Cross-sectional Anatomy D Karthikeyan, Deepa Chegu
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BrainChapter 1

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BRAIN—AN OVERVIEW
Structure
Description
Significance
Forebrain
Prosencephalon
Comprised of: telencephalon or cerebral hemispheres and diencephalon; site of termination of cranial nerves I and II; contains lateral and third ventricles
Midbrain
Mesencephalon
Connects forebrain and hindbrain; site of origin of cranial nerves III and IV; contains cerebral aqueduct
Hindbrain
Rhombencephalon
Comprised of: metencephalon or pons and cerebellum and myelencephalon or medulla oblongata; site of origin for cranial nerves V-XII (except spinal part of accessory nerve); contains fourth ventricle
Telencephalon
Rostral part of forebrain
Comprised of: cerebral hemispheres and basal ganglia; contains lateral ventricles
Diencephalon
Caudal portion of forebrain
Comprised of: thalamus, metathalamus, subthalamus, epithalamus; contains third ventricle
Mesencephalon
Midbrain
Contains the corpora quadrigemina
Metencephalon
Rostral part of rhombencephalon
Comprised of: pons and cerebellum
Myelencephalon
Caudal part of rhombencephalon
Comprised of: medulla oblongata; medulla becomes continuous with the spinal cord at the level of the foramen magnum
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FEATURES OF THE BRAIN—LATERAL VIEW
Structure
Description
Significance
Cerebral hemispheres
Telencephalon
Comprised of: cortex featuring gyri, sulci, fissures and lobes; commissures connecting parts; basal ganglia; contains lateral ventricles; termination of the olfactory tract
Longitudinal fissure
Midline, sagittal cleft separating the paired cerebral hemispheres
Contains the falx cerebri
Frontal pole
The most anterior part of the cerebral hemisphere
Frontal pole is part of the frontal lobe
Temporal pole
The most anterior part of the temporal lobe
Occipital pole
The most posterior part of the cerebral hemisphere
Occipital pole is part of the occipital lobe; composedof primary visual cortex
Central sulcus
Separates frontal and parietal lobes
Separates the precentral gyrus (motor) from the postcentral gyrus (sensory)
Frontal lobe
Rostral to central sulcus
Contains prefrontal (emotions, personality) and precentral (primary and secondary motor) areas
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Parietal lobe
Separated from the frontal lobe by the central sulcus, separated from occipital lobe by line through parieto occipital sulcus
Contains the primary and secondary somatosensory areas
Temporal lobe
Separated from the frontal lobe by the lateral sulcus
Primarily concerned with hearing and memory/ learning
Occipital lobe
Posterior to an imaginary line through parieto-occipital sulcus
Contains the primary and secondary visual cortex
Precentral gyrus
Most caudal gyrus of the frontal lobe; it lies rostral to the central sulcus
Contains the primary motor cortex
Postcentral gyrus
Most rostral gyrus of the parietal lobe; it lies caudal to the central sulcus
Contains the primary sensory cortex
Superior temporal gyrus
Gyrus between the lateral sulcus and the superior temporal sulcus
Contains the primary auditory cortex
Middle temporal gyrus
Gyrus between the superior and inferior temporal sulci
Inferior temporal gyrus
Gyrus between the inferior temporal sulcus and the inferior margin of the temporal lobe
Insula
Portion of the cerebrum located deeply within the lateral sulcus
Also known as the island of Reil
Straight gyrus
Gyrus located on the medial side of the olfactory tract
Also known as: gyrus rectus
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Uncus
Portion of the cerebral cortex on the medial side of the parahippocampal gyrus and overlying the amygdala; located near the free edge of the tentorium cerebelli
Contains olfactory cortex
Longitudinal sulcus
Midline, sagittal cleft separating the paired cerebral hemispheres
Also known as: longitudinal fissure
Precentral sulcus
The sulcus anterior to the precentral gyrus
In conjunction with the central sulcus, it defines the precentral gyrus (motor)
Postcentral sulcus
The sulcus posterior to the postcentral gyrus
In conjunction with the central sulcus, it defines the postcentral gyrus (sensory)
Lateral sulcus
Separates frontal lobe and temporal lobe
The insula lies in the floor of this sulcus
Superior temporal sulcus
Sulcus between the superior and middle temporal gyri
Used to define the superior and middle temproal gyri
Inferior temporal sulcus
