9. 1- CEREBRUM
Two (2) cerebral hemispheres.
Connected to:
1. Each other by CORPUS CALLOSUM.
2. Brain stem by CEREBRAL PEDUNCLES.
- Outer gray matter (cerebral cortex) contains certain
areas with specific functions.
- Inner white matter composed of nerve fibers
conducting impulses TO & FROM cerebral cortex
10. EACH cerebral hemisphere divided into :
FOUR ( 4 )
LOBES:
1. Frontal
2. Parietal
3. Temporal
4. Occipital
11. 2- Brain stem
Formed of :
1- Midbrain
2- Pons
3- Medulla
Connected to:
1. Cerebral hemisphere
by cerebral peduncles
2. Cerbellum by cerebellar
peduncles
12. BRAIN STEM contains motor nuclei of cranial
nerves:
• 3 & 4 in MIDBRAIN
• 5, 6 &7 in PONS
• 9, 10, 11 & 12 in MEDULLA
N.B. 1, 2 & 8
are sensory nerves have no
motor nuclei
14. CLASSIFICATION OF CRANIAL NERVES
• SENSORY : contain only sensory fibers
1- Olfactory
2- Optic
8- Vestibulocochlear
• MOTOR : contain only motor fibers
3- Oculomotor
4- Trochlear
6- Abducent
11- Accessory
12- Hypoglossal
• MIXED : contain both sensory and motor fibers
5- Trigeminal
7- Facial
9- Glossopharyngeal
10- Vagus
15. Sensory cranial nerves
N. Name Function Assessment
1 Olfactory Smell Examination of
smell
2 Optic Vision Acuity, field &
fundus
8 Vestibular
part
Equilibrium Caloric and
rotational chair
Cochlear
part
Hearing Watch test,
Weber test
16. Motor cranial nerves
N. Name Function Assessment
3 Oculomotor Motor to superior, inferior and
medial recti; inferior oblique &
levator palpebrae superioris
Ptosis, pupil, eye
movements &
squint
Parasympathetic to sphincter
papillae and ciliary muscle
4 Trochlear Motor to superior oblique Look to opposite
shoulder
6 Abducent Motor to lateral rectus Lateral eye
movement
11 Accessory Motor to sternocleidomastoid
and trapezius
Elevaton of
shoulders and
neck rotation
12 Hypoglossal Motor to muscles of tongue Tongue
movements
17. Mixed cranial nerves
N. Name Function Assessment
5 Trigeminal Muscles of
mastication &
sensations of face
Face sensations &
power of muscles of
mastication
7 Facial Muscles of facial
expression & taste
sensation in ant. 1/3
of tongue
Muscles of facial
expression & taste
sensation in ant. 1/3 of
tongue
10 Vagus Sensation and
movements of
Larynx, pharynx,
thoracic and
abdominal organs
Palatal and pharyngeal
reflexes & movements of
uvula
9 Glossopharyngeal Taste in post 2/3 of
tongue & gen.
sensation
Taste & general
sensation and
pharyngeal reflex
18. 3- CEREBELLUM
• Behind the brain stem
• Formed of : * Medline vermis
* Two cerebellar
hemispheres
• Composed of :
Outer grey matter and inner
white matter
19. MB
Pons C
MO
Superior peduncle connects cerebellum with MIDBRAIN.
Middle peduncle connects cerebellum with PONS.
Inferior peduncle connects cerebellum with MEDULLA
OBLONGATA
CEREBELLAR PEDUNCLES
28. UPPER MOTOR NEURON
(pyramidal system)
* Originates in motor area 4 & premotor area 6
* Terminates at the anterior horn cells (AHCs)
of the different levels of the spinal cord.
* It supplies the opposite side of the body.
29. LOWER MOTOR NEURON
• Formed of AHCs & Peripheral motor nerves
(which transmit the motor impulses to the
voluntry muscles).
30. EXTRA PYRAMIDAL SYSTEM
• Originates from centers at various levels of CNS
mainly the BASAL GANGLIA.
• It controls the opposite side of the body.
CEREBELLAR SYSTEM
• Composed of Neo, Archi & Paleo- cerebellum.
• It co-ordinates the movements of the same side of
the body.
31. UMNL LMNL
Tone Increased, with
‘clasp knife’ quality
Decreased
Clonus Present Absent
Fasciculations Absent Present
Muscle Wasting Absent, but disuse
atrophy eventually
results
Present (within 2-3
weeks)
Tendon Reflexes Increased. Extensor
plantar reflexes.
Decreased or
absent. Flexor
plantar reflexes.
Distribution Whole limbs, with
more weakness in
the upper limb
extensors and lower
limb flexors
Specific muscle
groups affected (e.g.
in the distribution of
a spinal segment, or
just the proximal
muscles, etc.)