5.2.2 Reflex Actions

• Reflex actions are controlled by the spinal cord and the autonomic nervous system.
• Voluntary actions are controlled by the brain.


  True
• Steps in the neural pathway of a reflex arc

  1️⃣ Receptor detects stimulus

  2️⃣ Sensory neuron carries signal to spinal cord

  3️⃣ Relay neuron transmits signal

  4️⃣ Motor neuron carries signal to effector

  5️⃣ Effector responds to produce reflex
• Which neuron carries the electrical signal from the receptor to the spinal cord?

  Sensory neuron
• Steps in the path of a nerve impulse in the reflex arc

  1️⃣ Receptor detects stimulus and converts it into an electrical signal

  2️⃣ Sensory neuron carries the signal to the spinal cord

  3️⃣ Relay neuron receives the signal in the spinal cord

  4️⃣ Motor neuron carries the signal to the effector

  5️⃣ Effector responds to the signal
• Match the component of a reflex arc with its role:

  Sensory neuron ↔️ Carries signal to spinal cord

  Interneuron (Relay neuron) ↔️ Transmits signal to motor neuron

  Motor neuron ↔️ Carries signal to effector

  Effector ↔️ Produces reflex action
• What system controls reflex actions?

  Spinal cord and autonomic nervous system
• Sensory neurons transmit electrical signals from receptors to the spinal cord
• What allows the body to respond quickly to stimuli without conscious thought?

  Reflex actions
• What type of reflex actions are controlled by the brainstem and involve skeletal muscle movements?

  Somatic reflex actions
• Sneezing is an example of an autonomic reflex action.

  False
• Examples of reflex actions include the knee-jerk reaction and pupil dilation.
• What is an example of a voluntary action?

  Deciding to walk
• The relay neuron transmits the electrical signal to the motor neuron in the reflex arc.


  True
• The effector in a reflex arc responds to the motor neuron signal by producing the reflex action
• Receptors in a reflex arc detect a stimulus and convert it into an electrical signal
• Reflex actions are automatic and rapid
• Steps in the path of a nerve impulse in the reflex arc

  1️⃣ Receptor detects stimulus and converts it into an electrical signal

  2️⃣ Sensory neuron carries the signal to the spinal cord

  3️⃣ Relay neuron receives the signal in the spinal cord

  4️⃣ Motor neuron carries the signal to the effector

  5️⃣ Effector responds to the signal
• The motor neuron carries the signal from the spinal cord to the effector
• Effectors respond to motor neuron signals by producing the reflex action.

  True
• Match the type of reflex action with its nervous system and example:

  Somatic Reflex Actions ↔️ Brainstem, Withdrawal reflex

  Autonomic Reflex Actions ↔️ Autonomic nervous system, Heart rate
• The pupil dilates in response to low light levels due to the autonomic nervous system
• Which type of action is blinking to clear dust from your eyes?

  Voluntary action
• Match the characteristic with the correct type of action:

  Automatic, rapid response ↔️ Reflex Actions

  Conscious, deliberate response ↔️ Voluntary Actions
• Voluntary actions are controlled by the brain and involve conscious thought.


  True
• Reflex actions are controlled by the spinal cord.
• The receptor in a reflex arc detects the stimulus and converts it into an electrical signal.
• What is the role of a motor neuron in a reflex arc?

  Sends signals to the effector
• Reflex actions involve conscious thought

  False
• What is another name for relay neurons in a reflex arc?

  Interneurons
• Match the type of action with its description:

  Reflex action ↔️ Automatic, rapid response

  Voluntary action ↔️ Conscious, deliberate response
• Steps in the reflex arc of a motor neuron signal

  1️⃣ Relay neuron receives signal

  2️⃣ Signal is transmitted to motor neuron

  3️⃣ Motor neuron carries signal to effector

  4️⃣ Effector produces reflex action
• Sensory neurons carry electrical signals from receptors to the spinal cord
• Autonomic reflex actions regulate involuntary functions via the autonomic nervous system
• What happens during the knee-jerk reaction when the patellar tendon is tapped?

  Quadriceps muscle contracts
• Contrast the key differences between reflex actions and voluntary actions:

  1️⃣ Reflex actions are rapid, automatic responses

  2️⃣ Reflex actions bypass the brain

  3️⃣ Voluntary actions involve conscious thought

  4️⃣ Voluntary actions are controlled by the brain
• What controls voluntary actions in the body?

  The brain
• Voluntary actions involve conscious thought and control by the brain.


  True
• Reflex actions are controlled by the spinal cord
• Voluntary actions are controlled by the spinal cord.

  False