The document discusses the cerebrum and its structures. It notes that the cerebrum is the largest part of the brain and is divided into two hemispheres by a longitudinal fissure. Each hemisphere consists of an outer cortex and inner white matter. The cortex is folded into gyri and sulci. The major lobes of the cerebrum are the frontal, parietal, occipital and temporal lobes, each with distinct functions. The document outlines Brodmann areas within the cortex and their roles, and discusses lesions or injuries to different cortical areas and their clinical effects.

1. Cerebrum
Sameera Mushtaq

2. Course

3. Learning Objectives
• Introduction
• Cerebral Lobes
• Cortical areas & functions
• Clinical notes

4. CEREBRAL HEMISPHERE

5. CEREBRUM
• The cerebrum is the largest part of the
brain, situated in the anterior and middle
cranial fossae of the skull and occupying
the whole concavity of the vault of the
skull.

6. CEREBRUM

7. CEREBRUM
• Each cerebral hemisphere consists of
an outer cerebral cortex and an inner
white matter.
• A longitudinal cerebral fissure
incompletely separates the cerebrum
into 2 halves; right and left.Each
hemisphere extends from the frontal
to the occipital bones in the skull.

8. General Appearance of the Cerebral Hemispheres
• The cerebral hemispheres are the largest
part of the brain; they are separated by a
deep midline fissure, the longitudinal
cerebral fissure.
• The fissure contains the sickle-shaped fold
of the dura mater, the falx cerebri, and the
anterior cerebral arteries.
• In the depths of the fissure, the corpus
callosum, connects the hemispheres across
the midline.
• A second horizontal fold of the Dura mater
separates the cerebral hemispheres from the
cerebellum and is called the tentorium
cerebelli.

9. Cerebral Cortex
• Cerebral Cortex or Cerebral Mantel is formed by an outer grey
matter layer, which is thrown into a convoluted pattern of ridges and
furrows called GYRI and SULCI respectively.
• Deep into the cerebral cortex is an inner mass of white matter, which
forms the bulk of the cerebrum and contains myelinated nerve fibers
that convey information to or from the cerebral cortex.

11. Gyri and Sulci
Shallow depression is
known as Sulcus
Deep depression is
known as Fissure
Elevated portion is
known as Gyrus

14. Sulci of cerebrum
• Lateral sulcus (Sylvius): between frontal, Parietal &
temporal lobes.
• Central sulcus (Rolando): Separates frontal from
parietal lobes
• Parieto-occipital sulcus: Separates Parietal & occipital
lobes

17. Fissures of the Cerebrum
Longitudinal
Fissure Separates 2 hemispheres
Transverse Fissure
Separates Cerebrum
from Cerebellum
Lateral Fissure
Continuation of Lateral
Sulcus
Separates F & T lobes

18. LOBES OF THE BRAIN
Frontal Lobe
Parietal lobe
Occipital lobe
Temporal lobe
Insular lobe

19. Frontal lobe
• Largest Lobe
• 3 sulci: Precentral sulcus, Superior &
inferior frontal sulci
• 4 gyri: Precentral gyrus, Superior, middle
& inferior gyri
• Controls
• Voluntary movement
• Emotions
• Memory formation
• Personality formation
• Help in decision making

21. Parietal Lobe
• Present b/w Central sulcus & Parietooccipital
Sulcus
• Sulcus: Postcentral & Intraparietal
• Gyri: Postcentral, superior parietal lobule,
inferior parietal lobule with supramarginal &
angular gyri
• Controls:
• language and symbol use
• visual perception
• sense of touch, pressure, and pain
• giving meaning to signals from other sensory
information

22. Temporal lobe
• Lies inferior to lateral sulcus
• Sulci: superior & inferior
• Gyri: superior, middle &
inferior
• Controls
• Memory
• Hearing
• Understanding Language
• Organization And Patterns

23. Occipital lobe
Present posterior to the parietal
and temporal lobes
• Parieto-occipital sulcus
• Lateral occipital
• Calcarine sulcus
• Controls:
• Light
• Color
• Movement
• Spatial Orientation

25. INSULAR LOBE
• Location: floor of lateral sulcus; seen only when temporal & frontal
lobes are separated
• 3-4 short anterior gyri
• 1-2 long posterior gyri
• Controls: not totally understood
• homeostasis
• compassion and empathy
• self-awareness
• cognitive function
• social experience

26. Internal Structure of the Cerebral Hemispheres
• The cerebral hemispheres are covered with a layer of grey matter, the
cerebral cortex
• Located in the interior of the cerebral hemispheres are the:
 Lateral Ventricles
 Basal Nuclei (Masses Of Grey Matter)
 Nerve Fibres
• The nerve fibres are embedded in neuroglia and constitute the white matter

27. Lateral Ventricles
• There are two lateral
ventricles, and one is present
in each cerebral hemisphere.
• Each ventricle is a roughly C-
shaped cavity lined with
ependyma and filled with
cerebrospinal fluid.
• The lateral ventricle
communicates with the cavity
of the third ventricle through
the interventricular foramen.

