Unit 5

8 Sagittal MRI Images of the Head 15 Transaxial MRI Images 15 Coronal MRI Images

On campus students must draw and identify the anatomy on the line- drawings on the next three slides. Students in the degree completion course should have an understanding of basic anatomy that makes testing on the drawings unnecessary. But if you need a refresher try the drawings. The ability to visualize is important to the study of cross sectional anatomy.

First page number in parenthesis is Netter’s 3rd edition Second page number in parenthesis is Netter’s 4th edition

Unit 5 Introduction

1. Vertebral arteries2. Common carotid arteries3. Basilar artery4. Anterior communicating artery5 Anterior cerebral arteries6. Middle cerebral arteries7. Internal carotid arteries8. External carotidl arteries 9. Posterior cerebral arteries10. Posterior communicating arteries

Can you draw (or visualize) these anatomical structures:

An exercise in cross sectional anatomy recognition of theCircle of Willis

See plates 131-134(138-141)

4

567

8

9 3

2

1

9

Rt Lt

Circle of Willis Drawing

10

1. Superior sagittal sinus2. Inferior sagittal sinus3. Great cerebral vein (of Galen)4. Straight sinus5. Confluence of sinuses6. Occipital sinus7. Transverse sinus8. Sigmoid sinus9. Internal jugular vein

Can you draw (or visualize) these anatomical structures:

An exercise in cross sectional anatomy recognition of theVenous Sinuses

See plates 97-98(103-104)

43

2

1

5

6

78

9

Venous Sinuses Drawing

1. Frontal (anterior) horn of Lateral ventricle2. Body (central part) of lateral ventricle3. Trigone of lateral ventricle (not in Netter)4. Occipital (posterior) horn of lateral ventricle5. Temporal (inferior) horn of lateral ventricle6. Interventricular foramen (of Monro)7. Interthalamic adhesion8. 3rd ventricle9. Cerebral aqueduct (of Sylvius)*10. 4th ventricle11. Foramen of Luschka12. Lateral recess 13. Median aperture (Foramen of Magendie)14. Central canal of spinal cord

Can you draw (or visualize) these anatomical structures:

An exercise in cross sectional anatomy recognition of the Ventricles of the Brain

4

5

6

7

89 3

21

1011

12

See plate 102-103(108-109)

13

14Ventricular System Drawing

1. External jugular vein 2. External auditory canal (or meatus)3. Mastoid process of the temporal bone (4)4. Adipose (fat) 5. Zygomatic process of the temporal bone

6. Internal jugular vein7. Frontal process of the zygoma (2)8. Sulci of brain* (99)(105)9. Gyrus of brain**10. Convolutions of brain**11. Facial muscles (50)(54)

* The depressions in the surface of the brain (sulcus = singular)** Raised area between the sulci (gyri = plural)*** The twisted course the gyri take

4

5

6

7

89

3

2

1

10

Reference

These sagittal sections are from right to left. The imagespresented here, one to seven, go to midline. Because allthe anatomy seen is on the right side or in the midsagittal plane, right is not labeled and need not be labeled for testing purposes.

11

Sagittal Images 1 & 2

Sagittal Images 1-4

1. Internal jugular vein* 2. Zygomatic bone (4)3. Cerebellum4. Vitreous humor in eyeball5. Lateral sulcus (Sylvian fissure) (99)(105)

6. Lens of eye7. Maxillary sinus (45)(49)8. Internal carotid artery9. External carotid artery10. Facial artery (65)(69)11. Temporal horn of the lateral ventricle12. Trigone of the lateral ventricle**13. Occipital horn of the lateral ventricle***

* The lateral wall is seen on image 2, but the internal jugular is large, and seen in these two sections.** Although Netter did not label the section where the body, occipital, and temporal horns converge, it is evident on sagittal images.***The ventricles of this patient are not as prominent as are sometimes seen.

