1. The Nervous System and Behavioral Disorders

2. Nervous System Controls body functions with electric impulses
Two physical systems
Central nervous system
Brain
Spinal cord
Peripheral nervous system
All other nerve tissue

3. Nervous System (con’t)
Two functional systems
Somatic nervous system
Controls skeletal muscles
Autonomic nervous system
Controls:
Smooth muscles
Cardiac muscles
Glands

4. Anatomic Divisions of Nervous System

5. The Neuron Basic functional unit of nervous system
Two types of fibers extend from cell body
Dendrite
Carries impulses toward cell body
Axon
Carries impulses away from cell body
Some covered with myelin

6. The Neuron (con’t) Types of neurons Sensory neurons Motor neurons
Transmit impulses towards CNS
Motor neurons
Transmit impulses away from CNS
Connecting neurons
Contact at synapse

8. Nerves Bundles of neuron fibers in PNS
Ganglion = collection of cell bodies along nerve pathway
Most nerves contain both sensory and motor fibers

9. The Brain Cerebrum Largest part of brain
Composed mostly of white matter
Also houses cerebral cortex
Thin outer layer of gray matter
Higher brain functions
Divided into two hemispheres
Deep groove separates hemispheres
Called longitudinal fissure

10. Meninges Set of three protective layers covering brain and spinal cord
Dura mater
Outermost layer
Arachnoid
Middle layer
Pia mater
Thin, vascular inner layer
Attached directly to brain and spinal cord tissue

11. External Surface of the Brain

12. The Spinal Cord
Extends from medulla oblongata to between 1st and 2nd lumbar vertebrae
Consists of:
Gray matter
Central area surrounded by white matter
White matter
Contains tracts for impulses

22. Vascular Disorders Stroke or cerebrovascular accident
Any occurrence of brain tissue not getting oxygen
3rd leading cause of death in developed world
Leading cause of neurologic disability
Risk factors:
Hypertension
Atherosclerosis
Heart disease
Diabetes mellitus
Cigarette smoking
Heredity

23. Trauma Epidural hematoma Subdural hematoma Concussion
Bleeding between dura mater and skull bone
Usually results from blow to side of head
Subdural hematoma
Bleeding between dura mater and arachnoid
Usually results from blow to front or back of head
Concussion
Can result from blow to head or fall
May also encounter contrecoup injury

24. Infections Viral meningitis (another form) Bacterial meningitis
Inflammation of meninges
Common symptom is stiff neck
Diagnosed with lumbar puncture
Viral meningitis (another form)
Encephalitis (inflammation of the brain)
Also includes other viruses that affect CNS:
Rabies
Polio
HIV

25. Neoplasms
Tumors originating in nervous system, usually involving neuroglia
Called gliomas
Symptoms are dependent on size and location:
Seizures
Headaches
Vomiting
Muscle weakness
Interference with one of the senses (hearing, vision)

26. Degenerative Diseases
Multiple sclerosis
Patchy loss of myelin with hardening of tissue in CNS
Symptoms:
Vision problems
Tingling, numbness in arms
Urinary incontinence
Tremor
Stiff gait
Exact cause is unknown

27. Degenerative Diseases (con’t)
Parkinson disease
Failure of midbrain neurons to secrete dopamine
Leads to:
Tremors
Muscle rigidity
Flexion at joints
Akinesia
Emotional problems
Treated with L-dopa

28. Degenerative Diseases (con’t)
Alzheimer disease
Unexplained degeneration of neurons
Atrophy of cerebral cortex
May cause:
Progressive loss of recent memory
Confusion
Mood changes

29. Epilepsy Seizures caused by abnormal electric brain activity
Seizures vary:
Brief and mild (petit mal)
Major (grand mal)
Serious seizures result in loss of consciousness and convulsions
Diagnosed with EEG revealing brain activity abnormalities
Treated with antiepileptic and anticonvulsive drugs

30. Sleep Disturbances Dyssomnia = general term for sleep disorders
Insomnia
Insufficient or nonrestorative sleep
Narcolepsy
Brief, uncontrollable “attacks” of sleep
Treated with:
Stimulants
Regulation of sleep habits
Short daytime naps
Sleep apnea
Failure to breathe for brief periods during sleep
Usually results from upper airway obstruction

31. Behavioral Disorders Anxiety disorders Generalized anxiety disorder
Chronic excessive and uncontrollable worry
May be accompanied with:
Muscle tensing
Restlessness
Dyspnea
Palpitations
Insomnia
Irritability

32. Behavioral Disorders (con’t)
Panic disorder
Anxiety with episodes of intense fear
Phobias
Extreme, persistent fears centered around objects or situations
Obsessive-compulsive disorder
Condition w/ repetitive behaviors to relieve anxiety
Attention-deficit-hyperactivity disorder
Difficult to diagnose due to overlapping symptoms
Treated with stimulant drugs

33. Depression Usually coexists with physical or emotional conditions
Characterized by feelings of:
Feelings of sadness
Hopelessness
Lack of interest
Dysthymia
Form of depression triggered by serious event
Bipolar disorder
Depression with episodes of mania

34. Psychosis Mental state with gross misconception of reality
Characterized by:
Delusions
Paranoia
Hallucinations
Schizophrenia
From of chronic psychosis

35. Drugs Used in Treatment
Psychotropic drugs
Acts on mental state
Category of drugs includes:
Antianxiety (anxiolytics)
Mood stabilizers
Antidepressants
Antipsychotics (neuroleptics)