Sulcus between thIe middle and inferior temporal gyri
Used to define the middle and inferior temporal gyri
Parieto-occipital sulcus
Sulcus between the parietal and occipital lobes
Landmark used to define the borders of the parietal and occipital lobes when viewing the cerebral hemisphere from a medial perspective
Preoccipital sulcus
A shallow notch in the inferior surface of the cortex (superior to the cerebellum) as seen in lateral view
A surface landmark for defining the border between the parietal and occipital lobes
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Brainstem
Comprised of: midbrain, pons and medulla oblongata
Origin of most of the cranial nerves
Midbrain
Mesencephalon
Connects forebrain and hindbrain; the site of origin of cranial nerves III and IV; contains cerebral aqueduct
Pons
Anterior portion of the metencephalon
The site of origin of cranial nerves V, VI, VII and VIII; forms part of the anterior wall of the fourth ventricle
Medulla oblongata
Also known as: myelencephalon; most caudal portion of the brainstem
It is continuous with the spinal cord at the foramen magnum; upper portion forms the floor of the fourth ventricle; the site of origin for cranial nerves VIII, IX, X, XI (cranial root), and XII
 
FEATURES OF THE BRAIN—INFERIOR VIEW
Structure
Description
Significance
Cerebral hemispheres
Telencephalon
Comprised of: cortex featuring gyri, sulci, fissures and lobes; commissures connecting parts; basal ganglia; contains lateral ventricles; termination of the olfactory tract (cranial nerve I)
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Longitudinal fissure
Midline, sagittal cleft separating the paired cerebral hemispheres
Longitudinal sulcus
Frontal pole
The most anterior part of the cerebral hemisphere
Frontal pole is part of the frontal lobe
Temporal pole
The most anterior part of the temporal lobe
Occipital pole
The most posterior part of the cerebral hemisphere
Occipital pole is part of the occipital lobe; composed of primary visual cortex
Frontal pole
Rostral to central sulcus
Contains prefrontal (emotions, personality) and precentral (primary motor) areas
Temporal lobe
Separated from the frontal lobe by the lateral sulcus
Primarily concerned with hearing and memory/learning
Occipital lobe
Posterior to an imaginary line through parieto-occipital sulcus
Contains the primarily visual cortex
Limbic lobe
Structures on the medial surface of the cerebral hemisphere which surround the rostral brainstem; includes the subcallosal gyrus, cingulate gyrus and parahippocampal gyrus
Primarily concerned with emotions and memory
Parahippocam-pal, gyrus
Gyrus on the inferior surface of the temporal lobe that lies lateral to the midbrain
The uncus is a medial projection of the parahippocampal gyrus
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Straight gyrus
Gyrus located on the medial side of the olfactory tract
Gyrus rectus
Lingual gyrus
Gyrus lying inferior to the calcarine sulcus
Contains primary visual cortex
Uncus
Portion of the cerebral cortex on the medial side of the parahippocampal gyrus and overlying the amygdala; located near the free edge of the tentorium cerebelli
Contains olfactory cortex
Apex of cuneus
Portion of the cuneus seen in an inferior view of the cerebral hemisphere
Contains part of the visual cortex
Longitudinal sulcus
Midline, sagittal cleft separating the paired cerebral hemispheres
Longitudinal fissure
Olfactory sulcus
Sulcus that defines the lateral margin of the straight gyrus
Contains the olfactory bulb and tract
Mamillary body
Part of the hypothalamus; a small spherical projection on the inferior surface of the floor of the third ventricle posterior to the hypophysis
Involved with memory and learning
Brainstem
Comprised of: midbrain, pons and medulla oblongata
Origin of most of the cranial nerves
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Midbrain
Mesencephalon
Connects forebrain and hindbrain; the site of origin of cranial nerves III and IV; contains cerebral aqueduct
Pons
Anterior portion of the metencephalon
The site of origin of cranial nerves V VI, VII and VIII; forms part of the anterior wall of the fourth ventricle
Medulla oblongata
Myelencephalon; most caudal portion of the brainstem
It is continuous with the spinal cord at the foramen magnum; upper portion forms the floor of the fourth ventricle; the site of origin for cranial nerves VIII, IX, X, XI (cranial root), and XII
Olfactory bulb
Flattened, oval enlargement at the anterior tip of the olfactory tract
