1. Central Nervous System
Department of Biology, WCU

2. Components Spinal cord and brain Spinal cord brain to conus medullaris
two way conduction
protected by meninges

3. Spinal cord structure
Sulcus and fissure

4. Spinal cord structure White matter (axons) Gray matter
cell bodies from multipolar neurons and unmylenated processes
letter “H”
Horns
Gray commissure

5. Spinal cord structure Sensory-motor integration
afferent dorsal sensory
efferent ventral motor

6. Spinal cord structure
Dorsal root ganglia

7. Spinal cord structure
Dorsal and ventral root enlargement (cervical, lumbar)

8. Spinal cord structure Horn subdivisions somatic sensory
visceral sensory
visceral motor
somatic motor

9. Spinal cord structure White matter Ascending pathways
myelinated and unmyelinated axons
Ascending pathways
signals (touch, temp., muscle stretch) to brain
Descending pathways
signals (fine and course movement) to spinal cord

10. Spinal cord structure
Commissural pathways
ascending and descending

11. Spinal cord damage Paralysis Paraplegia Quadriplegia
thoracic vertebrae
Quadriplegia
cervical vertebrae

12. Brain development Third week of embryogenesis CNS develops from ……..
neural plate, neural fold, neural tube (4th week)
neural crest: sensory neurons, ganglia

13. Brain development Divisions prosencephalon mesencephalon
rhombencephalon

14. Brain development
prosencephalon …..
mesencephalon
rhombencephalon …..

15. Cerebrum
Telencephalon
83% of mass
Diencephalon

16. Ventricles
Expansions of neural tube
Continuous
Naming

17. Ventricles
Septum pellucidum
Cerebral aqueduct
Subarachnoid space

18. Cerebral fluid
Functions
cushioning
buoyancy
nutrients
Choroid plexus

19. Medulla oblongata Inferior brain stem Myelencephalon Pyramids
Nerve crossover

20. Pons and cerebellum Metencephalon Borders fourth ventricle
Information receiver and sender

21. Cerebellum 11% mass Lobes, hemispheres, vermis Layers
outer gray cortex
middle arbor vitae
Inner cerebral nuclei

22. Cerebellum
Peduncles
superior
middle
inferior

23. Cerebellar processing
1. Signal received by cerebrum and
cerebellum simultaneously
2. Cerebrum initiates muscle contraction
3. Cerebellum receives info. from receptors
4. Cerebellum dispatches signal to cerebrum
5. Cerebrum adjusts muscle contraction accordingly

24. Mesencephalon Location Corpora quadrigemina, cerebral aqueduct
A. superior colliculi (vision)
B. inferior colliculi (auditory)

25. Diencephalon Location 1. Thalamus 80% of volume
group impulses and relay

26. Diencephalon 2. Hypothalamus Location
Function: visceral control center
blood pressure
emotions
temperature
hormones via pituitary

27. Diencephalon 3. Epithalamus Location: roof of 3rd. Ventricle
Pineal (sleep-wake cycle)
melatonin
Choroid plexus

28. Telencephalon Cerebral hemispheres Functions muscle contraction memory
understanding
communication
perception

29. Reticular formation Loosely clustered neurons 3 groupings
midline raphe
medial nuclear
lateral nuclear
Input from muscles
Alerts the cerebral cortex