1. Special sense I – VISION

2. Visual pathway

4. Lesion in optic nerve leads to loss of vision on the same side of lesion optic tract: *Left optic tract is responsible for vision in nasal half of left visual field and temporal half of right visual field *right optic tract is responsible for vision in nasal half of right visual field and temporal half of left visual field

5. II- HEARING

6. Auditory pathway

8. External ear: collect sounds & direct it to tympanic membrane Middle ear: sounds vibrate the tympanic membrane then transmitted to auditory ossicles Types of conduction: 1- ossicular conduction 2- air conduction 3- bone conduction Austachian tube: responsible for equalizing pressure on either side of tympanic membrane

12. III- TASTE

13. Taste buds situation

14. Taste pathway

16. Taste sensation

18. IV- SMELL

19. Smell pathway

20. VisionHearingSmellTaste Receptor Rods & consHair cell in organ of corti Olfactory receptorTaste buds Site In retinaInner earNoseTongue Nerve Optic nerveAuditory nerve “vestibulocochlear “ Olfactory nerve*Anterior 2/3 of tongue: fibers of facial nerve *Posteior 1/3 of tongue: glossopharyngeal nerve *Vagal fibers from other regions Relay in thalamus RelayNot relay in thalamus Relay Cerebral cortex Occipital roleTemporal lobeOlfactory cortex includes structures which form apart of limbic system Parietal lobe