ct sectional anatomy chapter 3 brain Flashcards | Human Anatomy

The brain is a delicate organ that is surrounded andprotected
by three membranes called the

meninges pg 90

blank separates the two cerebellar hemispheres.

The falx cerebelli pg 90

blank separates the pia mater from the arachnoidmater. This
space contains cerebrospinal fluid thatcirculates around the
brain and spinal cord and providesfurther protection to the
central nervous system (CNS

subarachnoid space
90

Skull fractures with rupture of the meningeal arteriescan cause
a life-threatening condition known as

epidural hematoma (EDH

is a collection of blood from ruptured vessels located in the
subdural space

A subdural hematoma (SDH)

MENINGES

WHAT THE ORDER OF MENINGES OF THE BRAIN?

Dura materPia materArachnoid

DAP

VENTRICULAR SYSTEM

BLANK provides a pathway for the circulation of the cerebral spinal
fluid (CSF) throughout the CNS.

The ventricular system

WHAT FLOW THROUGH THE VENTRICULAR SYSTEM?

cerebral spinal fluid

HOW MANY VENTRICLES OR FLUID FILLED CAVITES DOES THE VENTRICULAR
SYSTEM HAVE?

four fluid-?lled cavities (ventricles) located deep within the brain

WHAT ARE THE TWO MOST SUPERIOR VENTRICLES?

The two most superior cavities are the right and left lateralventricles.?

WHAT SEPERATES THE TWO SUPERIOR RIGHT AND LEFT VENTRICLES?

are separated at the midline by a thin membraneknown as the
septum pellucidum

WHAT DOES THE SEPTUM PELLUCIDUM DO?

SEPERATES THE TWO SUPERIOR RIGHT AND LEFT VENTRICLES?

LATERAL VENTRICLES HAVE HOW MANY EXTENSIONS?

3

The lateral ventricles consist of a central portioncalled the body
and three extensions: the frontal (anterior),occipital (posterior),
and temporal (inferior) horns

The lateral ventricles consist of a central portioncalled the body
and three extensions: the frontal (anterior),occipital (posterior),
and temporal (inferior) horns 93

The junction of the body andthe occipital and temporal horns form a
triangular area CALLED BLANK

trigone (atria

The lateral ventricles communicate inferiorly with the third
ventricle via the paireD BLANK

interventricular foramen (foramen of Monro

The anterior wall of the third ventricle is formed by a thin membrane
termed the?

lamina terminalis

The third ventricle communicates with the fourth ventricle using what duct?

the cerebral aqueduct (aqueduct of Sylvius

what ventricle is a diamond-shaped cavity located anterior to the
cerebellum and posterior to the pons

The fourth ventricle

HOW DOES THE FOURTH VENTRICLE LIE TO THE CEREBELLUM?

POSTERIOR

CSF exits the ventricular system throughforamina in the fourth
ventricle to communicate with thesubarachnoid space within the basal
cisterns. The major exit route is the BLANK?

median aperture (foramen of Magendie)

WHATis frequently used as a landmarkto determine if the midline of
the brain has shifted as aresult of trauma or pressure?

The septum pellucidum 93

Located within the ventricular system is a networkof blood
vessels and nerve cells termed BLANK?

choroid plexus,

WHAT IS CHOROID PLEXUS?

a network of blood vessels and nerv

WHAT produces CSF?

CHOROID PLEXUS
PG99

WHAT MAKES THE CHOROID PLEXUS NOTICEABLE?

Frequently, the choroid plexus ispartially calci?ed, making it more
noticeable on computed tomography (CT) images

Excess CSF is reabsorbed in the dura sinuses by way of blank?

arachnoid villi pg 99

Enlargements of the arachnoid villi are termed

granulations

Cisterns pg 100

The subarachnoid space is a relatively narrow, fluid- ?lled space
surrounding the brain and spinal cord.There are locations, primarily
around the base of thebrain, where the subarachnoid space becomes
widened(Figure 3.17). The combined term for these widenedareas or
pools of CSF is the basal (subarachnoid)cisterns (Figure 3.20). Each
cistern is generally namedafter the brain structure it borders.

