brain and cranial nerves

cerebrum

largest, most superior portion of the brain

cerebral hemispheres

“halves” of the cerebrum, divided into right and left; surfaces are highly folded

corpus callosum

located deep in the brain; c-shaped bundle of white matter that connects the cerebral hemispheres

cerebral cortex

thin, superficial layer of gray matter that covers the cerebrum

gyri (singular gyrus)

prominent fold or ridge on the surface of the cerebrum

sulci (singular sulcus)

shallow groove on the surface of the cerebrum

fissure(s)

deep, elongated groove on the surface of cerebrum; separates larger brain regions

longitudinal fissure

deep cerebral fissure that almost completely separates the two cerebral hemispheres

lateral sulcus

separates temporal and frontal lobes

parietal-occipital sulcus

separates parietal and occipital lobes

central sulcus

separates frontal and parietal lobes

precentral gyrus

located anterior to the central sulcus

postcentral gyrus

wide lateral fold located posteriorly to the precentral gyrus and central gyrus

frontal lobe

largest lobe in the human brain; located behind the forehead and most anteriorly in the cerebrum

parietal lobes

located between the frontal and occipital lobes, beneath the parietal bone

temporal lobes

each located on the lateral sides of the head/cerebrum, right behind the temples and ears

occipital lobe

smallest of the four lobes; located most posterior in the cerebrum

insula

small region of the cerebral cortex folded deep within the lateral sulcus; separates the temporal lobes from the frontal and parietal lobes

cerebellum

second-largest part of the brain; partially hidden by the cerebral hemispheres

cerebellar hemispheres

two large, lateral parts that sit on either side of the vermis

cerebellar cortex

outer layer of gray matter surrounding the cerebellum

folia

ridges on the surface of the cerebellum

vermis

narrow central structure that connects the two cerebellar hemispheres

arbor vitae

branching pattern of white matter located inside of the cerebellum; “tree of life”

diencephalon

division of the brain that includes the epithalamus, thalamus, and hypothalamus

thalamus

the walls of the diencephalon

hypothalamus

the floor of the diencephalon; region of the brain containing centers involved with subconscious regulation of visceral functions, emotions, drives, and coordination of neural and endocrine functions

pineal gland

nervous tissue in the posterior portion of the roof of the diencephalon; located in the epithalamus

anterior commissure

bundle of white matter nerve fibers that crosses the brain’s midline; connects cerebral hemispheres

interthalamic adhesion

a projection of gray matter that extends from the thalamus into the ventricle

mammillary bodies

a component of the limbic system; nuclei in the hypothalamus that affect eating reflexes and behaviors

optic chiasm

where optic nerve crosses

optic nerve

the second cranial nerve (II), which carries signals from the retina to the optic chiasm

optic tract

the tract over which nerve impulses from the retina are transmitted between the optic chiasm and the thalamus

pituitary gland

endocrine gland located in the sella turcica of sphenoid bone; connected to the hypothalamus by the infundibulum

infundibulum

a tapering, funnel-shaped structure in the brain that connects the pituitary gland and the hypothalamus

brainstem

the brain minus the cerebrum, diencephalon, and cerebellum; only includes the midbrain, pons, and medulla oblongata

midbrain

the mesencephalon; the region between the diencephalon and the pons

tectum

roof of the midbrain; posterior to the cerebral aqueduct

corpora quadrigemina

two pairs of sensory nuclei contained in the tectum

superior colliculi

one of two parts of the corpora quadrigemina; processes visual sensations

inferior colliculi

one of two parts of the corpora quadrigemina; processes auditory sensations

aqueduct of midbrain

a narrow channel on the posterior surface of the midbrain; aka cerebral aqueduct

tegmentum

the area anterior to the cerebral aqueduct

cerebral peduncles

nerve fiber bundles on the anterolateral surfaces of the midbrain

pons

the portion of the metencephalon that is anterior to the cerebellum; “seahorse belly”

transverse fibers

horizontally striated fibers on the pons

medulla oblongata

the most caudal of the brain regions; also called the myelencephalon

olive

oval-shaped swelling on the anterior surface of the superior medulla oblongata in the brainstem

central canal

passageway traveling superiorly through the medulla oblongata; opens to become the fourth ventricle

ventricles

spaces within the brain filled with cerebrospinal fluid

lateral ventricles

wing-shaped chambers filled with fluid within a cerebral hemisphere

septum pellucidum

thin plate of brain tissue that separates the two lateral ventricles

interventricular foramina

opening that allows fluid movement between the third and lateral ventricles

third ventricle

ventricle in the diencephalon; located between the two lateral ventricles

choroid plexus

vasculature located inside the fluid-filled ventricles of the brain

fourth ventricle

narrow canal connected to the third ventricle by the cerebral aqueduct

meninges

connective tissue layers surrounding the brain

dura mater

rough and fibrous outermost layer of the spinal cord

arachnoid mater

located just beneath the dura mater; the middle meningeal layer

pia mater

deepest layer that hugs the brain; consists of a meshwork of elastic and collagen fibers that are firmly bound to underlying neural tissue

falx cerebri

fold of dura mater that projects between the cerebral hemispheres in the longitudinal cerebral fissure

tentorium cerebelli

protects the cerebellum and separates it from the cerebral hemispheres; extends across the cranium at right angles to the falx cerebri

falx cerebelli

divides the two cerebellar hemispheres along the midsagittal line inferior to the tentorium cerebelli

superior sagittal sinus

lies within the falx cerebri; large and more superior dural venous sinus

inferior sagittal sinus

lies within the falx cerebri; large and more inferior dural venous sinus

transverse sinus

paired dural venous sinus that runs along the occipital bone

limbic system

located between the cerebrum and diencephalon; commonly known as the motivational system because it’s responsible for the desire to perform tasks

amygdala

one of few cerebral nuclei; acts as an interface between the limbic system, cerebrum, and various sensory systems; “almond”

cingulate gyrus

sits superior to the corpus callosum; nucleus inferior to the floor of the lateral ventricle

fornix

tract of cerebral white matter that connects the hippocampus with the hypothalamus

hippocampus

concealed by the gyri; a nucleus inferior to the floor of the lateral ventricle

olfactory nerve (I)

most superior cranial nerve

olfactory tracts

runs directly inferior to the frontal lobe

olfactory bulbs

located at the end of olfactory tracts; termination site of olfactory nerve (I)

optic nerve (II)

superior to mammillary bodies and optic tract

oculomotor nerve (III)

located behind pituitary gland, inferior to mammillary bodies

trochlear nerve (IV)

thin, line-shaped nerve adjacent to trigeminal nerve (V)

trigeminal nerve (V)

adjacent to trochlear nerve (IV); thicker and slightly inferior

abducens nerve (VI)

located on the pons; line-shaped and more medial than other nerves

facial nerve (VII)

superior and medial to vestibulocochlear nerve (VIII)

vestibulocochlear nerve (VIII)

two nerves next to each other; inferior to facial nerve (VII)

glossopharyngeal nerve (IX)

adjacent to the olive; thin line-shaped nerve superior to vagus nerve (X)

vagus nerve (X)

adjacent to the olive; posterior to hypoglossal nerve (XII)

accessory nerve (XI)

most inferior and closest to the brainstem

hypoglossal nerve (XII)

adjacent to the olive and the medulla oblongata