cerebrum, sulci and gyri of cerebrum, lobes of cerebrum, frontal lobe , parietal lobe, temporal lobe and occipital lobe, sulci and gyri presnet in each lobes, and the functional areas , of cerebrum, brodmann areas of cerebrum, borders and surfaces of cerebrum, insula,

1. Cerebrum
DR SANA YASEEN
ANATOMY DEPARTMENT
KIMS

2. OBJECTVES
• Describe sulci and gyri of
cerebrum
• Describe sulci and gyri of
frontal, parietal, temporal and
occipital lobe.
• Functional area of cerebrum
• Bodmanns area

3. INTRODUCTON
– Cerebrum is the largest part of brain (wt 1500gm)
– It is composed of 2 cerebral hemisphere (right
and left)
– The 2 hemisphere are partially seperated by
medial longitudinal fissure. (falx cerebri- the dual
folds of dura mater is located in the median
logitudinal fissure.at the bottom of fissure the two
hemisphere are connected by corpus callosum
(commisural fibers connecting same are of two
cerebral hemisphere)
– The surface of hemisphere are covered by grey
mater ( mainly neuronal cells and denrites)
known as cerebral cortex.

4. – The surface of cerebral
hemisphere has elevated folds
called gyri separated by
depression called sulci
– Within the white matter are
masses of grey matter called
basal ganglion nuclei
– Each hemisphere has fluid filled
cavity called ventricles filled with
CSF.
– Is the origination of conscious
thought processes, intellectual
functions, memory storage and
retrieval, and complex motor
patterns

5. External Features of The Cerebrum
Gyri
– Elevated ridges “winding” around the brain.
Sulci:
– Small grooves dividing the gyri
Central Sulcus:
Divides the Frontal Lobe from the Parietal Lobe.
Fissures:
Deep grooves, generally dividing large regions/lobes of the
brain.
Longitudinal Fissure:
Divides the two Cerebral Hemispheres.
Transverse Fissure:
Separates the Cerebrum from the Cerebellum.
Gyri (ridge)
Sulci
(groove)
Fissure
(deep groove)

9. LONGITUDINAL CEREBRAL FISSURE.
– It contains sickle-shaped fold of dura
mater, falx cerebri, & anterior cerebral
arteries.
– In depths of the fissure, the great
commissure, the corpus callosum,
connects the hemispheres across the
midline.
– A second horizontal fold of dura mater
separates the cerebral hemispheres from
cerebellum and is called tentorium
cerebelli

10. EXTERNAL FEATURES Of Cerebral Hemisphere
– It has 3 surfaces:
Superolateral surface,Medial surface, Inferior surface
- 3 borders:
superomedial, inferolateral (orbital part is called supercilliary
bordder) , inferomedddial (divided into medial orbital and medial
occipital border)
- 3 poles:
frontal, temporal and occipital

11. MAIN SULCI
– Central sulci:
Divides frontal and parital lobe
– Lateral sulci:
Divides frontal and parietal lobe from temporal
lobe
– Parieto-occipital sulci:
Present between parietal and occipital lobe
– Calcarine sulci:
Present on medial surface
– Lobes are named according to the cranial
bones under which they lie.

12. Lobes of the Brain
– Frontal
– Parietal
– Occipital
– Temporal
* Note: Occasionally, the Insula is considered the fifth lobe. It
is located deep to the Temporal Lobe.

13. – insula lies at bottom
of deep lateral sulcus
and cannot be seen
from the surface
unless the lips of the
sulcus are separated

14. FRONTAL LOBE
– It occupies area anterior to central sulcus and superior to lateral sulcus.
– divided by three sulci into four gyri.
– The precentral sulcus runs parallel to central sulcus, & precentral gyrus lies
b/w them.
– Extending anteriorly from precentral sulcus are superior and inferior
frontal sulci.
– superior frontal gyrus lies superior to the superior frontal sulcus, the
middle frontal gyrus lies between the superior and inferior frontal sulci,
and the inferior frontal gyrus lies inferior to the inferior frontal sulcus.

