Occipital Lobe

MEHWISH ASLAM RAHEEMI OCCIPITAL LOBE

Posterior most of the brain lobes, associated primarily with vision.

GYRI & SULCI1)No distinguishable gyri.2)Sulci present.i.e Parieto-occipital sulcus separating the

occipital lobe from parietal lobe and the calcarine sulcus (medial surface) extending from the posterior part of corpus callosum up to the occipital pole.

3)Parieto-occipital sulcus makes an acute angle with the calcarine sulcus.

AREAS•PRIMARY VISUAL AREA•SECONDARY VISUAL AREA

PRIMARY VISUAL AREA• Location: Posterior walls of Calcarine sulcus.• Morphology: Thin cortex with striations seen by the

naked eye . Hence, Striated Cortex.• Function: Associated with afferent visual fibers from

the ipsilateral temporal fibers and contralateral nasal fibers through the lateral geniculate body to the PVA.

• Defect/Lesion: Leads to crossed homonymous hemaniopia.

SECONDARY VISUAL CORTEX

• Location: around the Primary visual cortex medially and laterally.• Function: Associates vision with past experience . Helps in Appreciation & Recognition.•Defect/Lesion : Disability to recognize Objects.

OCCIPITAL EYEFIELD• Depends on stimulus.• Involuntary.• Reflex tracking movement• Difference b/w Frontal & Occipital eye field:

The formal is independent of stimulus , voluntary scanning movement.

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