Lab 2: Functional Anatomy of the Brain

ventricles

A series of interconnected cavities within the adult brain

gray matter

Comprised of neuronal cell bodies and synapses.

white matter

Tracts that pass signals to/from different parts of the nervous system. Appears lighter in color due to the presence of myelin around its nerve fibers.

cortex

An additional outer layer of gray matter located in the cerebrum and cerebellum.

cerebrospinal fluid (CSF)

Produced from the choroid plexus. Bathes the brain by circulating through the ventricles.

lateral ventricles

A set of paired ventricles lying within the cerebral hemispheres.

septum pellucidum

A thin membrane that separates the lateral ventricles anteriorly.

interventricular foramen

Connection between lateral ventricles and third ventricle

third ventricle

Is surrounded by the diencephalon. Located between the lateral ventricles and the cerebral aqueduct.

cerebral aquedect

The part of the ventricle system that passes through the midbrain.

fourth ventricle

Diamond-shaped ventricle that is bordered anteriorly by the pons and posteriorly by the cerebellum.

central canal

Where CSF circulates in the medulla and spinal cord.

dura mater

The outermost meninx. It is fibrous and provides a resilient layer around the brain.

dural sinuses

Sublayers of the dura that have divided to form a route for blood. The purpose of this structure is to drain blood away from the brain and scalp.

arachnoid mater

Located on the innermost surface of the dura. Its delicate strands extend across the subarachnoid space to the pia mater.

pia mater

Menix that directly directly covers the brain.

subarachnoid space

Filled with CSF to provide a watery cushion surrounding the brain.

arachnoid granulations

Extensions of the arachnoid mater that allow excess CSF to be absorbed by the dural sinuses.

choroid plexus

Produces CSF.

lobes

Divisions of the cerebral hemisphere. Includes the frontal, parietal, occipital, temporal, and insular varieties.

insular lobe

The lobe tucked away in the lateral sulcus.

gyri

Ridges that cover the surface of the cerebrum.

sulci

Grooves that cover the surface of the cerebrum.

central sulcus

Separates the frontal from parietal lobes.

lateral sulcus

Divides the temporal from frontal and parietal lobes.

longitudinal fissure

The large cleft between the right and left hemispheres.

precentral gyrus

Located on the frontal lobe. Site of the primary motor cortex.

primary motor cortex

The region of the cortex that issues motor commands to the body.

postcentral gyrus

Located on the parietal lobe. Site of the somatosensory cortex.

somatosensory cortex

The region of the cortex that receives information regarding the general senses of the body.

visual cortex

Located in the occipital lobe.

auditory cortex

Along with the olfactory cortex, it is located in the temporal lobe.

olfactory cortex

Along with the auditory cortex, it is located in the temporal lobe.

gustatory (taste) cortex

Located in the insular lobe.

multimodal association areas

Found throughout the cortex, these areas integrate inputs from multiple senses. The prefrontal cortex is an example.

prefrontal cortex

A multimodal association area of the cortex known to be important in social interactions and personality.

commissural fibers

Connect the cortex to the cortex of the opposite hemisphere. The vast majority of fibers cross at the corpus callosum.

corpus callosum

White matter tracts that connect the two hemispheres of the brain.

fornix

A small commisure visible inferior to the corpus callosum

projection fibers

Connect the cortex to lower brain regions or the spinal cord. These fibers control muscles and relay senses to and from the body.

association fibers

Connect the cortex to adjacent regions of the same hemisphere.

basal nuclei

Also known as basal ganglia. These clusters of gray matter have many roles, primary among them is the regulation of movement initiation and the coordinated control of antagonistic muscle pairs (ex: biceps/triceps). Parkinson's disease results in over-activity of this structure.

midbrain

Region of the brain directly affected by Parkinson's disease. This region regulates activity of the basal nuclei.

diencephalon

Comprised of the thalamus, hypothalamus, and epithalamus.

thalamus

"Relay station of the brain." The site of synapse for nearly all sensory pathways. Signals are routed from the spinal cord or lower brain regions to the appropriate region(s) of the cerebral cortex.

interthalamic adhesion

two halves of the the thalamus make contact through the third ventricle.

hypothalamus

Contains several nuclei regulating many bodily functions (autonomic control, emotional center, body temperature control, sleep cycle control, pituitary control).

epithalamus

During development, this region above the thalamus develops into the pineal body and choroid plexus.