Reference

4 5

6

7

89

32

1

10

1112

13

Sagittal Images 3 & 4

1. Roots of teeth* (52)(56)2. Internal carotid artery3. Scalp4. Outer table of the skull5. Diploe layer of the skull6 Inner table of the skull7. Optic nerve (80, 81)(84,85)

8. Frontal sinus9. Corpus callosum10. Body of the lateral ventricle11. Inferior nasal concha (turbinate) (33)(37)12. Middle nasal concha (turbinate)13. Middle nasal meatus14. Nasopharynx (33, 59)(37, 63)15. Soft palate16. Oropharynx17. Siphon of the internal carotid artery (carotid siphon)**18. Ethmoid air cells

* Of mandible. Maxilla directly above.** Not labeled in Netter, but the siphon (the S shaped terminal portion of the internal carotid) is nicely illustrated in plate 130 (136).

45

6

7

8 9

3

21

10

11

12

13

14

15

Reference

16

17

Sagittal Images 5 & 6

18

#6

Sagittal Images 5 & 6

1. Tongue 2. Nasal septum3. Sphenoid sinus4. Sphenoid bone (6)5. Genu of the corpus callosum (100)(106)6. Body (trunk) of the corpus callosum7. Splenium of the corpus callosum8. Epiglottis9. Body of C2 10. Odontoid process (dens)11. Anterior tubercle of C1 (15)(17)12. Posterior tubercle of C113. Cerebellar tonsil (107)(113)14. Body of the lateral ventricle*15. Occipital lobe of the cerebrum16. Confluence of sinuses

* Just lateral to the septum pellucidum

4

8

9

32

110

11

12

13

Reference

Image 7A, 7B, & 7C are the same image, in the midsagittal plane

Plate 100 (106) is an excellent correlation to this imagePlate 101 (107) is also good for structures around the base

56

7

14

16

15

#7A

Sagittal Image 7A

Sagittal Image 7

1. Superior sagittal sinus 2. Inferior sagittal sinus3. Straight sinus*4. Great cerebral vein (Vein of Galen)5. Stalk of the pituitary gland (Hypophysis)**6. Chiasmatic (suprasellar) cistern*** (103) (109)7. Spinal cord8. Medulla oblongata****9. Pons10. Cerebral peduncle

* In the tentorium cerebelli (98, 100) (104,106)** The pituitary gland is in this section, but is difficult to differentiated from the bone of the sella turcica *** Fluid filled space surrounding the stalk of the pituitary****The medulla, pons, and midbrain (mesencephalon) make up the brain stem. See 7C for parts of the midbrain.

4

5

6

7

8

9

10

Reference

12

3

#7B

Sagittal Image 7B

1. Thalamus 2. 3rd ventricle*3. Optic chiasm4. Mammillary body5. Interpeduncular cistern6. Prepontine cistern7. Cerebral aqueduct (aqueduct of Sylvius)8. Quadrigeminal plate (lamina)*9. Pineal body (gland)10. Quadrigeminal cistern11. 4th ventricle12. Cisterna magna

* The (midbrain) mesencephalon is the most superior part of the brain stem. It is comprised of the cerebral peduncles (see 7B #10), the cerebral aqueduct (of of Sylvius), and the quadrigeminal plate.

456

7

10

11

3

28

9

Reference

#7C

1

12

Sagittal Image 7C

Sagittal Image 7

1. Alveolar process of the maxilla* 2. Rt masseter muscle (57)(61)3. Cisterna magna4. Rt & Lt vertebral arteries** (17, 130)(21,136)

5. Rt lobe of the cerebellum6. Lt cerebellar tonsil7. Medulla oblongata***8, Rt maxillary sinus9. Rt ramus of the mandible10. Internal occipital protuberance (inion) (9)

* Black holes are sockets are the teeth** On exiting the vertebral foramen in the 1st cervical vertebra (image #1) the vertebral arteries turn posterior (image #3) and enter the cranium through the foramen magnum***On image #2 the spinal cord (image 1) is in transition to the medulla. The shape of the medulla is clearly seen on image 3.