16. LATERAL SULCUS
– The lateral sulcus is
found on the inferior and
lateral surfaces of the
cerebral hemisphere.
– It divides into three rami.
anterior horizontal
ramus, anterior
ascending ramus &
posterior ramus .
Posterior ramus

17. PARIETAL LOBE
– It occupies area posterior to central sulcus and
superior to the lateral sulcus;
– Postcentral sulcus runs parallel to the central
sulcus, and the postcentral gyrus lies between
them.
– Running posteriorly from the
Middle of the postcentral sulcus is the
intraparietal sulcus.
– Superior to the intraparietal sulcus is the superior
parietal
lobule (gyrus), and inferior to the intraparietal
sulcus is the inferior parietal lobule (gyrus).

18. TEMPORAL LOBE
– It occupies area inferior to
lateral sulcus. lateral
surface of the this lobe is
divided into three gyri by
two sulci.
– The superior and middle
temporal sulci divide lobe
into superior, middle, &
inferior temporal gyri;

19. OCCIPITAL LOBE
– Is the smallest lobe
– parieto ocipital sulcus begins on
the superior margin of hemisphere
and passes down and anteriorly on
medial surface to meet calcarine
sulcus.
– It separates parietal and occipital
lobe on lateral surface

21. INFERIOR SURFACE
– Medial occipitotemporal gyrus
extends from the occipital pole to
the temporal pole.
– It is bounded medially by collateral
sulci and laterally by the
occipitotemporal sulcus. The
occipitotemporal gyrus lies lateral
to the sulcus and is continuous with
inferior temporal gyrus .
– On the inferior surface of the
frontal lobe, the olfactory bulb and
tract overlie a sulcus called the
olfactory sulcus.

22. – Collateral sulcus is situated on
the inferior surface of the
hemisphere.
– This runs anteriorly below the
calcarine sulcus.
– Calcarine sulcus: begins under
posterior en of corpus callosum
and arches upward and backward
to reach occipital pole also extend
to lateral surface
– it is joined at acute angle by
parieto ocipital sulcus about half
way along its length

23. – B/w collateral sulcus and calcarine
sulcus is the lingual gyrus.
– Anterior to the lingual gyrus is the
parahippocampal gyrus; the latter
terminates in front as the hook like
uncus.
– The uncus is an anterior extremity
of the parahippocampal gyrus. It
is separated from the apex of the
temporal lobe by a slight fissure
called the incisura temporalis

24. MEDIAL SURFACE
– The lobes of the cerebral hemisphere are
not clearly defined on the medial and
inferior surfaces.
– Corpus callosum, which is the largest
commissure of brain, locatedd centrally.
– Cingulate gyrus continues above corpus
callosum until it reaches its posterior end.
– The gyrus is separated from the corpus
callosum by the callosal sulcus.
– cingulate gyrus is separated from the
superior frontal gyrus by the cingulate
sulcus
– Precentral lobule: are of brain
surrounding central sulci
o Anterior part- precentral gyrus
o Posterior part- post central gyrus
– cuneus: triangular area between parieto-
occipital sulcus (above) and calcarine
sulcus (below) and superior meial margin
(behind).
– Precuneus: area of cortex bounded by
upturned end of cingulate gyrus(
anteriorly) , parieto-occipital sulcus
(posteriorly).

26. FUNCTIONAL OR BRODMANN AREAS
OF CEREBRAL CORTEX
– Various areaas of the cerebral cortex perform specific functions. Human cortex has been
described to have three types of functional areas.
– Motor area: control voluntary movement. Mainly present in frontal lobe.
– Sensory area: conscious awaremessperception of general somatic sensations (pain
temperature, touch, proprioception) and special sensation ( vison, hearing, taste, smell).
– Association area: almost 70% of the cortex is association cortex. These areas are usually
present close to the sensory areas. It integrate various types of sensation information and to
ddirect behaviour, communication andd intellect diverse information.

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