84 Position of Brain and Great Sensory Organs

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2.3 Brain and Sensory Organs

1 Vertex of the skull and dura mater

2 Frontal lobe covered by arachnoid

and pia mater

3 Frontal sinus

4 Nasal cavity

5 Oral cavity

6 Tongue

7 Occipital lobe

8 Cerebellum

9 Base of skull

10 Spinal cord

11 Vertebral column

12 Brain stem

13 Eye and optic nerve (n. II)

Dissection of the brain with pia mater and arachnoid in situ. The head is cut in half

except for the brain, which is shown in its entirety.

Sagittal section through the head with brain and sensory

organs (schematic drawing). The eye with the optic nerve is

located within the orbit; the labyrinth organ, within the petrous bone.

The cranial cavity harbours the

brain, the cerebellum, and the brain

stem from where the cranial nerves

emerge and exit the skull through

various openings and fissures. The

great sensory organs are located

within the orbit (eye), the nasal

cavity (olfactory system), and the

petrous portion of the temporal

bone (vestibulocochlear organ). The

brain is enwrapped by the pia mater

containing the brain vessels. The

dura mater is firmly attached to

the skull and provides shelter and

stabilization for the brain. Interposed

between pia and dura mater lies the

arachnoid containing the cerebrospinal

fluid.

Scalp and Meninges 85

Subarachnoid cisterns of the brain (midsagittal section).

Green = cisterns; blue = dural sinus and ventricles;

red = choroid plexus of third and fourth ventricles; arrows = flow of

cerebrospinal fluid.

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Cross section of the scalp and the meninges.

The subarachnoid space (23) is shown.

1 Skin

2 Galea aponeurotica

3 Skull diploe

4 Dura mater

5 Arachnoid and pia mater

with cerebral vessels

6 Frontal belly of occipitofrontalis

muscle

7 Branch of middle meningeal artery

8 Pericranium (periosteum)

9 Lateral and medial branches of

supra-orbital nerve

10 Orbicularis oculi muscle

11 Zygomatico-orbital artery

12 Auriculotemporal nerve and

superficial temporal artery and

vein

13 Superior auricular muscle

14 Occipital belly of occipitofrontalis

muscle

15 Occipital nerve

16 Occipital artery and vein

17 Greater occipital nerve

18 Sternocleidomastoid muscle

19 Frontal lobe

20 Chiasmatic cistern

21 Interpeduncular cistern

22 Arachnoid granulations

23 Subarachnoid space

24 Superior sagittal sinus

25 Inferior sagittal sinus

26 Corpus callosum

27 Straight sinus

28 Confluence of sinuses

29 Cerebellum

30 Cerebellomedullar cistern

31 Cerebral cortex

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Lateral aspect of the head. Scalp, vertex of the skull, and meninges are demonstrated

by a series of window-like openings.

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86 Meninges: Dura Mater and Dural Venous Sinuses

Median sagittal section through the head and neck.

1 Falx cerebri

2 Corpus callosum and septum pellucidum

3 Interventricular foramen and fornix

4 Choroid plexus of third ventricle and

internal cerebral vein

5 Third ventricle and interthalamic adhesion

6 Pineal body and colliculi of the midbrain

7 Cerebral aqueduct

8 Mamillary body and basilar artery

9 Straight sinus

10 Fourth ventricle and cerebellum

11 Pons and falx cerebelli

12 Medulla oblongata

13 Central canal

14 Cerebellomedullary cistern

15 Dens of the axis (odontoid process)

16 Spinal cord

17 Superior sagittal sinus

18 Anterior cerebral artery

19 Anterior commissure

20 Frontal sinus

21 Crista galli

22 Optic chiasma

23 Pituitary gland (hypophysis)

24 Superior nasal concha

25 Middle nasal concha and sphenoid

sinus

26 Inferior nasal concha

27 Pharyngeal opening of auditory tube

28 Superior longitudinal muscle of

tongue

29 Vertical muscle of the tongue

30 Uvula

31 Genioglossus muscle

32 Pharynx

33 Epiglottis

34 Geniohyoid muscle

35 Mylohyoid muscle

36 Hyoid bone

37 Vocal fold and sinus of larynx

38 Esophagus

Meninges: Dura Mater and Dural Venous Sinuses 87

1 Falx cerebri

2 Position of middle meningeal

artery and vein

3 Internal carotid artery

4 Optic nerve (n. II)

5 Frontal sinus

6 Oculomotor nerve (n. III)

7 Diploe

8 Dura mater

9 Superior sagittal sinus

10 Straight sinus

11 Trigeminal nerve (n. V)

12 Facial and vestibulocochlear nerve

(n. VII and n. VIII)

13 Tentorium cerebelli

14 Pituitary gland (hypophysis)

15 Inferior sagittal sinus

16 Sigmoid sinus

17 Confluence of sinuses

18 Inferior petrosal sinus

19 Transverse sinus

20 Superior petrosal sinus

21 Cavernous and intercavernous sinuses

Dura mater and venous sinuses of the dura

mater (left lateral aspect). (Schematic drawing.)

