PRACTICE QUESTIONS

1. The receptor organ detecting rotary acceleration and deceleration of the head is located in the:

a. Utricle

b. Saccule

c. Ampulla of the semicircular duct

d. Scala media of the cochlea

e.

2. Which two of the following are not generally associated with the macula?

a. Otoliths

b. CupuIa

c. Detection of linear acceleration of the head

d. Hair cells

e. Normal nystagmus

3. You are presented with a dog with a head tilt, com­pulsive circling, and spontaneous nystagmus. The most likely site of this dog's pathological lesion is the:

a. Oculomotor nucleus

b. Cerebral cortex

c. Vcstibular system

d. Orvical spinal cord

e. Spinal accessory (eleventh cranial) nerve

4. Which one of the following statements is false?

a. All hair cells of a single utricle are oriented in the same direction with respect to their cilia.

b. In a single vestibular hair cell, displacement of the cilia toward the largest cilium increases the firing rate of the hair cells associated sensory neuron.

c. The axons of sensory neurons Synaptically associated with vestibular hair cells form the eighth cranial nerve.

d. A gelatinous layer is associated with the vestibular macula.

e. The vestibular nuclear complex is located in the brainstem.

5. If a normal dog is sitting on a piano stool and I start to spin (accelerate) the stool to the right, which two of the following will be false regarding the observed nystagmus?

a. The pattern of nystagmus observed at the start of rotation will be seen in reverse briefly after the spinning is abruptly stopped.

b. An intact medial longitudinal fasciculus (MLF) is important for producing the nystagmus.

c. The nystagmus will continue long after constant velocity is achieved.

d. The eyes will drift slowly to the left, as far as they can go, and then flip rapidly back to the right.

e. Nystagmus will often be observed long after the spinning has stopped, while the dog is stationary.