Chapter 10 Medical Terminology and Chapters 8 – 9 Body Structures: THE NERVOUS SYSTEM

FUNCTIONS OF THE NERVOUS SYSTEM Coordinates and controls all bodily activities with the brain at the center of control Coordinates and controls all bodily activities with the brain at the center of control When the brain ceases function, the body dies When the brain ceases function, the body dies

STRUCTURES OF THE NERVOUS SYSTEM BRAIN BRAIN SPINAL CORD SPINAL CORD NERVES NERVES SENSORY ORGANS SENSORY ORGANS CNS (central) CNS (central) PNS (peripheral) PNS (peripheral) 12 pairs cranial nerves 31 pairs of spinal nerves ANS (autonomic) ANS (autonomic) Peripheral nerves Ganglia on either side of the spinal cord

NERVES – one or bundles of neuron cells (carrying impulses) connecting brain and spinal cord with body Tract: bundle or group of nerve fibers located within the brain Tract: bundle or group of nerve fibers located within the brain Ascending: carry impulses toward brain Ascending: carry impulses toward brain Descending: carry impulses away from brain Descending: carry impulses away from brain Ganglion: knotlike mass or group of nerve cells located outside the CNS Ganglion: knotlike mass or group of nerve cells located outside the CNS Plexus: network of intersecting nerves and blood or lymphatic vessels Plexus: network of intersecting nerves and blood or lymphatic vessels

dtc.pima.edu/biology/160alpha/ lesson9/lesson9h.ht

Innervation: supply of nerves to body part, stimulation of a body part through action of nerves Innervation: supply of nerves to body part, stimulation of a body part through action of nerves Receptors: sites in sensory organs that receive external stimulation Receptors: sites in sensory organs that receive external stimulation Send stimulus through the sensory neurons to the brain for interpretation Send stimulus through the sensory neurons to the brain for interpretation Stimulus: excites or activates nerve causing an impulse Stimulus: excites or activates nerve causing an impulse Impulse: wave of excitation transmitted through nerve fibers and neurons Impulse: wave of excitation transmitted through nerve fibers and neurons

REFLEXES Automatic, involuntary response to change, inside/outside body Automatic, involuntary response to change, inside/outside body Maintenance of heart rate, breathing rate, and blood pressure = reflex actions Maintenance of heart rate, breathing rate, and blood pressure = reflex actions Coughing, sneezing, and reactions to painful stimuli are also reflex actions Coughing, sneezing, and reactions to painful stimuli are also reflex actions

THE NEURONS – THE BASIC CELL OF THE NERVOUS SYSTEM 3 types described according to function (ACE) 3 types described according to function (ACE) Afferent: sensory, emerge from skin, carry impulses toward brain Afferent: sensory, emerge from skin, carry impulses toward brain Connecting: carry impulses from one neuron to another Connecting: carry impulses from one neuron to another Efferent: carry impulses away from brain toward muscles and glands Efferent: carry impulses away from brain toward muscles and glands

NEURON PARTS Each neuron contains a cell body, several dendrites, a single axon, and terminal end fibers Each neuron contains a cell body, several dendrites, a single axon, and terminal end fibers Dendrites: receive impulses and conduct them to the cell body Dendrites: receive impulses and conduct them to the cell body Axon: extends away from the cell body, conducts impulses away from the nerve cell Axon: extends away from the cell body, conducts impulses away from the nerve cell Some but not all axons protected by myelin Some but not all axons protected by myelin Terminal end fibers: lead the nervous impulse away from the axon and toward the synapse Terminal end fibers: lead the nervous impulse away from the axon and toward the synapse Synapse: space between two neurons or between a neuron and receptor organ

dendrites axon terminal end fibers Synaptic pathway

NEUROTRANSMITTERS Chemical messengers that transmit messages between nerve cells allowing a nerve impulse to jump across the synapse from one neuron to another Chemical messengers that transmit messages between nerve cells allowing a nerve impulse to jump across the synapse from one neuron to another news/neurology.html

