| CNS | consist of the brain, brainstem, and spinal cord |
| PNS | all of the nerves in the body |
| ANS | incorporates parts of both the CNS and PNS; controls the internal organs |
| sympathetic nervous system | the division of the ANS that arouses the body, mobilizing its energy in stressful situations; fight or flight |
| parasympathetic nervous system | division of the ANS that calms the body, conserving it's energy; feed or breed |
| neuron | one cell of the nervous system, in CNS or PNS |
| nerve | a bundle of axons from multiple neurons traveling together in the PNS |
| afferent neuron | carries sensory information from PNS to CNS. |
| efferent neuron | carries motor information to the muscles or glands |
| interneuron | provides a route of communication within the CNS |
| cranial nerves | 12 pairs of nerves, named with Roman numerals, all except CNI originate on the brainstem; consist of sensory and motor functions |
| sensory functions | Cranial nerves; smell, vision, hearing, taste, touch and pain, sensation for the face, and proprioception for talking and swallowing |
| motor functions | Cranial nerves; facial expressions, blinking, eye movement, pupil dilation, tear and saliva production, chewing, talking, and swallowing |
| spinal nerves | 31 pairs of the nerves C1-8, T1-12 L1-5 S1-5 and Co1; They are named for the vertebrae above, except in the cervical spine; There are 7 cervical Vertebrae, but 8 pairs of cervical spinal nerves |
| dermatomes | cutaneous area that sends sensory info to a specific spinal cord level |
| myotomes | the muscles innervated by a specific spinal cord level |
| brachial plexus | formed from the ventral rami of C5-T1; under clavicle and under arm |
| superior trunk | C5 and C6 |
| middle trunk | C7 |
| inferior trunk | C8 and T1 |
| trunks | split into anterior and posterior divisions and reecombine to form cords |
| posterior cord | all posterior divisions |
| lateral cord | anterior divisions of the superior and middle trunks |
| medial cord | anterior division of the inferior trunk |
| terminal branches | Axillary nerve, Radial Nerve, Musclocutaneous nerve, Ulnar nerve, Median nerve |
| axillary nerve | (C5-6) posterior cord |
| radial nerve | (C5-T1) posterior cord |
| musculocutaneous nerve | (C5-7) lateral cord |
| ulnar nerve | (C7-T1) medial cord |
| median nerve | (C6-T1) lateral and medial cords |
| lumbosacral plexus | formed from the ventral rami of L1-S3; less dividing and joining as the brachial plexus |
| major motor nerves | Obturator nerve, Femoral nerve, Superior gluteal nerve, Inferior gluteal nerve, Sciatic nerve |
| obturator nerve | L2-4 |
| femoral nerve | L2-4 |
| superior gluteal nerve | L4-S1 |
| inferior gluteal nerve | L5-S2 |
| sciatic nerve | (L4-S3) splits at the knee into the common peroneal and tibial nerves |