The Brain

• Hindbrain


  • Lowest portion of the brain; located at the skull’s rear
  • Consists of the medulla, cerebellum, and pons
• Medulla


  • Responsible for life-sustaining functions such as breathing, swallowing, and heart rate
• Pons


  • Involved in functions related to attention, sleep and arousal and respiration
• Cerebellum


  • The “little brain” that controls all involuntary, rapid and fine motor movements
  • Injury to cerebellum may impair motor coordination and cause stumbling and loss of muscle tone
• CRANIAL NERVES

  • Olfactory Nerve (I)
  • Optic Nerve (II)
  • Oculomotor Nerve (III)
  • Trochlear Nerve (IV)
  • Trigeminal Nerve (V)
  • Abducens Nerve (VI)
  • Facial Nerve (VII)
  • Vestibulocochlear Nerve (VIII)
  • Glossopharyngeal Nerve (IX)
  • Vagus Nerve (X)
  • Accessory Nerve (XI)
  • Hypoglossal Nerve (XII)
• The medulla and pons


  Control breathing, heart rate, and other vital functions through the cranial nerves
• Midbrain


  • Located between the hindbrain and forebrain
  • Important for hearing and sight
  • One of several places in the brain that pain is registered
• Superior Collicus


  • Coordination of eye movements, particularly in response to visual stimuli
• Inferior Colliculus


  • Receives auditory information from the ears and is involved in the localization of sound sources
• Tegmentum


  • The coordination of fine motor movements
• Reticular formation


  • Functions of attention, sleep and arousal
• Substantia Nigra


  • Produces dopamine, a neurotransmitter involved in coordinating smooth and controlled movements
• Damage in the reticular formation


  May result in a coma
• Forebrain


  • Largest division of the brain – Cerebrum, Thalamus, and Hypothalamus
• Cerebrum


  • Responsible for thinking and language
• Thalamus


  • Relays and translates incoming messages from the sense receptors, except those for smell
• Hypothalamus


  • Governs motivation and emotional responses; keeps the body’s system within a healthy range; regulates sleep-wake cycles, sexual arousal, and appetite
• Basal Ganglia


  • Involved in the coordination of voluntary movements, procedural learning, and habits
• Cerebral Cortex

  • The outer surface of the cerebrum that regulates most of the complex behaviors
• Cerebral Cortex


  The outer surface of the cerebrum that regulates most of the complex behaviors
• Basal Ganglia


  A group of subcortical structures lateral to the thalamus, including the caudate nucleus, the putamen, and the globus pallidus
• Basal Ganglia


  1. Integrate motivational and emotional behavior to increase the vigor of selected actions

  2. Critical for learned skills and habits, as well as other types of learning that develop gradually

  3. Damage to the basal ganglia impairs movement, as in conditions such as Parkinson’s disease and Huntington’s disease
• Damages and Disorders to the Basal Ganglia

  • Parkinson’s Disease - tremors, rigidity, and bradykinesia
  • Huntington’s Disease - involuntary movements, cognitive decline, and psychiatric symptoms
  • Tourette Syndrome - characterized by repetitive, involuntary movements and vocalizations
  • Obsessive-Compulsive Disorder (OCD) - repetitive behaviors
• Limbic System


  A system in the brain that includes the hippocampus and amygdala, involved in memory and emotions
• Limbic System

  1. Hippocampus - plays a role in the formation of new memories

  2. Amygdala - processes basic emotions like fear and aggression and the memories associated with them

  3. Williams Syndrome - a rare genetic disorder involving amygdala damage
• Damages and Disorders to the Limbic System

  • Post-Traumatic Stress Disorder (PTSD)
  • Alzheimer’s Disease
  • Major Depressive Disorder
  • Temporal Lobe Epilepsy
  • Schizophrenia
  • Kluver-Bucy Syndrome
  • Borderline Personality Disorder
• Lobes of the Brain

  • Frontal lobe - coordinates messages from other cerebral lobes; higher-level cognitive functions like thinking, planning, and personality characteristics
  • Parietal lobe - integration of sensory information like touch and temperature
• Cerebral lobes

  • Higher-level cognitive functions like thinking, planning, and personality characteristics
• Precentral gyrus


  • Specialized for the control of fine movements, such as moving a finger
• Parietal lobe


  • Integration of sensory information like touch and temperature; involved in spatial abilities; essential for numerical information
• Lobes of the Brain

  • Occipital lobe - processing of visual information; primary visual cortex/striate cortex
  • Temporal lobe - smell and hearing; balance and equilibrium; language comprehension; complex visual processing and facial recognition
• Cortical Blindness is the destruction of any part of the striate cortex
• A tumor in the temporal lobe may give rise to elaborate auditory or visual hallucinations, whereas a tumor in the occipital lobe ordinarily evokes only simple sensations, such as flashes of light
• Louis Victor Leborgne, known as Tan, lost the ability to speak despite normal intelligence
• Wernicke's area is responsible for language comprehension while Broca's area is for language production
• Aphasia is the inability to use or understand language that usually results from brain damage
• Wernicke's Aphasia is difficulty understanding language (listening) while Broca's Aphasia is difficulty in sequencing and producing language (talking)
• The cerebrum has two distinct halves, left and right hemisphere, connected by the corpus callosum
• Roger Sperry pioneered in the field of hemisphere specialization and conducted the Split-Brain Experiment by cutting the corpus callosum
• Brain Disorders

  • Meningitis - inflammation of the meninges
  • Hydrocephalus - obstruction of CSF flow leading to increased pressure on the brain
  • Dementia - memory loss and decline in intellectual functioning
  • Encephalitis - swelling of the brain caused by viral infection
  • Epilepsy - disrupts nerve cell activity in the brain and causes seizures