1. CNS Structures
Meninges
Spinal cord
Brain

2. Meninges
Membranes between the bone and soft tissues of the nervous system
Function: ?
3 layers: Orange analogy
Dura mater
Arachnoid mater
Pia mater
Meningitis (?)

4. Dura Mater Outermost layer Contains many blood vessels and nerves
Attaches to the inside of the cranial cavity and forms the internal periosteum (???) of the surrounding skull bones
Forms partitions between lobes of the brain
Continues into vertebral canal
Terminates as a blind sac below the end of the spinal cord

5. Arachnoid Mater
Thin, weblike membrane located between dura and pia maters
Lacks blood vessels
Spreads over brain and spinal cord, but does not dip into grooves and depressions on their surfaces

6. Pia Mater
Cerebrospinal fluid (CSF) – clear, watery fluid that fills space between arachnoid and pia maters
Pia mater – very thin and contains many nerves and blood vessels that nourish cells of the brain and spinal cord
Hugs surfaces and follows all irregular contours of brain and spinal cord
Subdural hematoma (?)

8. Spinal Cord
Slender nerve column that passes downward from the brain into the vertebral canal
Starts at the foramen magnum and ends between first and second lumbar vertebrae

9. Structure of Spinal Cord
31 segments that each give rise to a pair of spinal nerves

10. Functions of the Spinal Cord
What do you think would be the functions of the spinal cord?
Conducting nerve impulses
Serving as a center for spinal reflexes
Nerve tracts (major nerve pathways) of the spinal cord are made up of axons that provide 2-way communication between brain and body parts:
Ascending tracts - sensory information to brain
Descending tracts – motor impulses from brain