The Brain

• cerebrum

• diencephalon

• brainstem

• cerebellum

what are the four main regions of the brain?

gyri

the elevated folds of the outer surface of the brain

sulci

the depressions or valleys between the gyri of the outer surface of the brain

• telencephalon

• diencephalon

• mesencephalon

• metencephalon

• myelencephalon

what are the five regions of the brain during the fifth week of fetal development?

telencephalon

the region of the brain during fetal development that later forms the cerebrum

diencephalon

the region of the brain during fetal development that later forms the thalamus, hypothalamus, and epithalamus

metencephalon

the region of the brain during fetal development that later forms the pons and cerebellum

myelencephalon

the region of the brain during fetal development that later forms the medulla oblongata

• motor neuron bodies

• dendrites

• branching axon terminals

• unmyelinated axons

what does gray matter contain?

• myelinated axons

• dendrites

• neuroglial cells

what does white matter contain?

cortex

external sheets of gray matter that cover the surface of most of the adult brain

medulla

the inner region of white matter

diffuse axonal injury (DAI)

a brain injury where gray and white matter shear at the interface due to sudden deceleration or a car crash, most severe cases, the patient never regains consciousness

meninges

the connective tissue membranes that surround, support, and partition portions of the brain

pia mater

the innermost of the cranial meninges that is composed of delicate connective tissue and tightly adheres to the brain

arachnoid mater

the middle of the meninges that contains spider like collagen and elastic fibers called trabeculae

subarachnoid space

a space located deep to the arachnoid mater that contains the trabeculae, arteries and veins, and cerebrospinal fluid

subdural space

a potential space located between the arachnoid mater and the meningeal later of the dura mater, this is only a potential space unless blood or fluid accumulates there

subdural hematoma

a condition where blood or fluid accumulates in the potential space of the subdural space

dura mater

the outermost of the cranial meninges that is the strongest and has two fibrous layers

meningeal layer

the deep layer of the dura mater that is usually fused to the other layer except in areas where the two layers separate to form dural venous sinuses

periosteal layer

the superficial layer of the dura mater that forms the periosteum on the internal surface of the cranial bones

dural venous sinuses

large, blood filled spaces that appear between the meningeal and periosteal layers of the dura mater and drain blood from the brain to the internal jugular veins

epidural space

a potential space between the dura mater and the overlying skull bones that contains arteries and veins that nourish the meninges and bones of the cranium, this space is a potential space that only becomes an actual space due to an epidural hematoma

epidural hematoma

blood accumulation in the epidural space of the cranium

dural septa

the meningeal layer of the dura mater extends as flat partitions into the cranial cavity

falx cerebri

the dural septa that is the largest and projects into the longitudinal fissure between the two hemispheres of the cerebrum, it attaches anteriorly to the crista galli of the ethmoid bone and the frontal crest of the frontal bone, and posteriorly to the tentorium cerebelli and the internal occipital crest of the occipital bone

subfalcine brain herniation

a shift of one of the cerebral hemispheres under the falx cerebri due to swelling, bleeding, or a tumor (brain goes under falx cerebri)

tentorium cerebelli

the dural septa that runs horizontally and separates the occipital and frontal lobes of the cerebrum from the cerebellum, it essentially sits on the cerebellum

tentorial notch (tentorial incisure)

a small opening in the tentorium cerebelli that allows for passage of the brainstem

falx cerebelli

the dural septa that runs vertically and partially divides the cerebellum

diaphragma sellae

the smallest dural septa that forms a roof over the sella turcica, covering the pituitary gland, there is a small opening that allows passage of the infundibulum of the pituitary gland

ventricles

the empty spaces inside the brain that contain CSF and are derived from the lumen (opening) of the neural tube

lateral ventricles

the two large ventricles that are located in the cerebral hemispheres

septum pellucidum

the thin partition that separates the lateral ventricles

third ventricle

the ventricle that is located within the diencephalon

fourth ventricle

the ventricle that is located between the pons and the cerebellum, it narrows and merges with the central canal in the spinal cord

occipital lobe and second ventricle (left lateral ventricle)

where did the bullet that killed Abraham Lincoln pass through?

between C4 and C5

where did the bullet that killed John Wilkes Booth pass through?

cerebrospinal fluid

the clear fluid that circulates in the ventricles and subarachnoid space

• buoyancy

• protection

• environmental stability

what three purposes does CSF have?

choroid plexi

the vascular structures that are formed by ependymal cells and line the ventricles and produce cerebrospinal fluid

cilia of ependymal cells

what helps circulate the cerebrospinal fluid?

arachnoid villi

fingerlike extensions of the arachnoid mater that project through the dura mater into the dural venous sinuses

arachnoid granulations

collections of arachnoid villi

• CSF produced by choroid plexi in ventricles

• flows through ventricles

• enters subarachnoid space

• drained back into blood via arachnoid villi that empty into dural venous sinuses

what is the order of circulation of CSF?

