Chapter 3 RADR 2340
Limbic system
"the emotional brain" (emotions, anger, aggression, fear, sorrow, sexual)
Review the axial MR image below. Which number labels the third ventricle?
#110
Review the axial MR T2-weighted image below. Number 16 labels the:
#16 Choroid plexuses
Refer to the image below. Which structure of the cerebellum is labeled as number 3?
#3- VERMIS
Refer to the image below. Which structure of the brainstem is labeled as number 4?
#4- Cerebral peduncle
Refer to the image below. Gray matter is labeled as what number?
#4- gray matter
Review the axial MR image below. Which number labels the fourth ventricle?
#5- Fourth Ventricle
Refer to the image below. Which structure of the brainstem is labeled as number 5?
#5- OLIVE
Review the midsagittal MR image below. The cerebellar tonsils are labeled as what number?
#5- Tonsils
Review the midsagittal MR image below. What number labels the cerebellar tonsils?
#5- Tonsils
Review the midsagittal MR image below. What structure of the brainstem is labeled as number 6?
#6- PONS
Review the coronal MR image below. What number labels the trochlear cranial nerve?
#6- Trochlear
Review the sagittal MR image below. The thalamus is labeled with the number?
#9- thalamus- MR Image
Three structures comprise the diencephalon:
(1) Epithalamus (2) Thalamus- largest component, forms the lateral walls (3) Hypothalamus
corpus callosum
(1) Rostrum - the inferior portion of the anterior curve ("R" in illustration) (2) Genu - the anterior curve ("G" in illustration) (3) Body - the upper arched portion ("B" in illustration) (4) Splenium - the posterior portion ("S" in illustration)
The parahippocampal gyrus encloses two structures of the limbic system:
(1) The amygdala (2) The hippocampus
Within the cerebral peduncles are two specialized areas:
*red nucleus (motor tract relays impluses from cerebrum to cerebellum) *substantia nigra (melanin, darker pigment). secretes dopamine, a neurotransmitter that is necessary for control of muscle reflexes
Which of the following structures are parts of the brainstem? Midbrain & Pons
1 and 2 only
Which of the following are parts of the limbic system of the brain? (1) Amygdala(2) Hypothalamus(3) Hippocampus
1 and 3 only
Which of the following brain structures are parts of the limbic system? (1) Fornix(2) Cingulate gyrus(3) Amygdala
1, 2, and 3
Which of the following are pure motor nerves in function? (1) Vagus(2) Trochlear(3) Hypoglossal
2 and 3 only
Hypothalamus (forms floor of 3rd ventricle)
A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.
What is the tegmentum of the brainstem?
A specialized sheath that connects all three portions of the brainstem
Suprasellar cistern
Also known as the chiasmatic cistern Located above the sella turcica Contains the optic chiasm and the circle of Willis
Which subarachnoid cistern runs along the lateral sides of the midbrain?
Ambient Cistern
The portion of the limbic system that functions in processing and expressing emotions, such as aggression, anger, and fear, is the:
Amygdala
The arteries that supply the frontal, parietal, and temporal lobes of the cerebrum, as well as the orbits, are the:
Anterior cerebral arteries
Cingulate Gyrus
Arch-shaped, raised cerebral fold that closely follows the superior arch of the corpus callosum
What are the basal nuclei?
Areas of gray matter located deep within the cerebrum that function together to coordinate muscle action and movement
Areas of gray matter located deep within the cerebrum that function together to coordinate muscle action and movement are termed the
Basal Nuclei
The right and left vertebral arteries unite to form the:
Basilar Artery
Which cranial nerve provides sensory and motor functions through branches to the eye regions as well as the upper and lower jaws?
CN V- Trigeminal Nerve
Which cranial nerve innervates the lateral rectus muscles of the eyes?
CN VI ABDUCENS
What is located in the subarachnoid space?
CSF- serves as the 3rd layer of cushion for the brain
The basal nuclei are the:
Caudate nucleus Runs along the lateral ventricle Includes three portions: head, body, and tail Lentiform nucleus Shaped like a lens (biconvex) Located between the insula, caudate nucleus, and thalamus Includes two divisions: globus pallidus and putamen Claustrum Thin, linear structure Located between the insula and lentiform nucleus Amygdala Small, almond-shaped nucleus Located anterior to inferior horn of lateral ventricle Functions as part of limbic system
Rope-like bands of white matter that pass through the midbrain are the:
Cerebral peduncles
The structure(s) that produce cerebrospinal fluid are termed:
Choroid Plexuses
Epithalamus (forms roof of 3rd ventricle)
Contains pineal body. Involved in olfactory senses and sleep/wake cycle
Which portion of the cerebellum relays motor impulses via the thalamus to the cerebrum?