Contains the olfactory mitral cells which are the origin of the axons that course through the olfactory tract; the olfactory nerve begins at the bipolar olfactory cells in the nasal mucosa and courses through the cribriform plate to the olfactory bulb
Olfactory tract
Ribbon-like nerve tract that courses from the olfactory bulb to the cerebral cortex; it courses in the olfactory sulcus
Carries the sense of smell
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Optic chiasm
Crossover point for the nasal fibers of both retinas
Lateral visual fields (medial retinal fibers) project to the contralateral occipital lobe
Hypophysis
Midline projection of neural and endocrine tissue attached to the floor of the diencephalon
Also known as: pituitary gland
 
FEATURES OF THE BRAIN—MID-SAGITTAL VIEW
Structure
Description
Significance
Cerebral hemispheres
Telencephalon
Comprised of: cortex featuring gyri, sulci, fissures and lobes; commissures connecting parts; basal ganglia; contains lateral ventricles; termination of the olfactory tract (cranial nerve I)
Longitudinal fissure
Midline, sagittal cleft separating the paired cerebral hemispheres
Longitudinal sulcus; contains the falx cerebri
Frontal lobe
Rostral to central sulcus
Contains prefrontal (emotions, personality) and precentral (primary motor) areas
Parietal lobe
Separated from the frontal lobe by the central sulcus, separated from occipital lobe by line through parieto-occipital sulcus
Contains the primary and secondary somatosensory areas
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Occipital lobe
Posterior to line through parieto-occipital sulcus
Contains the primary and secondary visual cortex
Limbic lobe
A border (limbus = Latin for border) of cortical tissue surrounding the third ventricle; comprised of: cingulate gyrus, parahippo-campal gyrus, uncus and other small portions of the adjacent cortex
Part of the brain responsible for behavior and emotions
Cingulate gyrus
The portion of the limbic lobe that lies superior to the corpus callosum
Cingulate gyrusis bounded by the callosal sulcus and the cingulate sulcus
Straight gyrus
Gyrus located on the medial side of the olfactory tract
Gyrus rectus
Lingual gyrus
The portion of the occipital lobe that lies inferior to the calcarine sulcus
Cortical projection of the upper half of the contralateral visual field
Cingulate sulcus
The sulcus that lies superior to the cingulate gyrus
Central sulcus
Separates the frontal lobe from the parietal lobe; separates sensory cortex from motor cortex
Fissure of Rolando
Parieto-occipital sulcus
Sulcus on the medial surface of the cerebral hemisphere that lies between the precuneus and the cuneus
Forms the boundary between the parietal lobe and the occipital lobe
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Calcarine sulcus
Sulcus between the lingual gyrus and the cuneus
Primary visual cortex is both superior and inferior to it
Cuneus
Part of the cerebral cortex that forms the upper wall of the calcarine fissure
Cortical projection of the lower half of the contralateral visual field
Pineal gland
Pineal body
Represents an endocrine gland attached to diencephalon
Corpus callosum
Midline part of great cerebral commissure
Connects paired cerebral hemispheres
Anterior commissure
A bundle of association fibers located anterior to the third ventricle
Connections between the left and right temporal lobes
Posterior commissure
A bundle of association fibers located posterior to the third ventricle, just inferior to the pineal gland
Connections between various areas of the right and left sides of the midbrain
Optic chiasm
Crossover point for the nasal fibers of both retinas
Lateral visual fields (medial retinal fibers) project to the contralateral occipital lobe
Thalamus
An egg-shaped collection of nuclei forming part of the lateral wall of the third ventricle
Distributes information to appropriate areas of the cerebral cortex
Hypothalamus
A collection on nuclei forming the anterior portion of the lateral wall of the third ventricle
Controls visceral activity and elicits phenomena associated with the emotions
Body of fornix
A group of nerve cell fibers arching beneath the corpus callosum
Main efferent fiber system of the hippocampal formation
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Hypophysis
Midline projection of neural and endocrine tissue attached to the floor of the diencephalon
Pituitary gland
Brainstem
Comprised of: midbrain, pons and medulla oblongata
