Transcript Anatomy of Brain

Dr. Rima Pathak
Gross Anatomy
Main Sulci & Gyri
Central
Cingulate
Parieto
Occipital
Precentral gyrus
Premotor area 6
Postcentral gyrus
Cingulate
Superior frontal
gyrus
Thalamus
Caudate
Infundibular stalk
Pineal gland
Mid brain
Sella
4th ventricle
Pons
Inf Cerebellum
medulla
Spinal cord
Median longitudinal fissure
Sup. Frontal
Cingulate
Inf. Frontal
Sylvian
Sup &
middle
Temporal
Cingulate gyrus
Middle Frontal Gyrus
Corpus callosum
Inf Frontal Gyrus
Insular cortex
Septum pellucidum
3rd Ventricle
Sup temporal gyrus
Inf Temporal Gyrus
hippocampus
Internal Carotid A
lens
Eye ball
Optic nerve
Ethmoid air cells
Temporal horn of
lat ventricle
Nasopharynx
Internal carotid artery
Inf. Temporal gyrus
Inf pons
Vermis
Formation of Basilar
artery
Parieto occipital
sulcus
Transverse Sinus
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Frontal Lobe
Falx cerebri
Caudate
Thalamus & 3rd
Ventricle
Putamen
Choroid plexus
4th Ventricle
Splenium of corpus callosum
The Cerebral Hemispheres
 Central sulcus (of Rolando)
 Lateral sulcus (of Sylvius);
 Parietooccipital sulcus;
 Calcarine sulcus.
 Preoccipital notch
divide each
cerebral hemisphere
Frontal Lobe
 Anterior tip of the
brain (the frontal pole)
to the central sulcus.
 Inferiorly  lateral
sulcus/ Sylvian
Fissure.
 Medially extends
anterior to an
imaginary line from
the top of the central
sulcus to the corpus
callosum.
 Attention
 Behavior,
 Abstract thinking,
 Problem solving,
 Creative thought,
 Emotion,
 Intellect,
 Initiative,
 Judgment,
 Coordinated movements,
 Muscle movements, smell,
 Physical reactions,
 and Personality.
 Broca's Area opercular and triangular sections of
the inferior frontal gyrus. Expressive language,
speech. Damage .Sparse Relevant Speech/Low
word output.
Parietal Lobe
 Anteriorly Central sulcus to an imaginary line
connecting the top of the parietooccipital sulcus and
the preoccipital notch.
 Inferiorly it is bounded by the lateral sulcus and the
imaginary continuation of this sulcus to the posterior
boundary of the parietal lobe.
 Medially surface, it is bounded posteriorly by the
corpus callosum and calcarine sulcus, anteriorly by
the frontal lobe
 Posterior by the parietooccipital sulcus.
 four anatomical boundaries:
 the central sulcus
 the parieto-occipital sulcus
 the lateral sulcus (sylvian fissure)
 the medial longitudinal fissure the two hemispheres.
 Sensory cortex is located in the front part of the
parietal lobe. Receives information from the spinal
cord about the sense of touch, pressure, pain, and
the perception of the position of body parts and their
movements.
 Fissure of Rolando (central sulcus) to the parieto-
occipital fissure behind. Below, it is limited anteriorly
by the fissure of Sylvius, while its posterior portion
merges into the temporosphenoidal lobe.
Temporal lobe
 Superiorly: to the lateral sulcus and the line
forming the inferior boundary of the parietal lobe
 Posteriorly: it extends to the line connecting the top
of the parietooccipital sulcus and the preoccipital
notch.
 Medial surface: its posterior boundary is an
imaginary line from the preoccipital notch to the
splenium of the corpus callosum.
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 Functions include comprehension, naming, verbal
memory and other language functions. Sound processing
is controlled by the temporal lobes- in the Broca’s area
and Wernicke’s area.
 The underside (ventral) part high-level visual processing
of complex stimuli such as faces (fusiform gyrus) and
scenes (parahippocampal gyrus) object perception and
recognition.
 The medial temporal lobes (near the Sagittal plane that
divides left and right cerebral hemispheres) are thought
to be involved in episodic/declarative memory.
 The hippocampi seem to be particularly important for
memory function - particularly transference from short to
long term memory and control of spatial memory and
behavior.
 Auditory & Visual memories, language, hearing &
speech, language, behavior
 Wernicke's Area surrounds auditory cortex:
 understanding & formulating speech. Damage 
Verbegeration/ Word salad.
Occipital lobe
 Controls vision
 homonomous vision loss
from similarly positioned
"field cuts" in each eye.
 visual hallucinations.
 parietal-temporal-occipital
lesions color agnosia,
movement agnosia, and
agraphia.
Brainstem
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Cerebrum  Spinal cord
Motor and Sensory pathways
Cardiac and Respiratory
Reflexes
Originating in the brainstem
10 of the 12 cranial nerves
Midbrian
 center for ocular motion
 The tectum (L. roof) of the midbrain consists of
paired lumps, the superior and inferior colliculi
(L. small hills).
