Year 9 Science, 3.3

In a reflex action, the __________ bypasses the ___________

• Motor neuron, brain

• Sensory neuron, brain

• Sensory neuron, spinal cord

• Motor neuron, spinal cord

A change in the external environment that initiates an impulse is known as a

• synapse

• response

• stimulus

• receptor

Effectors are best described as

• organs that interpret stimuli

• structures that respond to stimuli

• tissues that initiate stimuli

• cells that transmit stimuli

True or false:

A reflex signal must travel to the brain before a response to the stimulus can occur.

• True

• False

What is a reflex?

• an automatic movement in response to a stimulus

• the gap between neurons where chemical reactions occur

• the part of the brain responsible for involuntary movements

• a muscle memory

Which is a correct route of an impulse in a reflex arc?

• receptor → sensory neuron →interneuron → motor neuron → effector

• effector → receptor→ motor neuron →sensory neuron → interneuron

• sensory neuron → effector → motor neuron → receptor → interneuron

• motor neuron → sensory neuron →interneuron → effector

In a reflex arc, the sensory neuron leads to the ___________ and the motor neuron leads to the __________

• Spinal cord, CNS

• CNS, muscle

• Spinal cord, muscle

• Muscle, CNS

What happens in the spinal cord during a reflex arc?

• The stimulus causes a sensory neuron to generate a nerve impulse

• The nerve impulse carries a signal to be directly sent to a sensory neuron

• The motor neuron causes a contraction

• The nerve impulse carries a signal to be directly sent to a motor neuron

If you pick up a hot plate _____________ receptors in your ___________ detect this change

• Sensory, skin

• Sensory, muscle

• Motor, skin

• Intermediate, muscle

Tags

NGSS.MS-LS1-8

Receives message from CNS about how an muscle or gland ought to react in response to an object, event, or person.

• Stimulus

• Effector

• Sensory Neuron

• Motor Neuron

• Interneuron