Structure and function of the Brain

1. Lesson 1:The Structure and Function of the Brain

2. Lobes of the Brain

3. 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 two main types of functional areas in the cerebral cortex:
1. the primary cortices first receive information from the environment for example:The primary
visual cortex, primary auditory cortex )
2.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

4. 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.
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 ControlsTop

5. 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.

6. 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

7. 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 FromTop

8. Sensory homunculus—Similar to motor homunculus but it
tells the brain how much power is needed for sensory
perception of different body parts.

9. 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.

10. Temporal Lobe
Primary Area in theTemporal Lobes – The Primary
Auditory Cortex
Auditory – sound – information is sent to the primary
auditory cortex, located slightly above and in front of the
ears.

11. Association Areas inTemporal 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

12. Occipital Lobe
Primary Area in the Occipital Lobes – The Primary Visual
Cortex
Visual information from the eyes is sent to the PrimaryVisual
Cortex in the occipital lobe at the back of each cerebral
hemisphere.

13. Association Areas in Occipital Lobe
The association cortex of the occipital lobes is
important in
Selection, organisation and integration of
features of visual stimuli.