One of the largest cisterns is the blank?

cisterna magna.

Bleeding within the subarachnoid space is called a
subarachnoidhemorrhage (SAH). The most common causeof a SAH is a
ruptured aneurysm. Patients with thiscondition will commonly present
to the emergency departmentcomplaining of the worst headache of their
lives. Bloodwithin the subarachnoid space acts as a chemical irritant
to thebrain and causes an increase in intracranial pressure

What is the largest portion of the Brain?

cerebrum pg 102

what are the divisions of the cerebrum?

divided into left and right cerebral hemispheres

Each hemisphere contains neural tissue arranged in
numerousfolds called blank?

gyri

The gyri are separated by shallow grooves called sulci and by deeper
grooves called fissures

These gyri are important to identify because the precentralgyrus is
considered the motor strip of the brain and the postcentral gyrus is
considered the sensory strip of the brain. Other gyri important for
imaging include the cingulate,parahippocampal, and superior temporal gyrus

The two main ?ssures of the cerebrum are the longitudinal fissure
andthe lateral (Sylvian fissure

WHAT ARE THE TWO MAIN FISSURES OF THE CEREBRUM?

The two main ?ssures of the cerebrum are the longitudinal fissure
andthe lateral (Sylvian fissure

WHAT FISSURE DIVIDES THE the left and right cerebral hemispheres?

longitudinal ?ssure

WHAT FISSURE IS THE falx cerebri LOCATED IN?

longitudinal ?ssure

Numerous blood vessels, primarily branches of the middle
cerebralartery, follow the course of the lateral ?ssure

Numerousblood vessels, primarily branches of the middle
cerebralartery, follow the course of the lateral ?ssure

Gray and White Matter Organization

The cerebrum as a whole has many critically importantfunctions,
including thought, judgment, memory, anddiscrimination

BLANK IS (neuron cell bodies

gray matter

WHERE IS GREY MATTER LOCATED ?

N THE CEREBRUM

WHAT IS THE outermost portion of the cerebrum?

cerebral cortex

HOW THICK IS THE The cerebral cortex?

approximately 3 to 5 mm thick.

WHAT FUNCTION DOES THE cerebral cortex CONTROL?

body movemenT and activity.

The cortex notonly receives sensory input but also sends instructions
tothe muscles and glands for control of body movement and activity.

he cortex notonly receives sensory input but also sends instructions
tothe muscles and glands for control of body movement and activity.

Deep in the cortex is the white matter,which contains ?bers that
create pathways for the transmissionof nerve impulses to and from the
cortex. The largest and densest bundle of white matter ?bers within
the cerebrum is the corpus callosum

Deep in the cortex is the white matter,which contains ?bers that
create pathways for the transmissionof nerve impulses to and from the
cortex. Thelargest and densest bundle of white matter ?bers within

WHAT ARE THE four parts of the corpus callosum, from anteroinferior
to posterior

rostrum, genu, body, and splenium

Two other important bundles of white matter ?bers arethe
anterior and posterior commissures (Figures 3.29 and3.30). The
anterior commissure crosses the midline withinthe lamina
terminalis and connects the anterior portionsof each temporal
lobe (Figures 3.33 and 3.34). The posteriorcommissure is a
pathway made of several ?bers that

transmit nerve impulses for pupillary (consensual)
lightreflexes. This pathway crosses the midline posterior to
thethird ventricle, immediately above the cerebral
aqueductand inferior to the pineal gland (Figure 3.34).

Cerebral Lobes
108

Cerebral Lobes 108

HOW MANY DIVISIONS ARE IN THE CEREBRAL CORTEX?

4

WHAT ARE THE DIVSIONS CEREBRAL CORTEX?

frontal, parietal, occipital,and temporal (

WHAT BRAIN LOBE FUNCTION IS reasoning, judgment, emotional response,
planning andexecution of complex actions, and control of
voluntarymuscle movement.?

frontal lobE

WHAT BRAIN LOBE IS in speech production and contains the motor speech center?

frontal lobe

WHAT AREA IS INVOLVED IN in the coordination or programming of motor
movements for the production of speech AND sound

Broca�s area.

