2.3.3 Reflex Actions

• Reflex actions involve conscious planning.

  False
• The reflex arc involves the spinal cord and not the brain.
• Match the feature with the type of action:

  Speed ↔️ Reflex action

  Thought process ↔️ Conscious action

  Pathway ↔️ Spinal cord and reflex arc

  Example ↔️ Pulling hand from hot stove
• Reflex actions are conscious responses to stimuli.

  False
• Match the neurone type with its role in the reflex arc:

  Sensory neurone ↔️ Transmits signal from receptor to spinal cord

  Relay neurone ↔️ Connects sensory to motor neurone in spinal cord

  Motor neurone ↔️ Carries signal from spinal cord to effector
• The relay neurone connects the sensory neurone to the motor neurone within the spinal cord.
• What are synapses in the context of reflex transmission?

  Junctions between neurons
• Motor neurons cause muscles to contract, allowing you to pull your hand away from a hot stove.

  True
• Steps in a reflex arc

  1️⃣ Receptor detects stimulus

  2️⃣ Sensory neurone transmits signal

  3️⃣ Relay neurone connects sensory and motor neurones

  4️⃣ Motor neurone carries signal to effector

  5️⃣ Effector produces response
• The sensory neurone transmits the signal from the receptor to the spinal cord.
• What is the role of the sensory neurone in a reflex arc?

  Transmits signal from receptor
• An effector in a reflex action is a muscle or gland
• Match the neuron type with its role in a reflex arc:

  Sensory neuron ↔️ Transmits signal from receptor to spinal cord

  Relay neuron ↔️ Connects sensory to motor neuron

  Motor neuron ↔️ Carries signal to effector
• Neurons communicate without direct contact at synapses.

  True
• Match the type of reflex with its function and example:

  Protective ↔️ Prevents injury; withdrawing from heat

  Homeostatic ↔️ Maintains internal stability; regulating blood pressure
• What is the pathway taken by reflex actions called?

  Reflex arc
• What are reflex actions defined as?

  Rapid, automatic responses
• Match the component of the reflex arc with its function:

  Receptor ↔️ Detects the stimulus

  Sensory neurone ↔️ Transmits signal to spinal cord

  Relay neurone ↔️ Connects sensory to motor neurone

  Motor neurone ↔️ Carries signal to effector

  Effector ↔️ Produces the response
• Conscious actions involve the brain, while reflex actions do not.


  True
• Where does the sensory neurone transmit the signal from the receptor?

  Spinal cord
• What is the role of the sensory neurone in a reflex arc?

  Transmits signal from receptor
• What is the role of a relay neurone in a reflex arc?

  Connects sensory to motor neurone
• Why does the reflex arc allow the body to react quickly to stimuli?

  Bypasses the brain
• When an action potential reaches the presynaptic neuron, it triggers the release of neurotransmitters into the synaptic cleft.
• What are reflex actions in biological terms?

  Automatic responses to stimuli
• Reflex actions are slower than conscious actions due to the complexity of the pathway.

  False
• The motor neurone carries the signal from the spinal cord to the effector.

  True
• The relay neurone connects the sensory neurone to the motor neurone within the spinal cord.
• What is the purpose of the reflex arc in the body?

  React quickly to stimuli
• Order the steps in synaptic transmission during a reflex action:

  1️⃣ Action potential reaches presynaptic neuron

  2️⃣ Neurotransmitters released into synaptic cleft

  3️⃣ Neurotransmitters bind to receptors on postsynaptic neuron

  4️⃣ New action potential generated on postsynaptic neuron
• Why are synapses essential for reflex actions?

  Ensure rapid and precise communication
• Which part of the nervous system coordinates reflex actions?

  Spinal cord
• Reflex actions occur through a pathway called the reflex arc.
• What is the typical speed of a reflex action compared to a conscious action?

  Rapid
• What is the pathway of a reflex arc?

  Receptor > Sensory neurone > Relay neurone > Motor neurone > Effector
• The reflex arc allows the body to react quickly without involving the brain.
• The relay neurone connects the sensory neurone to the motor neurone within the spinal cord.
• The motor neurone carries the signal from the spinal cord to the effector.

  True
• Match the neurone type with its role in the reflex arc:

  Sensory neurone ↔️ Transmits signal from receptor to spinal cord

  Relay neurone ↔️ Connects sensory to motor neurone in spinal cord

  Motor neurone ↔️ Carries signal from spinal cord to effector
• Steps in synaptic transmission

  1️⃣ Action potential reaches presynaptic neuron

  2️⃣ Neurotransmitters released into synaptic cleft

  3️⃣ Neurotransmitters bind to receptors on postsynaptic neuron

  4️⃣ New action potential generated on postsynaptic neuron