Brain and Cranial Nerves

• The brain receives sensory input, integrates new and stored information, makes decisions, and executes responses through motor activities.
• The cerebellum, located at the back of the skull, controls balance and coordination.
• The cerebral cortex is the outer layer of gray matter that covers most of the brain's surface.
• The medulla oblongata, located near the base of the skull, regulates vital functions such as breathing and heart rate.
• The medulla oblongata is responsible for regulating heart rate, breathing, blood pressure, swallowing, vomiting, sneezing, coughing, and reflex actions such as blinking or withdrawing from painful stimuli.
• Supraoptic region is superior to optic chiasm and contains paraventricular nucleus, supraoptic nucleus, anterior hypothalamic nucleus, and suprachiasmatic nucleus.
• Paraventricular and supraoptic nuclei form hypothalamohypophyseal tract which extends from infundibulum to the posterior lobe of the pituary.
• In the infant, the epidural anesthesia may reach inferiorly to the third lumbar vertebra.
• Adults' epidural anesthesia typically extends from L3-L5.
• Neonates' epidural anesthesia typically extends from L1-L2.
• The Brain stem and Reticular formation are located between the spinal cord and diencephalon.
• The Brain stem consists of three structures: Medulla oblongata, pons, and midbrain.
• The Reticular formation extends through the brain stem, a netlike region of interspersed grey and white matter.
• The Medulla oblongata is continuous with the superior part of the spinal cord and forms the inferior part of the brain stem.
• The Medulla oblongata begins at the foramen magnum and extends to the inferior border of the pons, a distance of 3 cm.
• The white matter of the Medulla oblongata contains all sensory (ascending) tracts and motor (descending) tracts.
• The Medulla oblongata has a pyramid bulge on the anterior aspect, and the large corticospinal tract from the cerebrum to the spinal cord is superior to the junction of the Medulla oblongata with the spinal cord.
• Ninety percent of axons in the left pyramid cross to the right side and vice versa.
• The olfactory area is responsible for the identification of odors and discrimination among different odors.
• During olfactory processing, the right hemisphere has more activity than the left hemisphere.
• Wernicke’s area, located in the left temporal and parietal lobes, is a broad region that interprets the meaning of speech by recognizing spoke words.
• The prefrontal cortex, located in areas 9, 10, 11, 12, makes up a person’s personality, intellect, complex learning abilities, recall of information, initiative, judgment, foresight, reasoning, conscience, intuition, mood, planning for future, and development of abstract ideas.
• Prefrontal cortex damage can lead to a person becoming rude, inconsiderate, incapable of accepting advice, moody, inattentive, less creative, unable to plan for the future, and incapable of anticipating consequences of rash or reckless words or behavior.
• The premotor area, located in area 6, is a motor association area immediately anterior to the primary motor area.
• The frontal eye field area, located in area 8, controls voluntary scanning movements of the eyes.
• Aphasia is an inability to use or comprehend words due to damage to Broca’s area, Wernicke’s area, or other language areas located in the left hemisphere.
• Hemispheric lateralization refers to the almost symmetrical right and left sides of the brain with subtle anatomical differences.
• Two-thirds of the population have a larger planum temporale, including the Wernicke’s area, on the left than on the right, indicating functional asymmetry and hemispheric lateralization.
• Language is located in the left hemisphere, visual and spatial skills are located in the right hemisphere, and females are less likely to suffer aphasia after damage to the left hemisphere.
• The anterior commissure is 12% larger and the corpus callosum has a broader posterior portion in females.
• Alpha rhythmic waves at 8-13 Hz are present in nearly all normal individuals when awake and resting with eyes closed; they disappear during sleep.
• Beta waves, which appear when the nervous system is active, are between 14-30 Hz.
• Theta waves, which normally occur in children and adults experiencing emotional stress, are between 4-7 Hz.
• Delta waves, which are normal in awake infants and during sleep in adults, are between 1-5 Hz.
• Concussion in sport has the highest incidence of brain waves.
• The hippocampus has cells reported to be mitotic and is responsible for some aspects of the memory that develop neurons in the elderly.
• The cerebrum functions in memory and its impairment results in memory impairment.
• The posterior half of both hemispheres receive sensory impulses in the sensory areas of the cerebral cortex.
• Primary sensory areas receive sensory information from peripheral sensory receptors and are adjacent to primary areas.
• Sensory association areas integrate sensory experiences into a meaningful pattern of recognition and awareness.