Question

Chapter 9: CENTRAL NERVOUS SYSTEM

a) What are gray and white matter composed of in the CNS?

b) What are clusters of cell bodies called if they are located in the CNS? How about the PNS? What are bundles of axons called in the CNS? How about the PNS?

c) What are the three meninges? Describe their functions and relative locations.

d) What two fluids make up the extracellular environment in the brain?

e) Describe where cerebrospinal fluid is produced, where it flows and where it is reabsorbed.

f) Describe what the blood-brain barrier is. How can it select what passes and what does not? What freely passes across the blood-brain barrier? How does the blood-brain barrier affect clinical treatment of brain diseases?

g) Describe why diabetics who are hyperglycemic frequently suffer from hypoglycemic shock.

h) Describe the 6 main brain regions. Include their major functions and any structures housed within them.

i.) Describe the highly organized structure AND function of the cortex (why is the brain furrowed?)

j) What are the limbic system and reticular formation?

k) What are the four diffuse modulating systems (refer to book)? How are they named/characterized? What happens when there are deficiencies in communication within the system?

l) Describe the hypotheses for why we sleep. What are the benefits of REM vs deep (stage 4) cycles of sleep?

m) Describe Process S and C, and how the balance between them both drives sleep and wakefulness.

n) How is mood different than emotion?

o) What is one common cause for depression and give one example for how it can be clinically treated?

Answer 1

1) Gray matter consists of neuronal cell bodies, neuropils, glial cells, synapses, and capillaries. White matter consists of myelinated axons that connects the gray matter. The mylinated axons are also called as tracts and the myelin acts as an insulator.

2) A cluster of cell bodies in called nucleus if it is found in the Central nervouis system and are called ganglion if found in the Peripheral nervous system (PNS). Bundles of axon found in CNS is called as tract and in PNS it is called as nerve.

3) Meninges is of three layers - Dura mater, Arachanoid mater and Pia mater. All three layers protect the brain and are called protective membranes.

• Dura mater - It is the outer most layer of the meninges and is located close to the skull and vertebrae. The dura mater is thick and envelops the arachnoid mater. It surrounds and supports the large dural sinuses carrying blood from the brain toward the heart.
• Arachanoid mater - It is the middle layer of the meninges. Cerebro-spinal fluid (CSF) circulates in the subarachnoid space (between arachnoid and pia mater).
• Pia mater - Pia mater is the innermost layer and surrounds the brain and spinal cord. They protect the brain and the sinuses contain the CSF.

4) Interstitial fluid (ISF) and Cerebro-spinal fluid (CSF) make up the extracellular environment of the brain. ISF surrounds the parenchymal cells of the brain and spinal cord. CSF fills the larger spaces within and around the CNS.