Gyri
Folds on the outer surface of the brain
Sulci
Shallow depressions between folds on the brain
Primary brain vesicles
Formations from the embryonic neural tube that will give rise to the brain
Prosencephalon
Primary brain vesicle representing the forebrain
Mesencephalon
Primary brain vesicle representing the midbrain; superior portion of the brainstem; houses CNIII and CNIV
Rhombencephalon
Primary brain vesicle representing the hindbrain
Telencephalon
Secondary brain vesicle arising from the prosencephalon and eventually forming the cerebrum
Diencephalon
Secondary brain vesicle arising from the prosencephalon and eventually forming the thalamus, hypothalamus, and epithalamus
Mesencephalon
The only primary vesicle that does not form a new secondary vesicle
Metencephalon
Secondary brain vesicle arising from the rhombencephalon and eventually forms the pons and cerebellum
Myelencephalon
Secondary brain vesicle arising from the rhombencephalon and entually forms the medulla oblongata
Gray matter
Matter of the brain that houses motor neuron and interneuron cell bodies, dendrites, telodendria, and unmyelinated axons
White matter
Matter of the brain that derives its color from myelinated sheaths
Cerebral cortex
External layer of gray matter that covers the surface of most of the adult brain
Cerebral nuclei
Internal clusters of gray matter that lies deep the the white matter
Ganglion
Cluster of neuron cell bodies within the PNS
Center
Group of CNS neuron cell bodies with a common function
Nucleus
Center that displays discrete anatomic boundaries
Nerve
Axon bundle extending through the PNS
Nerve plexus
Network of nerves
Tract
CNS axon bundle in which the axons have a similar function and share a common origin and destination
Funiculus
Group of tracts in a specific area of the spinal cord
Pathway
Centers and tracts that connect the CNS with body organs and systems
Cranial meninges
Three connective tissue layers that protect the brain from the cranium
Pia mater
The innermost of the cranial meninges; highly vascularized and tightly adheres to the brain
Arachnoid
Middle cranial meninx
Arachnoid trabeculae
Web of elastic fibers of the arachnoid meninx
Subarachnoid space
Space immediately deep to the arachnoid meninx
Subdural space
A potential space between the arachnoid and dura mater meninges
Dura mater
Outermost cranial meninx; composed of a meningeal layer and a periosteal layer
Meningeal layer
Deep layer of the dura mater
Periosteal layer
Superficial layer of the dura mater
Dural venous sinuses
Blood-filled spaces where the meningeal and periosteal layers are not fused
Epidural space
A potential space between the bones of the skull and the dura mater meninx
Cranial dural septa
Flat partitions formed from the meningeal layer of the dura mater
Falx cerebri
Largest of the four dural septa; attaches anteriorly to the ethmoid bone and posterioinferiorly to the internal occipital crest; along the margins are the superior and inferior sagittal sinuses
Tentorium cerebelli
Horizontally oriented fold of dura mater that separates the occipital and temporal lobes of the cerebrum from the cerebellum; transverse sinus runs with posterior border and anterior has tentorial notch
Tentorial notch
An opening in the anterior region of the tentorium cerebelli that allows for the passage of the brain stem
Falx cerebelli
A sickle-shaped vertical partition that divides the left and right cerebellar hemispheres; occipital sinus runs along posterior vertical border
Diaphragma sellae
Smallest of the dural septa that forms a roof over the sella turcica of the sphenoid bone. A small opening allows for the passage of the infundibulum
Ventricles
Cavities or expansions within the brain that are derived from the lumen of the embryonic neural tube
Septum pellucidum
A thin medial partition that separates the two lateral ventricles
Third ventricle
A smaller ventricle that lies within the diencephalon
Interventricular foramen
Foramen of Munro; an opening through with the lateral ventricles communicate with the third ventricle
Cerebral aqueduct
Mesencephalic aqueduct, aqueduct of the midbrain, aqueduct of Sylvius; a passageway that connects the third ventricle with the tetrahedron-shaped fourth ventricle
Cerebrospinal fluid (CSF)
A clear, colorless liquid that circulates in he ventricles and subarachnoid space
Choroid plexus
A structure in the ventricles that produces CSF; composed of ependymal cells and the capillaries that lie within the pia mater
Ependymal cells
Cells in the choroid plexus that produce CSF
Arachnoid villi
Fingerlike extensions of the arachnoid that project through the meningeal layer of the dura mater into the dural venous sinuses that drain excess CSF
Cerebrum
Area of the brain associated with conscious thought processes and the origin of all complex intellectual functions
Fissures
Deep grooves that separate adjacent gyri
Longitudinal fissure
Deep groove that separates the left and right cerebral hemispheres
Tracts
Bundles of myelinated axons
Corpus callosum
Largest of the white matter tracts, a commissural tract that connects the left and right cerebral hemispheres and serves as the main communications link between them
Hemisphere lateralization
Functional differences between the left and right cerebral hemispheres
Central sulcus
Deep groove that serves as the boundary between the frontal lobe and the parietal lobe
Lateral sulcus
Deep groove that separates the frontal and parietal lobes from the temporal lobe
Precentral gyrus
Mass of nervous tissue immediately anterior o the central sulcus, associated with voluntary motor functions, concentration, verbal communication, decision making, planning, and personality
Parieto-occipital sulcus
Groove that separates the parietal and occipital lobes
Postcentral gyrus
