ESPIRITU

• Neurobiologic theories


  Pertaining to the nervous system, help understand how the brain works and causes of differences in brain function

  
• Psychopharmacology


  The use of medications to treat mental illness, related to neurobiologic theories
• Central Nervous System


  • Comprises the brain, the spinal cord, and associated nerves that control voluntary acts
• Structures of the brain


  • Cerebrum
  • Cerebellum
  • Brain stem
  • Limbic system

  
• Cerebrum

  • Divided into two hemispheres (right and left)
  • All lobes and structures are found in both halves except for the pineal body
  • Pineal body is an endocrine gland that influences other glands
  • Corpus callosum connects the two hemispheres and coordinates their functions
  • Left hemisphere controls right side of body and is for logical reasoning, right hemisphere controls left side and is for creative thinking
• Lobes of the cerebrum

  • Frontal lobes
  • Parietal lobes
  • Temporal lobes
  • Occipital lobes
• Frontal lobes

  • Control organization of thought, body movement, memories, emotions, and moral behavior
  • Regulate arousal, focus attention, and enable problem solving and decision-making
  • Abnormalities associated with schizophrenia, ADHD, and dementia
• Cerebellum

  • Center for coordination of movements and postural adjustment
  • Receives and integrates information from all areas of the body
  • Inhibited transmission of dopamine associated with lack of smooth coordinated movements in Parkinson's and dementia
• Brain stem

  • Includes midbrain, pons, and medulla oblongata
  • Medulla contains vital centers for respiration and cardiovascular functions
  • Pons bridges the gap structurally and functionally, serving as a primary motor pathway
  • Midbrain connects the pons and cerebellum with the cerebrum, includes reticular activating system and extrapyramidal system
  • Reticular activating system influences motor activity, sleep, consciousness, and awareness
  • Extrapyramidal system relays information about movement and coordination
• Locus coeruleus


  • A small group of norepinephrine-producing neurons in the brain stem, associated with stress, anxiety, and impulsive behavior
• Limbic system

  • Includes thalamus, hypothalamus, hippocampus, and amygdala
  • Thalamus regulates activity, sensation, and emotion
  • Hypothalamus involved in temperature regulation, appetite, endocrine function, sexual drive, and impulsive behavior
  • Hippocampus and amygdala involved in emotional arousal and memory
  • Disturbances implicated in memory loss in dementia and poorly controlled emotions and impulses in psychotic or manic behavior
• Neurotransmitters


  Chemical substances manufactured in neurons that aid in transmission of information throughout the body
• Neurotransmission


  Electrochemical messages pass from dendrites, through soma, down axon, and across synapses to dendrites of next neuron
• Reuptake

  Neurotransmitters transported back from synapse to axon to be stored for later use
• Metabolism and inactivation

  Neurotransmitters metabolized and inactivated by enzymes, primarily monoamine oxidase (MAO)
• Major neurotransmitters

  • Dopamine
  • Norepinephrine
  • Epinephrine
  • Serotonin
  • Histamine
  • Acetylcholine
  • Neuropeptides
  • Glutamate
  • Gamma-Aminobutyric Acid
• Dopamine


  • Located primarily in brain stem, synthesized from tyrosine
  • Implicated in schizophrenia and other psychoses, as well as Parkinson's disease
  • Antipsychotic medications block dopamine receptors and reduce dopamine activity
• Norepinephrine


  • Most prevalent neurotransmitter in nervous system
  • Excess implicated in anxiety disorders, deficits may contribute to memory loss, social withdrawal, and depression
  • Involved in control of complex movements, motivation, cognition, and regulation of emotional responses
  • Synthesized from tyrosine
• Epinephrine


  • Limited distribution in brain but controls fight or flight response in peripheral nervous system
• Serotonin


  • Found only in the brain, derived from tryptophan
  • Plays important role in anxiety, mood disorders, and schizophrenia
  • Contributes to delusions, hallucinations, and withdrawn behavior in schizophrenia
  • Some antidepressants block serotonin reuptake, leaving it available longer in synapse, improving mood
• Histamine


  • Role in mental illness under investigation
  • Involved in peripheral allergic responses, gastric secretions, cardiac stimulation, and alertness
  • Some psychotropic drugs block histamine, resulting in weight gain, sedation, and hypotension
• Acetylcholine

  • Found in brain, spinal cord, and peripheral nervous system, particularly at neuromuscular junction
  • Synthesized from dietary choline
  • Decreased acetylcholine-secreting neurons in Alzheimer's disease
  • Reduced acetylcholine receptors in myasthenia gravis
• Glutamate


  • Implicated in brain damage caused by stroke, hypoglycemia, sustained hypoxia or ischemia, and some degenerative diseases
• Gamma-Aminobutyric Acid


  • Major inhibitor
• Amine


  • Role of histamine in mental illness is under investigation
  • Involved in peripheral allergic responses, control of gastric secretions, cardiac stimulation, and alertness
  • Some psychotropic drugs block histamine, resulting in weight gain, sedation, and hypotension
• Acetylcholine


  • Found in the brain, spinal cord, and peripheral nervous system, particularly at the neuromuscular junction of skeletal muscle
  • Synthesized from dietary choline found in red meat and vegetables
  • People with Alzheimer disease have decreased acetylcholine-secreting neurons
  • People with myasthenia gravis have reduced acetylcholine receptors
• Glutamate


  Implicated in brain damage caused by stroke, hypoglycemia, sustained hypoxia or ischemia, and some degenerative diseases such as Huntington or Alzheimer
• Gamma-Aminobutyric Acid (GABA)


  • Major inhibitory neurotransmitter in the brain
  • Modulates other neurotransmitter rather than to provide a direct stimulus
  • Drugs that increase GABA function, such as benzodiazepines, are used to treat anxiety and to induce sleep
• Computed tomography (CT)


  • Also called computed axial tomography
  • A precise x-ray beam takes cross-sectional images (slices) layer by layer
  • A computer reconstructs the images on a monitor and also stores the images on magnetic tape or film
  • Used to diagnose primary tumors, metastases, and effusions and to determine the size of the ventricles of the brain
  • Some people with schizophrenia have been shown to have enlarged ventricles; this finding is associated with a poorer prognosis and marked negative symptoms
  • The person undergoing CT must lie motionless on a stretcher-like table for about 20 to 40 minutes as the stretcher passes through a tunnel-like "ring" while the serial x-rays are taken
• Magnetic resonance imaging (MRI)


  • Type of body scan, an energy field is created with a huge magnet and radio waves
  • The energy field is converted to a visual image or scan
  • Produces more tissue detail and contrast than CT and can show blood flow patterns and tissue changes such as edema
  • It can also be used to measure the size and thickness of brain structures
  • Persons with schizophrenia can have as much as 7% reduction in cortical thickness
  • The person undergoing an MRI must lie in a small, closed chamber and remain motionless during the procedure, which takes about 45 minutes
  • Those who feel claustrophobic or have increased anxiety may require sedation before the procedure
  • Clients with pacemakers or metal implants, such as heart valves or orthopedic devices, cannot undergo MRI