Transcript Brain and Nervous System

Brain and Nervous
System
CLICK ON YOUR SPACE BAR OR
MOUSE TO MOVE THROUGH THIS
POWERPOINT!
QUESTION
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What is a NEURON?
ANSWER
A neuron is a nerve cell that is the
basic building block of the nervous
system.
 highly specialized nerve cells are
responsible for communicating
information in both chemical and
electrical forms.
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Question
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How many parts does a neuron have?
ANSWER
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Three
Question
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What are the 3 parts of a NEURON?
And the Answer Is…
 Cell
Body
 Axon
 Dendrites
QUESTION
What does a Cell Body do?
ANSWER
Each neuron cell body is a center for
receiving and sending nerve impulses.
Cell body also makes proteins.
QUESTION
What does an AXON DO?
ANSWER!
Carries messages.
 A tube like structure
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QUESTION
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What is the function of dendrites and Axons?
The difference between Dendrites and
Axons Of a Neuron are?
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Axons
Take information away from the cell body
Smooth Surface
Generally only 1 axon per cell
No ribosomes
Can have myelin
Branch further from the cell body
Dendrites
Bring information to the cell body
Rough Surface (dendritic spines)
Usually many dendrites per cell
Have ribosomes
No myelin insulation
Branch near the cell body
QUESTION
What is the resting potential?
ANSWER
When a neuron is NOT sending a signal it is at
“REST.”
 When at rest the inside of the neuron is – neg
charged.
 At rest potassium K+ can cross through the
membrane easily.
 At rest (CL-) chloride and sodium (NA+) have a
more difficult time passing. At rest there are
more?
 sodium ions on the outside of the neuron and less
potassium on the inside.
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QUESTION?
What Is Action Potential?
 Also know as a Nerve impulse.
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ANSWER
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Action potential occurs when a neuron
send information down an axon, AWAY
from the CELL BODY!
The Action potential is an explosion o9f
electrical activity.
 That is created by depolarizing current.
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QUESTION
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Explain the mechanism for action potential
ANSWER
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Action potentials are caused by an exchange of ions across the neuron
membrane. A stimulus first causes sodium channels to open. Because
there are many more sodium ions on the outside, and the inside of the
neuron is negative relative to the outside, sodium ions rush into the
neuron. Remember, sodium has a positive charge, so the neuron
becomes more positive and becomes depolarized. It takes longer for
potassium channels to open. When they do open, potassium rushes out
of the cell, reversing the depolarization. Also at about this time, sodium
channels start to close.
QUESTION
What is the refractory period?
Answer
is a period of time during which an organ or cell is incapable of
repeating a particular action, or (more precisely) the amount of
time it takes for an excitable membrane to be ready for a second
stimulus once it returns to its resting state following an excitation.
It most commonly refers to electrically excitable muscle cells or
neurons.
QUESTION
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Transmission of nerve impulse from one
neuron to another happens how?
Answer
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1. Polarization of the neuron's membrane: Sodium is
on the outside, and potassium is on the inside.
2. Resting potential gives the neuron a break.
3. Action potential: Sodium ions move inside the
membrane.
4. Repolarization: Potassium ions move outside, and
sodium ions stay inside the membrane.
5. Hyperpolarization: More potassium ions are on
the outside than there are sodium ions on the inside.
6. Refractory period puts everything back to normal:
Potassium returns inside, sodium returns outside.
Question
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What are the parts of a synapse?
ANSWER
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1. a presynaptic ending that contains
neurotransmitters, mitochondria and other
cell organelles,
2. a postsynaptic ending that contains
receptor sites for neurotransmitters and,
3. a synaptic cleft or space between the
presynaptic and postsynaptic endings.
QUESTION
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What are the different types of
neurogleal cells?
Answer
Astrocytes
 Oligodendrocytes
 Ependymal cells
 Schwann cells
 Satellite cells
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What do they do?
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The most abundant type of macroglial cell, astrocytes (also
called astroglia) have numerous projections that anchor neurons
to their blood supply. They regulate the external chemical
environment of neurons by removing excess ions, notably
potassium, and recycling neurotransmitters released during
synaptic transmission.
Oligodendrocytes are cells that coat axons in the central
nervous system (CNS) with their cell membrane forming a
specialized membrane differenciation called myelin, producing
the so-called myelin sheath. The myelin sheath provides
insulation to the axon that allows electrical signals to propagate
more efficiently.
Ependymal cells, also named ependymocytes, line the cavities of
the CNS and make up the walls of the ventricles. These cells
create and secrete cerebrospinal fluid(CSF) and beat their cilia to
help circulate that CSF.
Continued
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Similar in function to oligodendrocytes, Schwann cells provide
myelination to axons in the peripheral nervous system (PNS).
They also have phagocytotic activity and clear cellular debris that
allows for regrowth of PNS neurons.
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Satellite cells are small cells that line the
exterior surface of PNS neurons and help
regulate the external chemical environment.
What Comprises the CNF?
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The BRAIN and the SPINAL CORD 
Question
What Is Broca’s Area and
what does it do?????
Hmmmmm
The Answer Is…
Brocas Area is Involved in language
processing, speech or sign production,
and comprehension.
Question For ya
What nerve is affected by Bellas Palsy?
ANSWER IS~~~
THE FACIAL NERVE Of Course 
Question
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What are the components of a
reflex arc?
ANSWER
RELEX ARC CoNSISTs OF 5 MAIN PARTS
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Sensory neuron
CNS integration center
And effector {Think Scammer} (scamr)
Motor neuron
Receptor
To remember that these relate to the reflex arc think
scammers arc you…..lol
CONTINUED
Step 1) Heat ( a stimulus)
Step 2) Pain receptor stimulated
Step 3) Signal passed along sensory neuron
Step 4) Signal passed to relay neuron
Step 5) Signal passed to motor neuron
Step 6) Signal passed to muscle for response
( move hand away from fire)
Question
What type of reflex would a knee jerk
be?
ANSWER IS>>>
Stretch reflex of course……because there is only
one synapse in the circuit needed to complete the
reflex. A stretch reflex is a muscle contraction in
response to stretching within the muscle. It is a
monosynaptic reflex which provides automatic
regulation of skeletal muscle length.
Label The Neuron
ANSWER
Question
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What are the general affects of
sympathetic stimulation?
ANSWER
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dilates pupil
increases heart rate
dilates air passages in lung
reduces gut motility
increases blood glucose level
reduced urine output
sweating
shunting of blood to vital organs (skin turns pale, blood to
gut is cut off, blood only goes to brain, heart, necessary
muscles)
piloerector muscles (raise hair and goosebumps)
FIGHT OR FLIGHT REACTION….Think Sympathy for those
in a bad situation where they have to feel fight or flight.
Question
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Explain the parasympathetic nervous
system…..
AnSwEr
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part of the autonomic nervous
system which usually prepares
the organism to deal more
effectively with a situation
of peace, rest, and recovery.