MYELIN SHEATH PROTECTIVE COVERING OVER SOME NERVE CELLS PROTECTIVE COVERING OVER SOME NERVE CELLS Spinal Cord White Matter of the Brain White color of myelinated nerve fibers Most Peripheral Nerves Gray Matter: non-myelinated nerves of the brain and spinal cord

nucleus Cell body dendrite axon Myelin sheath Nodes of Ranvier

THE CENTRAL NERVOUS SYSTEM Meninges Meninges Dura Mater Dura Mater Arachnoid Membrane Arachnoid Membrane Pia Mater Pia Mater Cerebrospinal Fluid Cerebrospinal Fluid The Cerebrum The Cerebrum Cerebral Hemispheres Cerebral Hemispheres Lobes Lobes Ventricles Ventricles The Thalamus The Thalamus The Hypothalamus The Hypothalamus The Cerebellum The Cerebellum The Brainstem The Brainstem The Midbrain The Midbrain The Pons The Pons The Medulla Oblongata The Medulla Oblongata The Spinal Cord The Spinal Cord als_pages/neurolog.htm training.seer.cancer.gov/ module_anatomy/unit5...

MENINGES 3 Layers of connective tissue that enclose brain and spinal cord 3 Layers of connective tissue that enclose brain and spinal cord Dura Mater – outermost membrane Dura Mater – outermost membrane Arachnoid Membrane – second layer, loosely attached to allow flow of fluid between layers Arachnoid Membrane – second layer, loosely attached to allow flow of fluid between layers Pia Mater – third layer, located closest to brain and spinal cord, rich in supply of blood vessels Pia Mater – third layer, located closest to brain and spinal cord, rich in supply of blood vessels Subarachnoid space: below arachnoid membrane, above pia mater – contains cerebrospinal fluid Subarachnoid space: below arachnoid membrane, above pia mater – contains cerebrospinal fluid Epidural space: above the duramater – within surrounding bone walls – cushions Dura Mater Epidural space: above the duramater – within surrounding bone walls – cushions Dura Mater Subdural space: below the dura membrane – above the arachnoid membrane Subdural space: below the dura membrane – above the arachnoid membrane

CEREBRUM – cerebral: pertaining to cerebrum or brain Largest/uppermost portion of the brain Largest/uppermost portion of the brain Responsible for all thought, judgment, memory, association, and discrimination Responsible for all thought, judgment, memory, association, and discrimination Cerebral Cortex: made up of gray matter, the outermost layer of the cerebrum Cerebral Cortex: made up of gray matter, the outermost layer of the cerebrum

CEREBRAL LOBES Frontal – controls motor functions Frontal – controls motor functions Parietal – receives and interprets Parietal – receives and interprets nerve impulses from the sensory receptors Occipital – controls eyesight Occipital – controls eyesight Temporal Lobe – Temporal Lobe – controls senses of hearing and smell

THALAMUS – produces sensations by relaying impulses to/from the cerebral cortex and the sense organs of the body Hypothalamus: 7 regulatory functions Hypothalamus: 7 regulatory functions Controls heart rate, blood pressure, respiratory rate, and digestive tract activity by regulating autonomic nervous system Controls heart rate, blood pressure, respiratory rate, and digestive tract activity by regulating autonomic nervous system Regulates emotional responses and behavior Regulates emotional responses and behavior Regulates body temperature Regulates body temperature Regulates food intake by controlling hunger sensations Regulates food intake by controlling hunger sensations Regulates water balance and thirst Regulates water balance and thirst Regulates sleep-wake cycles Regulates sleep-wake cycles Regulates endocrine system activity Regulates endocrine system activity

CEREBELLUM Second largest part of the brain Second largest part of the brain Receives incoming messages regarding movement within joints, muscle tone, and positions of the body Receives incoming messages regarding movement within joints, muscle tone, and positions of the body From here messages are distributed to corresponding parts of the brain that control skeletal muscles From here messages are distributed to corresponding parts of the brain that control skeletal muscles

THE BRAINSTEM – connects cerebral hemispheres with the spinal cord The Midbrain – extends from the lower surface of the cerebrum to the pons – The Midbrain – extends from the lower surface of the cerebrum to the pons – provides conduction pathways to and from higher and lower centers provides conduction pathways to and from higher and lower centers The Pons – at the base of the brain The Pons – at the base of the brain Nerve cells cross from one side of the brain to control the oppositie side of the body (injuries) Nerve cells cross from one side of the brain to control the oppositie side of the body (injuries) The Medulla Oblongata – located at the lowest part of the brainstem The Medulla Oblongata – located at the lowest part of the brainstem Controls basic life functions including the muscles of respiration, heart rate, and blood pressure Controls basic life functions including the muscles of respiration, heart rate, and blood pressure

