1. Nervous System Chapter 15
Medical Terminology
Nervous System
Chapter 15

2. Nervous System Coordinates many activities of the body
senses changes in internal and external environment
interprets these changes
coordinates appropriate response in order to maintain homeostasis
When the brain ceases functioning, the body dies

3. Structures
nerve is one or more bundles of impulse carrying fibers that connect the brain & spinal cord with body

4. Nervous Tissue Neurons - transmit impulses Neuroglia - support neurons
sensory (afferent, ascending)
motor (efferent, descending)
Neuroglia - support neurons

5. Neuron
dendrites-rootlike structures that receive impulses and conduct them to the cell body
cell body - contains nucleus
axon-extends away from the cell body and conducts impulses away from the nerve cell

6. Neuron Anatomy Myelin sheath - insulation
accelerates impulse transmission
appears as white covering
myelin on axons in brain and spinal cord gives white appearance
unmyelinated fibers, dendrites, and nerve cell bodies comprise gray matter of brain and spinal cord

7. Neuron Anatomy (peripheral nerves)
Schwann cell
type of neuroglial cell wrapped around axon
forms the myelin sheath
Neurolemma (neurolemmal sheath)
permits a damaged axon to regenerate
neurolemma NOT found in Central nerves

8. Neurotransmitters
Synapse- space between two neurons or between a neuron and a receptor organ.
Impulses are passed from one neuron to another at a junction called the synapse.
Electrical current within neuron causes release of chemical substance called a neurotransmitter.

9. Neurotransmitter diffuses across the synapse to receptor sites on the dendrite of the next neuron.
Generates the next electrical stimulus.
Terminal ends of the axon release a transmitter substance that affects the dendrites of the next neuron.
One way transmission of the impulse is assured because only the axons release these chemicals.

10. Neuroglia gli/o or nerve glue neuroglia or glial cells
astrocytes - blood brain barrier
oligodendrocytes - facilitate myelin development
microglia - phagocytic properties
ependyma - assist in CSF circulation

11. Divisions Central Nervous System Peripheral Nervous System
brain and spinal cord
Peripheral Nervous System
cranial nerves and spinal nerves
fibers are sensory or motor
Autonomic Nervous System
ganglia on either side of the spinal cord
sympathetic nervous system
parasympathetic nervous system

12. Brain
Cerebrum
Cerebellum
Diencephalon
Brainstem

13. Cerebrum Cerebrum Cerebellum Medulla Oblongata
Two hemispheres divided by a fissure
Lobes
frontal, parietal, temporal, occipital
Cortex, gray color

14. Lobes Frontal Parietal Occipital Temporal motor functions
receives & interprets information
Occipital
eyesight
Temporal
hearing & smell

15. Cerebellum
receives incoming messages regarding movement within joints, muscle tone, and position of the body.
relay these messages to other parts of brain to control skeletal activity
movement, coordination, balance

16. Thalamus below the cerebrum
monitors sensory stimuli by suppressing some and magnifying others

17. Hypothalamus-a regulator
Autonomic Nervous System
emotional responses/behavior
body temperature
food intake= hunger
water balance and thirst
sleep-wake cycles
endocrine system activity

18. Brainstem stalk-like portion of the brain
midbrain - conduction pathways
pons - nerve cells cross from one side to the other
medulla oblongata - basic life functions
origin for 10 of 12 cranial nerves
controls respiration, blood pressure, heart rate

19. Spinal Cord housed within vertebral column continuos with brain stem
ascending and descending nerve tracts
protected by CSF and meninges
gray matter in internal section - not protected by myelin sheath
myelinated white matter in outer area

20. Meninges dura mater arachnoid pia mater epidural subdural
subarachnoid space
contains CSF
pia mater
blood vessels and lymph

21. Bell’s Palsy Facial paralysis Treatment
functional disorder of VII cranial nerve
asthenia
keratitis
dysphasia
Treatment
anti-inflammatory drugs

22. Cerebrovascular Disease
Arteriosclerosis
cerebrovascular accident (CVA, apoplexy)
ischemia
transient ischemic attack
hemiparesis
hemiplegia
aphasia
ataxia

23. Seizure Disorders Epilepsies Convulsions dysrhythmias in the brain
etiology: brain injury, congenital anomalies, metabolic disorders, brain tumors
Convulsions

24. Parkinson’s Disease Progressive neurological disorder
deterioration of portion of brain controlling movement
bradykinesia, hypokinesia, tremors, shuffling gait.
Treatment: l-dopa

25. Multiple Sclerosis Progressive degenerative disease of CNS
Inflammation, hardening, and loss of myelin throughout spinal cord and brain
Impeded transmission of electrical impulses
tremors, muscle weakness, slowness of movements
etiology: autoimmune, or slow virus

26. Alzheimer’s Disease Progressive neurological disorder
plaques develop in cerebral cortex
memory loss, cognitive decline, and personality changes
leading cause of senile dementia
research: some meds prevent breakdown of brain chemicals

27. Oncology Intracranial tumors Signs and Symptoms primary sites
metastatic sites
Signs and Symptoms
headaches
papilledema
personality changes

28. Agnosia
asthenia
ataxia
cerebral palsy
closed head trauma
coma
concussion
Guillian-Barre syndrome
herpes zoster (shingles)

29. Huntington’s chorea
hydrocephalus
lethargy
neural tube defect
paraplegia
paresis

30. transient ischemic attack (TIA)
Paresthesia
poliomyelitis
quadriplegia
Reye’s syndrome
sciatica
syncope
vasovagal
transient ischemic attack (TIA)

31. Cerebral angiography
echoencephalography
electroencephalography (CCG)
myelography
computed tomography (CT scan)

32. Surgical and Therapeutic Procedures
Cryosurgery
spinal puncture, spinal tap
trephination
vagotomy

33. Pharmacology Analgesics \anticonvulsants antidepressants hyponotics
opiates
psychtropic drugs
sedatives
tranquilizers

34. Abbreviations
ALS
ANS
CNA CP
CSF
CT scan
CVA
CVD

35. Abbreviations
EEG
ICP LP
MRI MS
R/O
TIA

36. End
Chapter 15
Nervous System