Dentate nucleus
The epithalamus, thalamus, and hypothalamus are portions of the:
Diencephalon
The portion of the diencephalon that forms the roof of the third ventricle is the:
Epithalamus
All of the following are pure sensory nerves in function, except:
FACIAL
Refer to the image below. Which dural fold is labeled as number 3?
Falx cerebelli
Which of the following functions as an efferent pathway connecting the hippocampus to the mammillary bodies and to other functional areas of the brain?
Fornix
Review the axial MR image below. Which ventricular structure is labeled as number 4?
Frontal Horn of lateral ventricle
The division of the brain that contains the language centers is the:
Frontal lobe
The cortex of the cerebrum is comprised of:
Gray Matter
Refer to the image below. Number 4 labels the:
Gray matter of cerebral cortex
The short, deep vein formed by the junction of the internal cerebral and basal veins is the:
Great cerebral vein
The cranial nerve known as the glossopharyngeal nerve is number:
IX glossopharyngeal nerve.
The portion of the midbrain that relays auditory stimuli to the thalamus is the:
Inferior colliculi
The portion of the diencephalon that connects the pituitary gland to the hypothalamus is the:
Infundibulum
White matter, forming corpus striatum "striped body"
Internal capsule - separates the thalamus and caudate nucleus from the lentiform nucleus External capsule - separates the claustrum from the lentiform nucleus Extreme capsule - separates the claustrum from the cortex of insula
The communicating channel between the lateral and third ventricles is
Interventricular foramen
What is the function of cerebrospinal fluid?
It serves as a cushion to protect the brain.
The middle cerebral artery supplies the:
Lateral cerebrum and basal ganglia
The primary divisions of the cerebellum are the:
Lateral hemispheres
Prepontine cistern
Lies below and anterior to the pons Connected to the cerebellopontine angle cistern laterally
Interpeduncular cistern
Located between the midbrain peduncles Communicates inferiorly with the prepontine cistern
Cerebellopontine angle (CPA)
Located lateral and anterior to the pons and cerebellum Contains cranial nerves V, VII, and VIII as well as the superior and anterior inferior cerebellar arteries
Quadrigeminal cistern
Located posterior to the midbrain colliculi (quadrigeminal plate) between the splenium of the corpus callosum and the superior cerebellum
Mammillary Bodies
Memory recognition and relay station, receiving impulses from the fornix and transmitting them to the thalamus and midbrain
Three structures comprise the brainstem:
Midbrain Pons Medulla oblongata
The portion of the cerebellum that connects it to the pons is the:
Middle peduncles
Sagittal MRI - Cerebellum
Note The fourth ventricle appears triangular in this plane and is immediately anterior to the cerebellum. The cerebellar tonsils project downward from the lateral hemispheres and toward the medulla oblongata.
The olfactory nerve is cranial nerve number:
ONE
The division of the brain that contains the visual perception centers is the:
Occipital Lobe
Refer to the image below. Which cranial nerve is labeled as number 1?
Oculomotor
Cranial nerve III controls several eye muscles and is also known as the:
Oculomotor nerve
Cisterna magna
One of the largest cisterns Located in the lower posterior fossa between the medulla oblongata, occipital bone, and the hemispheres of the cerebellum Continuous with the subarachnoid space of the spinal canal
Midsagittal MRI of brain
Outlining the lateral ventricle is the corpus callosum. The anterior curve is termed the genu and the posterior curve, the splenium. The third ventricle is not visible because the thalamus provides the lateral wall, and this patient has an adhesion in the thalamus
The division of the brain located posterior to the central sulcus is the:
Parietal lobe
Tentorium cerebelli
Partition between the cerebrum and the cerebellum
Falx cerebelli
Partition between the two cerebellar hemispheres
The portion of the diencephalon that acts as the biologic clock for the body is the:
Pineal Gland
All of the following are part of the diencephalon, except: Thalamus Epithalamus Pit. Gland Pons
Pons
In the cerebral arterial circle (of Willis), which artery connects the anterior circulation with the vertebral-basilar circulation?
Posterior communicating artery
Refer to the image below. Which ventricular structure is labeled as number 7 in this axial MR image?
Posterior horn of lateral ventricle
The branch of the vertebral artery that supplies the inferior cerebellum is the:
Posterior inferior cerebellar artery (PICA)
What is the function of the choroid plexuses?
Produces CSF
The functions of the mammillary bodies are:
Relay of impulses from the amygdala and hippocampus to the thalamus
Which of the following describes the functions of the pons?
