Practical

Question 1

Muscle spindle innervation; fibres running to all intrafusal fibres in central range.

Answer 1

Group 1a fibres

Question 2

Muscle spindle innervation; fibres running to all intrafusal fibres not to central region.

Answer 2

Group II fibres. Little innervation to dynamic nuclear fibres.

Question 3

Gamma fibres. Not to central region.

Answer 3

y(d) lead to dynamic bag fibres. y(s) fibres innervate static nuclear bag fibres and chain fibres.

Question 4

alpha fibre innervation

Answer 4

a motor neurons to intrafusal fibres are called B fibres.

Question 5

Waves in Hoffman’s reflex

Answer 5

First M wave (efferent fibres)

Second H wave (afferent fibres)

Question 6

Length of spindle

Answer 6

5-10mm

Question 7

Fibres in spindle

Answer 7

2 or 3 bag fibres, 2-10 chain fibres.

Question 8

Refractive error

Answer 8

1/(focal length at far point) - 2D

Question 9

Range of accommodation

Answer 9

difference in refractive error between near and far points

Question 10

angle subtended = …

Answer 10

= 57 x 60 x s/d (to get in minute arcs.
= 57 x s/d to get in degrees
= s/d to get in radians.

Question 11

1 minute arc on retina

Answer 11

5 microns. A foveal cone has a diameter of 2.5 microns.

Question 12

dB SPL =

Answer 12

20log10 (pressure/2x10 to the -5)

Question 13

dB =

Answer 13

20log10(A/B)