Question

Static equilibrium is maintained by
(a)Sacculus
(b)Utriculus
(c) Semicircular canals
(d)Both (a) & (b)

Answer 1

Hint: Static equilibrium happens when the bodies are at rest. It is caused when a solid object isn't moving because its influences are balanced. The sum of the forces acting on the bodies is zero in static equilibrium.

Complete answer:
Static equilibrium is maintained by sacculus and utriculus. The position of the head which permits the central nervous system to maintain stability and posture when the body and head are not moving. It is detected by mechanoreceptors which are present in the vestibule of the inner ear. The utricle and saccule are the receptors for static equilibrium. Saccule is smaller within the two membranous sacs. It contains a specialized mechanoreceptor and maculae for the detection of static equilibrium. The larger membrane sacs in the vestibule of the inner ear contain one utricle. It contains a specialized mechanoreceptor and maculae for the detection of static equilibrium.

Additional Information: Semicircular canals are interconnected tubes that are located in the innermost part of the ear, the inner ear. There are three semicircular canals which are horizontal, superior, and posterior. The Bony labyrinth consists of the semicircular canal at right angles from each other. The superior and posterior semicircular canals are placed vertically at right angles with each other. The movement of the head in different planes caused by the orientations of canals. The lateral semicircular canal and the horizontal planes make an angle of 30 degrees with each other. It detects angular acceleration of the head when it is turned and the superior posterior canals detect vertical head movements when it is moved up or down. For the rotatory movements, sensory inputs are provided by the semicircular canal or semicircular ducts. Endolymph is a fluid that is filled in each canal and contains motion sensors within it.
So, the correct answer is 'Both (a) & (b)'.

Note: Jean Pierre Flourens noted that the pigeons continue to fly in a circle by destroying the horizontal semicircular canal of pigeons. He does so to show the purpose of semicircular canals. The inner ear is responsible for hearing and balance. The innermost part of the ear is the cochlea which is about the size of a pea.