Q. What is bathing in Cerebro-Spinal Fluid?
The CNS is bathing in Cerebro-Spinal Fluid (or CSF): similar to plasma, less protein, rich in ascorbic acid, different in ions Na+ and K+). If RBCs may indicate meningitis, tumors, MS, ... (spinal tap).
The Blood Brain barrier (BBB): no other organ is so dependent on exactly maintaining a constant environment than the brain. The BBB refers to the fact that cerebral capillaries are least permeable in body. Only water, amino acids, sugar can freely go in.
Cranial Nerves: 12 pairs primarily serving the head and neck. Described by name, number, course, and function. These include sensory and motor functions.
Spinal Nerves: 31 pairs. Named for the region of the cord from which they arise. Each spinal nerve divides into dorsal and ventral branches (or ramifications).