5. CEREBRUM :
•Largest part of brain, situated in the anterior & middle cranial fossae of
the skull and occupying the whole concavity of vault of skull
•Having 2 parts: diencephalon forms central core, telencephalon
forms cerebral hemisphere
• The 2 cerebral hemisphere, connected by “corpus callosum” ( mass of
white matter)
• Each hemisphere extends from frontal to the occipital bones, above
anterior and middle cranial fossae and posteriorly above tentorium
cerebelli
•The hemisphere separated by depth cleft, the longitudinal fissure (into
which projects falx cerebri) 5
6. • Surface of hemisphere(cortex) composed of grey
matter
• Cerebral cortex is thrown into Gyri (folds), which are
separated by sulci (fissure) -----> thus surface area is
greatly increased
• Sulci ÷ hemisphere into lobes.
• There are 4 lobes :
1. FRONTAL LOBE
2. PARIETAL LOBE
3. OCCIPITAL LOBE
4. TEMPORAL LOBE
6
8. 1.FRONTAL LOBE :
situated in front of central sulcus & above lateral sulcus
2.PARIETAL LOBE :
situated behind the central sulcus & above the lateral sulcus
3.OCCIPITAL LOBE :
Lies below the parieto-occipital sulcus
4. TEMPORAL LOBE :
Below the lateral sulcus
8
10. 1.PRECENTRAL GYRUS :
•Lies immediately anterior to the central sulcus which is “MOTOR AREA”
• large Motor nerve cell in this area controls voluntary movement on the
opposite side of the body
•In motor area, body is represented in an innervated position
•In motor area nerve cell control movement of feet located in the upper
part & control movement of face & hands in lower part.
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12. 2.POSTCENTRAL GYRUS :
•Lies posterior to central sulcus known as “SENSORY AREA”
•Small nerve cells in this area receive and interpret sensation of pain , touch &
pressure from opposite side of body.
3.SUPERIOR TEMPORAL GYRUS :
•Lies below lateral sulcus
•Control movement employed in speech
•Middle area of this gyrus is concerned with the reception and interpretation of
sound known as“AUDITORY AREA”
12
13. BROCA’S AREA (Motor speech area)
•Lies just above lateral sulcus
•Control movement employed in speech
•It is dominant in;
•Right hemisphere left-handed person
•Left hemisphere right-handed person
VISUAL AREA :
•Situated on the posterior pole & medial aspects of cerebral hemisphere in
the region of calcarian sulcus
•It is receiving area for visual impression
•Cavity of cerebral hemisphere called “LATERAL VENTRICLE”
LATERAL VENTRICLE :
Lateral ventricle communicate with the 3rd ventricle through “Inter
ventricular foramina”.
13
15. FUNCTIONS OF CEREBRUM :
•It helps in initiation & control of all voluntary of body parts &
governs the lower part of nervous system .
•It is the centre of all intelligent behavior .
15
17. Diencephalon
• Almost completely hidden from the surface of the brain.
• Divided into 2:
• Dorsal thalamus
• Ventral hypothalamus
• THALAMUS:
• Egg shaped large mass of gray matter that lies on either side of
the 3rd ventricles, it’s a great relay station on the afferent sensory
pathway to the cerebral cortex
• Its anterior end round and narrow--- forms the posterior
boundary of inter ventricular foramina.
• Its posterior end expanded and forms pulvinar
17
18. Diencephalon
• HYPOTHALAMUS:
• Lies below the thalamus
• Forms the lower part of the lateral wall and floor of the 3rd
ventricle
• Following structures are found in the floor of the 3rd ventricle
• Optic chiasma
• Tuber cinereum
• Infundibulum
• Mammillary bodies
• Posterior perforated substances
• Functions:
• Body homeostasis through ANS & neuroendocrine system
• Play vital role in emotional behavior
18
19. Diencephalon
• PEDUNCLES:
• Large bundles of fibers connecting the cerebral and cerebellar
hemispheres to the brain stem are called peduncles
• Lateral ventricle cavity located within each cerebral
hemisphere
• 3rd ventricle cavity of diencephalon
• 4th ventricle cavity of hind brain
19
22. MID BRAIN
• LOCATION:
• It is a narrow part of the brain.
• It passes through tentorial notch.
• It connects the fore brain to the hind brain.
22
23. • It comprises of 2 lateral halves called as
CEREBRAL PENDUNCLES.
POSTERIOR
ANTERIOR
Divided by Pigmented band of gray matter called as
SUBSTANTIA NIGRA
CRUS CEREBRI TEGMENTUM 23
24. • The narrow cavity of Mid Brain is CEREBRAL
AQUEDUCT.
• It connects the 3rd ventricle with the 4th ventricle.
