reflexes 3

Question 1

what type of sensory fibre are golgi tendon fibres composed of?

Answer 1

type IB fibres

Question 2

How do the type IB mechxnosensitive fibres detect change in the tendon tension?

Answer 2

collagen fibres surround the sensory fibres in a ‘scissor’ like way. when the tendon stretches, the collagen fibres compress onto the sensory fibres.

Question 3

what happens in terms of the action potential the sensory fibres produce when they are compressed by the collagen fibres?

Answer 3

the generator potentials are increased and signal frequency speeds up

Question 4

how does the golgi tendon organ inhibit the alpha motor neurone which is innervating the muscle?

Answer 4

it synapses on an inhibitory interneurone in the spinal cord which in turn inhibits the alpha motor neurone

Question 5

what is rotatory nystagmus?

Answer 5

eye movements (usually used by spinning) driven by moving visual images

Question 6

what is post rotatory nystagmus?

Answer 6

eye movements which occur after a movement, caused by disruption if the fluid in inner ear canals

Question 7

what reflex response is initiated by the sympathetic nervous system when alarmed or excited?

Answer 7

activation of radial muscles of the iris dilate the pupil.

Question 8

what type of neurons constrict the pupil?

Answer 8

parasympathetic neurons

Question 9

how do baroreceptors (activated by increased blood pressure) decrease blood pressure?

Answer 9

1. depress tonic sympathetic activity to arterioles, causing dilation
2. increase vagal activity to heart and decrease HR