Mass of nervous tissue immediately posterior to the central sulcus, associated with general sensory functions
Temporal lobe
Lobe that is inferior to the lateral sulcus and underlies the temporal bone; involved in hearing and smell
Occipital lobe
Lobe that forms the posterior region of each hemisphere and immediately underlies the occipital bone; responsible for processing incoming visual information and storing visual memories
Insula
A small lobe deep to the lateral sulcus, associate with memory and interpretation of taste
Primary (sensory) motor cortex
The cortex located within the precentral gyrus; neurons project contralaterally to control voluntary functions
Motor speech area
Broca area; usually located within the inferolateral portion of the left frontal lobe; responsible for controlling muscular movements necessary for vocalization
Frontal eye field
Area on the superior surface of the middle frontal gyrus, which is immediately anterior tot he premotor cortex in the frontal lobe; control and regulate eye movements for reading and binocular vision
Primary somatosensory cortex
Cortex within the postcentral gyrus of the parietal lobes; reeive somatic sensory informaiton from touch, pressure, pain, and temperature receptors
Primary visual cortex
Cortex within the occipital lobe; receives and processes incoming visual information
Primary auditory cortex
Cortex within the temporal lobe; receives and processes auditory information
Primary gustatory cortex
Cortex within the insula; involved in processing taste information
Primary olfactory cortex
Cortex within the temporal lobe; provides conscious awareness of smells
Association areas
Areas that integrate new sensory inputs with memories of past experiences
Premotor cortex
An association area located in the frontal lobe, immediately anterior tot he precentral gyrus; responsible for coordinating learned, skilled motor activies
Somatosensory association area
An association area located in the parietal lobe and lies immediately posterior to the primary somatosensory cortex; interprets sensory information and responsible for integrating and interpreting sensations to determine the texture, temperature, pressure
Auditory association area
An association area located within the temporal lobe, porsteroinferior to the primary auditory cortex; interprets the characteristics of sound and store memories of sounds heard in the past
Visual association area
An association area located in the occipital lobe and surrounds primary visual area; processes visual information by analyzing color, movement, and form, and to use this information to identify what is seen
Functional brain region
A region that acts like a multi-association area between lobes for integrating information from association areas
Wernicke area
A functional brain region, typically in the left hemisphere involved in recognizing, understanding, and comprehending spoken or written language
Gnostic area
Common integrative area; a functional brain region composed of regions of the parietal, occipital, and temporal lobes; integrates all sensory, visual, and auditory information being processed by the association areas within these lobes
Central white matter
White matter that is deep to the gray matter of the cerebral cortex and composed primarily of myelinated axons
Association tracts
Tracts that connect different regions of the cerebral cortex within the same hemisphere
Arcuate fibers
Fibers that compose short association tracts; they connect neighboring gyri within the same lobe
Longitudinal fasciculi
Fibers that compose longer association tracts and connect gyri in different lobes of the same hemisphere
Commissural tracts
Tracts that extend between the cerebral hemispheres through axonal bridges called commissures
Projection tracts
Tracts that link the cerebral cortex to the posterior brain regions and the spinal cord; i.e. corticospinal tracts that carry motor signals from the cerebrum to the brainstem and spinal cord
Cerebral (basal) nuclei
Paired, irregular masses of gray matter buried deep within the central white matter in the basal region of the cerebral hemispheres; sometimes incorrectly called the basal ganglia
Caudate nucleus
C-shaped nucleus that stimulates appropriate muscles to produce the pattern and rhythm of arm and leg movements associated with walking
Amygdaloid body (amygdala)
Limbic system structure; an expanded region at the tail of the caudate nucleus; participates in expression of emotions, control of behavior activities, and development of moods
Putamen
Mass of gray matter, part of the lentiform nucleus, that functions in controlling subconscious muscular movement
Globus pallidus
Mass of gray matter, part of the lentiform nucleus, that both excites and inhibits the activities of the thalamus to control and adjust muscle tone
Claustrum
A thin sliver of gray matter immediately internal to the insula that processes visual information at a subconscious level
Corpus striatum
Describes the striated or striped appearance of the internal capsule as it passes among the caudate nucleus and the lentiform nucleus
Epithalamus
Structure that partially forms the posterior root of the diencephalon and covers the third ventricle; posterior portion houses the pineal gland and the habenular nuclei
Pineal gland
Endocrine gland that secretes melatonin
Habenular nuclei
Part of the epithalamus that helps relay signals from the limbic system to the mesencephalon and are involved in visceral and emotional responses to odors
Thalamus
Paired oval masses of gray matter that lie on each side of the third ventricle
Interthalamic adhesion
A small, midline mass of gray matter that connects the right and left thalamic bodies
Thalamic nuclei