Relays sensory information between the spinal cord, cerebellum, and cerebrum and has some function in controlling autonomic responses, such as respirations
The structure that separates the lateral ventricles is the:
Septum pellucidum
The dural sinus that is a continuation of the transverse sinus along the parietal, temporal, and occipital bones is the
Sigmoid
Sagittal MRI - Basal nuclei T2- weighted MR
Since the basal nuclei are made of gray matter, look for the lighter structures surrounded by darker white matter. The internal capsule is a thin strip of white matter that separates the thalamus from the lentiform nucleus
tonsils
Small prominence's on the inferior aspect of the cerebellar hemispheres
Which dural sinus is located at the junction of the falx cerebri and tentorium cerebelli?
Straight sinus
Parahippocampal gyrus
Structure that encloses the amygdala and hippocampus
There are three pairs of cerebellar peduncles:
Superior cerebellar peduncles - connect the cerebellum to the midbrain Middle cerebellar peduncles - connect the cerebellum to the pons Inferior cerebellar peduncles - connect the cerebellum to the medulla oblongata
Which of the following brainstem structures functions in coordinating eye movements with those of the head?
Superior colliculi
The portion of the cerebellum that connects it to the midbrain is the:
Superior peduncles
Which dural sinus is located at the superior border of the falx cerebri?
Superior sagittal sinus
A specialized sheath that connects all three portions of the brainstem is the:
Tegmentum
The division of the brain located inferior to the lateral fissure is the:
Temporal Lobe
Which dural fold separates the cerebrum from the cerebellum?
Tentorium cerebelli
The portion of the diencephalon that acts to transmit sensory impulses to the cerebral cortex is the:
Thalamus
MRA - Axial circle of Willis
The anterior communicating artery joins these two arteries at the top of the cerebral arterial circle. The middle cerebral arteries are seen laterally at this level.
What important function does the cerebral arterial circle (of Willis) serve?
The arterial circle provides collateral circulation in the event of an obstruction.
Axial MRI - Cerebral hemispheres
The bright CSF outlines the convoluted gyri bright white signal of the cerebrospinal fluid The longitudinal fissure is evident, running the length of the cerebrum, dividing it into the right and left cerebral hemispheres
MRI coronal - Gray & white matter
The cerebral cortex is comprised of gray matter and demonstrates darker in T1-weighted images. White matter comprises the deeper tissues and appears lighter in this image. The appearances of gray and white matter are reversed in T2-weighted MR images
Coronal MRI- Dural Folds
The definitive line between the two cerebral hemispheres is the dural fold, termed the "falx cerebri". The tentorium cerebelli is another dural fold, It is located between the inferior cerebral hemispheres and the superior cerebellum. The tentorium cerebelli acts as a divider between these two portions of the brain.
Sagittal MRI - Falx cerebelli & tentorium cerebelli
The dura, the outermost layer of the meninges, is labeled near the frontal lobe, but it is continuous around the entire central nervous system. The tentorium cerebelli is again seen in this image. It is easy to see how it separates the cerebellum from the cerebrum. The two cerebellar hemispheres are separated by the falx cerebelli, seen posterior to the cerebellum in this image.
What is the purpose of the dural folds?
The dural folds serve as partitions or dividers for portions of the brain.
Axial CT- Falx Cerebri
The falx cerebri is labeled at the anterior and lines the longitudinal fissure that divides the cerebrum into right and left hemispheres.
Axial MRI - Basal nuclei T2- weighted MR
The head of the caudate is the easiest to locate first since it lies adjacent to the anterior (frontal) horn of the lateral ventricle. The internal capsule is the thin band of white matter that separates the caudate nucleus from the lentiform nucleus. The lentiform nucleus is lateral to the internal capsule and is the larger, lighter structure in that region.
List the components of the limbic system
The hippocampus, amygdala, olfactory tracts, fornix, cingulate gyrus, and mammillary bodies are the components of the limbic system.
From which artery does the internal carotid artery arise?
The internal carotid artery arises from the bifurcation of the common carotid into the external and internal carotids.
What is the primary division of the cerebellum?
The lateral hemispheres are the primary division of the cerebellum.
Axial MRI - Medulla
The medullary cistern is just anterior, and cranial nerves IX and X can be seen near their insertion points on the patient's left side.
Coronal MRI - Pons
The pons is again seen, but now it is in the midline and inferior. The third ventricle is the slit-like, bright-white structure in about the middle of the image. The interventricular foramen (of Monroe) is also seen connecting the lateral ventricles to the third, but it is not labeled. The lateral ventricles are seen as well as their connecting structure, the corpus callosum. The fornix is also labeled at the end of the lateral ventricles. On each side of the pons, shaped like a sea horse, is the hippocampus of the limbic system.