Origin of most of the cranial nerves
Midbrain
Mesencephalon
Connects forebrain and hindbrain; the site of origin of cranial nerves III and IV; contains cerebral aqueduct
Pons
Anterior portion of the metencephalon
The site of origin of cranial nerves V, VI, VII and VIII; forms part of the anterior wall of the fourth ventricle
Medulla oblongata
Myelencephalon; most caudal portion of the brainstem
It is continuous with the spinal cord at the foramen magnum; upper portion forms the floor of the fourth ventricle; the site of origin for cranial nerves VIII, IX, X, XI (cranial root), and XII
Cerebellum
Posterior part of metencephalon
Largest part of hindbrain; important for coordination of movement
 
FEATURES OF THE BRAINSTEM
Structure
Description
Significance
Midbrain
Mesencephalon
Connects forebrain and hindbrain; site of origin of cranial nerves III and IV; contains cerebral aqueduct
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Pons
Anterior portion of metencephalon
Site of origin of cranial nerves V, VI, VII and VIII; forms part of the anterior wall of the fourth ventricle
Medulla oblongata
Myelencephalon; most caudal portion of brainstem
Continuous with the spinal cord at the foramen magnum; upper portion forms the floor of the fourth ventricle; site of origin for cranial nerves IX, X, XI (cranial root), and XII
 
SURFACE FEATURES OF THE BRAINSTEM AS SEEN ON MID-SAGITTAL VIEW
Structure
Description
Significance
Midbrain
Tectum
The roof of the midbrain, formed by the superior and inferior colliculi; located dorsal to the cerebral aqueduct
Also known as: quadrigeminal plate
Superior colliculus
Paired elevations of midbrain tectum
Part of corpora quadrigemina; important for reflex movements of eye, head and neck
Inferior colliculus
Paired elevations of midbrain tectum
Part of corpora quadrigemina; important for auditory reflexes
Tegmentum
The collection of cells and nerve fibers located ventral to the ventricle system in the midbrain, pons and medulla
Gives rise to the middle cerebellar peduncle
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Cerebral aqueduct
Canal connecting third and fourth ventricles, passing through midbrain
Also known as: aqueduct of Sylvius
Pons
Fourth ventricle
Midline space between cerebellum posteriorly and pons and upper medulla anteriorly
Communicates anterosuperiorly with third ventricle via cerebral aqueduct; drains CSF via median aperature and lateral aperatures
Central canal of spinal cord
Small opening in the center of the spinal cord
Continuous with the central canal of the medulla and, through it, with the fourth ventricle of the brain
 
VENTRICULAR SYSTEM OF THE BRAIN
Structure
Description
Significance
Lateral ventricle
Paired spaces within cerebral hemispheres
They drain cerebrospinal fluid to the third ventricle via the interventricular foramina (of Monro)
Third ventricle
Midline space within the diencephalon between the paired dorsal thalami and the hypothalamus
Communicates rostrolaterally with paired lateral ventricles via interventricular foramina, communicates posteroinferiorly with fourth ventricle via cerebral aqueduct
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Fourth ventricle
Midline space between cerebellum posteriorly and pons and upper medulla anteriorly
Communicates anterosuperiorly with third ventricle via cerebral aqueduct; drains CSF via median aperature and lateral aperatures
Choroid plexus
Vascular membranes that occur within the ventricles
Production of cerebrospinal fluid
Interventricular foramen
Communication between the lateral ventricle and the third ventricle; paired, one on each side
Also known as: foramina of Monro
Cerebral aqueduct
Canal connecting third and fourth ventricles, passing through midbrain
Also known as: aqueduct of Sylvius
Median aperature
Midline, irregular foramen draining fourth ventricle posteroinferiorly into cerebellomedullary cistern
Also known as: foramen of Magendie
Lateral aperature
Paired foramina draining fourth ventricle laterally into cerebellomedullary cistern
Also known as: foramina of Luschka
Central canal of spinal cord
Small opening in the center of the spinal cord
Continuous with the central canal of the medulla and, through it, with the fourth ventricle of the brain
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BLOOD SUPPLY TO THE BRAIN
Artery
Source
Branches
Supply to
Notes
Anterior spinal
Contributions received from several arteries (vertebral, posterior intercostal, subcostal, lumbar, lateral sacral aa.)
