Central Nervous System – Chapter 12 Review

A comprehensive set of 45 question-and-answer flashcards covering embryonic development, protective structures, brain regions, neural pathways, dysfunctions, and higher mental functions of the central nervous system.

What causes the neural tube defect spina bifida?

Failure of the neural tube to completely close during embryonic convergence.

Which specialized structure produces cerebrospinal fluid (CSF)?

The choroid plexuses—ependymal cell layers lining the brain’s ventricles.

List the meningeal layers from outermost to innermost.

Dura mater, arachnoid mater, pia mater.

What space separates the arachnoid mater from the dura mater?

The subdural space.

What is the function of arachnoid granulations?

They project into the superior sagittal sinus to reabsorb CSF into venous blood.

Name three lipid-soluble substances that can freely cross the blood–brain barrier.

Fats (lipids), oxygen and carbon dioxide gases, and fatty acids (also alcohol, nicotine, anesthetics).

Define cerebral lateralization.

The phenomenon in which functions are shared but not equally divided between the two hemispheres, creating cerebral dominance.

Which white-matter fibers connect the two cerebral hemispheres?

Commissural fibers—most prominently the corpus callosum.

Which diencephalic structure is the major sensory relay center (except olfaction)?

The thalamus.

Which diencephalic region serves as the visceral control center for homeostasis?

The hypothalamus.

Which midbrain nucleus releases dopamine and degenerates in Parkinson’s disease?

The substantia nigra (especially its pars compacta).

What collective name is given to the superior and inferior colliculi?

The corpora quadrigemina.

What fibrous extension anchors the conus medullaris of the spinal cord to the coccyx?

The filum terminale (covered in pia mater).

Name the three principal directions of spinal cord white-matter tracts.

Ascending, descending, and transverse tracts.

Which type of paralysis results when ventral root or ventral horn neurons are destroyed, preventing any impulses from reaching muscles?

Flaccid paralysis.

Define ischemia in the context of a cerebrovascular accident (stroke).

A reduction in blood supply that impairs oxygen and nutrient delivery to brain tissue.

Which neurodegenerative disease is caused by huntingtin protein accumulation leading to basal nuclei and cortical degeneration?

Huntington’s disease.

Name the two cortical regions classically associated with language processing.

Broca’s area (language production) and Wernicke’s area (language comprehension).

Differentiate short-term memory from long-term memory.

Short-term (working) memory holds limited information briefly; long-term memory has large capacity and is more permanent, continually modified by rehearsal, association, and emotion.

What fills the brain’s ventricles and central canal of the spinal cord?

Cerebrospinal fluid.

State the primary function of the cerebellum.

To coordinate voluntary motor activity by comparing intended movements with incoming sensory information.

Which cerebral white-matter fibers connect regions within the same hemisphere?

Association fibers.

Which basal nuclei component is most associated with motor control, learning, memory, and executive function?

The caudate nucleus.

What is the purpose of the cauda equina?

It is the bundle of lumbar, sacral, and coccygeal nerve roots that extend beyond the spinal cord and exit at their respective foramina.

Which brain system maintains cortical alertness and filters repetitive stimuli?

The reticular formation (reticular activating system).

What embryonic flexures help shape the developing brain?

The midbrain, cervical, and pontine flexures.

Which CNS tissue type consists mainly of myelinated axons?

White matter.

What are the three functional areas of the cerebral cortex?

Motor areas, sensory areas, and association areas.

Which fibers connect the cerebral cortex to lower brain regions and the spinal cord?

Projection fibers.

Name the three divisions of the brain stem.

Midbrain, pons, and medulla oblongata.

Which portion of the brain stem houses cardiovascular and respiratory centers?

The medulla oblongata.

What connects the two cerebellar hemispheres?

The vermis.

What collective term describes transient episodes of reversible numbness or paralysis that warn of impending stroke?

Transient ischemic attacks (TIAs).

Which limbic system structures are key to emotion and memory?

The amygdaloid body (amygdala) and hippocampus.

What condition involves swelling of brain tissue following injury?

Cerebral edema.

Which degenerative disease involves beta-amyloid plaques, neurofibrillary tangles, and loss of cholinergic neurons?

Alzheimer’s disease.

What is the largest commissure in the brain?

The corpus callosum.

Which midbrain passage contains CSF and connects the third and fourth ventricles?

The cerebral aqueduct.

What spinal cord groove runs anteriorly and partially divides it into right and left halves?

The ventral (anterior) median fissure.

Damage to which roots or tracts causes loss of sensation or paresthesias?

Dorsal roots or ascending sensory tracts.

Which neurodegenerative disorder progressively destroys ventral horn motor neurons, leading to muscle weakness and atrophy?

Amyotrophic lateral sclerosis (ALS).

What phenomenon allows only strong, unusual, or significant sensory impulses to reach consciousness?

Sensory filtering by the reticular activating system.

Which basal nuclei segment regulates voluntary movement and is divided into internal and external portions?

The globus pallidus (internal GPi and external GPe).

Which brain lobe is most responsible for executive functions such as judgment and decision making?

The frontal lobe.

What pair of spinal cord enlargements accommodates nerves serving the limbs?

The cervical and lumbar enlargements.

Which structure of the epithalamus secretes melatonin to regulate sleep–wake cycles?

The pineal gland.