1. Nervous System Central BrainSpinal Cord Peripheral + Cranial nerves SomaticAutonomic

2. PRINCIPLES OF BRAIN ORGANISATION CELLS: 1. NEURONS or nerve cells: - Functional units of brain. - 10¹¹ in number. - Parts: Soma or cell body, dendrites, axon & axon terminals. - Classification: A. Myelinated ; Unmyelinated. B. Unipolar ; Bipolar ; Multipolar. C. According to the neurotransmitter secreted: e.g. cholinergic, dopaminergic.

3. 2. GLIAL CELLS: - 10-50 times more than neurons. - In PNS - Schwann cells: Facilitates conduction of action potential along the axon. - In CNS - Oligodendrocytes: Myelin formation. Microglia: Scavenger cells. Astrocytes : Form Blood-Brain Barrier.

4. BRAIN Four principal parts: 1.Brain stem 2.Cerebellum 3.Diencephalon 4.Cerebrum Protected by: 1.Cranial vault 2.Meninges : Duramater Arachnoidmater Piamater Extesions of duramater:  Falx cerebri: separates two cerebral hemispheres  Falx cerebelli: separates two cerebellar lobes  Tentorium cerebelli: separates cerebrum from cerebellum

5. CSF CIRCULATION

7. BRAIN STEM Lowermost part of brain which continues below with spinal cord. Has three parts: 1.Medulla 2.Pons 3.Midbrain

11. LIMBIC SYSTEM (Papez’s circuit) –amygdala –hippocampus –fornix –septum –hypothalamus –cingulate gyrus –mammillary bodies

12. Subcortical Structures of the Limbic System These brain areas are closely connected in structure and function. Pathology in schizophrenia and other major mental illnesses is thought to lie somewhere in the complex interconnections in the limbic system.

16. The synapse typically has two parts: A presynaptic structure containing packets of signaling chemicals, or neurotransmitters and a postsynaptic structure on the dendrites of the receiving neuron that has receptors for the neurotransmitter molecules.

17. Arcuate fasciculus Right and left arcuate fasciculus (Raf & Laf). Also shown are the right and left superior longitudinal fasciculus (Rslf & Lslf), and tapetum of corpus callosum (Ta).

18. Figure 15.12 Centers of Somatic Motor Control

19. Figure 15.10 Descending (Motor) Tracts in the Spinal Cord

20. Figure 15.11 The Corticospinal Pathway

21. Figure 15.6 Sensory Pathways and Ascending Tracts in the Spinal Cord

22. Figure 15.8a, b The Posterior Column Pathway and the Spinothalamic Tracts

23. Figure 15.8c The Posterior Column Pathway and the Spinothalamic Tracts

26. ANS

27. Serotonin 5HT and Norepinephrine in the brain Limbic System Locus Ceruleus (NE Source) Prefrontal Cortex Raphe Nuclei (5-HT source)