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Science for Medicine > Reflexes > Flashcards

Flashcards in Reflexes Deck (14)
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1
Q

What are spinal reflexes simple building blocks for?

A

Movement

2
Q

What is the simplest reflex?

A

Stretch

3
Q

What follows a stretch reflex?

A

A sharp tap to the inelastic tendon, allowing muscle fibres to stretch.

4
Q

Many spindle sensory afferents activate the ______ motoneuron pool to the muscle which was stretched.

A

Alpha

5
Q

How does the brain find out about length of muscles?

A

Spindle afferent information being sent through the somatosensory cortex.

6
Q

What causes the inverse stretch reflex?

A

Afferent nerves from the golgi tendon organs.

7
Q

In the golgi-tendon organ reflex, the agonist muscle is ______ and the antagonist muscle is ______.

A

Inhibited, excited.

8
Q

What does the golgi tendon organ prevent?

A

Muscles contracting so hard the tendon insertion is torn from the bone.

9
Q

What do flexor reflexes use information from?

A

Pain receptors

10
Q

What happens during flexor reflexes if the limb is moved away and that’s it?

A

Nothing

11
Q

How do we prevent nothing happening during flexor reflexes?

A

Excitatory interneurons excite the contralateral extensors, inhibiting the contralateral flexors allowing sensory information to the brain

12
Q

Can reflexes be over-ridden?

A

Yes

13
Q

How is a stretch reflex overridden?

A

There is a strong inhibition which hyperpolarizes alpha motoneurons.

14
Q

What can cause muscles to become extremely resistant to stretch?

A

High gamma motoneuron activation of muscle spindles.