pineal body

Produces melatonin, which prepares the body for sleep.

brainstem

Comprised of the midbrain, pons, and medulla oblongata.

midbrain

Narrow region between the pons and thalamus.

red nucleus

Part of the midbrain that coordinates gross limb movements.

substantia nigra

Part of the midbrain that controls the basal nuclei. These dopamine-releasing neurons degenerate in Parkinson's disease leaving the basal nuclei unregulated.

cerebral peduncles

Large bundles of axons containing projection fibers that permit communication between the cerebral hemispheres and lower parts of the central nervous system.

superior colliculi

Nuclei on the posterior side of the midbrain that initiate visual reflexes, such as the coordination of eye and head movements when tracking a moving object.

inferior colliculi

Nuclei on the posterior midbrain that receive auditory information and coordinate reflexive actions in response to sounds.

corpora quadrigemina

Comprised of the superior and inferior colliculi.

pons

Contains mostly tracts of white matter passing to and from the cerebral cortex, making no connections within. It also contains nuclei that regulate sleep and autonomic function.

cerebellar peduncles

Large bundles of tracts of white matter passing into the cerebellum.

cerebellum

"Little Brain." Receives information from both the cerebral hemispheres and proprioceptors in the muscles and joints to calculate coordinated movements of the body. It is also involved in sensory, linguistic, emotional, planning/scheduling, and other non-motor functions.

arbor vitae

White matter within the cerebellum that exhibits a distinct tree-like branching pattern.

vermis

"Worm." A miniature third "lobe" at the center of the cerebellum.

medulla

Contains mostly white matter tracts. Contains the pyramids on its external surface. Also contains nuclei that regulate many functions of the body including: cardiovascular centers, respiratory centers, and autonomic centers.

pyramids

Large external ridges on the anterior surface of the medulla that contain the corticospinal tracts.

limbic system

Includes structures in the cerebral cortex, basal nuclei, thalamus, and hypothalamus. These structures coordinate to recognize social cues and elicit emotions and memory.

reticular formation

A loosely organized series of nuclei extending throughout the brainstem. It has an important role in filtering sensory information on its way to the cortex.

reticular activating system (RAS)

Keeps from conscious thought the multitude of stimuli coming from all of your tactile, visual, auditory, olfactory, and gustatory receptors. While constantly informing the brain, such information is not always desirable to the conscious mind and can detract from one's focus.

olfactory tract

An extension of the cerebral hemisphere. Visible on the surface of the brain.

olfactory bulb

Where the olfactory nerve synapses.

optic nerve

Carries information from the retina of the eye to the optic chiasm.

optic chiasm

Where about half of the optic nerve fibers cross to the opposite side of the brain.

optic tract

How information from the optic nerve travels to the thalamus.

Cranial Nerve I

Olfactory Nerve

Olfactory Nerve

Sensory from olfactory epithelium

Cranial Nerve II

Optic Nerve

Optic Nerve

Sensory from retina

Cranial Nerve III

Oculomotor Nerve

Oculomotor Nerve

Motor to most extrinsic eye muscles

Cranial Nerve IV

Trochlear Nerve

Trochlear Nerve

Motor to a single extrinsic eye muscle.

Cranial Nerve V

Trigeminal Nerve

Trigeminal Nerve

Motor to chewing muscles; sensory to face, oral, and nasal cavities.

Cranial Nerve VI

Abducens Nerve

Abducens Nerve

Motor to a single extrinsic eye muscle

Cranial Nerve VII

Facial Nerve

Facial Nerve

Motor to facial expression muscles; sensory from taste buds

Cranial Nerve VIII

Vestibulocochlear (Acoustic) Nerve

Vestibulocochlear (Acoustic) Nerve

Sensory from inner ear

Cranial Nerve IX

Glossopharyngeal Nerve

Glossopharyngeal Nerve

Motor to pharynx; sensory from taste buds

Cranial Nerve X

Vagus Nerve

Vagus Nerve

Motor and sensory to thoracic and abdominal organs

Cranial Nerve XI

Spinal Accessory Nerve

Spinal Accessory Nerve

Motor to neck and muscles

Cranial Nerve XII

Hypoglossal Nerve

Hypoglossal Nerve

Motor to tongue muscles

Mnemonic to remember 1st letter of nerves

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Mnemonic to remember Sensory, Motor, or Both

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