Dura mater and venous sinuses of the dura mater. The brain has been removed (oblique lateral aspect).

88 Meninges: Dura Mater

1 Cranial cavity with dura mater

(right cerebral hemisphere

has been removed)

2 Frontal sinus

3 Hypophysial fossa with pituitary

gland

4 Sphenoidal sinus

5 Nasal cavity

6 Soft palate (uvula)

7 Oral cavity

8 Tongue

9 Skin

10 Calvaria

11 Dura mater

12 Tentorium cerebelli

13 Confluence of sinuses

14 Infratentorial space (cerebellum

and part of the brain stem have

been removed)

15 Vertebral canal

16 Frontal branch of middle

meningeal artery and veins

17 Middle meningeal artery

18 Diploe

19 Parietal branch of middle

meningeal artery and vein

20 Occipital pole of left hemisphere

covered with dura mater

Median section through the head. Demonstration of dura mater covering the cranial

cavity. Brain and spinal cord are removed (right half of the head, as seen from medial).

Dissection of dura mater and meningeal vessels. Left half of calvaria removed.

Meninges: Pia Mater and Arachnoid 89

1 Calvaria and skin of the

scalp

2 Dura mater (divided)

3 Position of lateral sulcus

4 Frontal lobe covered by

arachnoid and pia mater

5 Frontal sinus

6 Olfactory bulb

7 Sphenoidal sinus

8 Dura mater on clivus and

basilar artery

9 Atlas (anterior arch,

divided)

10 Soft palate

11 Tongue

12 Epiglottis

13 Vocal fold

14 Position of central sulcus

15 Superior cerebral veins

16 Tentorium (divided)

17 Cerebellum

18 Cerebellomedullary cistern

19 Position of foramen

magnum and spinal cord

20 Dens of axis

21 Intervertebral disc

1 Superior cerebral veins

2 Position of central sulcus

3 Position of lateral sulcus and

cistern of lateral cerebral fossa

4 Frontal pole

5 Lateral sulcus (arrow)

6 Temporal pole

7 Pons and basilar artery

8 Vertebral arteries

9 Superior anastomotic vein

10 Occipital pole

11 Inferior cerebral veins

12 Hemisphere of cerebellum

13 Medulla oblongata

Dissection of the brain with pia mater and arachnoid in situ. The head is cut in half

except for the brain, which is shown in its entirety.

Brain with pia mater and arachnoid. Frontal pole to the left (lateral aspect).

90 Brain: Median Sections

1 Parietal lobe

2 Thalamus, third ventricle, and

intermediate mass

3 Great cerebral vein

4 Occipital lobe

5 Colliculi of the midbrain and

cerebral aqueduct

6 Cerebellum

7 Medulla oblongata

8 Central sulcus

9 Corpus callosum

10 Frontal lobe

11 Fornix and anterior commissure

12 Hypothalamus

13 Optic chiasma

14 Midbrain

15 Temporal lobe

16 Pons

17 Fourth ventricle

18 Spinal cord

19 Inferior concha and nasal cavity

20 Alveolar process of maxilla

21 Tongue

22 Dens of axis

23 Oral part of pharynx

24 Alveolar process of mandible

25 Epiglottis

Brain and brain stem, median section. Frontal pole to the right.

Median section through the head. (MRI scan, cf. section on opposite page.)

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Brain: Median Sections

1 Frontal lobe of cerebrum

2 Occipital lobe of cerebrum

3 Corpus callosum

4 Anterior commissure

5 Lamina terminalis

6 Optic chiasma

7 Hypothalamus

8 Thalamus and third

ventricle

9 Colliculi of the midbrain

10 Midbrain (inferior portion)

11 Cerebellum

12 Pons

13 Fourth ventricle

14 Medulla oblongata

15 Central canal

16 Spinal cord

Median section through the head. Regions of the brain. Falx cerebri removed.

I. Prosencephalon 1. Telencephalon (cerebral

(forebrain) hemispheres, striatum, etc.)

2. Diencephalon (thalamus,

metathalamus, hypothalamus, etc.)

II. Mesencephalon 3. Mesencephalon (colliculi,

(midbrain) cerebral peduncles, tegmentum)

III. Rhombencephalon 4. Metencephalon

(hindbrain) (pons, cerebellum)

5. Myelencephalon

(medulla oblongata)

Main divisions of the brain

I–III = primary brain vesicles; 1–5 = secondary brain vesicles

Diencephalon, midbrain, pons, and medulla oblongata are collectively termed

the brain stem.

Scheme of brain divisions (cf. table). (Schematic drawing.)

Red = choroidal plexus.

