Consider the following statements: Touching a flame is an urgent and dangerous situation and we drag our hands involuntarily. This fast reaction is attributable to which of the following structures of the nervous system? 1. Spinal Cord 2. Motor Neuron 3. Brain 4. Sensory neuron How many of the statement given above are correct?

When you touch a flame, the following structures of the nervous system are involved in processing the sensory information and initiating a response:

Structures of the Nervous System Affected

Sensory Receptors

• Location: In the skin, specifically in the dermis and epidermis.
• Function: Detect changes in temperature, pressure, and pain. For touching a flame, thermoreceptors (temperature-sensitive receptors) and nociceptors (pain receptors) are primarily activated.

Sensory Neurons

• Location: These neurons transmit sensory information from the receptors in the skin to the central nervous system (CNS).
• Function: Carry the signal from the sensory receptors to the spinal cord and brain.

Spinal Cord

• Function: Acts as a relay station for sensory information coming from the body and a place where reflexes can be processed. For a quick reflex action, the spinal cord processes the information almost instantaneously.

Brain

• Thalamus: Acts as a relay station, processing sensory signals and directing them to appropriate areas of the brain.
• Somatosensory Cortex: Located in the parietal lobe of the brain, this area is responsible for interpreting sensory information related to touch, temperature, and pain.
• Motor Cortex: Sends out signals to muscles to react to the sensation, such as pulling your hand away from the flame.

Motor Neurons

• Function: Transmit signals from the brain or spinal cord to muscles to initiate a physical response, such as withdrawing your hand from the flame.
• Hence the correct answer is 1, 2, 3 and 4.