Nervous.

Encephal/o refers to the brain. Encephalitis is inflammation of the brain. Myel/o refers to the spinal cord (and also bone marrow). Myelitis is inflammation of the spinal cord. Neur/o refers to nerves. Oste/o refers to bone.

The synapse is the gap between neurons. Impulses travel from one neuron to another through the release of neurotransmitters into the synapse. The dendrite, cell body, and axon are all parts of a neuron. Impulses begin at the dendrite, travel to the cell body, and down the axon.

Ependymal cells are glial cells that produce cerebrospinal fluid (CSF). Astrocytes provide nutrients to neurons. Microglia are phagocytes that engulf debris. Neurons transmit impulses, and they are not glial cells.

The medulla is part of the brainstem. It connects the brain to the spinal cord and contains centers regulating heart rate and respiration. The hypothalamus is deep within the brain and controls many biological processes. The cerebellum is at the back of the brain and helps with coordination. The pituitary gland is an endocrine gland below the hypothalamus.

The meninges cover and protect the brain and spinal cord. They have three layers, and the outermost is the dura mater. The arachnoid mater is the middle layer, between the pia and dura. The pia mater is the innermost layer. Astrocytes are glial cells found within the brain and spinal cord, not part of the meninges.

Glosso- refers to the tongue. The hypoglossal nerve is the 12th cranial nerve and controls tongue movement. The oculomotor nerve (CN III) helps with eye movement. The vestibulocochlear nerve (CN VIII) helps with hearing. The trigeminal nerve (CN V) handles facial sensations.

Lumbar puncture (also called a spinal tap) is a procedure where a needle is inserted between two lumbar vertebrae to collect cerebrospinal fluid. A CT scan is an imaging procedure. An electroencephalogram (EEG) records electrical activity of the brain. Neuralgia is nerve pain (-algia = pain), not a procedure.

Paresis means weakness and hemi means half. Hemiparesis is weakness of one side of the body. For example, right hemiparesis means weakness of the right arm and leg. Plegia means paralysis, while paresis means weakness. Paraplegia is paralysis of both legs. Paraparesis is weakness of both legs. Hemiplegia is complete paralysis (not just weakness) of one side of the body.

A stroke is a brain injury from a vascular cause, either blockage or rupture of a blood vessel. It is also called a cerebrovascular accident (CVA). Multiple sclerosis is caused by damage to the myelin sheath covering nerves. Cerebral contusion is traumatic bruising of the brain. Parkinson's disease is a movement disorder caused by loss of dopamine-producing neurons.