Anatomy of Auditory and Visual Pathways Flashcards
Label the diagram of the inner ear
How many turns do the conical spirals of the cochlea feature?
2.5 turns
Describe the spiral ganglion
The spiral ganglion is a group of bipolar neurons stimulated by hair cells whihc carries action potentials from organ of Corti to cochlear nuclei in the pons
Label the vestibulocochlear nerve
Label the pathway of auditory stimuli
Describe the pathway of auditory stimuli
Superior olivary nucleus and nucleus of lateral lemniscus are important in sound localization and as relays for stapedial and tensor tympany reflexes.
Superior to the cochlear nuclei some fibres are crossed and some are not, therefore input above this level is essentially bilateral.
How is the primary auditory cortex organised?
Fibres carrying information regarding low frequency sound end in the anterolateral part of the auditory cortex.
Fibres carrying information regarding high frequency sound end in the posteromedial part of the auditory cortex.
Tonotopic Organization is Present in the Auditory Cortex
Describe clinical signs of damage to Broca’s area (BA 44, 45)
Broca’s Aphasia
Patient’s have difficulty in producing language, often using few words and only saying the most important words in a sentence. They do not usually have difficulty comprehending language.
Termed: Broca’s, motor or expressive
aphasia.
Describe clinical signs of damage to Wernicke’s Area (BA 22)
Wernicke’s Aphasia
Patient’s have difficulty comprehending language. These patients can manifest defects ranging from words out of order to meaningless words. Termed: Wernicke’s, sensory or receptive aphasia.
The coordination of the body’s positional equalibrium requires what inputs?
Maintenance of equilibrium uses information from:
- Vision
- Proprioception
- The Vestibular Apparatus (Labyrinth
Why is there no primary vestibular cortex?
The projection of vestibular information onto the cerebral cortex is bilateral and is less well defined than for other senses.
There is no agreed region of brain that is activated exclusively by vestibular stimulation (i.e. no primary vestibular cortex).
Where are the cortex areas assoicated with vestibular input processing?
- An area of the parietal cortex just posterior to the area of the postcentral gyrus that represents the hand and mouth.
- An area just rostral to the primary auditory cortex.
- Posterior insular cortex
Label the basic anatomy of the eye
Label the cells of the retina
Label the visual pathway
