Texts and atlases

This listing includes neuroanatomical textbooks and atlases, as well as clinical texts recent publications (since 2000) have been preferentially selected. Afifi, A.K. and Bergman, R.A., Functional Neuroanatomy Text and Atlas, 2nd ed., Lange Medical Books, McGraw-Hill, New York, 2005. This is a neuroanatomical text with the addition of functional information on clinical syndromes. A chapter on the normal is followed by a chapter on clinical syndromes (e.g., of the cerebellum). The book is richly...

Dorsomedial nucleus

The thalamus of both sides is shown in this diagram, focusing on the medial nuclear mass of the thalamus, the dorsomedial nucleus, one of the most important of the association nuclei of the thalamus see Figure 11 and Figure 12 . Shown below is the amygdala with one if its pathways, the ventral amygdalofugal fibers, projecting to the dorsomedial nucleus see Figure 75A and Figure 75B . This pathway brings emotional information to the thalamus. The dorsomedial nucleus collects information from a...

Cdroms

Numerous CDs are appearing on the market, and their evaluation by the teaching faculty is critical before recommending them to learners. In addition, several of the newer textbooks and atlases now have an accompanying CD-ROM. It is indeed a difficult task to obtain and review all the CDs now available and perhaps one that can be shared with students after they have completed their program of study on the nervous system. A listing of the CD-ROMs available can be viewed on the Web site...

Coronal brain section photographic view

This section is taken posterior to the one shown in Figure 29 and includes the inferior horn of the lateral ventricle see Figure 20A and Figure 73 . The basal ganglia, putamen and globus pallidus, are no longer present see Figure 22 and Figure 25 . The corpus callosum is seen in the depth of the interhemispheric fissure, and at this plane of section the fornix is found just below the corpus calluo-sum. The lateral ventricles are present, as the body of the ventricle, and choroid plexus is seen...

Ventricles anterior view

The ventricular system is viewed from the anterior perspective in this illustration. One can now see both lateral ventricles and the short interventricular foramen of Monro on both sides, connecting each lateral ventricle with the midline third ventricle see Figure 28B and Figure 29 . It is important to note that the thalamus diencepha-lon is found on either side of the third ventricle see also Figure 9A . CSF flows from the third ventricle into the aqueduct of the midbrain. This ventricular...

The extended amygdala

Ventral Amygdalofugal Pathway

A group of cells extends medially from the amygdaloid nucleus and follows the ventral pathway the ventral amygdalofugal pathway, Figure 75B and Figure 77B through this basal forebrain region. These neurons receive a variety of inputs from the limbic cortical areas and from other parts of the amygdala. Its output projects to the hypothalamus and to autonomic-related areas of the brain-stem, thereby influencing neuroendocrine, autonomic, and, perhaps, somatomotor activities. Dementia is a general...

Intracerebellar circuitry

Fastigial Nucleus

The cerebellum is being presented from the dorsal perspective as in Figure 9A . The third ventricle is situated between the two diencephala the pineal gland is seen attached to the posterior aspect of the thalamus. Below are the colliculi, superior and inferior. On the right side of the illustration, the cerebellar hemisphere has been cut away, revealing the interior on this side. The cerebellum is organized with cortical tissue on the outside, the cerebellar cortex. The cortex consists of...

Photographic view with overlay

Real Broca Area

This illustration shows the blood supply to the cortical areas of the dorsolateral aspect of the hemispheres it has been created by superimposing the blood vessels onto the photographic view of the brain the same brain as in Figure 14A . After coursing through the depths of the lateral fissure see Figure 58 and Figure 59B , the middle cerebral artery emerges and breaks into a number of branches that supply different parts of the dorsolateral cortex the frontal, parietal, and temporal areas of...

Spinal cord longitudinal view photograph

Cauda Equina Spinal Cord

This is a photographic image of the spinal cord removed from the vertebral canal. The dura-arachnoid has been opened and the anterior aspect of the cord is seen, with the attached spinal roots from this anterior perspective, most of the roots seen are the ventral i.e., motor roots. The spinal cord is divided into parts according to the region innervated cervical 8 spinal roots , thoracic 12 spinal roots , lumbar 5 spinal roots , sacral 5 spinal roots , and coccygeal 1 root . The nerve roots...

Auditory pathway

Auditory Pathway Tonotopy Cochlea

This illustration shows the projection of the auditory system fibers from the level of the inferior colliculus, the lower midbrain, to the thalamus and then to the cortex. Auditory information is carried via the lateral lemnis-cus to the inferior colliculus see Figure 37 and Figure 40 , after several synaptic relays. There is another synapse in this nucleus, making the auditory pathway overall somewhat different and more complex than the medial lemniscal and different than the visual pathways...