 This is dorsal to the cerebral aqueduct
Pons
 coordinating eye and facial movements, facial
sensation, hearing and balance.
 This consists of:
 A protruding basal portion, which is oval in the
sagittal section;
 And the overlying pontine tegmentum, which forms
part of the floor of the 4th ventricle.
Medulla
 breathing, blood pressure, heart rhythms and
swallowing
 reticular activating system is found in the midbrain,
pons, medulla and part of the thalamus. It controls
levels of wakefulness, enables people to pay
attention to their environments, and is involved in
sleep patterns
 The point of attachment of most cranial nerves
Optic Pathway
 Optic Chiasm is
located beneath
the hypothalamus
and is where the
optic nerve
crosses over to the
opposite side of
the brain
Cingulate Gyrus
 This is immediately superior to the corpus callosum.
 it continues as the parahippocampal gyrus of the
temporal lobe.
 These 2 gyri give the appearance of encircling the
diencephalon.
 They, together with the olfactory bulb and tract, and
certain other small cortical areas, are often referred
to separately as the limbic lobe (L. limbus, border).
Pituitary Hypothalamus
Complex
 Hypothalamus is a region of the brain in partnership
with the pituitary gland that controls the hormonal
processes of the body as well as temperature, mood,
hunger, and thirst.
 This is inferior to the thalamus.
 It is separated from it by the hypothalamic sulcus in the wall of the
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3rd ventricle.
It also forms the floor of the ventricle.
Its inferior surface includes the infundibular stalk and the mammillary
bodies.
The hypothalamus is the major visceral control centre of the brain.
It is involved in the limbic system as well.
Basal Ganglia
Caudate
 The round body bulging into the lateral ventricle and
forming its floor is the caudate nucleus
Thalamus
 located near the center
of the brain and controls
input and output to and
from the brain
 sensation of pain and
attention.
 borders on the 3rd ventricle.
 major importance in both sensory and motor systems.
 The line of attachment of the roof of this ventricle is
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marked by a horizontally oriented ridge, the stria
medullaris thalami.
medial surface of the 2 thalami fuse in many brains called
the interthalamic adhesion or massa intermedia.
Posteriorly, the thalamus protrudes over the most rostral
part of the brainstem.
Anteriorly, it abuts the interventricular foramen.
No sensory information (except olfactory information)
reaches the cerebral cortex without prior processing in
the thalami.
anatomical loops characteristic of motor systems,
typically involve the thalami .
Putamen & Globus Pallidus
Insular cortex
 buried in the depths of the lateral
sulcus.
 It is concealed from view by
portions of the frontal, parietal, and
temporal lobes.
 The portion of a given lobe
overlying the insula is called an
operculum (L. lid).
 There are frontal, parietal, and
temporal opercula.
Pineal Region
 on top of the midbrain behind the thalamus
 Pineal Gland controls the response to light and
dark.
 Its principal hormone melatonin, a derivative of
amino acid tryptophan.
stimulated by darkness and
inhibited by light.
 Follows circadian cycle with peak levels morning.
Hippocampus & Amygdala
 Short term memory to
long term memory.
 The Papez Circuit.
 Amygdala controls
emotions, social
inhibitions, aggression
Cerebellum
 lower back of the head and is connected to the brain
stem.
 It is the second largest structure of the brain and is
made up of two hemispheres.
 The cerebellum controls complex motor functions
such as walking, balance, posture, and general
motor coordination
Ventricular System
 Four Ventricles of
the brain are
connected cavities
within the brain,
where cerebrospinal
fluid is produced
 cavity shown in the
septum pellucidum is
the so-called fifth
ve.ntricle
Lateral Ventricles
 Two ventricles enclosed in the cerebral hemispheres
are called the lateral ventricles (first and second).
They each communicate with the third ventricle
through a separate opening called the Foramen of
Munro
Third Ventricle
 The third ventricle is in the center of the brain, and
its walls are made up of the thalamus and
hypothalamus.
 The third ventricle connects with the fourth ventricle
through a long tube called the Aqueduct of Sylvius.
Fourth Ventricle
 CSF flowing through the
fourth ventricle flows
around the brain and
spinal cord by passing
through another series of
openings
 Medial Mono Magendie
 Bilateral Lushka
Lateral film
Anterior Film
THANK YOU
 Hippocampal atrophy is a highly sensitive indicator of
incipient AD. It's evaluation by MRI volumetry provides
entirely additional data to support the diagnosis. In
contrast, simpler measurements or T2 relaxometry
provided only little diagnostic aid. The volume of the
hippocampus correlated significantly with clinical severity
assessed by MMSE, and with tests assessing delayed
recall, which is considered to be affected early in
dementia and may reflect hippocampal dysfunction.
 2. The volume of the hippocampus is not significantly
affected by normal aging.
 AAMI can be differentiated from dementia by
hippocampal volumetry
 Three-Dimensional Fast Spoiled Gradient-Recalled
(3D-SPGR) magnetic resonance imaging (MRI)
 Standard 1.5 Tesla MRI
 Modified T1 Post Contrast
 Contiguous Sections
 2mm – 1mm thickness
 256 x 256 grid