Semicircular canals of inner ear

SEMICIRCULAR CANALS OF INNER EAR

Q. 1

Semicircular canal perceives ___________

 A

Linear acceleration

 B

Angular acceleration

 C

Both

 D

None

Q. 1

Semicircular canal perceives ___________

 A

Linear acceleration

 B

Angular acceleration

 C

Both

 D

None

Ans. B

Explanation:

 

They respond to angular acceleration and deceleration.

The three canals lie at right angles to each other but the one which lies at right angles to the axis of rotation is stimulated the most.

Thus horizontal canal will respond maximum to rotation on the vertical axis and so on.

Due to this arrangement of the three canals in three different planes, any change in position of head can be detected.


Q. 2

Which of the following structures is responsible for detecting rotational acceleration?

 A

Cochlea

 B

Fovea centralis

 C

Saccule

 D

Semicircular canals

Q. 2

Which of the following structures is responsible for detecting rotational acceleration?

 A

Cochlea

 B

Fovea centralis

 C

Saccule

 D

Semicircular canals

Ans. D

Explanation:

The semicircular canals are responsible for detecting rotational acceleration. As the head is rotated, fluid currents in the endolymph cause the deflection of the cupula and stimulate its hair cells. The magnitude of the fluid currents is proportional to the rotational acceleration, and the direction is related to the direction of the acceleration.

The cochlea is the inner ear structure in which the mechanical energy of sound waves is transduced into neural impulses.
 
The fovea centralis is the location on the retina responsible for most color vision. The saccule and utricle are inner ear structures that detect linear acceleration.

Q. 3

Arcuate eminence of the petrous temporal bone is caused by :

 A

Superior semicircular canal

 B

Posterior semicircular canal

 C

Lateral semicircular canal

 D

Cochlea

Q. 3

Arcuate eminence of the petrous temporal bone is caused by :

 A

Superior semicircular canal

 B

Posterior semicircular canal

 C

Lateral semicircular canal

 D

Cochlea

Ans. A

Explanation:

A i.e. Superior Semicircular Canal;


Q. 4

Horizontal semicircular canal is

 A

Anterior

 B

Superior

 C

Posterior

 D

Lateral

Q. 4

Horizontal semicircular canal is

 A

Anterior

 B

Superior

 C

Posterior

 D

Lateral

Ans. D

Explanation:

D i.e Lateral


Q. 5

Crus commune is a part of:

 A

Cochlea

 B

Middle ear

 C

Semi circular canal

 D

Vestibule

Q. 5

Crus commune is a part of:

 A

Cochlea

 B

Middle ear

 C

Semi circular canal

 D

Vestibule

Ans. C

Explanation:

 

Semicircular Canals

  • There are 3 semicircular canals – the lateral, posterior and superior which lie in a plane of right angles to one another
  • Each canal has an ampullated end which opens independently into the vestibule and a non ampullated end
  • The non-ampullated ends of posterior and superior canals unite to form a common channel called the crus commune.
  • So the three canals open into the vestibule by 5 openings.

 

 

Q. 6

Semicircular canals are stimulated by:

 A

Gravity

 B

Linear acceleration

 C

Rotation

 D

Sound

Q. 6

Semicircular canals are stimulated by:

 A

Gravity

 B

Linear acceleration

 C

Rotation

 D

Sound

Ans. C

Explanation:

Q. 7

Horizontal semicircular canal responds to:

 A

Horizontal acceleration 

 B

Rotational acceleration

 C

Gravity

 D

Anteroposterior acceleration

Q. 7

Horizontal semicircular canal responds to:

 A

Horizontal acceleration 

 B

Rotational acceleration

 C

Gravity

 D

Anteroposterior acceleration

Ans. B

Explanation:

Q. 8

Angular movements are sensed by:

 A

Cochlea

 B

Saccule

 C

Utricle

 D

Semicircular canals

Q. 8

Angular movements are sensed by:

 A

Cochlea

 B

Saccule

 C

Utricle

 D

Semicircular canals

Ans. D

Explanation:

Q. 9

True about semicircular canals is:         

September 2005

 A

Submerged in a fluid called endolymph

 B

Base of cupula is in close contact with afferent fibres of cochlear division of the eight cranial nerve

 C

Arranged at right angles to each other

 D

Associated with hearing

Q. 9

True about semicircular canals is:         

September 2005

 A

Submerged in a fluid called endolymph

 B

Base of cupula is in close contact with afferent fibres of cochlear division of the eight cranial nerve

 C

Arranged at right angles to each other

 D

Associated with hearing

Ans. C

Explanation:

Ans. C: Arranged at right angles to each other

3 semicircular canals in each vestibular apparatus known as anterior, posterior and lateral (horizontal) semicircular canals. They are arranged at right angles to each other.

They are filled with endolymph

Base of cupula is in close contact with afferent fibers of vestibular division of the eight cranial nerve



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