Chapter 12 Part 2 Central Nervous System

Medulla oblongata

Inferiormost part of the brain stem.

Cerebral peduncles

Contain fibers (motor tracts) that carry motor output from cerebrum to other regions of CNS.

Substantia nigra

area of midbrain

involved in motor control.

Chloroid plexus

layer of ependymal cells lining ventricles of the brain

produce cerebrospinal fluid.

Decussation of pyramids

Crossover points of corticospinal tracts passing through medulla oblongata.

Vermis

Connects two hemispheres of cerebellum.

Folia

Folds of cerebellar cortex.

Arbor vitae

White matter of cerebellum

looks like a tree.

Limbic system

Functional brain system involved in emotional response and memory formation.

Amygdaloid body

Acts as interface between limbic system, cerebrum, and various sensory systems.

Recognizes angry or fearful facial expressions, assesses danger, and elicits fear response.

Psychosomatic illness

When strong emotions cause physical symptoms.

Reticular formation

nerve network

travels through brainstem and thalamus outward to cerebral cortex

plays an important role in controlling arousal.

Reticular activating system

Diffuse brain stem neural network

receives wide variety of sensory input

maintains wakefulness of ht cerebral cortex.

Broca's area

Controls language muscle formation and execution

area of frontal lobe, usually in left hemisphere

directs muscle movements involved in speech.

Wernicke's area

Area of brain involved in understanding spoken and written language.

Memory

Storage and retrieval of information in brain.

Short-term memory

Temporary holding of information in brain

limited to 7 or 8 pieces of information.

Long-term memory

relatively permanent and limitless storehouse of the memory system

Includes knowledge, skills, and experiences.

Memory consolidation

strengthening of neural network that represents a memory.

EEG

electroencephalogram

amplified recording of waves of electrical activity that sweep across the brain's surface

waves measured by electrodes placed on scalp

Brain waves

Patterns of electrical activity generated by brain.

Alpha waves

relatively slow brain waves of relaxed, awake state.

Beta waves

Smaller and faster brain waves

indicat alert mental activity.

Theta waves

Brain waves indicat

early stages of sleep

also common in awake children.

Delta waves

high-amplitude, slow brain waves

associated with deep sleep when reticular activating system is suppressed.

Epileptic seizures

Abnormal electrical discharges of groups of brain neurons

during which no other messages can get through.

Aura

sensory experience or hallucination preceding an epileptic seizure or migraine headache.

Syncope

Fainting or sudden loss of consciousness caused by lack of blood supply to cerebrum.

Coma

State of prolonged unconsciousness with lower oxygen consumption than sleep or other forms of unconsciousness.

Brain death

State of irreversible coma, even though life-support measures may have restored other body organs.

Non-rapid eye movement

state of sleep

body is nearly motionless

Slow heart rate, breathing, and brain-wave activity

Rapid eye movement

Stage of sleep

rapid eye movements, alert EEG pattern, and dreaming occur.

Narcolepsy

sleep disorder

individual slips into abrupt sleep from awakened state.

Orexins

Chemical messengers from hypothalamus

play role in wakefulness and vigilance.

Insomnia

Chronic inability to obtain amount or quality of sleep needed.

Blood brain barrier

Mechanism that inhibits passage of materials from the blood into brain tissues

reflects relative impermeability of brain capillaries.

Concussion

Injury of brain

occurs when strong force causes brain to hit inside wall of skull, temporarily altering brain function.

Contusion

bruised brain caused when force of blow to head is great enough to rupture blood vessels and cause permanent damage.

Subdural hemorrhage

Collection of blood on surface of the brain under membranes

Can put pressure on brain and force brain stem through foramen magnum, resulting in death.

Cerebral edema

Swelling of brain associated with traumatic head injury.

Cerebrovascular accidents

Condition in which brain tissue is deprived of blood supply,

blockage of cerebral blood vessel

stroke.

Alzheimer's disease

degenerative brain disease resulting in progressive loss of memory and motor control, and increasing dementia.

Parkinson's disease

Neurodegenerative disorder of basal nuclei due to insufficient secretion of neurotransmitter dopamine

symptoms include tremor and rigid movement.

Huntington's disease

Hereditary disorder leading to degeneration of basal nuclei and cerebral cortex.