WHAT LOBE is associated with the perception of temperature, touch,
pressure, vibration,pain, and taste and is involved in writing and in
some aspects of reading.?

The parietal lobe

WHAT lobe is involved in the conscious perception of visual stimuli

occipital lobe

Located on the superior temporal gyrus is theauditory cortex, which
can be divided into primary andsecondary auditory areas (Figures 3.32
and 3.35). Theprimary auditory area, Heschl�s gyrus, receives the
majorauditory sensory information from the bilateral cochlea,whereas
the secondary auditory area, Wernicke�s area, isThe center for
comprehension and formulation of speech

what another name for the fifth lobe?

insula

Deep in the temporal lobe is another area of cortical gray matter
termed the insula (island of Reil),often referred to as the ?fth lobe.
The insula is separated from the temporal lobe by the lateral ?ssure
and is thought to mediate motor and sensory functions of the

The basal nuclei (ganglia) are a collection of
subcorticalgray matter consisting of the caudate
nucleus,lentiform nucleus, and claustrum (Collectively, they
contribute to the planningand programming of muscle action and
movement.The largest basal nuclei are the caudate nucleus and
lentiform nucleus. Both nuclei serve as relay

The basal nuclei (ganglia) are a collection of
subcorticalgray matter consisting of the caudate
nucleus,lentiform nucleus, and claustrum (Collectively, they
contribute to the planningand programming of muscle action and
movement.The largest basal nuclei are the caudate nucleus and
lentiform nucleus. Both nuclei serve as relay
pg 110

blank are a collection of subcorticalgray matter consisting of the
caudate nucleus,lentiform nucleus, and claustrum (Collectively, they
contribute to the planningand programming of muscle action and
movement.The largest basal nuclei are the caudate nucleus and
lentiform nucleus. Both nuclei serve as relay

The basal nuclei (ganglia)
pg 110

The diencephalon is a complex of structures within
the brain, whose major components are the thalamus and hypothalamus.
The diencephalon functions as a relay station for sensory information,
as an interactive site between the central nervous and endocrine
systems, and is closely associated with the limbic system.

The diencephalon is a complex of structures within
the brain, whose major components are the thalamus and hypothalamus.
The diencephalon functions as a relay station for sensory information,
as an interactive site between the central nervous and endocrine
systems, and is closely associated with the limbic system. 113

the thalamus and hypothalamus make up what ?

The diencephalon

WHAT IS THE FUNCTION OF THE The diencephalon?

functions as a relay station for sensory information

WHAT TWO BODY SYSTEM DOES THE diencephalon RELAY INFORMATION TOO?

central nervous and endocrine systems

The thalamus serves as a relay station to and from
the cerebral cortex for all sensory stimuli, with the exception of the
olfactory nerves

The hypothalamus functions to integrate the activities of the
autonomic, endocrine, and limbic systems helping to maintain
homeostasis as it controls regulation of temperature, appetite, sexual
drive, andsleep patterns

BLANK functions to integrate the activities of the
autonomic, endocrine, and limbic systems helping to maintain
homeostasis as it controls regulation of temperature, appetite, sexual
drive, andsleep patterns

hypothalamus

BLANK is sometimes called the master gland because it controls
andregulates the functions of many other glands through
theaction of its six major types of hor

Pituitary Gland

BLANK is an important structure that has a strong role in the
transition of short-term memory to long-term memory.

The hippocampus

BLANK coordinates the actions of the autonomic and
endocrinesystems and is concerned with decision-making,
emotional processing, and aggressive and sexual behavior

amygdala

BLANK are two small roundedbodies in the floor of the posterior
hypothalamusresponsible for memory and motivation

The mamillary bodies

The brainstem is a relatively small mass of
tissuepacked with motor and sensory nuclei, making it
vitalfor normal brain function. Ten of the 12 cranial
nervesoriginate from nuclei located in the brainstem.
Itsmajor segments are the midbrain, pons, and medulla

