Transcript Introduction to the brain and behaviour

Introduction to the brain
and behaviour
Amazing brain facts
Cerebral cortex
Cerebral hemispheres
Corpus callosum
Amazing brain facts
Your skin weighs twice as much
as your brain.
Your brain uses 20% of total
oxygen pumping around your
body.
750ml of blood pumps through
your brain every minute
It consists of 100 billion neurons.
Time until unconsciousness after
loss of blood supply to brain is 8 –
10 secs.
Approximately 75% of it is water.
If you could harness the power
used by your brain you could
power as a 10 watt light bulb!
Male brain
Female brain
Cerebral cortex
It is the convoluted or folded outer
layer or covering of the two
hemispheres.
It is around 2mm thick
It contains ¾ of the entire brain’s
neurons.
Its bulges and grooves account for
the increased surface area.
It is involved with information
processing activities such as
perception, language, learning,
memory, thinking, problem solving,
control of voluntary body movements.
The cerebral cortex
It is believed that the size of a
species’ cerebral cortex is
linked to intellectual ability.
The bigger the cerebral cortex,
the more capable the organism
is of intelligent behaviour such
as thinking, problem solving
and decision making.
Homer Simpson’s Brain
Four cortical lobes
Cortical areas
Cortical areas
1. Sensory cortex areas – receive and
process information from the senses.
2. Motor cortex area – receives,
processes and sends information about
voluntary bodily movements.
3. Association cortex areas – integrate
sensory, motor and other information
and are involved in complex mental
abilities.
Cerebral hemispheres
These are the two almost symmetrical
brain structures that appear to be
separated by a deep groove
(longitudinal fissure) running from the
front to back of the brain.
They are connected at several points
by strands of nerve tissue.
They are referred to respectively as
the left and right hemispheres.
While they share some common
functions, they also have specialised
functions.
Eg. the left hemisphere receives
sensory information from the right side
of the body and controls movements
on the right side.
Left hemisphere is primarily involved
with language, right hemisphere is
primarily involved with spatial tasks
and recognition of faces.
Corpus callosum
The corpus callosum is a
bridge of nerve tissue that
connects the left and right
cerebral hemispheres.
It serves as the main
communication pathway
or cross over station for
neural messages
between the two cerebral
hemispheres.
It comprises over 200
million nerve fibres.
Can you find the corpus callosum
on this MRI image?
Sample exam questions
Question 1 (VCAA 2005)
The major function of the corpus callosum is to
A. coordinate autonomic functions such as breathing
and heart rate.
B. connect the somatosensory cortex to the motor
cortex.
C. transfer information between the right and left
hemispheres.
D. connect Wernicke’s area to Broca’s area.
Sample exam questions
Question 1 (VCAA 2005)
a. The deeply furrowed or grooved layer of
tissue that covers the cerebral hemispheres is
known as the __________________.
(1 mark)
b. List two main functions of this grooved
layer of tissue.
1. _________________________________
2. _________________________________
(2 marks)
Sample exam questions
Question 1 (Checkpoints 2006)
What purpose is served by the convolutions in the
cerebral cortex of the brain?
A. They allow more blood to flow to the neurons as the
brain requires more oxygen and nutrients than other
organs of the body.
B. They provide some protection against injury by acting
as a shock absorber if the brain is jolted.
C. They allow the brain more room to grow because
they progressively unfold as the person ages.
D. They give the brain a larger surface area which
means more neurons can be packed into a smaller area.
Sample exam questions
Question 1
What is the ‘corpus callosum’?
__________________________________
(1 mark)
What is its main function?
__________________________________
(1 mark)
Sample exam question from VCAA
2006
Question 1
The cerebral cortex
A. acts as a protective layer covering the brain.
B. connects the right hemisphere with the left hemisphere.
C. is responsible for voluntary muscle movements.
D. increases the strength of the immune system.
Question 2
The cerebral cortex is approximately ____________ thick.
A. 2 to 5 millimetres
B. 6 to 10 millimetres
C. 2 to 5 centimetres
D. 6 to 10 centimetres
Question 3
The ________________ is a band of nerve fibres connecting the left and
right hemispheres.
A. cerebral cortex
B. cerebral hemisphere
C. corpus callosum
D. cerebellum