Axial MRI - Pons
The pons is located almost in the middle of the image. The cerebellum is visible in the posterior portion, with the most inferior portions of the cerebrum seen in the anterior. The basilar artery is seen as the bright white dot just anterior and centered to the pons. The fourth ventricle, seen here as a dark hole, is on the posterior aspect of the pons.
Which artery branches from the basilar closest to the cerebral arterial circle (of Willis)?
The posterior cerebral artery (PCA) branches from the basilar artery almost at its junction to the posterior communicating artery.
Before the vertebral arteries unite, which arteries branch from each one?
The posterior inferior cerebellar arteries (PICA) branch from each vertebral artery prior to their anastomosis into the basilar artery.
MRA - Sagittal veins
This is a sagittal MRA image. Several vessels of the brain are labeled. Use this key to identify the labeled vessels: aca = anterior cerebral artery, ba = basilar artery, bv = basal vein of Rosenthal, ica = internal cerebral artery, icv = internal cerebral vein, sgs = sigmoid sinus, smcv = superficial middle cerebral vein, sts = straight sinus, ss = sagittal sinus, ts = transverse sinus, va = vertebral artery, vc = venous confluence, vg = vein of Galen.
CT - Circle of Willis
This is an axial CT image demonstrating the cerebral arterial circle
MRA - Axial veins
This is an axial MRA image. Several vessels of the brain are labeled. Use this key to identify the labeled vessels: bv = basal vein of Rosenthal, sgs = sigmoid sinus, sts = straight sinus, ts = transverse sinus, vc = venous confluence, vg = great cerebral vein (of Galen).
Axial MRI - Lateral & Third ventricle
Toward the posterior aspect, note the posterior, or occipital, horns of the lateral ventricles opening between the lateral ventricles and the third ventricle, the interventricular foramen
Ambient cistern
Tracks the lateral midbrain Connects the interpeduncular and quadrigeminal cisterns
Olfactory tract functions
Transmit the sense of smell, which is integrated into the limbic system
All of the following are pure motor nerves in function, except:
Trigeminal
The largest cranial nerve is the:
Trigeminal
Refer to the image below. Number 3 labels the:
White Matter
The accessory nerve is number:
XI
Fornix
a fiber tract that extends from the hippocampus to the mammillary body
The middle layer of the meninges is the:
arachnoid
Choroid plexuses
capillary bundles that project from the pia mater into the ventricles. produce cerebrospinal fluid
Circle of Willis
cerebral arterial circle, is located at the base of the brain, surrounding the sella turcica
Axial MRI - Midbrain
cerebral peduncles are labeled in the anterior midline of the brain. The white space in between the peduncles is the interpeduncular cistern.
Coronal MRI - Lateral ventricles
coronal T2-weighted MR image, so the cerebrospinal fluid is bright white and white matter demonstrates darker than gray matter. The fourth ventricle is of interest and is seen in the middle of the cerebellum as a thin slit of bright white due to the presence of cerebrospinal fluid
Coronal MRI - Medulla
coronal, T-1 weighted MR of the medulla oblongata and olives.
The space between the cranial bones and the meninges is the:
epidural
dentate nucleus
gray matter mass deep in white matter of arbor vitae
Medulla oblongata
medulla controls the vital functions of the body, such as respirations, heart rate, and blood pressure.
Review the midsagittal MR image below. What structure of the brainstem is labeled as number 7?
medulla oblongata
Midsagittal MRI - Brainstem
medulla oblongata is labeled. Just superior to it, the egg-shaped structure is the pons, with the midbrain sitting on top of it. Of note, the pituitary gland is labeled as the hypophysis cerebri in this image. The pineal body is also visible on the posterior aspect of the midbrain, shaped like a short worm.
White matter in the brain is composed of:
myelinated fibers
Which of the following is a pure sensory nerve in function?
optic
Review the coronal MR image below. What structure of the diencephalon is labeled as number 2?
pineal body
falx cerebri
separates cerebral hemispheres Lines the longitudinal fissure
What is the name of the space between the dura mater and arachnoid membrane?
subdural space
Thalamus (forms the lateral walls)
the brain's sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Coronal MRI - Basal nuclei
the caudate nucleus is easily seen following the curve of the anterior horns of the lateral ventricles. The darker strip lateral to the caudate nucleus is the internal capsule. The next portion is lighter and is the putamen portion of the lentiform nucleus.
Axial CT - Fourth ventricle
the fourth ventricle is visible posterior to the pons
midsagittal MRI - Lateral ventricles 1
the frontal, or anterior, horns of the lateral ventricles as well as the occipital, or posterior, horns of the lateral ventricles.
Coronal MRI - Lateral & fourth ventricles
wing-shaped lateral ventricles