Pial arterial plexus
Meninges; spinal cord; medulla (dorsal motor nucleus of cranial nerve X, nucleus ambiguous, spinal accessory nucleus and hypoglossal nucleus)
Anterior spinal artery anastomoses with the nterior radicular brs. of the spinal rami of the vertebral, posterior intercostal, subcostal, lumbar and lateral sacral artery
Basilar
Formed by the joining of the two vertebral aa.
Pontine brs., anterior inferior cerebellar a., superior cerebellar a., two posterior cerebral aa. (terminal brs.)
Pons (motor nucleus of cranial nerve V, chief sensory nucleus of cranial nerve V, abducens nucleus, facial nucleus, superior salivatory nucleus); oculomotor nucleus; nucleus of Edinger-Westphal; cerebellum; posterior cerebrum
Basilar a. contributes blood to the cerebral arterial circle
Cerebellar, anterior inferior
Basilar a.
Labyrinthine a. (usually)
Pons (motor nucleus of cranial nerve V, chief sensory nucleus of cranial nerve V, abducens nucleus, facial nucleus, superior salivatory nucleus); cerebellum; inner ear
Anterior inferior cerebella a. shares its region of supply with branches of the basilar a.
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Cerebellar, posterior inferior
Vertebral a.
Posterior spinal a.
Part of cerebellum; medulla (cochlear nucleus, vestibular nucleus, dorsal motor nucleus of cranial nerve X, nucleus ambiguous)
Posterior inferior cerebellar a. shares its region of supply with the vertebral a. and anterior spinal a. (watershed region)
Cerebellar, superior
Basilar a.
No named branches
Upper cerebellum; trochlear nucleus
There may be more than one superior cerebellar a. arising from the basilar a. on each side
Cerebral, anterior
Internal carotid a.
Anterior communicating a., medial frontobasal a., polar frontal a., callosomarginal a., precuneal a.
Medial and inferior portions of the frontal lobe; medial side of the parietal lobe; corpus callosum and part of the limbic lobe; olfactory bulb and tract; optic nerve, optic chiasm and optic tract
The anterior communicating a. unites the two anterior cerebral aa. across the midline
Cerebral arterial circle
An anastomotic circle of blood vessels formed by portions of the following vessels: posterior cerebral aa. (2); posterior communicating aa. (2); internal carotid aa. (2); anterior cerebral aa. (2); anterior communicating a.
This is an anastomotic loop; major named vessels connect here, but there are no named branches of the arterial circle
Brain and midbrain
Also known as: arterial circle of Willis
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Middle cerebral
Internal carotid a.
Lateral frontobasal a.; prefrontal sulcal a.; precentral sulcal a.; central sulcal a.; anterior parietal a.; posterior parietal a.; anterior, middle and posterior temporal aa.
Frontal, parietal and temporal lobes, especially on their lateral surfaces
The middle cerebral a. is the direct continuation of the internal carotid a.
Posterior cerebral
Basilar a.
Posterior cerebral a.; anterior and posterior temporal brs.; medial occipital a.
Part of the brainstem (oculomotor nucleus, nucleus of Edinger-Westphal, trochlear nucleus); medial and inferior portions of the temporal lobe; occipital lobe
The two posterior cerebral aa. are the terminal brs. of the basilar a.
Anterior communicating
Anterior cerebral a.
Perforating aa.
An anastomotic connection
Anterior communicating a. is a short vessel of anastomosis which crosses the midline to join the paired anterior cerebral aa.; it is part of the Circle of Willis
Posterior communicating
Internal carotid a.
