1. Which part of the neuron is responsible for receiving signals? A. Axon B. Dendrite C. Soma D. Myelin Sheath Answer: B. Dendrite Rationale: Dendrites are tree-like extensions at the beginning of a neuron that help to increase the surface area of the cell body and are typically where signals are received from other neurons. 2. What is the primary function of the myelin sheath? A. To generate electrical impulses B. To receive neurotransmitters C. To protect and insulate axons D. To regulate ion concentrations Answer: C. To protect and insulate axons Rationale: The myelin sheath is a fatty layer that covers the axons of many neurons. It acts as an insulator to increase the speed at which electrical impulses propagate along the nerve cell. 3. Which structure is not part of the central nervous system? A. Brain B. Spinal Cord C. Ganglion D. Medulla Oblongata Answer: C. Ganglion Rationale: The central nervous system consists of the brain and spinal cord. A ganglion is a structure containing a number of nerve cell bodies, typically linked by synapses, and is part of the peripheral nervous system. 4. What type of cells form the blood-brain barrier? A. Astrocytes B. Oligodendrocytes C. Microglia D. Ependymal cells Answer: A. Astrocytes Rationale: Astrocytes are star-shaped glial cells in the brain and spinal