THE SPINAL CORD – pathway for impulses going to and from the brain Contains all the nerves that affect the limbs and lower part of the body Contains all the nerves that affect the limbs and lower part of the body Protected by Cerebral Spinal Fluid and meninges Protected by Cerebral Spinal Fluid and meninges Grey Matter = internal section Grey Matter = internal section White Matter = outer portion of the spinal cord White Matter = outer portion of the spinal cord nerve/nerveb4.htm

THE PERIPHERAL NERVOUS SYSTEM - PNS Consists of: Consists of: Cranial nerves: 12 pairs originating from under the brain Cranial nerves: 12 pairs originating from under the brain Each nerve of a pair serves half the body Each nerve of a pair serves half the body Both nerves in a pair are identical in function Both nerves in a pair are identical in function Identified by Roman numerals named for the area or function they serve Identified by Roman numerals named for the area or function they serve Spinal nerves: 31 pairs Spinal nerves: 31 pairs Usually named for the artery they accompany or the body part they innervate Usually named for the artery they accompany or the body part they innervate Femoral nerve innervates muscles associated with the femur Femoral nerve innervates muscles associated with the femur

aer2.sbc.edu.hk/~bio/

THE AUTONOMIC NERVOUS SYSTEM - ANS Controls involuntary actions of the body Controls involuntary actions of the body 2 divisions: function to maintain homeostasis 2 divisions: function to maintain homeostasis Sympathetic: prepares body for emergency and stressful situations Sympathetic: prepares body for emergency and stressful situations Parasympathetic: returns body to normal after a stressful response Parasympathetic: returns body to normal after a stressful response

MEDICAL SPECIALTIES RELATED TO THE NERVOUS SYSTEM Anesthesiologist Anesthesiologist Neurologist Neurologist Neurosurgeon Neurosurgeon Psychiatrist Psychiatrist Psychologist Psychologist

PATHOLOGY OF THE NERVOUS SYSTEM Head and Meninges Head and Meninges Cephalalgia: headache Cephalalgia: headache Migraine Headache Migraine Headache Encephalocele Encephalocele Hydrocephalus : increased amount of CSF Hydrocephalus : increased amount of CSF Meningocele: protrusion of membranes through a defect in the skull or spinal column Meningocele: protrusion of membranes through a defect in the skull or spinal column Meningitis Meningitis asp

DISORDERS OF THE BRAIN Alzheimer’s disease: associated with degenerative changes in the brain structures Alzheimer’s disease: associated with degenerative changes in the brain structures Cognition: mental activities associated with thinking, learning, and memory Cognition: mental activities associated with thinking, learning, and memory Encephalitis Encephalitis Parkinson’s disease Parkinson’s disease Tetanus Tetanus

BRAIN INJURIES Amnesia: disturbance in the memory marked by total or partial inability to recall past experiences – cause BI, illness, or psychological disturbances Amnesia: disturbance in the memory marked by total or partial inability to recall past experiences – cause BI, illness, or psychological disturbances Concussion: violent shaking up or jarring of the brain Concussion: violent shaking up or jarring of the brain Cerebral Contusion: bruising of brain tissue as result of BI Cerebral Contusion: bruising of brain tissue as result of BI Cranial Hepatomas: collection of blood trapped in the tissues of the brain Cranial Hepatomas: collection of blood trapped in the tissues of the brain

ALTERED STATES OF CONSCIOUSNESS Conscious: alert Conscious: alert Syncope: fainting Syncope: fainting Lethargy: lowered level of consciousness, listlessness, drowsiness, and apathy Lethargy: lowered level of consciousness, listlessness, drowsiness, and apathy Coma : loss of consciousness Coma : loss of consciousness Delirium: associated with high fever, sudden onset where patient is confused, disoriented, and unable to think clearly Delirium: associated with high fever, sudden onset where patient is confused, disoriented, and unable to think clearly Dementia: slow, progressive decline in mental abilities including memory, thinking, judgment, and the ability to pay attention Dementia: slow, progressive decline in mental abilities including memory, thinking, judgment, and the ability to pay attention

