Presentation is loading. Please wait.

Presentation is loading. Please wait.

Health Occupations Nervous System.

Similar presentations

Presentation on theme: "Health Occupations Nervous System."— Presentation transcript:

1 Health Occupations Nervous System

2 Nervous System Complex & highly organized
Coordinates all of the many activities of the body Allows body to respond and adapt to changes that occur both inside and outside of the body

3 Neuron Also called nerve cell Basic structural unit of nervous system
Parts of neuron Cell body Nucleus inside cell body Nerve fibers Dendrites – carry impulses to cell body Axon – carry impulses away from cell body Many covered with myelin sheath (fat covering) Increases rate of transmission of impulses Insulates & maintains the axon

4 Neuron Axon lies close to dendrites of many other neurons
Synapse – space between neurons Impulses coming from an axon jump synapse to get to the dendrite of a neuron that will carry the impulses in the right direction Neurotransmitters – special chemicals located at end of axon to allow impulses to pass from neuron to another Impulses may follow many different routes

5 1. Dendrites 3. Nucleus 4. Axon 6. Terminal branches 5. Myelin Sheath 2. Cell body

6 Nerves Combination of many nerve fibers
Located outside brain & spinal cord Afferent – sensory Messages to brain & spinal cord Efferent – motor Messages from brain & spinal cord Associative – both sensory & motor

7 Divisions of nervous system
Central nervous system Brain Spinal cord Peripheral nervous system Nerves Autonomic nervous system Separate division of peripheral nervous system Controls involuntary body functions

8 Central nervous system
Brain Mass of nerve tissues Protected by membranes & cranium Cerebrum Largest & highest section of brain Convolutions – folds found on outer part Lobes Frontal, parietal, temporal, occipital Named after bones that surround them Responsible for reasoning, thought, memory, speech, sensation, sight, smell,hearing, & voluntary body movement

9 Brain Cerebellum Diencephalon Below back of cerebrum
Responsible for coordination of muscles, balance, posture, muscle tone Diencephalon Between cerebrum & midbrain Thalamus Relay center to direct sensory impulses to cerebrum Hypothalamus Regulates & controls ANS, temperature, appetite, water balance, sleep, constriction & dilation of blood vessels, anger, fear, pleasure, pain, affection

10 Brain Midbrain Pons Below cerebrum at top of brain stem
Responsible for conducting impulses between brain parts & eye reflexes Pons Below midbrain in brain stem Responsible for conducting messages to other parts of brain & reflexes like chewing, tasting, production of saliva, respiration

11 Brain Medulla oblongata Lowest part of brain stem
Connects with the spinal cord Responsible for regulating heartbeat, respiration, swallowing, coughing, & blood pressure

12 Ventricles Convolutions Cerebrum Cerebellum Midbrain Pons Medulla oblongata Spinal cord

13 Spinal cord Continues down from the medulla oblongata Ends at L1 or L2
Surrounded & protected by vertebrae Responsible for many reflexes Carries sensory messages to brain (afferent) Carries motor messages away from brain (efferent)

14 Meninges 3 membranes Cover & protect brain & spinal cord
Dura mater – thick, tough outer layer Arachnoid membrane – middle layer, delicate & weblike Pia mater – innermost layer Closely attached to brain & spinal cord Contains blood vessels that nourish nerve tissue

15 Ventricles 4 hollow spaces located in brain
Connect with each other & with subarachnoid space Filled with CSF Fluid circulates continually between ventricles & through subarachnoid space Serves as shock absorber Carries nutrients to brain & spinal cord Helps remove metabolic products & wastes Produced by choroid plexuses in ventricles After circulating, absorbed into blood vessels of the dura mater & returned to bloodstream through arachnoid villi

16 Peripheral Nervous System
Made up of all the nerves Consists of cranial nerves & spinal nerves Cranial nerves 12 pairs & branches Responsible for special senses like sight, hearing, taste, smell Receive general sensations like touch, pressure, pain, temperature Send out impulses for voluntary & involuntary muscle control

17 Peripheral Nervous System
Spinal nerves 31 pairs & branches Carry messages to & from spinal cord Sensory & motor 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 pair of coccygeal spinal nerves Each nerve goes directly to a particular part of the body or networks with other spinal nerves to form a plexus, supplying sensation to a larger segment of the body

18 Autonomic Nervous System
Part of PNS Helps maintain a balance in the involuntary functions of body, but allows body to react in emergency 2 divisions – sympathetic & parasympathetic Usually 2 systems work together Maintain homeostasis Controls involuntary body functions at proper rates

19 Autonomic Nervous System
Sympathetic Acts in time of emergency – fight/flight Prepares body to act Increases heart rate, respirations, BP Slows activity in digestive tract Parasympathetic Counteracts actions of sympathetic after emergency is over Slows heart rate, respirations Lowers BP Increases digestive activity

