CNIC Information System with Pakdata Cf In Pakistan
The structure and function of the brain
1. Lesson 5 The Structure and Function of the Brain
Sunday, 29 January 2012
2. Lesson 4: The Neuron
Exam Question
a) Label the diagram below (1 mark)
b) Describe how a neuron transmits information. (3 marks)
Sunday, 29 January 2012
3. b)
a) A neuron transmits
1. Synaptic Knob information by creating an
2. Myelin Sheath action potential.
3. Axon When a neuron is
4. Node of Ranvier stimulated, channels in its
5. Soma (cell body) membrane open, briefly
6. Dendrites allowing positively charged
7. Nucleus sodium ions to rush in, this
creates a change in electrical
activity leading to an action
potential.
Sunday, 29 January 2012
5. Cerebral Cortex
The cerebral cortex is the thin (3-5 mm thick) convoluted (folded) outer layer of the brain.
The value of the folding is that it enables a greater surface area of cerebral cortex to be contained
within the skull; this gives a greater volume and enables the cerebral cortex to contain more neurons
and more blood-vessels to get more oxygen and glucose (for energy) to this most fuel-hungry part
of the body.
There are three main types of functional areas in the cerebral cortex:
1. the sensory areas which receive information provided by the various senses (especially touch,
vision, and hearing);
2. The motor cortex which sends information to muscles so they can create bodily movements
3. The association areas which integrate sensory and motor information and are involved with
information processing activities such as language and speech, learning, memory, thinking and problem
solving
Sunday, 29 January 2012
6. Frontal Lobe
The frontal lobes are the largest lobes and occur on the top front halves of the
cerebral hemispheres. The primary motor cortex is at the back of the
frontal lobes. It runs across the top of the brain from left to right.
It is divided by the longitudinal fissure that separates the two hemispheres.
Specific areas of the motor cortex are responsible for the movement of
particular body parts.
· Right Controls Left/Left Controls Right
· Top Controls Bottom/Bottom Controls Top
Sunday, 29 January 2012
7. Motor homunculus— represents the body parts in terms of the
relative size of the area each of body part occupies along the primary
motor cortex.
Sunday, 29 January 2012
8. Association Areas in Frontal Lobe
Broca’s Area: the “Speech Production Centre” is part of the association cortex.
It is located in the left frontal lobe and is involved with the production of clear,
fluent speech. Broca’s area helps us with the structure of sentences and parts of
speech such as adjectives, prepositions and conjunctions. Broca’s area is involved
with analysing the grammatical structure of sentences that we hear as well as those
that we speak.
Other association cortex in the frontal lobes is involved in
Reasoning
Planning
Thinking
Sunday, 29 January 2012
9. Parietal Lobe
The parietal lobes are located on the top central part of the brain. Primary Areas in the Parietal
Lobes – The Primary Somatosensory Cortex
The primary somatosensory cortex is at the rear of the central fissure, immediately opposite the
primary motor cortex.
The primary somatosensory cortex registers the sense of touch, by receiving information about
pressure, pain, temperature, muscle movement and position from sensory receptors around the
body
It is divided by the longitudinal fissure that separates the two hemispheres.
Specific areas of the primary somatosensory cortex receive sensations from particular parts of the
body.
· Right Receives From Left/Left Receives From Right
· Top Receives From Bottom/Bottom Receives From Top
Sunday, 29 January 2012
10. Sensory homunculus—Similar to motor homunculus
but it tells the brain how much power is needed for sensory
perception of different body parts.
Sunday, 29 January 2012
11. Association Areas in Parietal Lobe
The association cortex of the parietal lobes is important in
Integrating visual information
Monitoring the body’s position in space
Determining where objects are located in
space.
Sunday, 29 January 2012
12. Temporal Lobe
Primary Area in the Temporal Lobes – The Primary
Auditory Cortex
Auditory – sound – information is sent to the primary
auditory cortex, located slightly above and in front of the
ears.
Sunday, 29 January 2012
13. Association Areas in Temporal Lobe
Wernicke’s area - the “Speech Reception Centre” is part of the association cortex. It is located in
the left temporal lobe and is involved with the reception and comprehension of speech.
* Stores the receptor codes for language or enables comprehension of speech/language
* Enables interpretation of the written word
* Is used for locating words from memory to express a particular meaning
* Is used for creating meaningful and/or grammatically correct speech
Other association cortex of the temporal lobes is important in
Memory - the ability to remember faces
Storing of episodic memories such as our first day at school or a particular
holiday
Recognition of objects
Sunday, 29 January 2012
14. Occipital Lobe
Primary Area in the Occipital Lobes – The Primary
Visual Cortex
Visual information from the eyes is sent to the Primary Visual
Cortex in the occipital lobe at the back of each cerebral
hemisphere.
Sunday, 29 January 2012
15. Association Areas in Occipital Lobe
The association cortex of the occipital lobes is
important in
Selection, organisation and integration of
features of visual stimuli.
Sunday, 29 January 2012
