Hearing Pt 3

Question 1

Where does sense of gravity and acceleration come from?

Answer 1

From hair cells in the vestibulae

Question 2

Where does sense of rotation come from?

Answer 2

From the semicircular canals

Question 3

What us equilibrium?

Answer 3

Sensation provided by receptors of the vestibular complex

Question 4

What do the saccule and utricle convey information on?

Answer 4

Position with respects to gravity

Question 5

What do hair cells do?

Answer 5

They provide information about direction and strength of mechanical stimuli

Question 6

What happens when you turn your head to the left?

Answer 6

Receptors in the semicircular canals are stimulated and tell you how rapid movement is and in which direction

Question 7

What happens when you tilt your head to the side?

Answer 7

The receptors in the semicircular canals report the angle involved and whether you tilt your head forward or backwards

Question 8

What does each semicircular duct contain?

Answer 8

The Ampulla which is a
An expanded region that contains the receptors
The region contains Crista which are hair cells which is bound to the cupula which is a gel like structure

Question 9

What is the cupula?

Answer 9

Is a structure in which the kinocilkia and sternocilla are embedded
It floats babove the receptor surface and when your head rotates In the plane of the duct.The movement of the endolymph along the length of the semicircular duct pushes the cupula to the side and distorts the receptor processes and movement of fluid in one direction stimulates hair cells and movement in opposite direction inhibits them and when the endolymph stop moving the elastic nature of cupula makes its return to its normal position

Question 10

What does horizontal rotation do?

Answer 10

It stimulates the hair cells of the lateral semicircular duct

Question 11

What does nodding yes do?

Answer 11

Excites the anterior semicircular duct

Question 12

What does tilting your head from side to side do?

Answer 12

It activates receptors in the posterior semicircular duct

Question 13

What does the utricle and saccule do?

Answer 13

They provide equilibrium sensations whether the body is moving or stationary and is connected with the endolymphatic duct which ends in the endolymphatic sac

Question 14

What is the Macula?

Answer 14

Oval structures where hair cells of the utricle and saccule are clustered and the hair cell processes are embedded in a gelatinous mass and the surface of the mass contain Statoconia

Question 15

What is Statoconia?

Answer 15

Densely packed carbonate crystals on the surface of the gelatinous mass and the Otolith is an ear stone which is made up of the gelatinous matrix and statoconia

Question 16

What is the Macula?

Answer 16

When your head is in normal upright position the statoconia sits at the top of the Macula and the weight presses on the Macula surface and pushes the hair cell processes down

Question 17

What are the pathways for equilibrium sensations?

Answer 17

Hair cells of vestibulae and semicircular duct are monitored by sensory neurons located in the adjacent vestibular ganglia and sensory fibers form the vestibular branch of the vestibulocochlear branch and the fibers innervate neurons within the pair of vestibular nuclei athe boundary between Pons and medulla

Question 18

What are the functions of the vestibular nuclei?

Answer 18

Send commands to motor nuclei in brain stem and spinal cord
Really info from vestibular complex to cerebral cortex
Relay information from vestibular complex to cerebellum
Integrate sensory information about balance and equilibrium from both sides of head

Question 19

What is Nystagmus?

Answer 19

Where eye movement occurs where body is stationary if either brain stem or internal eye is damaged
Where individuals have trouble controlling their eye movement

Question 20

What does the superior colliculi do?

Answer 20

It directs automatic movements of the eyes that occur in response to sensations of motions

Question 21

What does endolymph movement along the length of the duct do?

Answer 21

It moves the cupula and stimulates hair cells