1 Telencephalon (yellow) with lateral ventricles

2 Diencephalon (orange) with third ventricle,

optic nerve, and retina

3 Mesencephalon (blue) with cerebral aqueduct

4 Metencephalon (green) with fourth ventricle

5 Myelencephalon (yellow-green)

92 Brain: Arteries and Veins

1 Superior cerebral veins and

parietal lobe

2 Frontal lobe

3 Superficial middle cerebral vein and

cistern of lateral cerebral fossa

4 Temporal lobe

5 Occipital lobe

6 Inferior cerebral veins and

transverse occipital sulcus

7 Inferior anastomotic vein

8 Cerebellum

9 Medulla oblongata

Brain with pia mater. Cerebral veins (bluish). In the lateral sulcus the cistern of the

lateral fossa is recognizable. Frontal lobe to the left.

Arteries of the brain. Coronal section. Areas supplied by

cortical and central arteries. Dotted lines indicate boundaries of

arterial supply areas; arrows = direction of blood flow.

Coronal section through the right hemisphere, showing

arachnoid, pia mater, and the arterial blood supply (anterior

aspect).

1 Anterior cerebral artery

2 Middle cerebral arteries

3 Arachnoid

4 Cortex

5 Internal carotid artery

6 Frontal lobe (white matter)

7 Posterior cerebral artery

8 Caudate nucleus

9 Internal capsule

10 Insular lobe

11 Claustrum

12 Putamen

13 Posterior striate branch

14 Insular artery

15 Pallidostriate artery

16 Thalamic artery

17 Corpus callosum

18 Septum pellucidum

19 Lateral ventricle

20 Optic chiasma

Brain: Arteries 93

1 Olfactory tract

2 Anterior cerebral artery

3 Optic nerve (n. II)

4 Middle cerebral artery

5 Infundibulum

6 Oculomotor nerve (n. III) and

posterior communicating

artery

7 Posterior cerebral artery

8 Basilar artery and abducent

nerve (n. VI)

9 Anterior spinal artery

10 Vertebral artery

11 Cerebellum

12 Anterior communicating artery

13 Internal carotid artery

14 Superior cerebellar artery

and pons

15 Labyrinthine arteries

16 Inferior anterior cerebellar

artery

17 Inferior posterior cerebellar

artery

18 Medulla oblongata

19 Supratrochlear artery

20 Anterior ciliary arteries

21 Lacrimal artery

22 Posterior ciliary arteries

23 Ophthalmic artery with

central retinal artery

24 Trigeminal nerve (n. V)

25 Facial nerve (n. VII) and

vestibulocochlear nerve (n. VIII)

26 Glossopharyngeal nerve (n. IX),

vagus nerve (n. X), and

accessory nerve (n. XI)

27 Olfactory bulb

28 Posterior spinal artery

Arteries of the brain (inferior aspect, frontal pole above). Right temporal lobe and

cerebellum partly removed.

Arteries of the brain (inferior aspect). Right temporal lobe

and cerebellum partly removed. Note the arterial circle of Willis

around the infundibulum.

94 Brain: Arteries

1 Insula

2 Middle cerebral artery (2 branches:

a Parietal branches,

b Temporal branches)

3 Basilar artery

4 Vertebral artery

5 Central sulcus

6 Occipital lobe

7 Superior cerebellar artery

8 Cerebellum

9 Anterior cerebral artery

10 Ethmoidal arteries

11 Ophthalmic artery

12 Internal carotid artery

13 Posterior communicating artery

14 Posterior cerebral artery

15 Anterior inferior cerebellar artery

16 Posterior inferior cerebellar artery

Cerebral arteries. Lateral aspect of

the left hemisphere. The upper part of

the temporal lobe has been removed to

display the insula and cerebral arteries.

1 Interventricular foramen

2 Septum pellucidum

3 Frontal lobe

4 Anterior cerebral artery

5 Anterior commissure

6 Optic chiasma and infundibulum

7 Mamillary body

8 Oculomotor nerve (n. III)

9 Pons

10 Basilar artery

11 Corpus callosum

12 Fornix

13 Choroid plexus

14 Third ventricle

15 Pineal body

16 Tectum and cerebral aqueduct

17 Fourth ventricle

18 Cerebellum (arbor vitae, vermis)

19 Median aperture of Magendie

20 Medulla oblongata

Arteries of the brain.

Median section through the brain

and brain stem. Cerebral arteries

injected with red resin.

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Brain: Arteries

Arteries of the brain. Angiogram of the internal carotid artery (anterior aspect)

(courtesy of Prof. Dr. W. Huk, University of Erlangen-Nürnberg).

Cerebral arteries (schematic drawing).

Left hemisphere and brain stem have been removed.

Note the arterial circle of Willis around the sella turcica.

Main arteries for brain supply (MRI angiograph, anterior

aspect, courtesy of Prof. Dr. W. Bautz, University of ErlangenNürnberg).

1 Anterior cerebral artery

2 Orbit

3 Middle cerebral artery

4 Nasal cavity

5 Internal carotid artery

6 Arterial circle of Willis

7 Posterior communicating

artery

8 Posterior cerebral artery

9 Basilar artery

10 Vertebral artery

11 Subclavian artery

12 Aortic arch

13 Common carotid artery