1. NERVOUS SYSTEM
STRUCTURE

2. NEURON pg. 148 figure 8-1
Nerve cell; specially constructed to carry out it’s function
Transmitting a message from one cell to the next
Extensions from the neuron are:
Dendrite – may have several
Axon – only one per cell
Myelin sheath (neurilemma)
Covering over the axon which speeds up the nerve impulse as it travels along the axon

3. BRAIN pg. 153 figure 8-5 and 155 figure 8-7
Weighs 3 lbs.
Coverings
Meninges – membranous coverings
Cerebral cortex – outer cortex; gray matter
Highest center of reasoning and intellect
Ventricles
4 lined cavities filled with CSF
Cerebrum
a. Convolutions and sulci
b. Lobes
i. Frontal
ii. Parietal
iii. Occipital
iv. Temporal

4. Brain continued pg. 156 figure 8-8, 158 figure 8-10, and 160 figure 8-11
Cerebellum
Located behind the pons and below the cerebrum
Diencephalon – located b/t the cerebrum and midbrain
a. Thalamus
b. Hypothalamus
Brain stem – provides the pathway for the ascending and descending tracts
a. Midbrain
b. Pons
c. Medulla oblongata

5. SPINAL CORD pg. 161 figure 8-12 Continues down from the brain
Begins at the foramen magnum of the occipital bone and continues to the second lumbar vertebra
White and soft and lies within the _________
Made up of 31 segments
Then pair of spinal nerves
Protected by 3 layers of meninges
CSF fluid circulates over the cord

6. NERVES chap 9 tables 9-1 9-2 and figures 9-3 and 9-4
Cranial nerves
12 pairs beginning in the brain
Mainly deal with functions of the head and neck
Except vagus nerve (X) – responsible for ___ (pg. 175)
Designated by name and number
Name can give a clue to function
Spinal nerves
31 pairs originating at the spinal cord
Exit through openings in the vertebrae
Named according to region and level they exit
Largest is the sciatic nerve