• Cerebral Aqueduct
Posterior part TECTUM
It has4 small
surface
swellings
2 inferior
Colliculi
2 superior
Colliculli
( The Colliculli are deeply placed in between
the cerebellum and cerebellar hemispheres. )
In between 2
superior
colliculli
PINEAL BODY
24
27. • It is a small cone shaped glandular structure.
• Attached by a stalk to the region of posterior wall of
the 3rd ventricle.
• It consists of group of cells, the pinealocytes,
supported by glial cells.
27
29. - Influence the activities of
• Pituitary Gland
• The islets of Langerhans of pancreas
• The Parathyroid
• The Adrenals
• The Gonads
- Their actions are mainly inhibitory.
29
30. -Basillary Artey
- Posterior cerebral artery
- superior cerebellar artery
Occulomotor (iii) anterior aspects
trochlear(iv) only nerve arises from
posterior aspects of brain
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32. Introduction:
Composition Of
Pons:
• Composed of nerve fibers (neurons) which connect two halves of
the cerebellum.
• Also contains ascending and descending fibers, connecting the
forebrain, midbrain and spinal cord.
• Some of the nerve cells within the pons serve as relay station
while others form cranial nerve nuclei.
• connected to cerebellum by means of middle cerebral peduncle.
• It serves as a bridge between various parts of the nervous system,
including the cerebellum and cerebrum
• middle part of the brain stem that connects mid brain with medulla.
32
33. LOCATION:
• The pons lies on anterior surface of the cerebellum, inferior to
midbrain and superior to medulla oblongata.
Midbrain
Hindbrain
Pons
Cerebellum
Medulla
33
34. Sur faces of Pons
Divided into two
Ventral (basilar) Dorsal (tegmental)
Transverse
fibres
Vertical
nuclei
Pontine
nuclei
34
36. Pons: Origin of some important
nerves
Trigeminal
nerve (v)
• Feeling in the face
as well as
controlling the
muscles that are
responsible for
biting, chewing,
and swallowing.
Abducens
nerve (vi)
• Allows the
eyes to look
from side to
side.
Facial
nerve(vii)
• Controls
facial
expression.
Vestibularcochlear
nerve (viii)
• Allows
sound to move
from the ear
to the brain.
• Cranial nerve vi, vii & viii emerge b/w
pons and medulla and trigeminal nerve
is the only nerve emerges frompons
36
38. pons
• ADDITIONAL POINTS:
• DORSAL:
• Aqueduct of mid brain opens out at the upper border of the pons
into the cavity of 4th ventricle
• The 4th ventricle has a roof and floor. The floor is formed by pons
and medulla with major contribution from the pons.
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41. MEDULLA OBLONGATA
• LOCATION : Anterior part of posterior cranial
fossa.
• Extends from the lower border of pons to a plan
just above the 1st cervical nerve where it is
continous with the spinal cord.
• CONNECTION :
It connect inferior of pons to superior of spinal
cord .
Provide major pathway for nerve impulses
entering and leaving the skull .
It give rise to cranial nerve VI to XII.
41
43. MEDULLA OBLONGATA
• RELATIONS:
• Anteriorly clivus , meninges
• Posteriorly vallecula of cerebellum
• Serves as a conduct for ascending and descending nerve fibers
• Nuclei of cranial nerves III & IV are in midbrain
• Motor nucleus of cranial nerve V is in pons
• 3 sensory nuclei of cranial nerve V are in midbrain, pons &
medulla
• Motor nuclei of cranial nerve VI & VII are in the pons
• Nuclei of cranial nerve VIII over lap the junction of the pons
and medulla and lie in each
• Nuclei of cranial nerve IX, X, XI, XII are in medulla
43
44. MEDULLA OBLONGATA
PYRAMIDS:
• A median fissure is present on the anterior
surface of medulla and on each side of this is a
swelling called PYRAMID
• The pyramids are composed of bundles of nerve
fibers that originates in large nerve cells in the
precentral gyrus of the cerebral cortex
• Pyramids tapers below and here most of
descending fibers cross over to the opposite
side, forming the decussation of the pyramids 44
45. MEDULLA OBLONGATA
OLIVES:
• Present posterior to pyramids
• They are oval elevations composed of
olivary nuclei and nuclei of cranial nerves
• Behind olives are inferior cerebellar
peduncles which connect medulla to
cerebellum
45
49. LOCATION:
Lies with in:
Posterior cranial fossa
BENEATH TENTORIUM
CEREBELLI:
Posterior to pons and
medulla oblongata
Divided into two
hemispheres connected
by median portion:
VERMIS.
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53. Ventricles:
• Cavity of hind brain 4th ventricle which bound;
• In front by pons and medulla
• Behind by superior and inferior medullary vela and
cerebellum
• 4th ventricle connected to 3rd ventricle by cerebral
aqueduct
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