1. بسم الله الرحمن الرحیم

2. Each Cerebral hemisphere is made from:
 Cortex, a superficial gray mater
 Centrum Semiovale, a deep massive neuronal processes, (white mater)
Deep basal nuclei
Lateral ventricle

3. Ventricular System L V L V 3rd 4th Lateral Ventricles Third Ventricle
Cerebral Aqueduct
Fourth Ventricle
4th
Central Canal

6. Lateral Ventricle Body Horn Anterior Horn Posterior Horn Inferior Horn
Parietal Lobe
Frontal Lobe
Occipital Lobe
Temporal Lobe

7. Four Ventricles Lined by ependymal cells CSF filled chambers
Communicating with central canal of spinal cord
Lined by ependymal cells

10. Basal Nuclei
- The term basal nuclei (basal ganglia) is applied to a collection of masses of gray matter situated within each cerebral hemisphere.
They are the:
corpus striatum
the amygdaloid nucleus
the claustrum
The corpus striatum is situated lateral to the thalamus. It is almost completely divided by a band of nerve fibers, the internal capsule, into the caudate nucleus and the lentiform nucleus
The caudate nucleus, a large C-shaped mass of gray matter that is closely related to the lateral ventricle, Iies lateral to the thalamus

11. Brain white mater 1. Commissural fibers: 2. Association fibers:
Corpus callosum
Fornix
Anterior commisure
Posterior commisure
habenularc ommissure
2. Association fibers:
Long association
Short association fasciculus
Superior long association fasciculus
Inferior long association fascculus
Uncinate (frontotemporal) fasciculus
3. Projection fibers
Ascending
Descending

12. Red: projection fibres
Green: commissural fibres
Blue: association fibres

18. Forceps major & minor & tapetum

20. The anterior commissure is a small bundle of nerve fibers that crosses the midline in the lamina terminalis
When traced laterally a smaller or anterior bundle curves forward on each side toward the anterior perforated substance and the olfactory tract.
A larger bundle curves posteriorly on each side and grooves the inferior surface of the lentiform nucleus to reach the temporal lobes'

21. Anterior commissure

22. The posterior commissure is a bundle of nerve fibers that crosses the midline immediately above the opening of the cerebral aqueduct into the third ventricle
It is related to the inferior part of the stalk of the pineal gland
Various collections of nerve cells are situated along its length. The destinationsand functional significance of many of the nerve fibers are not known
However the fibers from the pretectal nuclei involved in the pupillary light reflex are believed to cross in this commissure on their way to the parasympathetic part of the oculomotor nuclei.

25. The fornix is composed of myelinated nerve fibers and constitutes the efferent system of the hippocampus that passes to the mammillary bodies of the hypothalamus
The nerve fibers first form the alveus,which is a thin layer of white matter covering the ventricular surface of the hippocampus and then converge to form the fimbria.
The fimbriae of the two sides increase in thickness and, on reaching the posterior end of the hippocampus, arch forward above the thalamus and below the corpus callosum to form the posterior columns of the fornix.
The two columns then come together in the midline to form the body of the fornix
The commissure of the fornix consists of transverse fibers that cross the midline from one column to another just before the formation of the body of the fornix
The function of the commissure of the fornix is to connect the hippocampal formations of the two sides.

29. Figure 9-10: The diencephalon

32. The habenular commissure is a small bundle of nerve fibers that crosses the midline in the superior part of the root of the pineal stalk
The commissure is associated with the habenular nuclei, which are situated on either
side of the midline in this region
The habenular nuclei receive many afferents from the amygdaloid nuclei and the hippocampus
These afferent fibers pass to the habenular nuclei in the stria medullaris thalami
Some of the fibers cross the midline to reach the contralateral nucleus through the habenular commissure
The function of the habenular nuclei and its connections in humans is unknown

33. Association fibers

42. Commissural fibers

45. Projection

47. Function of cerebral cortex
Cerebral Cortex is:
the outer layer of the cerebrum that consists of gray matter which deals with conscious motor action, sensation, memory, communication, reasoning, emotions, intelligence.

