The fourth ventricle is located ventral to the cerebellum and dorsal to the pons and medulla. It is bounded laterally by the gracile and cuneate tubercles and inferior cerebellar peduncles, and superiorly by the superior cerebellar peduncle. Its roof is formed by the superior cerebellar peduncle and medullary velum. Its floor contains landmarks like the median sulcus, facial colliculus, and hypoglossal triangle. Cerebrospinal fluid circulates from the fourth ventricle through the median aperture and exits into the subarachnoid space through the foramina of Luschka and Magendi.

1. Fourth ventricle
By
Dr. Noura El Tahawy

3. Sagittal section of the brainstem & cerebellum
The diagram showing the position of the fourth ventricle. Cerebrospinal fluid descends along
the aqueduct into the fourth ventricle and emerges into the subarachnoid space via three
apertures including the median aperture containing the arrow.

4. Sagittal hemisection of the brain
Sagittal hemisection of the brain to show the third and fourth ventricles.
Pia mater: red; ependyma: blue.

5. Fourth ventricle
Central canal →fourth ventricle →mesencephalic aqueduct→third ventricle
Position
Situated ventral to cerebellum, and
dorsal to pons and cranial half of
medulla

6. MRI scan of head in sagittal plane.

7. Projection of the ventricles onto the left surface of the brain.

8. Boundaries & floor of 4 th
ventricle

11. Posterior view of the brainstem.

12. Fourth ventricle
Boundaries
Inferolateral:
gracile and
cuneate tubercles,
inferior cerebellar
peduncles
Superolateral:
superior cerebellar
peduncle
Lateral recess

13. Floor of the Fourth ventricle
Pontine part
Median sulcus Vestibular area
Sulcus limitans
Medial eminence
- Facial colliculus:
overlies nucleus of
abducent n. and genu of
facial nerve
- Hypoglossal triangle •Striae medullares
Vestibular area
overlies vestibular
nuclei
Acoustic tubercle
overlying dorsal
cochlear nucleus
Inferior fovea
(Vagal triangle)

14. Floor of the Fourth ventricle
Medullary
part
-Inferior fovea
1- Hypoglossal
triangle:
overlying
hypoglossal
nucleus
2-Vestibular
triagle
3- Vagal triangle:
overlies dorsal
nucleus of
vagus nerve

15. Roof of 4 th Ventricle

17. Fourth ventricle
Roof
Rostral part:
-superior cerebellar
peduncle and superior
- medullary velum
Caudal part:
-inferior medullary
velum and choroid
plexus of fourth
ventricle
Three apertures
Median aperture (F.
of Magendi)
Two lateral
apertures (foramina
of Luschka)

18. Recesses of 4th
Ventricle

20. Tela choroidea and choroid plexus

21. The arrangement of tissues forming the choroid plexus.

22. CSF
The cerebral ventricular system and its relationship with the subarachnoid space .The
circulation of cerebrospinal fluid is indicated by arrows .

23. Transverse section through the superior sagittal sinus showing arachnoid villi .

24. Superior aspect of the cerebral hemispheres showing arachnoid granulations on the right
side .On the left side, the arachnoid mater has been removed .

25. Thanks
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