• choroid plexi

• hypothalamus

• pineal gland

in what three distinct locations is the blood-brain-barrier missing?

blood-brain-barrier

the combination of blood capillaries and astrocytes to create less permeable blood vessels to keep toxins and hazardous materials out of the fluids of the CNS

cerebrum (telencephalon)

the largest part of the brain responsible for conscious thought and intellectual functions

cerebral cortex

the outer gray layer of the cerebrum that contains gyri and sulci

cerebral medulla

the inner white layer of the cerebrum

cerebral hemispheres

the two halves of the cerebrum

longitudinal fissure

the deep separation of the cerebral hemispheres

corpus callosum

the white matter tract that connects the two hemispheres of the cerebrum

frontal lobes

the lobes of the cerebrum that are located at the front and form the anterior portion

• voluntary motor functions

• concentration

• verbal communications

• decision making

• planning

• personality

what are the responsibilities of the frontal lobes?

parietal lobes

the lobes of the cerebrum located internal to the parietal bones and form the superoposterior portion

• sensory functions

• understanding speech

• formulating speech

what are the responsibilities of the parietal lobes?

temporal lobes

the lobes of the cerebrum that are internal to the temporal bones

• hearing

• interpreting speech and language

• smell (olfaction)

what are the responsibilities of the temporal lobes?

occipital lobes

the lobes of the cerebrum located beneath the occipital bone

• processing incoming visual information

• storing visual memories

• eye movements

what are the responsibilities of the occipital lobes?

insula

the lobes of the cerebrum located deep to the temporal lobes

• memory

• taste

• empathy/emotions

what are the responsibilities of the insula?

• frontal

• parietal

• temporal

• cerebellum

which parts of the brain help with language and speech in general?

medulla oblongata

Where do the ascending and descending tracts between the brain and spinal cord cross over?

coup-contrecoup

injuries that occur to the cerebrum when a blow to the head causes the brain to shift forward and back, hitting the skull on both ends, this injury can also cause a diffuse axonal injury

diencephalon

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

epithalamus

the part of the brain that partially forms the posterior roof of the diencephalon and covers the third ventricle

pineal gland

the endocrine gland located in the epithalamus that is responsible for producing melatonin and regulating the circadian rhythm

thalamus

the paired oval masses of gray matter that lie on either side of the third ventricle, they are responsible for relaying all sensory information except the sense of smell

thalamus

which part of the brain filters out repetitive or non-essential sights and sounds?

hypothalamus

the part of the brain that is the anteroinferior region of the diencephalon

• master of autonomic nervous system

• secretes hormones

• temperature control

• emotional responses

• hunger and thirst

• regulates circadian rhythm with pineal gland

what are the functions of the hypothalamus?

antidiuretic hormone (ADH) and oxytocin

what hormones does the hypothalamus produce that are stored in the pituitary gland?

brainstem

the part of the brain that is a bidirectional passageway for all nerve tracts extending between cerebrum and spinal cord

mesencephalon

the superior portion of the brainstem that is concerned with visual and auditory reflexes as well as control of posture

pons

the most superior bulge of the brainstem that helps with sound localization and regulating breathing

medulla oblongata

the inferior bulge of the brainstem that is where many nerve tracts cross over

decussation

the process of nerve tracts crossing over

somatic twist

the evolutionary process that resulted in a huge rearrangement of the entire body

• sensory relay

• relay to thalamus

• cardiac center

• vasomotor center (controls vessel diameter)

• respiratory center

• vomiting

what are the functions of the medulla obongata?

cerebellum

the smaller part of the brain located under the cerebrum and is separated by the tentorium cerebelli

cerebellar cortex

the outer layer of gray matter of the cerebellum

arbor vitae

the inner layer of white matter of the cerebellum that resembles a tree

• muscle memory

• equilibrium and posture

• resting muscle tone

what are the main functions of the cerebellum?

cerebellar cognitive affective syndrome (CCAS)

cerebellar damage that subsequently displays defects with language, cognition, and behavior/mood

chiari malformation

inadequate room for the cerebellum that causes the cerebellar tonsils to be pushed out of the foramen magnum, it can be treated with decompressive surgery

reticular formation

a functional system of gray matter in the brain that contains a motor and sensory component

motor component

the component of the reticular formation that is responsible for regulating muscle tone at rest

sensory component

the component of the reticular formation that is responsible for alerting the cerebrum to incoming sensory information

reticular activating system

a component of the sensory component of the reticular formation that maintains a sense of awareness and consciousness, it keeps the cerebrum alert and awake

limbic system

a system in the brain that collectively processes and experiences emotions, it can influence the endocrine system, and is the reason certain smells bring back memories

rostrocaudal brain deterioration (brain code)

a medical sequence that occurs when the cerebrum pushes down through the tentorial incisure, because of head trauma, bleeding, tumors, or other inflammation

infarct

local area of dying or dead tissue

hemiplegia

contralateral paralysis of the body

transient ischemic attack

a temporary plug in a blood vessel that dissolves in a matter of minutes, but puts at risk for more serious blood vessel blockage in the future

aneuysm

a bulge in the wall of a cerebral artery that ruptures

transtentorial brain herniation

brain tissue shifts from one intracranial compartment to another, specifically through the tentorial notch

transforaminal herniation

a type of brain herniation where brain tissue is forced downward through the foramen magnum