48. Functions of Cerebral lobes
Frontal Lobe controls conscious muscle action, planning for movements, motor memory, voluntary eye movements.
Parietal Lobe Controls conscious interpretation of sensation from muscles, tongue and cutaneous areas.
Temporal Lobe --- conscious interpretation of auditory and olfactory sensations. Memory of sounds and smells.
Occipital Lobe the most posterior lobe of the cerebrum which deals with conscious seeing, eye focus and integrating visual memory with other sensations.

49. Insula (Island of Reil) (‘fifth lobe’)
Covered by parietal and temporal lobes, not visible from the outside within the lateral fissure
It is a component of a functional lobe which is called limbic lobe
Limbic lobe is related to emotional and autonomic response to external stimuli

50. Cerebral cortex Sensory Area of the Cerebral Cortex –
Located in areas posterior to the central sulcus. Receives and interprets conscious sensory impulses. The postcentral gyrus of the parietal lobe is a key ridge of gray matter that allows a person to judge the source of sensory stimuli.
Motor Area of the Cerebral Cortex ---
Located in areas anterior to the central sulcus. Plans and initiates impulses for conscious motor movements. The precentral gyrus of the frontal lobe is an another key ridge of gray matter that allows a person to operate specific areas of the body.
Association Area of Cerebral cortex

51. Cytoarchitecture of cerebral cortex

52. Cytoarchitecture of cerebral cortex

53. Cytoarchitecture of cerebral cortex

54. Cytoarchitecture of cerebral cortex

55. Cytostructure of cerebral cortex
1 – Molecular layer
2 – External granular layer
3 – External pyramidal layer
4 - Internal granular layer
5 – Internal pyramidal layer
6 – Multiform layer

57. Cytoarichitecture of cerebral cortex based on Brodmann divisioions
Brodmann area
Location
Function 17
Banks of cal.sul
Primary visual c
18, 19
Medial aspect of occipital lobe
Secondary visual cortex
3,1,2
Postcentral gyr.
primary somato. 4
Precentral gyr.
Primary motor 6
Sup&middle f.g.
Premotore cort.
44,45
Inf. front. gyirus
Speech
41,42
Sup. tem .gyr.
Auditory cortex

58. Function of Brain Structures Continued
Sensory Area of the Cerebral Cortex
Located in areas posterior to the central sulcus. Receives and interprets conscious sensory impulses. The postcentral gyrus of the parietal lobe is a key ridge of gray matter that allows a person to judge the source of sensory stimuli.
Motor Area of the Cerebral Cortex
Located in areas anterior to the central sulcus. Plans and initiates impulses for conscious motor movements. The precentral gyrus of the frontal lobe is a another key ridge of gray matter that allows a person to operate specific areas of the body.

59. Brain Structure Functions Continued
Association Areas Regions of the cerebral cortex that analyze, recognize and act on sensory input and communicate with the motor areas. Examples include the visual and auditory association areas.

60. Primary Motor Cortex

61. Somatic Sensory Cortex

62. 6 1 4 8
Supramarginal 10 3
Angular 2 22 44 41 42 17 45

66. Important areas in frontal cortex
Supplamentary cortex = medial surface of area 6 (area 24 in cingulate gyrus)
Prefrontal cortex = predominanatly area 9, 45 & 46
Premotor area = area 6 (which is in front of area 4)

67. The localisation of language functions in the human brain

69. Speech Speech area normally in left cerebral cortex
Wernicke’s area: Sensory speech
Broca’s area: Motor speech
Aphasia: Absent or defective speech or language comprehension
1) Broca’s aphasia (expressive aphasia, motor aphasia)
2) Wernicke’s aphasia (no comprehension & failure to convey meaning

71. How to speak in response to seeing a word or hearing it.
Figure 9-23: Cerebral processing of spoken and visual language

73. Spinal tap

74. Brain Herniation Syndromes
Herniation occurs when mass effect is severe enough to push intracranial
structures from one compartment into another. The 3 most clinically
important herniation syndromes are caused by heriation through the tentorial
notch (transtentorial), centrally and downward (central), and under the falx
cerebri (subfalcine)