The midbrain (mesencephalon), which is located
abovethe pons at the junction of the middle and posterior
cranialfossae, is the smallest portion of the brainstem.
Themidbrain is primarily composed of massive bundles
ofnerve ?ber tracts and can be divided into two major
segments:cerebral peduncles and the tectum �quadrigeminal

plate� (Figure 3.58). The midbrain surrounds the
cerebralaqueduct, which contains CSF and connects thethird
and fourth ventricles. Posterior to the cerebralaqueduct is the
tectum, which makes up the roof or dorsal

. The substantia nigra isinvolved with the production of dopamine, a
neuro transmitter in the brain that functions in the control of
muscular reflexes. Within the tegmentum of the midbrain,at the level
of the superior colliculi, is the red

...

periaqueductal gray matter, which surroundsthe
cerebral aqueduct. This area receives sensoryinput that conveys pain
and temperature to the brain

...

BLANK conveys pain and temperature to the brain

periaqueductal gray

Deep within the center of each cerebellar hemisphereis a
collection of nuclei called BLANK

dentate nucleus

CEREBRAL VASCULAR SYSTEM

131

CEREBRAL VASCULAR SYSTEM

131

The vascular supply to the brain is unique. In comparisonwith
the arteries in the body, the walls of the arteriesin the brain
are thin and weak, causing them to be susceptibleto aneurysms
and strokes.

The veins of the brain do not contain valves. This lack of valves
allows theblood to flow in either direction, creating a route
for blood-borne pathogens to pass from the body to the head and vice versa.

DO THE VEINS IN THE BRAIN HAVE VALVES?

NO

The capillaries of the brain areunlike those elsewhere in the body in
that they do notallow movement of certain molecules from their
vascularcompartment into the surrounding brain tissue.
Thisunique quality of impermeability is termed the bloodbrain barrier (BBB).

The presence of a normal BBB prevents large amounts of contrast
medium from entering the brain.

The presence of a normal BBB prevents large amounts of contrast
medium from entering the brain

Pathologic conditions can disrupt the integrity of the BBB, allowing
contrast to escape from the vessel into the surrounding tissues

However, there are some structures located within the brain that do
nothave a BBB, so they will naturally enhance when contrast
media is used.

It is normal for the pituitary gland,infundibulum, pineal gland,
choroid plexus, mucosalsurfaces of the nasopharynx and sinuses, venous
structures,and the meninges to be enhanced to varying degrees after
contrast administration

Arterial Supply

Arterial Supply 131

HOW DOES THE BRAIN RECIEVE BLOOD?

The brain receives arterial blood from two main pairs ofvessels
and their branches, the internal carotid arteriesand the
vertebral arteries

WHAT TWO STRUCTURES TAKE BLOOD TO THE BRAIN?

1. internal carotid arteries
2. vertebral arteries

Internal Carotid Arteries. The internal carotid
arteries supply the frontal, parietal, and temporal lobes of the brain
and orbital structures. These arteries arise from the bifurcation of
the carotid arteries in the neck and can be divided into seven segments

WHAT ARTERIE SUPPLIES BLOOD TO THE FRONTAL PART OF
THE BRAIN?

Internal Carotid Arterie

WHAT ARTERIE SUPPLIES BLOOD TO THE TEMPORAL PART OF
THE BRAIN?

Internal Carotid Arterie

WHAT ARTERIE SUPPLIES BLOOD TO THE PARIETAL PART OF
THE BRAIN?

Internal Carotid Arterie

PIFT
AWAY TO REMEMEBER

The internal carotid artery then turns forward within the cavernous
sinus, then up and backward through the dura mater, forming an S
shape(which is referred to as the carotid siphon

The middle cerebral artery is by far the largest of
thecerebral arteries and is considered a direct
continuationof the internal carotid artery. The middle
cerebralartery gives off many branches, as it supplies much
ofthe lateral surface of the cerebrum, insula, and anterior

WHAT IS THE LARGEST CEREBRAL ARTERY?

The middle cerebral artery

The four major segments of the middle cerebral artery are the
horizontal(M1), insular (M2), opercular (M3), and cortical (M4)

Branches of the middle cerebral artery are locatedwithin the
internal capsule, causing this area to be themost frequent site
of strokes.