4

67

3

21 Reference

5

8

9

10

4

Transaxial sections from base of skull to vertex of cranium.

Axial Images 1 & 2

Axial Images 1-4

1. Rt inferior nasal concha (turbinate) (33, 43)(37,47) 2. Nasopharynx* (59)(63)3. Rt & Lt vertebral arteries4. Inferior vermis of the cerebellum (107)(113)5. Rt mastoid process

6. Rt & Lt petrous portion of the temporal bone7. Lt facial artery8. Posterior cerebellar notch** (107)(113)

* The boundary between the oropharynx and nasopharynx would be close to image 2, where the hard and soft palate can be seen. Image 1 shows a semi lunar appearance to the anterior wall of the pharynx, which is the encroachment of the soft palate, nearing the uvula.** Space between cerebellar hemispheres.

Reference

6

7

3

2

1

3

4

5

8

Axial Images 3 & 4

1. Anterior nasal nares 2. Bony nasal septum*3. Coronoid process of the left mandible (4)4. Left vertebral artery**5. Rt external auditory (acoustic) meatus (canal)6. Head of the condylar process of the Lt mandible (Rt and Lt mandibular condyles)7. Unidentified bright object (UBO). An MRI artifact.8. Lt occipital lobe of the cerebrum

9. Cartilaginous nasal septum10. Rt transverse sinus11. Confluence of sinuses12. 4th ventricle (102, 109)(108,115)13. Lt middle nasal concha (turbinate) (33)14. Rt superior nasal concha (turbinate)15. Internal carotid arteries in carotid canals*** (8, 9, 130)(8, 9, 136)

* Comprised of the vomer bone and the perpendicular plate of the ethmoid bone, both of which would be seen on this section (6)** Seen as a streak or line on the left side, unlike the spot we have seen to this level. This is due to the left vertebral heading for midline to anastomose with the Rt vertebral to form the basilar artery. The right is doing the same, but appears differently due to asymmetry or rotation of the part.***Enters the external carotid opening (8) turns medially and anteriorly as it runs through the canal, then turns superiorly at foramen lacerum.

45

67

9

8

321

11 12

13

14

15

Reference

6

10

Axial Images 5 & 6

Axial Images 5-8

1. Sphenoid sinus* 2. Rt cerebellopontine angle cistern3. Lt internal carotid artery**4. Superior sagittal sinus5. Straight sinus6. Pons***

7. Pituitary gland (hypophysis)8. Rt internal carotid artery in the cavernous sinus (98, 130, 133) (104, 136, 140)9. Mesencephalon (midbrain)10. Basilar artery****11. Occipital (posterior) horn of the Lt lateral ventricle12. Superior vermis of the cerebellum (107)(113)

* On image 5 we saw the nasopharynx in approximately this position. On image 6 the nasopharynx is replaced by the body of the sphenoid bone that makes up the floor of the sphenoid sinus. Notice the septum in the sphenoid, which is common.** Just emerged from the canal, above foramen lacerum.***In front of the pons and between the cerebellopontine angle cisterns is the prepontine cistern.***It is difficult to see exactly which image the basilar first appears on, but the anastomosis occurs near the most superior part of the medulla oblongata.

Reference

4

5

6

9

32

1

10

7

8

12

11

Axial Images 7 & 8

1. Retrobulbar fat of the Lt eye (79)(83)2. Ethmoid air cells (44, 45)(48,49)3. Temporal horn of the Lt lateral ventricle4. Cerebral aqueduct (aqueduct of Sylvius) (101)(107)5. Rt ambient cistern6. Lt internal carotid artery in the cavernous sinus7. Chiasmatic (suprasellar) cistern8. Interpeduncular cistern (103)(109)9. Rt & Lt cerebral peduncles (cerebral crus)(101, 109) (107,115)10. Straight sinus

11. Lt optic nerve12. Medial rectus muscle of the Rt eye (79)(83)13. Rt & Lt mammillary bodies (101)(107)14. Stalk of the pituitary gland (hypophysis)15. Lt middle cerebral artery (132)(139)16. Quadrigeminal cistern17. Optic chiasm

