The brain is composed of the cerebrum, cerebellum, and medulla. The cerebrum controls higher functions and is divided into sensory, motor, and association areas. The cerebellum coordinates movement and balance, while the medulla regulates vital functions like breathing and heart rate. Specific areas of the brain control motor and sensory functions for different parts of the body. Language abilities are localized to Broca's and Wernicke's areas in the left hemisphere for most right-handed individuals.

1. The Brain
Dr shittu LAJ

2. The Brain
The human brain is the site of the major
coordination in the nervous system.

3. The BrainThe Brain
Cerebrum
Cerebellum
Medulla
Pituitary gland
Hypothalamus

4. Areas of the brain
 The brain is composed of Cerebral
Hemispheres, Cerebellum and Medulla
Medulla
Cerebral
Hemispheres
Cerebellum

5. medulla
 Controls autonomic activities including heart rate, and
ventilation rate
 Impulse transmitted from medulla via sympathetic or
parasympathetic branch of automatic nervous system
Medulla
Cerebral
Hemispheres
Cerebellum

6. cerebellum
 Co-ordination of body movement,
balance and posture
Cerebral
Hemispheres
Cerebellum

7.  Highly Folded and so has a large SA.
 Patients with injuries to specific parts of the
brain can be studied to see how their
functions are altered.
cerebrum/cerebral hemispheres
Medulla
Cerebral
Hemispheres
Cerebellum

8.  Different parts of the brain can be stimulated
electrically to see which muscles in the body
respond
 Conversely different parts of the body can be
stimulated to see which parts of the brain
show electrical activity.
 More recently MRI (magnetic resonance
imaging) has been used in brain study
cerebrum/cerebral hemispheres

10. Areas of the cerebrum
V is u a l s e n s o r y
a r e a
V is u a l a s s o c ia tio n
a r e a
P r o p r io c e p tio n s e n s o r y a r e a
M a in
m o to r
a r e a
M a in
s e n s o r y
a r e a
C o m p le x m o v e m e n t
m o to r a r e a
H ig h e r f u n c t io n s
a s s o c ia t io n a r e a
S p e e c h
a s s o c ia t io n
a r e a
S m e ll
s e n s o r y
a r e a A u d it o r y
s e n s o r y
a r e a
V is u a l a n d
a u d ito r y
a s s o c ia t io n
a r e a
C o m p r e h e n s io n
a s s o c ia t io n
a r e a
S e n s o r y
a r e a s
A s s o c ia t io n
a r e a s
M o to r
a r e a s

11. The Areas can be split into 3
groups
 Sensory Areas
 Motor Areas
 Association Areas

12. Association Motor
Sensory
Sensory
area for
impulses

13. cerebrum/cerebral hemispheres
•Sensory areas of the cerebral hemispheres receive impulses
from sense organs and transmit them to the association areas
•The association areas of the cerebral hemispheres receive
impulses - interpret them in the light of similar past experiences
and transmit impulses to motor areas
•The motor areas transmit impulses to the effectors
•The size of the sensory and motor areas is related to the
number of receptors in that area
•The left and right cerebral hemispheres control the opposite
sides of the body

14. Mapping of the sensory &
motor areas to the body
shoulder
wrist
hand
fingersthumb
e y e
fa c e
lip s
ja w
t o n g u e
swallowing
chewing
le g s
t o e s
neck
elbow
trunk
a n k le
h ip
M o t o r
C o r t e x
shoulder
wrist
forearm
hand
fingersthumb
e y e
fa c e
n o s e
lip s
g u m s
ja w
to n g u e
pharynx
abdomen
le g s
t o e s
g e n ita lia
elbow
trunk
f o o t
h ip
S e n s o r y
C o r t e x

15. Sensory & Motor Maps
 The maps show that regions of the body with many
sensory (or motor) neurones have corresponding
large areas of the cerebrum linked to them.
 So for example the lips occupy a larger region of
the sensory cortex than the shoulder, because
there are more sensory neurones in the lips.

16. Association Areas
 Are used to compare sensory input with previous
experiences, and make decisions
 These areas are involved in speech, understanding
and memory retrieval
 The frontal lobes are large in humans and it is
thought that they are responsible for higher
functions like abstract thought, personality &
emotion.

17. Speech
 The left side of the brain
 Patients with speech problems gave 1st
clues about
how the brain controls language
 1981 Dr Paul Broca described a patient who could
only say the word “tan”.
 When the patient died Broca examined the brain
and found damage to the left cerebral hemisphere
 This part of the brain is now know as Broca’s area

18. Broca’s Area
Broca’s area

19. Wernicke’s Area
 In 1967 Karl Wernicke noticed damage to another
region of the cortex.
 Werniche’s area is connected to Broca’s area by a
bundle of nerve fibres.
 If this was damaged the patient can understand
language but cannot repeat words.
 So Werniche’s area is concerned with
understanding language. Broca’s area is
concerned with controlling the muscles that
produce speech

20. Wernicke’s Area
Wernicke’s
area

21. Visual Processing
 The visual sensory area is at the back of the brain
& receives sensory input from the optic nerves
 The 2 hemispheres see slightly different images
from the opposite of the visual field, and
differences can be used to judge distance

22. Optic Chiasma

23. Summary
 Sensory areas – receive input from receptors
 Motor areas – Origin of impulses which bring
about voluntary movements
 These receive/transmit impulses from the
opposite side of the body
 Association areas – interpret sensory
information in the light of experience

24. A close shave