To better understand viral
meningitis, it helps to understand the anatomy of the brain.
Brain Anatomy The brain is well protected by:
- The scalp
- The skull
- The dura
- A tough 3-layer sheath that surrounds the brain and spinal cord
- Layers include the dura mater (strongest layer), arachnoid mater (middle layer), and pia mater (closest to the brain)
The brain is a complicated structure containing many parts. These include:
- The cerebrum:
- Made up of two cerebral hemispheres that are connected in the middle
- It is the largest part of the brain
- Each area of the cerebrum performs an important function, such as language or movement
- Higher thought (cognition) comes from the frontal cortex (front portion of the cerebrum)
- Outside of the cerebrum are blood vessels
- There are fluid-filled cavities and channels inside the brain
- The cerebellum:
- Located in the lower, back part of the skull
- Controls movement and coordination
- The brainstem and pituitary gland:
- Responsible for involuntary functions such as breathing, body temperature, and blood pressure regulation
- Pituitary gland is the "master gland" that controls other endocrine glands in the body, such as the thyroid and adrenal glands
- The cranial nerves:
- Twelve large nerves exit the bottom of the brain to supply function to the senses such as hearing, vision, and taste
- The cerebral blood vessels:
- A complicated system that supplies oxygenated blood and nutrients to the brain
The blood supply to the brain is divided into two main parts:
- Anterior cerebral circulation:
- The front of the brain is supplied by the paired carotid arteries in the neck.
- Posterior cerebral circulation:
- The back portion of the brain is supplied by the paired vertebral arteries in the spine.
Anatomy examples:
- Carotid artery branches shown on arteriogram
- Cerebral arteries viewed in cross-section through middle of brain
- Cerebral arteries viewed from bottom of brain
- Cerebral arteries on enhanced CT scan
- Cerebral arteries on arteriogram