Gray matter of the thalamus that projects to particular regions of the cerebral cortex; sensory impulses from all conscious senses, except olfaction, synapse on these nuclei
Hypothalamus
Master control center of ANS
Brainstem
Structure that connects the prosencephalon and cerebellum to the spinal cord; formed from the mesencephalon, pons, and medulla oblongata
Cerebral peduncles
Motor tracts located on the anterolateral surfaces of the mesencephalon; somatic mtor axons descend from primary motor cortex through the peduncles to the spinal cord
Tegmentum
Area in mesencephalon that contains pigmented red nuclei and the reticular formation; integrates information from the cerebrum and cerebellum and issues involuntary motor commands to the muscles of the back to help maintain posture
Red nuclei
Pigmented nuclei in the tegmentum region of mesencephalon; reddish color due to blood vessel density and iron pigmentation
Substantia nigra
Bilaterally symmetrical nuclei within the mesencephalon; houses clusters of neurons that produce neurotransmitter dopamine
Dopamine
A neurotransmitter that affects brain processes that control movement, emotional response, and ability to experience pleasure and pain
Tectum
Posterior region of mesencephalon; contains two pairs of sensory nuclei that are relay stations in the processing pathway of visual and auditory sensations
Superior colliculi
Superior nuclei of mesencephalon; "visual reflex centers"; help visually track moving objects and control reflexes
Inferior colliculi
Paired, inferior nuclei of mesencephalon; "auditory reflex centers"; control reflexive turning of the head and eyes in the direction of sound
Pons
A bulging region on the anterior part of the brainstem that forms from the part of the metencephalon; houses sensory and motor tracts that connect to the brain and spinal cord
Middle cerebellar peduncles
Transverse groups of fibers that connect the pons to the cerebellum
Autonomic respiratory centers
Pneumotaxic center and apneustic center; regulate the rate and depth of breathing and modify the activity of the respiratory center in the medulla oblongata
Pyramids
Two longitudinal ridges in the medulla oblongata that house the motor projection tracts (corticospinal tracts)
Superior olivary complex
Nuclei in the inferior pons that receives auditory input and is involved in the pathway for sound localization
Medulla oblongata
Structure formed from the mesencephalon that is the most inferior part of the brainstem; all communication between the brain and spinal cord involves tracts that ascend or descend through this structure
Decussation of the pyramids
Crossing over or tracts in the medulla oblongata, whereby each tract controls the voluntary movements of the opposite side of the body
Inferior olivary nucleus
Nuclei in the medulla oblongata that relay ascending sensory impulses, especially proprioceptive information, to the cerebellar cortex
Inferior cerebellar peduncles
Tracts that connect the medulla oblongata to the cerebellum
Nucleus cuneatus
Nuclei in the medulla oblongata that relays somatic sensory information to the thalamus; receives sensory information from arm and hand of same side
Nucleus gracilis
Nuclei in the medulla oblongata that relays somatic sensory information to the thalamus; receives sensory information from leg and lower limbs of same side
Medial lemniscus
Bands of myelinated fibers that exit the nuclei of the medulla oblongata and decussate in the inferior region of the medulla oblongata
Cardiac center
Autonomic nuclei group in the medulla oblongata that regulates both the heart's rate and its strength of contraction
Vasomotor center
Autonomic nuclei group in the medulla oblongata that controls blood pressure by regulating the contraction and relaxation of smooth muscle in the arterioles
Respiratory center
Autonomic nuclei group in the medulla oblongata that regulates the respiratory rate; influenced by the apneustic and pneumotaxic centers of the pons
Cerebellum
The second largest part of the brain that develops from the metencephalon; coordinates and tunes skeletal muscle movements and stores memories of previously learned movement patterns
Folia
Folds of the cerebellar cortex
Vermis
A narrow band of cortex that separates the left and right cerebellar hemispheres; receives sensory input reoprting torso position and balance
Primary fissure
Groove that separates the anterior and posterior lobes of each cerebellar hemisphere
Arbor vitae
White matter of the cerebellum
Cerebellar peduncles
Thick tracks that link the cerebellum to the brainstem
Superior cerebellar peduncles
Tracts that connect the cerebellum to the mesencephalon
Middle cerebellar peduncles
Tracts that connect the pons to the cerebellum
Inferior cerebellar peduncles
Tracts that connect the cerebellum to the medulla oblongata
Limbic system
System that is composed of multiple cerebral and diencephalic structures that collaboratively process and experience emotions
Cingulate gyrus
Limbic system structure; internal mass of cerebral cortex located within the longitudinal fissure and superior to the corpus callosum;, surrounds diencephalon, can only be seen in a sagittal section, and receives input from the other limbic system compone
Parahippocampal gyrus
Limbic system structure; mass of cortical tissue in the temporal lobe; function is associated with hippocampus
Hippocampus
Limbic system structure; a nucleus located superior to the parahippocampal gyrus that connects the the diencephalon via the fornix; essential in storing memories and forming long-term memory
Olfactory bulbs, tracts, and cortex
Limbic system structures, since odors can provoke certain emotions or be associated with certain memories
Fornix
A thin tract of white matter that connects the hippocampus with other diencephalon limbic system structures