The thalamus is primarily involved in relaying afferent information to the brain. CSF surrounds the brain, but not the spinal cord. The stretch reflex is an example of a monosynaptic reflex. The hypothalamus is primarily involved in control of locomotion. The membrane potential can be calculated by the Goldman equation.
Temporal summation involves the activation of multiple sensory nerve fibers.
Facilitated diffusion can move a solute against its concentration gradient. Reciprocal inhibition of a muscle will involve at least 2 synapses.