, NEURONS : THE ORIGIN OF BEHAVIOUR
-
neurons are the building blocks of the nervous system
→
they process information recieved from the outside world , communicate with one -
another and send messages to the body 's muscles and organs
'
Glial cells play a role in brain function , facilitating the communicative activity of neurons by forming the myelin sheath
COMPONENTS OF A NEURON
dendrites
"µµRG)n÷÷"#bhfgggd
terminal branches
of axon
. neurons are complex structures composed of three parts :
myelin sheath
""
→ ceuboa
ftp.j?&aJggpgUyggfhf&fB
,
has functions such as protein synthesis energy production
-
µWgf§[ °MfYgg§WgfhB&
my ne
'
and metabolism
µ
.
-
+ need body contains the nucleus which houses chromosome ,
vesicles
-
sending neuron
synaptic gap that contain DNA
neurotra.IIII.ie
( 7- relieving
←←
neuron
-
surrounded by a porous cell membrane that allows molecules to flow into and out of the cell
glia cell product of a
-
most neurons the axon is covered by myelin sheath
µ → dendrites
, a
( oiigodendrocytes)
→ an axon insulated with myelin can move efficiently transmit signals
-
recieve Information from other neurons and relay it to the cell body
-
in demye.li hating diseases the myelin sheath deteriorates ,
.
→ axon
slowdown of transmission
causing a transmits information to other neurons muscles or
glands
-
,
-
neurons do not touch eachother -
this gap is called the synapse
MAJOR TYPES OF NEURONS
→ the transmission of Information across the synapse is fundamental to
.
there are three
communication between neurons types of major types of neurons :
NEURONS SPECIALIZED →
sensory neurons
- the size and shape of neurons vary considerably -
recieve information from the external world
. the Purkinje -
elaborate treelike assemblage of dendrites -
have specialized endings on their dendrites that recieve
signals for light , sound , touch and smell
- → motor neurons
prymidal cells -
long triangular cell body and a single long dendrite with many
smaller dendrites -
carry signals to produce movement
'
bipolar cells -
few dendrites and a
single axon -
these neurons have long axons that can stretch to muscles
→ interneurons
-
connect all neurons by creating small circuits to perform simple and complicated tasks
THE ELECTROCHEMICAL ACTIONS OF NEURONS
ELECTRICAL SIGNALLING Nat
& kt
J§ µ
^
+
'
the " "" " ' " " " "" t" " " " " "" "" ° " " " " " "" " " " "" the " " " " " "" °
"" " " s " " ""
9 " " " " "" " " "
→ the there high concentration of Kt inside the neuron and low concentration outside
in
resting states , is a
→ the concentration of Kt is controlled by channels in the axon membrane that allow the flow in and out of the neuron +
*
in the
resting state these channels are open and other molecules generally closed
-
a)
& Nat .
the action potential is an electrical signal but it only occurs when the electric shock reaches a cer tain level or threshold
|§ ② &
- -
and with the characteristics at the same
magnitude
[1%9%4%1]
→ e always occurs same
a) electric simulation of the neuron shuts down the Kt channels and opens the Nat channels , allowing Nat to enter the axon
Kt Nat
b) b) the refractory period after the action potential the channels return to their Kt to flow out the axon this leaves
in
original state , allowing the . an
Kt Nat
&µ µ µ
abundance of kt outside and Nat inside the cells
c) chemical pump then reverses the balance of by moving not out of the axon and kt into the axon another action
a ion ions -
it can now
generate potential
-
.
the myelin sheath which is made up of glial cells that coat and insulate the axon facilitates the transmission of the action potential
Nat
-
the breakpoints in the myelin sheath are called nodes of ranker
c)
Nat → the
charge jumps from node to node and this is called Salta tory conduction axon nodes of ranveer
⑧
it helps speed the flow of information down the axon
µTy÷z
-
myelin sheath
Kt
-
neurons are the building blocks of the nervous system
→
they process information recieved from the outside world , communicate with one -
another and send messages to the body 's muscles and organs
'
Glial cells play a role in brain function , facilitating the communicative activity of neurons by forming the myelin sheath
COMPONENTS OF A NEURON
dendrites
"µµRG)n÷÷"#bhfgggd
terminal branches
of axon
. neurons are complex structures composed of three parts :
myelin sheath
""
→ ceuboa
ftp.j?&aJggpgUyggfhf&fB
,
has functions such as protein synthesis energy production
-
µWgf§[ °MfYgg§WgfhB&
my ne
'
and metabolism
µ
.
-
+ need body contains the nucleus which houses chromosome ,
vesicles
-
sending neuron
synaptic gap that contain DNA
neurotra.IIII.ie
( 7- relieving
←←
neuron
-
surrounded by a porous cell membrane that allows molecules to flow into and out of the cell
glia cell product of a
-
most neurons the axon is covered by myelin sheath
µ → dendrites
, a
( oiigodendrocytes)
→ an axon insulated with myelin can move efficiently transmit signals
-
recieve Information from other neurons and relay it to the cell body
-
in demye.li hating diseases the myelin sheath deteriorates ,
.
→ axon
slowdown of transmission
causing a transmits information to other neurons muscles or
glands
-
,
-
neurons do not touch eachother -
this gap is called the synapse
MAJOR TYPES OF NEURONS
→ the transmission of Information across the synapse is fundamental to
.
there are three
communication between neurons types of major types of neurons :
NEURONS SPECIALIZED →
sensory neurons
- the size and shape of neurons vary considerably -
recieve information from the external world
. the Purkinje -
elaborate treelike assemblage of dendrites -
have specialized endings on their dendrites that recieve
signals for light , sound , touch and smell
- → motor neurons
prymidal cells -
long triangular cell body and a single long dendrite with many
smaller dendrites -
carry signals to produce movement
'
bipolar cells -
few dendrites and a
single axon -
these neurons have long axons that can stretch to muscles
→ interneurons
-
connect all neurons by creating small circuits to perform simple and complicated tasks
THE ELECTROCHEMICAL ACTIONS OF NEURONS
ELECTRICAL SIGNALLING Nat
& kt
J§ µ
^
+
'
the " "" " ' " " " "" t" " " " " "" "" ° " " " " " "" " " " "" the " " " " " "" °
"" " " s " " ""
9 " " " " "" " " "
→ the there high concentration of Kt inside the neuron and low concentration outside
in
resting states , is a
→ the concentration of Kt is controlled by channels in the axon membrane that allow the flow in and out of the neuron +
*
in the
resting state these channels are open and other molecules generally closed
-
a)
& Nat .
the action potential is an electrical signal but it only occurs when the electric shock reaches a cer tain level or threshold
|§ ② &
- -
and with the characteristics at the same
magnitude
[1%9%4%1]
→ e always occurs same
a) electric simulation of the neuron shuts down the Kt channels and opens the Nat channels , allowing Nat to enter the axon
Kt Nat
b) b) the refractory period after the action potential the channels return to their Kt to flow out the axon this leaves
in
original state , allowing the . an
Kt Nat
&µ µ µ
abundance of kt outside and Nat inside the cells
c) chemical pump then reverses the balance of by moving not out of the axon and kt into the axon another action
a ion ions -
it can now
generate potential
-
.
the myelin sheath which is made up of glial cells that coat and insulate the axon facilitates the transmission of the action potential
Nat
-
the breakpoints in the myelin sheath are called nodes of ranker
c)
Nat → the
charge jumps from node to node and this is called Salta tory conduction axon nodes of ranveer
⑧
it helps speed the flow of information down the axon
µTy÷z
-
myelin sheath
Kt
