Q. Differentiate between• Motor neuron and sensory neuron• Endorphins and enkaphalins• CNS and PNS• Sympathetic and parasympathetic systems• Peptide and small molecule neurotransmitters

Sure, here are the differences:

1. Motor Neuron and Sensory Neuron:

   • Motor neurons carry signals from the central nervous system to the outer parts (muscles, skin, glands) of your body.
   • Sensory neurons carry signals from the outer parts of your body (like your skin) to the central nervous system.

2. Endorphins and Enkephalins:

   • Endorphins are neurotransmitters found in the pituitary gland, which are known to alleviate pain and induce feelings of pleasure or euphoria.
   • Enkephalins are pentapeptides involved in regulating nociception in the body. They are found in the brain and spinal cord and are similar to endorphins, and are also involved in pain reduction and body's response to stress.

3. CNS and PNS:

   • The Central Nervous System (CNS) consists of the brain and spinal cord.
   • The Peripheral Nervous System (PNS) consists of all the other neural elements, including the eyes, ears, skin, and other "sensory receptors".

4. Sympathetic and Parasympathetic Systems:

   • The sympathetic nervous system prepares the body for the "fight or flight" response during any potential danger.
   • On the other hand, the parasympathetic nervous system inhibits the body from overworking and restores the body to a calm and composed state.

5. Peptide and Small Molecule Neurotransmitters:

   • Peptide neurotransmitters are a small protein composed of amino acids, and they are involved in a wide range of brain functions, including analgesia and reward.
   • Small molecule neurotransmitters are low molecular weight organic compounds, and they include amino acids, amines, and purines. They are involved in fast synaptic transmission.