The motor system lecture 22

Question 1

What are the two components of posture and balance?

Answer 1

Centre of mass needs to be over the base support

Question 2

What system controls posture?

Answer 2

Vestibular system

Question 3

What are the two main components of the vestibular system?

Answer 3

Semi-circular canals and Otilith organs

Question 4

What are the three semi-circular canals?

Answer 4

Anterior vertical, horizontal and posterior vertical

Question 5

What type of acceleration do the semi-circular canals detect?

Answer 5

angular acceleration like spinning

Question 6

What type of acceleration do the Otilith organs detect?

Answer 6

Linear acceleration

Question 7

What are the two Otilith organs?

Answer 7

Utricle and saccule

Question 8

Describe the structure of the Otilith organs

Answer 8

They have hair cells within their membrane which have cilia in a gelatinous matrix. On top of the matrix are crystals of calcium carbonate. When there is linear acceleration, the crystals inertia changes which deforms the matrix and moves the cilia. this is what is detected by the vestibular nerve axons

Question 9

Describe the semi-circular canals structure

Answer 9

The tube is filled with endolymph. In centre is the ampulla which contains the capula, has kinocilium inside attached to hair cells. When there is angular acceleration, the fluid makes the capula sway and moves the kinocilia- detected by hair cells and afferent vestibular nerve