W03_01 Motor Control 1: Spinal Reflexes

Question 1

what are the receptors for muscle stretch called?

Answer 1

muscle spindle

Question 2

describe the pathway for muscle stretch response

Answer 2

muscle spindles stretched;
send AP along Ia afferents (through DRG);
synapse onto alpha motoneuron (in ventral horn);
through ventral rami to innervate muscle

Question 3

which fibres maintain sensitivity when the spindle shortens?

Answer 3

intrafusal muscle

Question 4

how do you increase sensitivity of the spindle?

Answer 4

ask person to do jendrassik maneuvre

Question 5

which receptor is at the tendon/muscle interface?

Answer 5

golgi tendon organ

Question 6

what kind of nervous fibres are innervated by the golgi tendon organ?

Answer 6

afferent 1b

Question 7

how do golgi tendon organs work for sensing tension?

Answer 7

1b afferent axons run between collagen fibres.

Question 8

name the pathway for 1b afferents

Answer 8

golgi tendon organs;
Ib afferent; 
Ib interneuron (takes many inputs);
motor neuron;
muscle

Question 9

how does the withdrawal function work in legs, in response to a noxious stimulus?

Answer 9

affected foot flexes to withdraw;

opposite foot extends to support weight.

Question 10

the flexion reflex system is similar to which normal process?

Answer 10

walking; is part of the spinal locomotor generator

Question 11

what is reflex gain?

Answer 11

the process of strengthening reflexes to allow the body to adapt more quickly

Question 12

what is the stumble corrective response?

Answer 12

when a foot catches during the swing-through phase; opposite foot jumps to clear the hurdle