© 2009 Delmar, Cengage Learning Chapter 8 Central Nervous System

© 2009 Delmar, Cengage Learning CNS Functions Communication and coordination system in the body Seat of intellect and reasoning

© 2009 Delmar, Cengage Learning The Nerve Cell Called the neuron Nucleus, cytoplasm, and cell membrane Dendrites Axons (only one per cell) –Neurilemma or myelin sheath

© 2009 Delmar, Cengage Learning Nervous Tissue/Cells Neuroglia Neurons –Sensory or afferent –Motor or efferent –Associative or interneurons Membrane excitability

© 2009 Delmar, Cengage Learning Synapse When messages go from one cell to the next cell Synaptic cleft Neurotransmitters

© 2009 Delmar, Cengage Learning Animation – Firing of Neurotransmitters Click Here to play Firing of Neurotransmitters animation

© 2009 Delmar, Cengage Learning Divisions of the Nervous System Central nervous system –Brain –Spinal cord Peripheral nervous system –12 pairs of cranial nerves –31 pairs of spinal nerves –Autonomic nervous system

© 2009 Delmar, Cengage Learning Effects of Aging Slowing nerve conduction Loss of brain size Slowing of reaction time Changes in sleep patterns

© 2009 Delmar, Cengage Learning The Brain Weighs about 1400 grams or 3 pounds 100 billion neurons Meninges and cerebrospinal fluid Without oxygen, brain damage occurs within 4-8 minutes

© 2009 Delmar, Cengage Learning The Brain Cerebrum Diencephalon Cerebellum Brain stem

© 2009 Delmar, Cengage Learning The Brain

© 2009 Delmar, Cengage Learning Memory Storage of old and new information Role of the hippocampus Short or long term memory

© 2009 Delmar, Cengage Learning Coverings of the Brain Dura mater Arachnoid mater Pia mater Cerebrospinal fluid

© 2009 Delmar, Cengage Learning Ventricles of the Brain Four lined cavities filled with cerebrospinal fluid 1 st and 2 nd –Right and left lateral ventricles 3 rd –Connected to the lateral ventricles by the interventricular foramen

© 2009 Delmar, Cengage Learning Ventricles of the Brain 4 th –Connected to the 3 rd by the cerebral aqueduct Choroid plexus

© 2009 Delmar, Cengage Learning CSF Formed inside the four ventricles Formation and flow of CSF (cerebrospinal fluid) Blood-brain barrier Lumbar puncture

© 2009 Delmar, Cengage Learning Cerebrum Largest part of the brain Weighs about 2 pounds Cerebral cortex Two hemispheres and longitudinal fissure Fissures and sulci Gyri or convulutions

© 2009 Delmar, Cengage Learning Five Major Fissures Longitudinal fissure Transverse fissure Central fissure Lateral fissure Parieto-occipital fissure

© 2009 Delmar, Cengage Learning Cerebral Functions Frontal lobe Parietal lobe Occipital lobe Temporal lobe Limbic lobe or system

© 2009 Delmar, Cengage Learning Diencephalon Located between the cerebrum and the midbrain Thalamus Hypothalamus

© 2009 Delmar, Cengage Learning Hypothalamus Autonomic nervous control Cardiovascular control Temperature control Appetite control Water balance

© 2009 Delmar, Cengage Learning Hypothalamus Manufacture of oxytocin Gastrointestinal control Emotional state Sleep control Mind-over-body experiences

© 2009 Delmar, Cengage Learning Cerebellum Located behind the pons and below the cerebrum Right and left cerebellar hemispheres connected by vermis Communicates with the rest of the CNS by three pairs of tracts called peduncles

© 2009 Delmar, Cengage Learning Cerebellar Function Maintenance of balance Maintenance of muscle tone Coordination of muscle movements

© 2009 Delmar, Cengage Learning Brain Stem Midbrain Pons Medulla oblongata

© 2009 Delmar, Cengage Learning Spinal Cord Begins at foramen magnum of the occipital bone Ends at the second lumbar vertebrae 31 pairs of spinal nerves Protected by meninges and other tissues White and gray matter Functions

© 2009 Delmar, Cengage Learning Disorders Meningitis Encephalitis Epilepsy Cerebral palsy

© 2009 Delmar, Cengage Learning Disorders Poliomyelitis Hydrocephalus Parkinson’s disease Essential tremor

© 2009 Delmar, Cengage Learning Disorders Multiple sclerosis West Nile virus Dementia Alzheimer’s disease

© 2009 Delmar, Cengage Learning Disorders Brain tumors Hematoma Spinal cord injuries –Quadriplegia –Paraplegia

© 2009 Delmar, Cengage Learning Headaches Tension Migraine Cluster