Perforating aa.
An anastomotic connection
A vessel of anastomosis which connects the internal carotid a. to the posterior cerebral a.; part of the cerebral arterial circle (of Willis)
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Ophthalmic
Internal carotid a.
Central retinal a., lacrimal a., muscular brs., anterior ethmoidal a., posterior ethmoidal a., medial palpebral a., supraorbital a., supratrochlear a., dorsal nasal a.
Optic nerve, optic chiasm optic tract, retina, extraocular mm., eyelids, forehead, ethmoidal air cells, lateral nasal wall, dorsum of the nose
Ophthalmic a. provides the only artery to the retina (central retinal a.)
Vertebral
Subclavian a. (1st part)
Spinal brs., muscular brs., anterior spinal a., posterior inferior cerebellar a., medullary brs., meningeal brs., basilar a.
Deep neck, cervical spinal cord, spinal cord; medulla (dorsal motor nucleus of cranial nerve X, nucleus ambiguus, spinal accessory nucleus and hypoglossal nucleus)
Vertebral a. anastomoses with the internal carotid a. in the cerebral arterial circle (of Willis); it courses through the transverse foramina of vertebrae C1-C6
Anterior spin
Contributions received from several arteries (vertebral, posterior intercostal, subcostal, lumbar, lateral sacral aa.)
Pial arterial plexus
Meninges; spinal cord; medulla (dorsal motor nucleus of cranial nerve X, nucleus ambiguous, spinal accessory nucleus and hypoglossal nucleus)
The anterior spinal a. anastomoses with the anterior radicular brs. of the spinal rami of the vertebral, posterior intercostal, subcostal, lumbar and lateral sacral aa.
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FIGURE 1.1: Diagram showing the circle of Willis
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FIGURE 1.2: Schematic for neck veins
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VENOUS DRAINAGE OF THE BRAIN
Vein
Tributaries
Drains into
Regions Drained
Notes
Great cerebral
Formed by the union of the paired internal cerebral vv.
Straight sinus
Deep portions of the cerebrum
Great cerebral v. is a very short vessel
Inferior cerebral
Tributaries are unnamed
Cavernous sinus, transverse sinus, superior petrosal sinus
Inferior aspect of the cerebral hemispheres
Inferior cerebral vv. are numerous
Superiorc cerebral
Tributaries are unnamed
Superior sagittal sinus
Superior aspect of the cerebral hemispheres
Superior cerebral vv. bleed into the subdural space when injured, resulting in a subdural hematoma; also known as: bridging vv.
Inferior sagittal sinus
Unnamed tributaries from the falx cerebri and cerebral hemispheres
Unites with the great cerebral v. to form the straight sinus
Medial surfaces fo the cerebral hemispheres
Inferior sagittal sinus is directly superior to the corpus callosum in the free margin of falx cerebri
Inferior petrosal sinus
Cavernous sinus
Sigmoid sinus, at its distal end
All regions drained by the cavernous sinus, including the orbit and brain
Inferior petrosal sinus lies within the dura mater along the inferior portion of the petrous part of the temporal bone
Occipital sinus
No named tributaries
Confluens of sinuses
Cerebellum
Lies within the dura mater at the base of the falx cerebelli
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Superior petrosal sinus
Cavernous sinus
Sigmoid sinus, at its proximal end
All regions drained by the cavernous sinus, including the orbit and brain
Superior petrosal sinus lies on the petrous ridge within the dura mater at the line of attachment of the tentorium cerebelli
Superior sagittal sinus
V. of the foramen cecum; superior cerebral vv.
Confluens of sinuses
Cerebral hemispheres
Superior sagittal sinus occupies the superior part of the falx cerebri; lateral lacunae receive grossly visible arachnoid granulations
Straight sinus
Inferior sagittal sinus, great cerebral vein, superior cerebellar vv.
Confluens of sinuses
deep parts of the cerebrum, cerebellum
Straight sinus lies within the junction of the falx cerebri and tentorium cerebelli; also known as: sinus rectus
Transverse sinus
Confluence of sinuses, inferior cerebral vv.
