FOURTH VENTRICLE By Dr Shivarama Bhat P

VENTRICLES 2 Lateral Ventricles. Third ventricle. Fourth ventricle. Terminal ventricle.

VENTRICLES

VENTRICLES

FOURTH VENTRICLE

The Fourth Ventricle (ventriculus quartus) Cavity of the hind-brain is situated in front of the cerebellum and behind the pons and behind upper half of the medulla oblongata.

FOURTH VENTRICLE PARTS Roof (dorsal wall) Floor (ventral wall) Lateral boundaries Four angles

LATERAL BOUNDARIES Upper Part:-- superior peduncle middle peduncle FOURTH VENTRICLE LATERAL BOUNDARIES Upper Part:-- superior peduncle middle peduncle Lower Part:– inferior peduncle fasciculus cuneatus fasiculus gracilis

Floor -RHOMBOID FOSSA Median sulcus Locus cerulus Sulcus limitans FOURTH VENTRICLE Floor -RHOMBOID FOSSA Median sulcus Locus cerulus Sulcus limitans Median eminence Vestibular area Superior fovea Facial colliculus Striae medullaris Inferior fovea Hypoglossal triangle Vagal triangle Area postrema

FOURTH VENTRICLE

DORSAL WALL Upper Portion of the roof Lower Portion Inferiorly FOURTH VENTRICLE DORSAL WALL Upper Portion of the roof superior peduncle superior medullary velum Lower Portion inferior medullary velum Inferiorly tæniæ of the fourth ventricle

FOURTH VENTRICLE ROOF

RECESSES

ROOF Three openings, a median and two lateral: FOURTH VENTRICLE Three openings, a median and two lateral: 1 median aperture (foramen Magendii), 2 lateral apertures (foramina of Luschka) By means of these three openings the ventricle communicates with the subarachnoid cavity

ANGLES Superior angle Inferior angle Two lateral angle FOURTH VENTRICLE ANGLES Superior angle Inferior angle Two lateral angle Superior angle- continuous with the lower end of the cerebral aqueduct. Inferior angle -opens into the central canal of the medulla oblongata. Two lateral angle

CHOROID PLEXUSES Highly vascular inflexions of the tela chorioidea Invaginate the lower part of the roof of the ventricle Each consists of a vertical and a horizontal portion The structure presents the form of the letter T, the vertical limb being double

HYDROCEPHALUS

Questions 4th ventricle – Long essay. Enumerate the connections of 4th ventricle – Short answer. Floor of 4th ventricle – Short essay. Roof of 4th ventricle – Short essay.