Nervous System: The Brain

• Forebrain, midbrain, and Hindbrain
• Midbrain + Pons + Medulla = Brainstem
• Telencephalon = cerebrum

Bumps

Grooves

A major sulcus or groove

• Cell bodies + Dendrites = Gray Matter
• Outer portions of cortex and cerebellum
• Subcortical structures

Axons

Dura Mater, Subarachnoid Space, and Pia Mater

Tough outer covering; forms dural sinuses to drain blood from brain

Contains Cerebrospinal Fluid

Surrounds brain, penetrates sulci

• Ventricles contain cerebrospinal fluid
• Choroid plexus lining ventricles produces the CSP

• Choroid plexus produces 500 ml of CSF per day
• Nervous system can hold about 150 ml at any given time
• Constantly being produced and the drained into blood

Bouyancy, Protection and Chemical Stability (gets rid of metabolic waste, excess hormone and neurotransmitters)

• Allows removal of CSF
• CSF analyzed for protein content, glucose levels, white blood cells as indicator of disease or infection (like meningitis)

• Buildup of excess CSF
• Can cause neuron death due to increased intracranial pressure

Neurons have an extremely high metabolic rate, so they need lots of glucose and oxygen (thus blood)

• Weakening or clot formation in arteries supplying brain can lead to stroke
• Symptoms of stroke vary depending on part of brain affected

• Tight junction of epithelial cells lining blood vessels
• Brain's best defense against infection
• Prevents most bacteria and other toxins from entering nervous system
• Permits water, glucose, oxygen, carbon dioxide, alcohol, caffeine, nicotine, anesthetics

A few areas don't have a BBB so that the brain can monitor blood glucose, temperature, pH, etc