anatomy of brain

1. ANATOMY OF BRAIN
SULCUS

2. TYPICAL CONTINOUS FISSURE
Interhemispheric fissure
Sylvian fissure ( lateral sulcus )
Parieto-occipital fissure
Collateral sulcus
Central sulcus
Calcarine Sulcus

3. Deep, mostly horizontal
Insula is buried within it
Separates temporal lobe from parietal and frontal lobes
SYLVIAN FISSURE

4. PARIETO - OCCIPITAL FISSURE
Very deep
Often y-shaped from sagittal view
X-shaped in horizontal and coronal views

5. MEDIAL SURFACE OF BRAIN

6. BASAL SURFACE OF BRAIN

7. FRONTAL LOBE
The frontal lobe constitutes the entire region in front of the central sulcus.
Immediately in front of the central sulcus lies the precentral gyrus, which is
the primary motor region of the cerebral cortex. In front of the precentral
gyrus, the rest of the frontal lobe is divided into superior, middle and
inferior frontal gyri.

8. FRONTAL LOBE
SULCI:
•Superior frontal sulcus.
•Inferior frontal sulcus.
•Precentral sulcus.
GYRI:
•Superior frontal gyrus.
•Middle frontal gyrus.
•Inferior frontal gyrus.
•Precentral gyrus

9. FRONTAL LOBE GYRUS
Lateral Surface
•Precentral Gyrus --- primary motor area
•Superior Frontal Gyrus
•Middle Frontal Gyrus
•Inferior Frontal Gyrus
•Pars Opercularis
•Pars Triangularis
•Pars Orbitalis
Medial Surface
•Medial Frontal Gyrus
•Paracentral Lobule
Basal Surface

13. PARIETAL LOBE
Behind the central sulcus, and above the lateral fissure, lies the parietal
lobe. Its most anterior part is the postcentral gyrus, which is the site of the
primary somatosensory cortex. Behind the postcentral gyrus, on the lateral
surface of the hemisphere, the intraparietal sulcus divides the rest of the
parietal lobe into superior and inferior parietal lobules.

14. PARIETAL LOBE
SULCI:
Post-central sulcus.
Intraparietal sulcus.
GYRI:
Post-central gyrus.
Superior parietal gyrus.
Inferior parietal gyrus.

15. PARIETAL LOBE GYRUS
Lateral Surface
Postcentral Gyrus ---- primary somatic area
Superior Parietal Lobule
Inferior Parietal Lobule ---- Wernicke’s area
Supramarginal Gyrus
Angular Gyrus
Medial Surface
Paracentral Lobule
Precuneus

20. The temporal lobe lies beneath the lateral fissure. On its lateral surface
the temporal lobe is divided into three principal gyri that run roughly
parallel to the lateral fissure: the superior, middle and inferior temporal
gyri. The superior temporal gyrus includes the primary auditory cortex.
TEMPORAL LOBE

21. Sulci:
Superior temporal sulcus (parallel sulcus).
Inferior temporal sulcus.
Gyri:
Superior temporal gyrus.
Middle temporal gyrus.
Inferior temporal gyrus.
TEMPORAL LOBE

22. Lateral Surface
Superior Temporal Gyrus
Middle Temporal Gyrus
Inferior Temporal Gyrus
Basal Surface
Occipitotemporal Gyrus
Medial Occipitotemporal Gyrus
Lateral Occipitotemporal Gyrus
TEMPORAL LOBE GYRUS

26. OCCIPITAL LOBE
The boundary between the parietal lobe and occipital lobe is not coincident
with a single sulcus on the lateral surface of the hemisphere; however, it is
clearly marked by the deep parieto-occipital sulcus on the medial surface.
The occipital lobe does not bear any important landmarks on its lateral
surface but on the medial surface, the prominent calcarine sulcus indicates
the location of the primary visual cortex.

