Nervous System

nervous system detects

changes, makes decisions and stimulates muscles and glands to respond and maintain homeostasis

neurons are

functional unit of the nervous system

sensory neurons are

afferent neurons

sensory neurons

receive signal and transport and transport to CNS

Central Nervous System includes

brain and spinal cord

peripheral nervous system

connects CNS to other body parts

peripheral nervous system includes

cranial and spinal nerves

interneurons are in

CNS

interneuron function

links neurons

motor neurons are

efferent neurons

motor neurons function

send signals to effectors

neuroglia are

supporting neurons

astrocyte form

brain-blood barrier

microgial cell is

phagocyte-neuron

oligodendroglia

form myelin (CNS)

Schwann cells

form myelin (PNS)

ependyma cells is

boundary

afferent nerve is

sensory nerve a

afferent nerve function

transmit towards brain and spinal cord

efferent nerve is

motor nerve

efferent nerve function

transmit signals away from brain and spinal cord

interneuron (CNS) is between

afferent and efferent

what part makes decisions

CNS

what part does not make decisions

PNS

neuron function: sensory function is

to “receive” information

neuron function: integrative

“coordinate” information

neuron function: motor function

to “act” decision

sensory neuron and interneuron is located

in PNS

interneuron and motor neurons is located

in CNS

multipolar neuron has

many process (branches), most neurons of CNS

multipolar neurons percentage of neurons

99

bipolar neurons has

two processes (branches)

bipolar neurons are in

eyes, ears, nose

unipolar neurons has

one process (branch)

unipolar neurons cell bodies are in

ganglia

unipolar neurons is

sensory

how many cell bodies for neurons

1

how many axons for neurons

only 1 , long

how many dendrite for neurons

1 and at least 1 , short

dendrites function

recieve neurotransmitters

cell bodies function

analyze signals

axon hillock function

check threshold

axon function

sends signals

myelin function

speeds up signals

synapse is

space between neurons

synpatic cleft separated the

2 neurons

presynaptic neurons function

send impulse

postsynaptic neurons function

receives impulse

nerve synapse action potential

open Ca-chanell

nerve synapse ca ions

enter presynaptic terminal

nerve synapse: synaptic vesicles

release neurotransmitters (exocytosis)

nerve synapse: neurotransmitters enter

synaptic space

nerve synapse: neurotransmitters bind to the

receptor on postsynaptic terminal

neurotransmitters excitatory

acetylcholine and glutamate

neurotransmitters inhibiraory

gamma-aminobutruric acid

nerve synpase happens in

between neurons

what is the signal inside of neuron

cell membrane potential

in neuron resting potential is

when there is no stimulation

in neuron action potential is

when there is a stimulation

resting membrane potential with no stimulation is called

rest potential

during RMP potassium is high

inside the cell

during RMP potassium is low

outside the cell

during RMP sodium inside the cell is

low

during RMP sodium outside the cell is

high

in RMP due to the difference in concentration K-ion diffuses

out of the cell

in RMP due to the difference in concentration Na-ion diffuses

into the cell

the RMP is maintained by

Na+/K+ pump

na+/k+ pump

3 Na kick out while 2 K bring in

the resting potential is

-70mV

dendrite respond to

stimulation

response to stimulation is called

local potenial change

in local potential changes neurotransmitters bind to

receptors on post synapse (dendrite of neuron)

once neurotransmitters bind to the receptors

the ion channels (na+ or Kt etc.) open

the ion chandelles open and ions

rush into or out of the neurons

if membrane potential becomes less negative (more positive)

the membrane is depolarized

if membrane potential becomes more negative

the membrane is hyperpolarized

all the change in membrane potential is analyzed/cooridanted at

axon hillock

threshold potential location

at axon hillock

if membrane potential is depolarized mV is

< -55mV

if membrane potential is depolarized < -55mV there is

no action at all

if membrane potential is depolarized at > - 55mV there is

action potential

at axon hillock, depolarization > -55mV →

“action” signal

at axon hillock, delopalrization > -55mV “action potential” opens

Na-channel

step 1 of conduction after Na channel opens

Na ions rush into cells, depolarize “neighbor”

step 2 of conduction after Na channel opens

Depolarized “region”, opens K-channel

step 3 of conduction after Na channel opens

K ions rush out cell, “depolarization

after action potential

concentration of Na and K are similar cross the cell membrane

after action potential the resting potential is reestablished by

Na+/K+ pump (3 Na our while 2 K in)

nerve impulses

action potentials are propagated down the length of axon

conduction of nerve impulse is

one-way

nerve synapse action potential

opens Ca-channel

during nerve synapse Ca ions

enter presynaptic terminal

synaptic vesicles release

neurotransmitters

during are synapse neurotransmitters enter

synaptic space

during nerve synapse neurotransmitters bind to the

receptor on postsynaptic terminal

action potential is a

all-or-none response

if a neuron axon responds at all

it responds completely with an action potential

action potential propagates

down the axe as a nerve impulse

a nerve impulse is conducted whenever a

stimulus of threshold intensity or above is applied to an axon

all impulses carried on an axon are

the same strength