Vertebral Arteries

The two vertebral arteries course along the medulla oblongata

and unite ventral to the pons, to form the basilar

artery

The two vertebral arteries course along the medulla oblongata

and unite ventral to the pons, to form the basilar

artery

WHEN The two vertebral arteries course along
the medulla oblongata

and unite ventral to the pons, to form BLANK?

basilaR
artery

The four major pairs of arteries are listedin order from inferior to
superior: posterior inferior cerebellar(PICA), anterior inferior
cerebellar (AICA), superiorcerebellar (SCA), and posterior cerebral (PCA

...

PICA

posterior inferior cerebellar(PICA

(AICA)

anterior inferior cerebellar

(SCA)

superiorcerebellar

(PCA)

posterior cerebral

The posterior cerebral arteries can be divided into four major
segments: precommunicating or peduncular (P1), ambient (P2), quadrige
minal(P3), and calcarine (P4) (Figure 3.94). The
precommunicatingsegment is a short segment that extends laterallyfrom
the basilar bifurcation to the posterior communicating

...

The calcarine P4 segment is located on the medial surface of the
occipital lobe. The distal posterior cerebral artery frequently
divides by bifurcation ortrifurcation into many branches, including
several temporal and occipital arteries (Figures 3.94, 3.101, and 3.102

...

Circle of Willis. The cerebral arterial circle, or
circle ofWillis, is a critically important anastomosis among the four
major arteries (two vertebral and two internalcarotid) feeding the brain.

Circle of Willis. The cerebral arterial circle, or
circle of Willis, is a critically important anastomosis among thefour
major arteries (two vertebral and two internalcarotid) feeding the brain.

The circle of Willis is formed by the anterior and posterior
cerebral, anterior and posterior communicating, and the internal
carotid arteries.

...

The circle is located mainly in the suprasellar cistern atthe base of
the brain. Many normal variations of thiscircle may occur in
individuals. The circle of Willis functionsas a means of collateral
blood flow between cerebral hemispheres in the event of blockagE

Venous Drainage

The venous system of the brain and its coverings areprimarily
composed of the dural sinuses, super?cialcortical veins, and
deep veins of the cerebrum.

The dural sinuses are very large veins located within the dura mater
of the brain

BLANK are very large veins located within the dura mater of the brain

dural sinuses

All the veins of the head drain into the dural sinuses and
ultimatelyinto the internal jugular veins of the neck.

ALL THE VEINS OF THE HEAD DRAIN INTO WHAT SINUSES?

dural sinuses

ALL THE VEINS OF THE HEAD DRAIN INTO WHAT VEIN?

internal jugular veins

The deep veins of the cerebrum drain WHAT?

white matter

CRANIAL NERVES

HOW MANY CRANIAL NERVES ARE THERE

12

All but the ?rst and second cranial nerves arisE from the brainstem

WHAT CRANIUM NERVES DONT ARISE FROM THE BRAIN STEM?

1 AND 2

Olfactory (I) IS WHAT TYPE OF NERVE?

Sensory

Olfactory (I) FUNCTION IS

Smell

WHAT NERVE IS LOCATED IN THE Olfactory foramina incribriform
plate of ethmoid bone

Olfactory (I)

WHAT NERVE DOES Sensory

Optic (II)

WHAT NERVE IS LOCATED IN THE Optic foramen

Optic (II)

WHAT NERVE DOES VISION

Optic (II)

WHAT NERVE IS LOCATED IN THE Superior orbital ?ssure

Oculomotor (III)

WHAT NERVE FUNCITION IS Movement of superior, inferior, and medial
rectus; inferior oblique; and levator palpebrae muscles

Oculomotor (III)

Trochlear (IV) IS WHAT TYPE OF NERVE

Motor

WHAT NERV IS LOCATED IN THE Superior orbital ?ssure

Trochlear (IV)

WHAT NERVE CONTROL Movement of superior oblique muscle

Trochlear (IV)

