Question

Question 48 1. Trace the path of sound from the outside of the ear to stimulating cranial nerve VIL 2. Describe the auditory pathway from stimulation of cranial nerve Vill to the brain HTML Editor -LE35 BIVA % + 2 y = x W 12pt o here to search

Answer 1

ANSWER :

1)Sound pathway :

Sound waves from outside -----> ear pinna -----> external acoustic meatus ------> vibrates tympanic membrane/ ear drum -----------> enter middle ear ------> vibrations are transmitted through 3 ossicles malleus, incus and stapes ---------> oval window -------> cochlea of the inner ear ------> hair cells of organ of corti in cochlea gets stimulated--------------> stimulates cochlear branch of vestibulocochlear nerve

2)Auditory pathway :

AUDTTORY PATHWAY PRIMARY AUDĪTORY CORTEX > MEDIALGENIWLATE BODY >INFERIOR COLLICULUS LATERAL SUPERIOR OLIVARYNUCLEUS COCHLEAR NUCLEUS LENNIS uus VESTIBULO COCHLEAR NERVE ( CN vill )

Vestibulocochlear nerve enters cranium through internal acoustic meatus ------> enters brainstem at cerebellopontine angle ------> cochlear nucleus ------> superior olivary nucleus ------> fibres from both lateral lemniscus , cochlear nucleus and superior olivary nucleus ----------> reaches inferior colliculs ------> medial geniculate body in thalamus -------> superior temporal gyrus(primary auditory cortex) , right under the lateral fissure.