Physiology VI: Sensory Transduction - Auditory and Vestibular Systems

Sound frequency is measured in [blank_start]Hertz[blank_end]

Name the bones of the middle ear from superficial to deep [blank_start]Malleus[blank_end] [blank_start]Incus[blank_end] [blank_start]Stapes[blank_end]

[blank_start]Tensor Tympani[blank_end]: Reduces the noise of loud sounds such as chewing or shouting [blank_start]Stapedius[blank_end]: Dampens vibrations of one of the ossicles to control the amplitude of sound waves being projected into the inner ear

The Stapes bone connected to the inner ear via the [blank_start]oval[blank_end] window

Label the anatomy of the cochlea.

[blank_start]Reissner's[blank_end] Membrane separates the scala vestibuli from the scala media The [blank_start]Basilar[blank_end] Membrane separates the scala media from the scala tympani

Scala vestibuli meets [blank_start]oval[blank_end] window Scala tympani meets [blank_start]round[blank_end] window

The point at which scala vestibuli meets scala tympani is called the [blank_start]helicotrema[blank_end]

The group of nerve cells in the cochlea that serve the sense of hearing by sending a representation of sound from the cochlea to the brain is called the [blank_start]spiral ganglion[blank_end]

The Organ of Corti contains two types of hair cells, inner and outer. [blank_start]Inner Hair Cells[blank_end] are primarily a source of afferent signals in the cochlear nerve. [blank_start]Outer Hair Cells[blank_end] primarily receive efferent outputs from the CNS to control hair stiffness and amplify membrane vibration

The membrane between the scala vestibuli and the organ of corti is called the [blank_start]tectorial[blank_end] membrane.

In regard to the auditory pathway, the Thalamic relay between the Inferior Colliculus and the Primary Auditory Cortex is via the [blank_start]Medial Geniculate[blank_end] Nucleus

Which of the following coloured areas of the brain shows the Primary Auditory Cortex?

The lateral and medial [blank_start]superior[blank_end] [blank_start]olivary[blank_end] nuclei are responsible for locating a sound in space

Fill in the the Central Auditory Pathway, from the cochlea to the primary auditory cortex: Cochlea [blank_start]Cochlear Nerve[blank_end] [blank_start]Vestibulocochlear Nerve[blank_end] [blank_start]Medial/Lateral Superior Olivary Nuclei[blank_end] [blank_start]Inferior Colliculus[blank_end] [blank_start]Medial Geniculate Nucleus[blank_end] Primary Auditory Cortex

The function of the vestibular organ is to establish an individual's orientation in the world (which way am I going, which was is up, etc). It does this by measuring acceleration. Head angular acceleration is measured by the [blank_start]semicircular canals[blank_end] Head linear acceleration is measured by the [blank_start]saccule and utricle[blank_end]

Which vestibular organ(s) detects rotational motion of the head?

Label the semicircular canal and its contents shown below.

In terms of the otolith organs: The [blank_start]Saccule[blank_end] detects movement in the vertical (sagittal) plane The [blank_start]Utricle[blank_end] detects movement in the horizontal plane

The otoconia are small crystals which lie on the otolithic membrane dictate the movement of the cilia of the otolithic hair cells. What chemical substance are these otoconia crystals made of? [blank_start]Calcium Carbonate[blank_end]

Each otolith organ (saccule & utricle) contains a central dividing line that separates it into two halves, each side with opposing polarity to the other. This allows each otolith organ to have multidirectional sensitivity (e.g. utricle can detect left and right). This dividing line is known as the [blank_start]Striola[blank_end].

Vestibular Reflexes: [blank_start]Vestibulo-ocular Reflex[blank_end] - Keeps eyes still while the head moves [blank_start]Vestibulo-colic Reflex[blank_end] - Keeps the head still in space while you walk [blank_start]Vestibulo-spinal Reflex[blank_end] - Adjusts posture for rapid changes in position