27. OCCIPITAL LOBE
Sulci:
Superior occipital sulcus (extension of intraparietal sulcus).
Inferior occipital sulcus (extension of inferior temporal sulcus).
Gyri:
Superior occipital gyrus.
Middle occipital gyrus.
Inferior occipital gyrus

28. Lateral Surface
Lateral Occipital Gyrus
Superior Occipital Gyrus
Inferior Occipital Gyrus
Medial Surface
Cuneus
Lingual Gyrus
Basal Surface
Lateral occipito-temporal gyrus (fusiform gyrus).
Medial occipito-temporal gyrus (lingual gyrus).
OCCIPITAL LOBE GYRUS

33. LIMBIC LOBE
On the medial surface of the hemisphere, certain portions of the frontal,
parietal and temporal lobes also constitute components of the limbic system.
Curving around the corpus callosum, and running parallel to it, lies the
cingulate gyrus , separated from the rest of the hemisphere by the cingulate
sulcus. The cingulate gyrus passes posteriorly and inferiorly round the
posterior portion of the corpus callosum to become continuous with
the parahippocampal gyrus of the temporal lobe. Deep to the parahippocampal
gyrus, within the temporal lobe lies the hippocampus. The cingulate gyrus,
parahippocampal gyrus and hippocampus are referred to as the limbic lobe.

34. LIMBIC LOBE GYRUS
Outer Ring
Cingulate Gyrus
•Isthmus of Cingulate Gyrus
•Parahippocampal Gyrus
•Uncus, Uncinate Gyrus
Inner Ring
•Hippocampal Formation
•Hippocampus, Ammon's Horn
•Dentate Gyrus
•Fasciolar Gyrus
•Supracallosal Gyrus

38. Lies deep in floor of sylvian fissure, overlapped by frontal, temporal
and parietal.
The insular lobe is thought to be involved in sensory and motor
visceral functions as well as taste perception.
INSULAR LOBE

39. INSULAR LOBE
Sulci:
Central sulcus.
Short insular sulcus.
Precentral sulcus.
Gyri:
Anterior insular lobule.
Posterior insular lobule.

41. SULCUS AND GYRUS
Coronal
Axial
Sagittal

42. SIGNS TO IDENTIFY SULCUS IN MRI
The midline sulcus sign:
The longest sulcus running horizontally and entering the interhemispheric
fissure is the central sulcus .
The M sign:
The typical upper case M shape of the inferior frontal gyrus is formed by
its parts ( orbitalis, triangularis, and opercularis ).

43. The bifid post cg sign:
Toward the interhemispheric fissure, the postcentral gyrus is medially
fissured, enclosing the pars marginalis of the cingulated sulcus with both
legs and thereby forming the characteristic bifid post cg sign.
The thin post cg sign:
On the surface, the precentral gyrus has a thicker anteroposterior diameter
compared with the postcentral gyrus, which is thinner.
SIGNS

44. SIGNS
The handknob:
Defined the "handknob " as 1 single -shaped dorsally convex bulge of the
precentral gyrus.
The upper T sign:
The intersection of the well-identifiable superior frontal sulcus with the
precentral sulcus has the shape of an upper case T. The pre cg can be found
immediately posterior to this T shape.

45. The L sign:
The sfg terminates in the pre cg, which runs laterally from the posterior end
of the sfg, therefore together forming an upper case L.
The lower T sign:
The inferior frontal sulcus posteriorly terminates in the pre sc, also in the
shape of an upper case T that is dorsally bordered by the pre cg.
SIGNS

46. Inverted omega sign :
The central sulcus more likely to have the shape of inverted omega.
The bracket sign:
The bihemispheric symmetric pars marginalis of the cingulate sulcus
forms an anteriorly opened bracket.
SIGNS

50. SAGITTAL

51. Superior frontal gyrus
Cingulate gyrus
Cingulate sulcus
Paracentral lobule
Marginal ramus of
Cingulate sulcus
Superior parietal lobule
Parietooccipital sulcus
Cuneus
Calcarine sulcus
Lingual gyrus
Fastigium, fourth ventricle
Subcallosal gyrus
Gyrus rectus

