Presentation- 2.pdf 187096for the longish

stroke

1. ANATOMY OF CEREBRAL
HEMISPHERES
&
VASCULAR SUPPLY
Dr. Hessa Al Omar
Neurology resident
PGY-2 -KFMMC

2. Contents:
vAreas of the brain
vLobes of the cerebral hemispheres
vAnatomical function of each lobe
vVascular supply of the brain

3. Areas Of The Brain
§The brain is composed of :
cerebral hemisphere , cerebellum and
medulla.
§The cerebral hemispheres constitute
the largestpart of the brain
§Divide into : right and left
hemispheres
§The hemispheres are separated
medially by deep cleft: longitudinal
cerebral fissure
§Linked by : corpus callosum

4. Corpus callosum
■Thicknerve tract, consisting of bundle ofcommissural
fibers, beneath thecerebral cortexin thebrain.
■It is the largestwhite matterstructure in thehuman
brain, about 10cm in length and consisting of
200–300 millionaxonalprojections.
■FUNCTION :
1-Facilitating communication between thetwo brain
hemispheres.
2-coordinate functions like movement,
sensory processing, and cognitive tasks.

5. Lobes of cerebral hemisphere

6. 1-Frontal Lobe :
■Largest lobe
Boundaries :
Central sulcus : ( frontal lobe , parietal lobe)
Lateral sulcus ”Sylvain fissure” : (frontal lobe ,
temporal lobe )
Functional area :
■Primary motor cortex = volunt. Muscle movement
( fine motor movements hands , face )
■Premotor area = planning / coordination of
movement
■Frontal eye field area = volunt. rapid eye
movement
■Prefrontal area: executive functions , complex
behavior , personality
■Speech area of borca: production of speech ,
muscles of speech

7. Normalfrontal lobe injured frontal lobe
1-personality / emotions /
intelligence
2-attention/ concentration
3-judgment
4-body movements
5-problem solving
6-speech ( speak , write )
1-contralateral weakness .
2-repetition of signal though.
3-unable to focus on a task.
4-change in social behavior and
personality
5-gaze control (deviated toward
lesion)
6-broca’saphasia ( cant’speak or
write )
Expressive inability

8. 2-parietal lobe
Functional areas:
■Primary somatosensory cortex:
-awareness of somatic sensations
( touch , pain and temp ) from the skin
-Information about muscle movements
and body position.
■Somatosensory association cortex:
-processing/analyzing somatic sensations
-memory and recognition of sensation
-proprioception ( coordination of visual ,
auditory and somatosensationstimuli)

9. Normal parietal lobe Injured parietal lobe
1-sense of touch , pain and temperature
2-distinguish in size , shape , color
3-spatial perception
4-visual perception
1-contralateral sensory loss
2-contralateral inf. Quadrantanopia
3-astereognosis
4-finger agnosia, agraphia, right-left
disoriantation

10. 3-Temporal lobe
■Functional areas :
■Primary auditory cortex :
awareness of auditory stimuli
■Auditory association cortex:
process , analyze , understand
, recognize memory of sounds
■Wernicke area: sensory
speech area: posterior
segment of the superior
temporal gyrus in the dominant
hemisphere

11. Normal temporal lobe Injured temporal lobe
1-speech : understanding language
2-memory
3-hearing
4-visual
1-Wernicke aphasia( difficult
understand language )
2-difficulty in recognize faces ,
naming objects
3-aggressive behavior
4-contralateral superior
quadrantanopia

12. 4-occipital lobe
■Boundries:
parieto-occipital sulcus :( occpital, parital)
Pre–occipital notch : (occipital , temporal)
■Functional areas :
Primary visual cortex :
awareness of visual stimuli ,
processing and interprets visual stimuli

13. Normal occipital lobe Injured occipital lobe
1-vision 1-contralateral hemianopia (
macular sparing )
2-Visual hallucinations
3-prosopagnosia

14. Blood supply to the Brain :
■Brain supply by 2 arteries :
1-internal carotid artery :
Supply the anterior
circulation of the brain
2-vertebrobasilar artery
Two Vertebral artery will ascend
up through foramen magnum
Join and become basilar artery
Supply the posterior circulation
of the brain

15. Internal carotid artery :
-Common carotid artery
will bifurcate into: ICA + ECA
-ICA : Will ascend up through
carotid canal in cranium base

16. Internal carotid Artery include 4 parts :
1-cervical
region in the neck
2-petrous
from carotid canal at
base of skull
into middle cranial fossa
3-cavernous
in cavernous sinus
in either side of pituitary
4-cerebral

17. ■Internal carotid artery : cerebral part branches :
1-Ophthalmic Artery.
2-Posterior communication artery .
3-Anterior cerebral Artery.
4-Middle cerebral artery.

18. Ophthalmic Artery :
-Run through : optic canal
-Supply : orbit of the eyes
-clinically important :
central artery of retina
-supply the retina if
occluded due to uncontrolled
DM , Clotting :
effect vision , blindness

19. Post Communicating Artery :
1-Connect the
internal carotid
artery to >> post
cerebral Artery .
2-connection
between the two
circulations in
each side .

20. Anterior cerebral Artery :
-supply the front part of cerebrum .
-on top of corpus callosum in between longitudinal cerebral
fissure .

21. Distribution of ACA :
-Medial aspect of cerebral
hemispheres back to
partial lobe.
-cross over corpus
collosum.

22. Anterior communicating
Artery :
-connecting
two anterior cerebral
arteries together .

23. Middle cerebral Artery :
MCA which run along
lateral sulcus
Distribution :
Lateral aspect of cerebral
hemispheres
Except :superior part of frontal
and partial lobe , inferior part of
temporal lobe

24. Posterior circulation:
■1-vertebral arteries :
-posterior inferior cerebellar Artery
-Anterior spinal artery
■2-basilar artery :
-Anterior inferior cerebellar artery
-superior cerebellar artery
-posterior cerebral artery

25. Vertebral arteries
-origin :
subclavian Artery.
-Ascending :
transverse foramen of
cervical vertebrae .
-Enter skull :
foramen magnum.
-Joining the other vertebral
A : basilar artery .

26. Posterior inferior cerebellar artery
-Branch of :
vertebral artery
-supply :
post-lower portion
of cerebellum

27. Anterior spinal artery :
-Branches from :
two vertebral artery
-supply :
front part of
spinal cord

28. Basilar artery :
-two vertebral arteries joining to inform
basilar artery .
-Distribute along the pons .

29. Anterior inferior cerebellar artery
-branch from: basilar artery
-supply :
front and bottom of cerebellum

30. Superior cerebellar artery
-supply the top of cerebellum

31. Posterior cerebellar artery :
-the end of the basilar artery branches
-supply:Dorsumof cerebrum
**CN III:
Run in between
them if have
aneurysm will
compress CN
lead to ocular
manifestations

32. PCA DISTRUBUITION:
-Occipital lobe
( visual cortex)
-temporal lobe
( posterior, inferior portion)

33. Circle of Willis:
-collateral circulations between 2
ICA & Vertibrobasilar artery.
-provide redundancy will permit the
circulation if part of circle
is occluded.
-located : around optic chiasm and
pituitary glans

34. THANK YOU FOR YOUR LEISINING