Sunkist Navel Orange (1 serving) 1  Calories: 80, Fat: 0g, Carbs: 21g, Protein: 1g. 2  Calories: 80, Fat: 0g, Carbs: 0g, Protein: 0g. 3  Calories: 100, Fat: 0g, Carbs: 21g, Protein: 1g. 4  Calories: 64, Fat: 0g, Carbs: 16g, Protein: 1g. 5  Calories: 0, Fat: 0g, Carbs: 0g, Protein: 0g. 6  Calories: 80, Fat: 0g, Carbs: 21g, Protein: 1g.
Cerebrospinal fluid (CSF) Cerebrospinal fluid (CSF), clear, colourless liquid that fills and surrounds the brain and the spinal cord and provides a mechanical barrier against shock. Formed primarily in the ventricles of the brain, the cerebrospinal fluid supports the brain and provides lubrication between surrounding bones and the brain and spinal cord. When an individual suffers a head injury, the fluid acts as a cushion, dulling the force by distributing its impact.
The brain is protected from bacterial invasion from the environment by the skull, the dura, the arachnoid membrane, the pia, and the glia limitans, which is a dense mesh of astrocytic processes on the surface of the brain. Consequently, most bacterial infections spread to the brain by the bloodstream.