Question

Match each cell type with the role that cell type plays in generating a stretch reflex.

1 extrafusal fiber

2 spindle stretch receptor

3 intrafusal fiber

4 alpha motor neuron

5 gamma motor neuron

A A muscle cell that can contract and generate force to move a body part

B an efferent neuron that fires to cause spindle stretch receptors to contract

C an efferent neuron that fires to cause intrafusal fibers to contract

D a muscle cell that serves

E a mechanoreceptive sensory neuron that fires faster the more its cell membrane is stretched/deformed

Answer 1

A. A muscle cell that can contract and generate force to move a body part - extrafusal fibres.

Extrafusal fibres are skeletal fibres which are responsible for force generation and muscle contraction .

B. an efferent neuron that fires to cause spindle stretch receptors to contract- alpha motor neurons

Alpha motor neurons serve extrafusal fibre and brings stimulation for their contraction.

C. an efferent neuron that fires to cause intrafusal fibers to contract - gamma motor neuron

Gamma motor neuron serves intrafusal fibres which are located in the muscle spindle.

D. a muscle cell that serves - intrafusal fibre

Intrafusal fibre is found in skeletal muscle spindle and contains stretch receptors which detects change in the rate of length.

E. a mechanoreceptive sensory neuron that fires faster the more its cell membrane is stretched/deformed - spindle stretch receptor.

Spindle stretch receptor is a mechanoreceptors found in the body of muscle which detects change in the length of muscle fibres and responses accordingly