52. Cingulate sulcus
Superior frontal gyrus
Cingulate gyrus
Precentral gyrus
Central sulcus
Marginal ramus of
Cingulate sulcus
Superior parietal lobule
Precuneus
Parietooccipital
sulcus
Cuneus
Calcarine sulcus
Lingual gyrus
Caudothallamic groove
Gyrus rectus
Frontomarginal Gyrus

53. Superior frontal gyrus
Corona radiata
Precentral sulcus
Central sulcus
Marginal ramus of
Cingulate sulcus
Superior parietal
lobule
Precuneus
Calcarine sulcus
Parietooccipital
sulcus
Inferior occipital gyrus
Lingual gyrus

54. Frontopolar gyrus
Frontomarginal
gyrus
Medial orbital gyrus
Posterior orbital gyrus
Inferior temporal gyrus Temporal horn,
Lateral ventricle
Lingual gyrus Inferior occipital gyrus
Middle occipital
gyrus
Superior occipital
gyrus
Parietooccipital sulcus
Superior parietal
lobule
Central sulcus

55. Central sulcus
Inferior temporal gyrus
Superior temporal
gyrus
MiddleTemporal gyrus

56. Central sulcus Superior parietal
gyrus
Superior occipital
gyrus
Middle occipital
gyrus
Inferior occipital
gyrus
Lingual gyrus
Inferior temporal gyrus
MiddleTemporal gyrus
Superior temporal
gyrus
Posterior orbital gyrus
Anterior orbital gyrus
Frontomarginal gyrus
Inferior frontal gyrus

57. Inferior frontal gyrus,
pars triangularis
Inferior frontal gyrus,
pars orbitalis
Superior Temporal gyrus
SuperiorTemporal sulcus
MiddleTemporal gyrus
InferiorTemporal gyrus
Inferior occipital gyrus
Anterior occipital sulcus
Middle occipital gyrus
Angular gyrus
Lateral fissure,
posterior segment
Postcentral sulcus
Central sulcus
Precentral sulcus
Superior frontal sulcus

58. AXIAL

59. Fusiform gyrus
InferiorTemporal gyrus
MiddleTemporal gyrus
SuperiorTemporal gyrus

60. Hippocampal gyrus
Parahippocampal gyrus
Superior Temporal gyrus
MiddleTemporal gyrus
InferiorTemporal gyrus

61. Amygdala Hippocampus
SuperiorTemporal gyrus
MiddleTemporal gyrus
InferiorTemporal gyrus
Lingual gyrus
Gyrus descendens
Inferior occipital gyrus
Temporo-occipital fissure

62. Hippocampus
Amygdala
Subcallosal gyrus
Olfactory sulcus
Gyrus rectus
Medial orbital gyrus
Posterior orbital gyrus
SuperiorTemporal gyrus
MiddleTemporal gyrus
InferiorTemporal gyrus
Temporo-occipital fissure
Middle occipital gyrus Gyrus descendens Lingual gyrus

63. Superior frontal gyrus Middle frontal gyrus
Lateral fissure
Inferior frontal gyrus,
pars orbitalis
Inferior frontal gyrus,
pars opercularis
Insula
Cingulate gyrus
Parieto-occipital fissure
Calcarine sulcus
Cuneus
Superior occipital gyrus
Intra-occipital sulcus
Middle occipital gyrus
Middle temporal gyrus
Superior temporal sulcus
Superior temporal gyrus
Lateral fissure
Inferior parietal gyrus

64. Middle frontal gyrus
Superior frontal gyrus
Inferior frontal gyrus
Postcentral gyrus
Inferior parietal gyrus
Lateral fissure
Superior temporal sulcus
Parieto-occipital sulcus
Superior occipital gyrus
Intra-occipital sulcus
Middle occipital gyrus
Superior temporal gyrus
Lateral fissure
Central sulcus

65. Superior occipital gyrus
Cuneus
Intra-occipital sulcus
Central sulcus
Central sulcus
Middle occipital gyrus
Precentral gyrus
Precentral sulcus

66. CORONAL

67. Paracentral lobule
Central Sulcus
Superior temporal gyrus
Middle temporal gyrus
Inferior temporal gyrus
Fusiform gyrus

68. THANK YOU