Sigmoid sinus
Brain
Lies within the line of attachment of the tentorium cerebelli to the inner surface of the calvaria
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FIGURE 1.3: Schematic showing dural venous sinuses
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FIGURE 1.4: Frontal radiograph of skull
  1. Frontal sinus
  2. Crista galli
  3. Cribriform plate
  4. Lesser wing of sphenoid
  5. Superior orbital fissure
  6. Superior border of petrous part of temporal bone
  7. Dense shadow of petrous part of temporal bone
  8. Perpendicular plate of the ethmoid
  9. Vomer
  10. Maxillary sinus
  11. Inferior concha
  12. Ramus of mandible
  13. Body of mandible26
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FIGURE 1.5: Lateral radiograph of skull
  1. Frontal sinus
  2. Ethmoidal sinus
  3. Sphenoidal sinus
  4. Maxillary sinus
  5. Anterior clinoid processes
  6. Hypophyseal fossa
  7. Posterior clinoid processes
  8. Clivus
  9. Great density of the petrous part of the temporal bone
  10. External acoustic meatus
  11. Mastoid cells
  12. Nasopharynx
  13. Angle of mandible
  14. Anterior arch of the atlas
  15. Dens of axis
  16. Posterior arch of the atlas
  17. Internal occipital protuberance
    1. Coronal suture
    2. Lambdoid suture
    3. The grooves for the branches of the middle meningeal vessels27
 
AXIAL ANATOMY—BRAIN
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FIGURE 1.6: Digital scanogram brain
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FIGURE 1.7: Axial CT at the level of medulla
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FIGURE 1.8: Axial CT at the level of pons
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FIGURE 1.9: Axial CT at the level of sella
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FIGURE 1.10: Axial CT at the level of suprasellar cistern
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FIGURE 1.11: Axial CT at the level of circle of Willis
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FIGURE 1.12: Axial CT at the level of tentorial hiatus
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FIGURE 1.13: Axial CT at the level of optic chiasma
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FIGURE 1.14: Axial CT at the level of ambient cistern
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FIGURE 1.15: Axial CT at the level of third ventricle
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FIGURE 1.16: Axial Ct at the level of basal ganglia
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FIGURE 1.17: Axial CT at the level of lateral ventricle
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FIGURE 1.18: Axial CT at the level of corona
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FIGURE 1.19: Axial CT at the supraventricular level
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FIGURE 1.20: Axial CT at the level of central fissure
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FIGURE 1.21: Axial CT at the level of centrum
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FIGURE 1.22: Schematic diagram showing the various sulci and gyri
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NAMED GYRI AND SULCI
AnG
angular gyrus cerebellum
FP
frontal pole
IFG
inferior frontal gyrus
IOG
inferior occipital gyrus
ITG
inferior temporal gyrus
LOG
lateral occipital gyrus
MFG
middle frontal gyrus
MTG
middle temporal gyrus
OG
orbital gyrus pons
oper
pars opercularis (IFG)
orb
pars orbitalis (IFG)
tri
pars triangularis (IFG)
poCG
postcentral gyrus
preCG
precentral gyrus
SFG
superior frontal gyrus
SOG
superior occipital gyrus
SPL
superior parietal lobe
STG
superior temporal gyrus
SmG
supramarginal gyrus
TP
temporal pole
cs
central sulcus (Rolandic)
hr
horizontal ramus
ifs
inferior frontal sulcus
ios
inferior occipital sulcus
ips
intraparietal sulcus
syl
lateral fissure (Sylvian)
los
lateral occipital sulcus
ls
lunate sulcus
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pof
parieto-occipital fissure
pocs
postcentral sulcus
precs
precentral sulcus
sfs
superior frontal sulcus
tos
transoccipital sulcus
vr
vertical ramus
ac
anterior commissure
cals
calcarine sulcus
cings
cingulate sulcus
CingG
cingulate gyrus
ccb
corpus callosum (body)
ccg
corpus callosum (genu)
ccs
corpus callosum (splenium)
cuneus
fornix
lingual
lingual gyrus
mb
mamillary bodies
PL
paracentral lobule precuneus
q
quadrigeminal plate