Brain and Cranial Nerves Review

A set of vocabulary flashcards covering the anatomy, function, and development of the human brain and the 12 pairs of cranial nerves.

Adult Human Brain (Weight)

The average weight of the adult brain is approximately $1.4\,kg$ ($3\,lb$).

Adult Human Brain (Volume)

The volume of the brain typically averages $1200\,mL$, though it can range from $750\,mL$ to $2100\,mL$ in functionally normal individuals.

Gyri

Rounded elevations on the surface of the cerebral cortex that increase surface area.

Sulci

Shallow depressions that separate the gyri of the brain.

Fissures

Deep grooves found on the surface of the cerebrum.

Cerebellum

The second-largest part of the brain responsible for coordinating complex somatic motor patterns and repetitive body movements.

Diencephalon

A region of the brain located under the cerebrum and cerebellum that includes the thalamus and hypothalamus.

Thalamus

Part of the diencephalon that relays and processes sensory information.

Hypothalamus

A region involved with emotions, autonomic function, and hormone production; it also connects to the pituitary gland.

Infundibulum

A narrow stalk connecting the hypothalamus to the pituitary gland.

Brainstem

A region that relays information between the spinal cord and the cerebrum or cerebellum; it includes the midbrain, pons, and medulla oblongata.

Midbrain

A brainstem structure that processes visual and auditory data, maintains consciousness, and generates reflexive somatic motor responses.

Pons

A brainstem structure that connects the cerebellum to the brainstem and contains nuclei for somatic and visceral motor control.

Medulla oblongata

The most inferior part of the brainstem that regulates autonomic functions such as heart rate, blood pressure, and digestion.

Prosencephalon

The primary brain vesicle also known as the 'forebrain.'

Mesencephalon

The primary brain vesicle also known as the 'midbrain.'

Rhombencephalon

The primary brain vesicle also known as the 'hindbrain.'

Septum pellucidum

A medial partition that separates the two lateral ventricles in the cerebral hemispheres.

Interventricular foramen

The opening through which the two lateral ventricles communicate with the third ventricle.

Cerebral aqueduct

A narrow canal in the midbrain that connects the third ventricle to the fourth ventricle.

Dura mater

The most superficial layer of the cranial meninges, consisting of an outer periosteal layer and an inner meningeal layer.

Falx cerebri

A large dural fold that projects between the cerebral hemispheres and contains the superior and inferior sagittal sinuses.

Choroid plexus

A combination of specialized ependymal cells and capillaries that produces approximately $500\,mL$ of cerebrospinal fluid (CSF) per day.

Arachnoid granulations

Large clusters of arachnoid villi in adults that absorb CSF into the venous circulation.

Ataxia

A disturbance in muscular coordination caused by damage to the cerebellum from trauma, stroke, or temporary impairment like intoxication.

Arbor vitae

The highly branched internal white matter of the cerebellum, often called the 'tree of life.'

Pineal gland

A structure in the posterior portion of the epithalamus that secretes the hormone melatonin.

Limbic system

A functional grouping of brain structures that establishes emotional states and facilitates memory storage and retrieval.

Association fibers

White matter fibers that form connections between different cortical areas within a single cerebral hemisphere.

Corpus callosum

A prominent band of commissural fibers that connects the two cerebral hemispheres.

Basal nuclei

Masses of gray matter embedded in the white matter of the cerebrum that direct subconscious activities like skeletal muscle tone and learned movement patterns.

Wernicke’s area

An integrative center primarily in the left cerebral hemisphere responsible for language comprehension.

Broca’s area

The motor speech area, primarily in the left hemisphere, which regulates the patterns of breathing and vocalization needed for speech.

Alpha waves

Brain waves observed in healthy, awake adults who are at rest with their eyes closed.

Beta waves

Higher-frequency brain waves that typically accompany intense concentration or mental stress.

Olfactory nerves (I)

Special sensory nerves responsible for the sense of smell.

Optic nerves (II)

Special sensory nerves responsible for the sense of vision.

Trigeminal nerves (V)

The largest cranial nerves, classified as mixed (sensory and motor), which provide sensation to the face and control muscles of mastication.

Vagus nerves (X)

Mixed cranial nerves widely distributed in the thorax and abdomen that control visceral organs and provide sensory information to the brainstem.