Human PhysiologyThe Central Nervous System
▪Thing to be covered▸Anatomy of the CNS▸The Spinal Cord▸The Brain
Human PhysiologyThe 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 PhysiologyThe Central Nervous System
▪Cerebrospinal Fluid (CSF)▸Cranial vault - 1.4L; cells - 1.0L; blood - 0.1-
0.15L; CSF - 0.2-0.3L▸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++, HCO3-,
and glucose
Human PhysiologyThe Central Nervous System
▪Path of CerebroSpinal Fluid
Human PhysiologyThe Central Nervous System
▪Three-dimensional view of the ventricles of the Brain
Human PhysiologyThe 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 PhysiologyThe 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 PhysiologyThe Central Nervous System
Human PhysiologyThe Central Nervous System
▪Organization of the grey matter of the spinal cord
Major ascending and descending pathways
of the spinal cord
Human PhysiologyThe Central Nervous System
▪The Brain▸Cerebrum▸Brain stem▸Cerebellum
▸Forebrain - cerebrum and diencephalon▸Brain stem - midbrain, pons, medulla
Human PhysiologyThe 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 PhysiologyThe 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 PhysiologyThe 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 PhysiologyThe Central Nervous System
▪The Cerebrum: Lobes and Fissures of the Cerebral Hemispheres: Lateral Left
Human PhysiologyThe 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 PhysiologyThe Central Nervous System
▪Major Regions of the Cerebral Hemipheres
Human PhysiologyThe Central Nervous System
▪Functional Area of the Cerebrum
Human PhysiologyThe Central Nervous System
▪Motor and Sensory Areas of the Cerebrum
Human PhysiologyThe Central Nervous System