Ophthalmic (V1) WHERE IS LOCATED

Superior orbital ?ssure

WHAT NERVE CONTOLS Sensation from cornea, scalp, eyelids, nasal
cavity, forehead

Ophthalmic (V1)

WHAT NERVE IS LOCATED IN Foramen rotundum

Maxillary (V2)

WHAT NERVE IS Sensation from upper lip, upper jaw and teeth,
maxillary sinuses, palate

Maxillary (V2)

WHAT NERVE IS IN THE Foramen ovale

Mandibular (V3)

WHAT NERVE FUNCTION Movement of muscles of mastication and suprahyoid
musclesSensation from lower jaw and teeth, TMJ, anterior 2/3 of tongue

Mandibular (V3)

WHAT NERVE CONTROLS Movement of lateral rectus muscle

Abducens (VI)

WHAT NERVE IS LOCATED Internal auditory canal, facial canal,
stylomastoid foramen

Facial (VII)

WHAT NERVE CONTROLS Movement of facial muscles and stapedius muscle
of middle earTaste from anterior 2/3 of tongue, floor of mouth
and palateSensation from EAM

Facial (VII)

Vestibulocochlear (VIII) WHERE IS IT LOCATED

Internal auditory canal

WHAT NERVE CONTROLS Sensation from vestibular structures for
equilibrium AND Hearing from cochlea

Vestibulocochlear (VIII)

Glossopharyngeal (IX) WHERE IS LOCATED

Jugular foramen

Glossopharyngeal (IX) WHAT DOES IT CONTROL

Movement of muscle for swallowingSensation from parotid gland,
carotid body and sinus, pharynx and middle earTaste from
posterior 1/3 of tongue

Vagus (X) WHERE IS IT LOCATED

Jugular foramen

WHAT DOES THE VAGUS CONTROL

Movement of pharyngeal and laryngeal musclesMovement of smooth
muscle in trachea, bronchi, digestive tract; moderatescardiac
pacemaker and vasoconstriction of coronary arteriesSensation
from EAM and dura mater of posterior cranial

Accessory (XI) WHERE IS LOCATED

Jugular foramen

WHAT NERVE CONTROL Movement of SCM and trapezius muscles

Accessory (XI) WHERE IS LOCATED
11

WHAT NERVE CONTROLS Movement of tongue muscles

Hypoglossal (XII)

The olfactory nerve is the nerve of smell

WHAT nerve is the nerve of smell

olfactory nerve

The axons of these cells unite to form 18 to 20 small
nervebundles that are known collectively as olfactory nerve

The optic nerve is the nerve of sight.

...

The oculomotor nerve moves the eye by supplying?bers to all
extraocular muscles of the eye except the

...

WHAT NERVE MOVES THE EYE

oculomotor nerve

The trochlear nerve innervates only the superior obliquemuscle
of the eye. It is the only cranial nerve that emergesfrom the
posterior surface of the brainstem

he trochlear nerve innervates only the superior obliquemuscle
of the eye. It is the only cranial nerve that emergesfrom the
posterior surface of the brainstem

WHAT NERVE is the only cranial nerve that emergesfrom the
posterior surface of the brainstem

The trochlear nerve

The abducens nerve supplies motor impulses to the lateralrectus
muscle of the eye.

The abducens nerve supplies motor impulses to the lateralrectus
muscle of the eye

WHAT NERVE nerve supplies motor impulses to the lateralrectus
muscle of the eye.

Abducens Nerve (CN VI)

The vestibulocochlear nerve exits the brainstem at
thepontomedullary junction and enters the internal
auditorycanal behind the facial nerve (Figure 3.58).
Thevestibulocochlear nerve has two distinct
components,vestibular and cochlear.

The vestibular branch picks up impulses from the
semicircular canals that aid in the maintenance of equilibrium.

...

The cochlear branch receivesimpulses from the
cochlea and separates these impulses into high and low frequencies for
the interpretation

...

The glossopharyngeal nerve supplies motor impulses
tothe muscles involved in swallowing. In addition, its
sensorycomponent can be divided into three groups: group1
innervates the posterior third of the tongue, Group 2

...