellite cell

surround soma in PNS

provide protective function as blood brain barrier

soma

cell body

processes

any extension from cell body

• axon

• dendrite

processes Axon

cell extension that delivers a signal or stimulus

processes Dedrite

cell extension that receives a signal or stimulus

parallel axons

nerve: bundle axon PNS

tract: bundle axon CNS

axon clusters

ganglion: group neuron cell bodies PNS

nucleus: group neuron cell bodies CNS

myelin

lipid-rich

insulate axon for better conduction

white matter

myelinated axons

white

gray matter

not myelinated

made of cell bodies, dendrite, unmyelinated axons

sensory

afferent, function

gather inf. from env using receptors

motor

efferent, function

responding to stimuli

generate command for body

integration

“association areas”, function

combine sensory inf with higher cognitive function

somatic

control

conscious sensation/voluntary response

autonomic

involuntary control

regulation of body (homeostasis)

• enteric nervous system

enteric nervous system

within digestive system

“mini” nervous system responsible fro digestive function

sensation

receive stimuli from env

5 conscious

unconscious

5 conscious

sight, smell, sound, touch, taste

unconscious

stretch receptor, chemoreceptor, proprioception

response

motor actin on stimuli

• move muscle, heart rate, digestion

voluntary response

somatic nervous system

you don’t need to “think about it”

• learned or reflex

involuntary response

autonomic nervous system

NS division: integration

higher brain function

compare env. stimuli to other stimuli to generate appropriate response

neuron types

unipolar

bipolar

multipolar

unipolar

1 process from soma

long axon split; dendrite synapse with target cell

sensory

bipolar

2 processes; 1 dendrite, 1 axon

multipolar

many dendrites

purkinje/pyramidal cell

upper motor neuron

response and travel down spinal cord to synapse with lower motor neuron

lower motor neuron

carries signal to effector

receptors

trigger actin potential along sensory neuron

sensory neuron

synapse with spinal cord neuron

nervous tissue

myelin

gray/white matter

guillain barré

autoimmune disease

attack myelin PNS

loss myelin; loss control of automatic/somatic control

cerebral cortex

inf processes and integrated'

• memory, emotion, learning

multiple sclerosis

autoimmune system

attack myelin CNS

loss myelin; pain/loss control organ control

spinal cord neuron

synapse with neuron in thalamus

• sensory relay area

thalamic neuron

synapse with neuron in cerebral cortex

myelin sheath

schwann cell wrap axon, leave membrane trailing, create large spiral layer

lipid-rich “blanket”

soma

cell body

axon

single process of neuron take away communication from soma toward target cell

• axon hillock

• axon terminal

axon hillock

initial segment

axon arises from soma

axon terminal

branch to “fingers” to synapse with many neurons

• synaptic bulb

synaptic bulb

enlargement at end of axon terminals

dendrite

one or more process of neuron recieve inf

bring to soma

nissl bodies

special ER of neuron

ribosome and both ER

node ranvier

space between two segment of myelin