STROKES – (CVA) damage to the brain that occurs when blood flow is disrupted due to vessel blockage or rupture Ischemic Attacks Ischemic Attacks TIA: temporary interruption in blood supply to brain: weakness, dizziness, or loss of balance TIA: temporary interruption in blood supply to brain: weakness, dizziness, or loss of balance Ischemic stroke: blood flow is blocked, affecting the cerebrum and damaging the controls of movement, language, and senses Ischemic stroke: blood flow is blocked, affecting the cerebrum and damaging the controls of movement, language, and senses Aphasia: inability to speak, write, or comprehend written or spoken word Aphasia: inability to speak, write, or comprehend written or spoken word Hemorrhagic Stroke – bleed – leak or rupture of blood vessel in brain Hemorrhagic Stroke – bleed – leak or rupture of blood vessel in brain

e60Neurology.htm

SLEEP DISORDERS Insomnia: abnormal inability to sleep Insomnia: abnormal inability to sleep Narcolepsy: recurrent uncontrollable seizures of drowsiness Narcolepsy: recurrent uncontrollable seizures of drowsiness and sleep napping_at_the_desk.asp narcolepsy.html

SPINAL CORD Myelitis: inflammation of the spinal cord Myelitis: inflammation of the spinal cord Myelosis: tumor of spinal cord Myelosis: tumor of spinal cord Multiple sclerosis Multiple sclerosis Poliomyelitis Poliomyelitis Post polio syndrome Post polio syndrome Radiculitis: pinched nerve, inflammation of root of spinal nerve Radiculitis: pinched nerve, inflammation of root of spinal nerve Spinal cord injuries Spinal cord injuries

CONVULSIONS AND SEIZURES – sudden, violent, involuntary contraction of a group of muscles caused by a disturbance in brain function Generalized tonic-clonic seizure: Generalized tonic-clonic seizure: Tonic convulsion: continuous muscular contraction resulting in rigidity and violent spasms Tonic convulsion: continuous muscular contraction resulting in rigidity and violent spasms Clonic convulsion: alternate contraction and relaxation of muscles resulting in jerking movements of the face, trunk, or extremities Clonic convulsion: alternate contraction and relaxation of muscles resulting in jerking movements of the face, trunk, or extremities Localized seizure: partial Localized seizure: partial

EPILEPSY Grand Mal Epilepsy: most severe form Grand Mal Epilepsy: most severe form Petit Mal Epilepsy: milder form, sudden, temporary loss of consciousness, lasting only a few seconds, they may not involve convulsive movements, and may not be noticed Petit Mal Epilepsy: milder form, sudden, temporary loss of consciousness, lasting only a few seconds, they may not involve convulsive movements, and may not be noticed Epileptic aura: experienced just before seizure, light or smell Epileptic aura: experienced just before seizure, light or smell

MENTAL HEALTH Developmental Disorders Developmental Disorders Substance-Abuse Disorders Substance-Abuse Disorders Schizophrenia and Other Psychotic Disorders Schizophrenia and Other Psychotic Disorders Mood Disorders Mood Disorders Panic Disorders Panic Disorders Anxiety Disorders Anxiety Disorders Phobias Phobias Somatoform Disorders Somatoform Disorders Impulse-Control Disorders Impulse-Control Disorders Personality Disorders Personality Disorders

DIAGNOSTIC PROCEDURES OF THE NERVOUS SYSTEM CT – CAT Scan CT – CAT Scan Echoencephalography Echoencephalography Electroencephalography Electroencephalography Encephalography Encephalography Myelography: radiographic study of spinal cord Myelography: radiographic study of spinal cord LOC: level of consciousness LOC: level of consciousness

Echo encephalography Electrical encephalography myelography Ct scan

TREATMENT PROCEDURES OF THE NERVOUS SYSTEM Medications to Treat Mental Disorders Medications to Treat Mental Disorders Pain Control Pain Control Sedative and Hypnotic Medications Sedative and Hypnotic Medications Anesthesia Anesthesia