28. Basal Nuclei
• Basal Nuclei
• The term basal nuclei (basal
ganglia) is applied to a
collection of masses of gray
matter situated within each
cerebral hemisphere.
• They are:
 The Corpus Striatum
(composed of Caudate and
Lentiform Nucleus)
 The Amygdaloid Nucleus
 The Claustrum

29. White Matter of the Cerebral Hemispheres
• The white matter is composed of myelinated nerve fibers of different
diameters supported by neuroglia.
• The nerve fibers may be classified into three groups according to their
connections:
• Commissural Fibers
• Association Fibers
• Projection fibers.

30. Blood supply of Brain
• The brain receives blood from two
sources: the internal carotid
arteries, which arise at the point in
the neck where the common carotid
arteries bifurcate, and the vertebral
arteries .The internal carotid
arteries branch to form two major
cerebral arteries,
the anterior and middle cerebral
arteries.

31. Cortical Areas of brain
• Cortical areas are areas of the brain located in
the cerebral cortex. They are primarily divided in
three parts
• Motor cortex
• Sensory cortex
• Associative areas

32. Who mapped the Earth first??
Anaximander:
The earliest
Greek known to
have made a
map of the
world.

33. Who mapped the Brain??
Korbinian Brodmann was a German
neurologist who became famous for
mapping the cerebral cortex and defining
52 distinct regions, known as Brodmann
areas.

34. Brodmann areas of the cerebral cortex
• Brodmann areas of
the cerebral
cortex are defined
by its
cytoarchitecture
(histological
structure and

35. Brodmann areas of the cerebral cortex

36. Cortical areas of Frontal lobe
Pre-central gyrus (Present in front of central sulcus)
Area 4 Primary motor cortex
Lesion: Contralateral spastic paralysis
Area 6 Premotor cortex and Supplementary motor cortex (Motor planning)
•Lesion: Apraxia (Unable to perform movements in correct sequence)
Area 8 Frontal eye field (Contralateral horizontal conjugate eye movements)
•Lesion: Contralateral horizontal conjugate gaze palsy
Area 44 Broca’s area (Motor speech centre only in Dominant hemisphere)
•Lesion: Comprehends language well but fails to express thoughts verbally or in written
•Non-fluent, motor or expressive aphasia
•Agraphia (inability to write)
Areas 9, 10 regulate emotions and higher mental functions.
Area 11 is associated with general olfaction.

37. Cortical areas of Parietal lobe
• Present in post-central gyrus (Present posterior to central sulcus)
• Areas 3,1 and 2: Discriminative touch, vibration, position sense, pain and temperature
• Lesion: Impairment of all somatic sensations in contralateral side of body.
• Area 43: Primary gustatory area (sensory)
• Areas 5 and 7: Somatosensory association cortex (Spatial awareness and Awareness
of body in general)
• Area 40 and Area 39 : Area 39 is also called the “reading center” and also plays
important role in arithmetic functions. Area 40 has a role in phonological processing and
emotional responses.
• Area 22: Also regarded as Wernicke area, region of the brain that contains motor
neurons involved in the comprehension of speech.

39. Lesion of speech areas
• Aphasia is an impairment of language, affecting the production or
comprehension of speech and the ability to read or write. Aphasia is always
due to injury to the brain-most commonly from a stroke, particularly in older
Individuals
• Broca’s area lesion (Broca's aphasia) There will be Broken
speech
• Wernicke’s area lesion (Wernicke’s aphasia)
• Speech is normal. Articulation is normal. But speech will not make sense.

40. T
Temporal lobe
• Area 41 and 42: Primary auditory cortex (Basic sound processing)
• Lesion: Unilateral lesion results in a slight loss of hearing and Bilateral
lesion results in cortical deafness.
Area 21 and Area: Part of the auditory association cortex
• Area 34: Primary olfactory cortex
• Lesion: Ipsilateral anosmia
• Area 28: fits can lead to olfactory and gustatory hallucinations
• Area 37: Familiar face recognition
• Lesion (Bilateral): Prosopagnosia (deficit in recognition of familiar faces,
such as those of family, friends, and colleagues)

41. Cortical areas of occipital lobe
• Primary visual cortex(17) = senses visual info
• Visual association cortex(18,19) = make perception
of visual info

43. LEARNING OUTCOMES
• Introduction
• Cerebral Lobes
• Cortical areas & functions
• Clinical notes