20 Diseases & Abnormal Conditions
Cerebral Palsy Disturbance in voluntary muscle action Caused by brain damage Lack of oxygen to brain &/or birth injury Prenatal rubella (German measles) & infections Spastic, athetoid, & atactic (most common) Symptoms Exaggerated reflexes & seizures Tense muscles & contractures Speech impairment Muscle spasms & tremors Mental retardation in some cases

21 Cerebral palsy Treatment but no cure PT, OT, & speech tx
Muscle relaxants & anticonvulsive druges Casts & braces Orthopedic surgery for severe contractures

22 Cerebrovascular Accident (CVA)
Stroke, apoplexy Blood flow to brain is impaired resulting in lack of oxygen & destruction of brain tissue Causes Cerebral hemorrhage HTN Aneurysm Weak blood vessel Occlusion or blockage Atherosclerosis Thrombosis (blood clot)

23 CVA Symptoms – vary depending on area & amount of brain tissue damaged
Loss of consciousness Weakness & vertigo Hemiplegia (paralysis on 1 side) Dysphagia (difficulty swallowing) Visual disturbances & difficulty swallowing Aphasia (speech impairment) Incontinence

24 CVA Immediate treatment 1st THREE hours
Thrombolytic (clot busting) drugs Angioplasty of cerebral arteries CT scans needed to determine cause Neuroprotective agents can be used to prevent permanent brain damage to neurons

25 CVA Treatment Depends on symptoms present
Directed toward helping person recover from OR adapt to symptoms present PT, OT, speech therapy ESSENTIAL

26 Encephalitis Inflammation of brain caused by virus, bacteria, or chemical agent Mosquitoes are common vector Symptoms vary – fever, extreme weakness, lethargy, visual changes, HA, N & V, stiff neck & back, seizures, coma Treatment – supportive Antiviral & antiseizure meds Maintenance of fluids & electrolytes Monitoring of respiratory & kidney function

27 Epilepsy Brain disorder associated with abnormal electrical impulses in neurons of brain Causes – brain injury, birth trauma, tumors, toxins (lead & carbon monoxide) Many cases are idiopathic Absence (Petit mal) seizures Milder, characterized by loss of consciousness lasting several seconds Common in children Usually disappears by late adolesence

28 Epilepsy Tonic-clonic (grand mal) seizures
Most severe Loss of consciousness lasting at least several minutes Convulsions with violent thrashing movements & shaking Hypersalivation, foaming at mouth Loss of body functions Treatment – antiseizure medications

29 Hydrocephalus Excessive accumulation of CSF in ventricles & subarachnoid space Usually caused by congenital defect, infection, or tumor that obstructs the flow of CSF Symptoms – Abnormally large head & prominent forehead with bulging eyes Irritability Distended scalp veins Retardation when pressure prevents proper development of brain

30 Hydrocephalus Treatment – surgical implantation of a shunt between ventricles & veins, heart, or abdominal peritoneal cavity to drain excess CSF

31 Meningitis Inflammation of meninges of brain &/or spinal cord caused by bacteria, fungus, virus, or toxins (lead, arsenic) Symptoms High fever HA, back & neck pain, stiffness N & V Delirium & confusion Coma & death if untreated Treatment – antibiotics, anticonvulsants, meds for pain & cerebral edema

32 Multiple Sclerosis Chronic, progressive, disabling condition resulting from degeneration of the myelin sheath in the CNS Usually occurs between 20 – 40 Unknown cause Progresses at different rates Early symptoms Visual disturbances Weakness, fatigue Poor coordination Tingling & numbness

33 Multiple sclerosis Later symptoms
Tremor, spasticity of muscles Paralysis Speech impairment Emotional swings incontinence Treatment – PT, muscle relaxants, steroids, psychological counseling Goal is to maintain functional ability

34 Neuralgia Nerve pain Caused by inflammation, pressure, toxins, & other diseases Treatment directed towards eliminating cause

35 Paralysis Brain or spinal cord injury destroys neurons & results in loss of function & sensation below level of injury Hemiplegia – paralysis on 1 side of body Paraplegia – paralysis in lower extremities Quadriplegia – paralysis of arms, legs, & body No cure, research being done towards repair Treatment – supportive, PT, OT

36 Parkinson’s Disease Chronic progressive condition involving degeneration of brain cells Usually occurs in people over 50 Symptoms Tremors, stiffness, muscle rigidity Forward leaning position & shuffling gait Difficulty stopping when walking Loss of facial expression & drooling Mood swings with frequent depression Behavior changes

37 Parkinson’s Disease Treatment but no cure
Levodopa used to relieve symptoms In selected cases, surgery to selectively destroy a small area of brain to control involuntary movements or implant a device PT to treat rigidity

38 Shingles or herpes zoster
Acute inflammation of nerve cells Caused by herpes virus, similar to chicken pox Characteristically, occurs in thoracic area on 1 side of body & follows path of the affected nerves Symptoms – fluid filled vesicles, severe pain, redness, itching, fever, abnormal skin sensations Treatment – relief of pain & itching until inflammation subsides, usually 1-4 weeks


Download ppt "Health Occupations Nervous System."

Similar presentations

Ads by Google