4

5

6789

3

2 1

10

1112

14

Reference

13

15

17

16

Axial Images 9 & 10

Axial Images 9-12

1. Rt middle cerebral artery 2. Rt anterior cerebral artery3. Choroid plexus in the trigone of the Lt lateral ventricle

4. Rt lateral sulcus (Sylvian fissure) (99)(105)5. 3rd ventricle6. Splenium of the corpus callosum (100, 104) (106,110)

Reference

4

5

3

2

1

6

Axial Images 11 & 12

1. Frontal (anterior) horn of the Rt lateral ventricle 2. Rt & Lt interventricular foramen (Foramen of Monro)3. Frontal sinus4. Body (central part) of the Rt lateral ventricle5. Genu of the corpus callosum6. Inferior sagittal sinus*7. Superior sagittal sinus8. Falx cerebri** (97)(103)9. Longitudinal fissure10. Septum pellucidum

* Close to the level of the splenium of the corpus callosum is the anastomosis of the straight sinus and inferior sagittal sinus **Reflection of dura mater In the longitudinal fissure

4

8

9

3

1

Reference

1

5

6

79

2

10

Axial Images 13-15

1. Superior sagittal sinus 2. Rt optic foramen3. Superior, middle, & inferior nasal concha (turbinates) (44)(48)4. Tongue

5. Frontal (anterior) horn of the left lateral ventricle6. Genu of the corpus callosum7. Lt temporal lobe of the cerebrum

4

56

7

32

1 Reference

Coronal sections from anterior to posterior

Coronal Images 2 & 3

Coronal Images 2-5

1. Inferior sagittal sinus 2. Lt lateral sulcus (Sylvian fissure)3. Rt & Lt internal carotid arteries

4. Septum pellucidum5. 3rd ventricle6 Optic chiasm 7. Throat (nasopharynx and oropharynx)

Reference

6

7

3

2

1

4

5

Coronal Images 4 & 5

1. Chiasmatic (suprasellar) cistern 2. Body (central part) of the Lt lateral ventricle

3. 3rd ventricle4. Rt & Lt interventricular foramen (Foramen of Monro)(102 bottom) (108 bottom)5. Interpeduncular cistern6. C2-C3 intervertebral disk space

5

43

2

1

Reference

4

6

Coronal Images 6 & 7

Coronal Images 6-9

1. Odontoid process of C2 (dens) 2. Rt & Lt vertebral arteries3. Rt atlantoaxial articulation (joint)4. Lt atlantooccipital articulation (joint)5. Choroid plexus in the body (central part) of the Lt lateral ventricle

6. Choroid plexus in the temporal horn of the Lt lateral ventricle7. Body of the corpus callosum*8. Rt external auditory (acoustic) meatus (canal)9. Pons

* Close to the splenium of the corpus callosum, but note that the communication between the right and left cerebral hemispheres persists through image 10 and 11.

Reference

4

5

6

7

8 9

3 2

1

Coronal Images 8 & 9

1. Falx cerebri* 2. Spinal cord

3. Choroid plexus in the 3rd ventricle4. Rt superior colliculus* (colliculi = plural) (108 & 109 top) (114 & 115 top)5. Cerebral aqueduct (aqueduct of Sylvius)6. 4th ventricle7. Tentorium cerebelli8. Inferior sagittal sinus

4

6

8

2

Reference

1

3

57

Coronal Images 10 & 11

Coronal Images 10-13

1. Choroid plexus 2. 4th ventricle3. Splenium of the corpus callosum

4 Longitudinal fissure*5. Straight sinus

* Behind the corpus callosum

Reference

4

3

2

1

5

Coronal Images 12 & 13

1. Rt cerebellar hemisphere 2. Occipital (posterior) horn of the lateral ventricles3. Superior sagittal sinus

3

1

Reference

2 Coronal Images 14-16

Coronal Images 14-16