Special Senses Flashcards
Which neurotransmitter do cells of the inner ear release, in order to cause an AP to fire?
Glutamate
When a K+ channel opens in the hair cells of the inner ear, what happens?
The K+ moves into the cell
Complete the sentence: the labyrinth has a ? exterior, what a smaller but similarly shaped ? labyrinth within it
Bony / membranous
What type of fluid fills the space between the bony and membranous labyrinths? What is this composed of?
Perilymph - plasma and CSF
The membranous labyrinth is filled with what type of fluid? What differentiates this from the fluid found between the bony and membranous labyrinths?
Endolymph / it has a higher K+ concentration
Sound causes vibration of the air, which in turn causes vibration of which structures?
The tympanic membrane and the ossicles (malleus, incus, stapes)
What structures in the inner ear work to attenuate the movement of the tympanic membrane and stapes respectively to protect against excessive noise damage?
Tensor tympani and stapedius muscles
Complete the sentence: vibration of the cochlea causes movement of the ? situated within an endolymph filled spiral organ, the ?, within the cochlea
Basilar membrane / Organ of Corti
Where in the inner ear is vibration of air converted to movement/vibration of fluid?
In the cochlea
Complete the sentence: vibration of fluid within the cochlea causes the ? within the Organ of Corti to bend against the ? which results in ?, generating an AP
Cilia of hair cells / tectorial membrane / depolarisation
After an action potential is generated in the Organ of Corti, what happens?
Physical vibration is converted into neural energy, and the AP is carried along the auditory nerve (part of CNVIII)
From the auditory nerve (part of CNVIII), information is passed into where?
The auditory cortex in the temporal lobe
Which structure of the inner ear can discriminate between different pitches?
Basilar membrane
The hair cells within the Organ of Corti are actually what?
Auditory receptors with stereocilia
What happens when the Organ of Corti is displaced?
The hair cells are displaced, resulting in the opening of K+ channels and the release of glutamate
Complete the sentence: the neurotransmitter released from the hair cells of the Organ of Corti are captured in nerve fibres which synapse on ? neurones with their cell bodies in the ?
Bipolar / spiral ganglion
The more hair cells in the Organ of Corti bend, the more they what?
Fire APs
Complete the sentence: the ? hair cells in the auditory system are more numerous and can be known as the ?
Outer / cochlear amplifier
Sensory afferents travelling in CNVIII project to which nuclei in the brainstem?
Cochlear and olivatory nuclei
After reaching the cochlear and olivatory nuclei, sensory afferents in CNVIII travel via where to where?
Inferior colliculus and thalamus / medial geniculate body
Where are the final destinations of sensory afferents in CNVIII?
Auditory cortex and association areas in the sensory cortex
What happens to right and left ear information at the brainstem?
The information is mixed
Which structure(s) of the vestibular system are responsible for detecting head angular acceleration, and hence head rotation?
The semicircular canals
Which structure(s) of the vestibular system are responsible for detecting head linear acceleration, and hence translational motion and gravity (tilt)?
Saccule and utricle
