Human Physiology The Central Nervous System ▪Thing to be covered ▸ Anatomy of the CNS ▸ The Spinal Cord ▸ The Brain

Human Physiology The Central Nervous System ▪Anatomy of the CNS ▸ The Skull or Cranium (for brain) ▸ The Vetebral Column (for spinal cord) ▸ Meninges –Dura mater (outermost layer) –Arachnoid membrane ( middle layer) –Pia mater (innermost layer)

Human Physiology The Central Nervous System ▪Cerebrospinal Fluid (CSF) ▸ Cranial vault - 1.4L; cells - 1.0L; blood L; CSF L ▸ Colorless, salty solution ▸ Continuously secreted from specialized cells (ependymal cells) in the choroid plexus in ventricles ▸ Ependyma actively transport Na + and solutes into ventricles ▸ Functions: Physical and chemical protection ▸ Contains little protein and lower K +, Ca ++, HCO 3 -, and glucose

Human Physiology The Central Nervous System ▪Path of CerebroSpinal Fluid

Human Physiology The Central Nervous System ▪Three-dimensional view of the ventricles of the Brain

Human Physiology The Central Nervous System ▪The Blood-Brain Barrier (BBB) ▸ Function - protection ▸ Brain capillaries much less permeable than others ▸ Protects the brain from blood composition fluctuations ▸ Can transport nutrients into the ISF ▸ Exceptions - posterior pituitary and vomiting center

Human Physiology The Central Nervous System ▪Divisions of the CNS ▸ Gray matter ▸ Nuclei ▸ White matter ▸ Tracts - ascending and descending ▸ Spinal cord –Dorsal root (afferent, sensory) –Ventral root (efferent, motor) –Dorsal horns –Ventral horns –Dorsal root ganglion

Human Physiology The Central Nervous System

Human Physiology The Central Nervous System ▪Organization of the grey matter of the spinal cord Major ascending and descending pathways of the spinal cord

Human Physiology The Central Nervous System ▪The Brain ▸ Cerebrum ▸ Brain stem ▸ Cerebellum ▸ Forebrain - cerebrum and diencephalon ▸ Brain stem - midbrain, pons, medulla

Human Physiology The Central Nervous System ▪The Brain Stem ▸ Contains the third and fourth ventricles ▸ 9 cranial nerves emerge (know tables 9-1 & 2 ) ▸ Medulla oblongata contains vital centers ▸ Pyramids ▸ Midbrain or mesencephalon controls eye and ear functions ▸ Reticular formation - arousal and sleep

Human Physiology The Central Nervous System ▪The Cranial Nerves (Know Table 9-1) ▸ I Olfactory ▸ II Optic ▸ III Oculomotor ▸ IV Trochlear ▸ V Trigeminal ▸ VI Abducens ▸ VII Facial ▸ VIII Vestibulocochlear ▸ IX Glossopharyngeal ▸ X Vagus ▸ XI Accessory ▸ XII Hypoglossal

Human Physiology The Central Nervous System ▪The Cerebellum ▸ Process sensory information ▸ Coordinates muscle activity ▸ Involves cordinating balance and equilibrium ▪The Diencephalon ▸ Composed of thalamus and the hypothalamus ▸ Also contains the pineal gland ▸ Thalamus has several nuclei and is described as a relay station for signals on their way to the cerebral cortex ▸ The hypothalamus contains centers for behaviorial drives and homeostasis (See Table 9-2 for more info) ▸ It controls both endocrine and autonomic functions ▸ Receives information from various sources

Human Physiology The Central Nervous System ▪The Cerebrum: Lobes and Fissures of the Cerebral Hemispheres: Lateral Left

Human Physiology The Central Nervous System ▪The Cerebrum: Lobes and Fissures of the Cerebral Hemispheres: Medial surface Lobes: 1.Frontal 2.Parietal 3.Occipital 4.Temporal 5.Limbic

Human Physiology The Central Nervous System ▪Major Regions of the Cerebral Hemipheres

Human Physiology The Central Nervous System ▪Functional Area of the Cerebrum

Human Physiology The Central Nervous System ▪Motor and Sensory Areas of the Cerebrum

Human Physiology The Central Nervous System