PROF. DR. ANSARI
(FOR BDS SEMESTER-II STUDENTS ONLY)
• Is the largest portion of the human brain.
• It consists of two cerebral hemispheres, which develop from
the embryonic forebrain.
• These hemispheres have an outer convoluted layer of gray
matter – the cerebral cortex – and an inner layer of white
• The two halves are linked by the corpus callosum.
• Each hemisphere of the cerebrum is subdivided into four
lobes visible from the outside. They are the
frontal, parietal, occipital, and temporal lobes.
The cerebrum is the integrating center for
memory, learning, emotions, and other highly complex
functions of the central nervous system.
• It is the slow growing and hidden part of
cerebrum, submerged by frontal lobe,
parietal, & temporal lobes.
• The middle cerebral artery emerges out from
the lateral sulcus and distributes to the
superolateral surface of hemisphere.
• The circular sulcus is seen in the insula.
The surface of cerebral hemisphere
• Shows various sulci and gyri, a modification of
surface of brain to accommodate large
amount of brain tissue within a limited space.
• There are three surfaces of cerebral
• Superolateral surface, inferior surface and
• The following important gyri and sulci are seen :• Central sulcus, precentral gyrus, post central
• Frontal lobe has superior frontal gyrus, middle
frontal gyrus and inferior frontal gyrus.
• The inferior frontal gyrus has cortical centre for
speech, Broca’s area.
• The lateral sulcus separates the temporal lobe
The temporal lobe
• Has three gyri, superior, middle and inferior
• By the help of 2 sulci, superior and inferior
temporal sulci, there are three temporal gyri.
• The superior temporal gyrus is having the site
for hearing, Heschel’s gyrus.
The precentral gyrus and post central
The dominant hemisphere
• The left side of the brain controls movement
of the right side of the body, and the right side
of the brain controls movement of the left half
of the body.
• For most of us, the left side of the brain is the
side necessary for speech. The dominant
The parietal lobe
• It has intraparietal sulcus that divides the parietal
lobe into superior parietal lobule and inferior
• Involved in perception of stimuli related to
touch, pressure, temperature, and pain.
• This region of the brain helps people understand
what they see and feel.
• It also controls how they understand and process
information about the environment around them,
such as distance and position of objects.
Each lobe is associated with:• Frontal Lobe- associated with
reasoning, planning, parts of
speech, movement, emotions, and problem
• Parietal Lobe- associated with
movement, orientation, recognition, perception
• Occipital Lobe- associated with visual processing
• Temporal Lobe- associated with perception and
recognition of auditory stimuli, memory, and
• You are who you are because of this lobe.
• This area determines personality and
• It's also involved in controlling judgment,
impulses, sexual behavior, language and
• Prefrontal lobotomy was performed to control
the aggressive/violent behavior /undesirable
behavior of prison inmates/mental asylum
• The original lobotomy operation is now rarely
performed, if ever, although many countries
still accept psychosurgery as a form of radical
control of violent behavior (Japan, Australia,
Sweden and India are among them).
The visual center is located in
• This area determines if you understand what
you're looking at.
• Damage to the occipital lobe could cause
hallucinations, make objects appear larger or
smaller then they are or make the colors look
The temporal lobe
• This region controls your hearing and the
ability to recognize words.
• It can also affect memory.
• Damage to the left side of this lobe can cause
problems remembering what people said.
• Damage to the right side might stop you from
recalling music or pictures.
Inferior surface of cerebral hemisphere
• It has a large tentorial surface and an orbital
• The orbital sulcus is an “H” shaped sulcus,
dividing the orbital gyri into, medial orbital
gyrus, lateral orbital gyrus, anterior and
posterior orbital gyrus.
• There is an olfactory sulcus lodging the
olfactory tract, medial to it is gyrus rectus.
Uncinate fits are preceded by
hallucination of disagreeable odors
Applied anatomy of uncus
• In situations of tumor, hemorrhage, or edema,
increased volume of the temporal lobe can push the
uncus against the brainstem and its corresponding
• If the uncus becomes herniated the structure lying just
medial to it, cranial nerve III, can become compressed.
• This causes problems associated with a non-functional
or problematic CNIII - pupil on ipsilateral side fails to
constrict to light, etc.
• Brainstem damage is typically ipsilateral to the
• What is the general
term given to a tract
connecting the two
• A) Commisure
• B) Funiculi
• C) Column
• D) Peduncle
• E. Projection fibers
• Which ventricle is
located centrally within
the brain, superior to
the hypothalamus ?
• A. Second
• B) Third
• C) Fourth
• D) Fifth
• E) Lateral
Which of the following would be
expected following damage to
the cortex that lies just in front of
the central sulcus?
A. Intense hyper sexuality
B. Visual hallucinations
C. Inability to discriminate tones
as low intensities
D. Difficulty in reading and writing
E. Difficulty in controlling muscles
of the body
Damage to visual association cortex
would be expected to produce:A. Problem in recognizing an object
B. Difficulty in playing a tune on a
C. Difficulty in naming an object a
person can touch (but not see)
D. Problems in naming a song the
person knew before sustaining the
E. An inability to recognize a familiar