Lower Insert

Hippocampus Cerebral Peduncles

This higher magnification of the hippocampal area allows one to follow the gray matter from the hippocampus proper medially and through an intermediate zone, known as the subicular region as in Figure 72B , until it becomes continuous with the gray matter of the parahip-pocampal gyrus. The hippocampus proper has only three cortical layers. The subicular region consists of four to five layers the parahippocampal gyrus is mostly a six-layered cortex. The configuration of the dentate gyrus also...

Thalamus motor circuits

Internal Capsule

The specific relay nuclei of the thalamus that are linked with the motor systems, the basal ganglia and the cerebellum, are the ventral lateral VL and the ventral anterior VA nuclei see Figure 12 and Figure 63 . These project to the different cortical areas involved in motor control, the motor strip, the premotor area, and the supplementary motor area as shown in the upper insets . These thalamic nuclei also receive input from these cortical areas, in line with the reciprocal connections of the...

Lower inset nerve roots

Need Images Cervical Nerve Root

The dorsal root sensory and ventral root motor unite within the intervertebral foramina to form the mixed spinal nerve see also Figure 5 . The nerve cell bodies for the dorsal root are located in the dorsal root ganglion DRG . Both the roots and the dorsal root ganglion belong to the peripheral nervous system PNS where the Schwann cell forms and maintains the myelin . During early development, the spinal cord is the same length as the vertebral canal and the entering exiting nerve roots...

Cranial nerve nuclei sensory

Spinal Cord Nursing

The cranial nerve nuclei with sensory functions are discussed in this diagram. It should be noted that the olfactory nerve CN I and the optic nerve CN II are not attached to the brainstem and not considered at this stage. Sensory information from the region of the head and neck includes the following Somatic afferents general sensations, consisting of touch both discriminative and crude touch , pain and temperature these come from the skin and the mucous membranes, via branches of the...

Cerebellar afferents

Vestibulo Cerebellum

Information relevant to the role of the cerebellum in motor regulation comes from the cerebral cortex, the brainstem, and from the muscle receptors in the periphery. The information is conveyed to the cerebellum mainly via the middle and inferior cerebellar peduncles. Inferior Cerebellar Peduncle The inferior cerebellar peduncle goes from the medulla to the cerebellum. It lies behind the inferior olivary nucleus and can sometimes be seen on the ventral view of the brainstem as in Figure 7 ....

Crosssection

Nucleus Ambiguus Wallenberg Sendromu

This cross-sectional level is often presented as typical of the medulla. The pyramids and inferior olive are easily recognized anteriorly. The medial lemniscus occupies the area between the olives, on either side of the midline see Figure 40 . The MLF lies behind dorsal the medial lemniscus, also situated adjacent to the midline. The fibers of the anterolat-eral system are situated dorsal to the olive. The descending nucleus and tract of the trigeminal system have the same location as seen...

White matter medial dissected view corpus callosum photograph

Corpus Callosum

The structures that are found within the depths of the cerebral hemispheres include the white matter, the cerebral ventricles, and the basal ganglia see Figure OA and Figure OL . The white matter consists of the myelinated axonal fibers connecting brain regions. In the spinal cord these were called tracts in the hemispheres these bundles are classified in the following way also discussed with Figure 16 association bundles, projections fibers, and commissural connections. The dissection of this...

Thalamus orientation

Thalamus Massa Intermedia

The diencephalon, which translates as between brain, is the next region of the brain to consider. The diencephalon, including both thalamus and hypothalamus and some other subparts, is situated between the brainstem and the cerebral hemispheres, deep within the brain. As shown diagrammatically see Figure 6 and photographically see Figure 7 and Figure 9A , the dienceph-alon sits atop the brainstem. The enormous growth of the cerebral hemispheres in the human brain has virtually hidden or buried...

Internal capsule projection fibers

Blood Supply Internal Capsule

The white matter bundles that course between parts of the basal ganglia and the thalamus are collectively grouped together and called the internal capsule. These are projection fibers, axons going to and coming from the cerebral cortex. The internal capsule is defined as a group of fibers located at a specific plane within the cerebral hemispheres in a region that is situated between the head of the caudate, the lentiform, and the thalamus see Figure OA, Figure OL, and Figure 25 . The internal...

Corpus callosum superior photographic view

In this photograph, the brain is again being viewed from directly above see Figure 13 , with the interhemispheric fissure opened. The dural fold between the hemispheres, the falx cerebri, has been removed from the interhemi-spheric fissure. This thick sheath of dura keeps the two halves of the hemispheres in place within the cranial cavity. A whitish structure is seen in the depths of the fissure the corpus callosum. One of the other major features of the cerebral cortex is the vast number of...

Spinal cord cervical region photograph

Ventral Dorsal Roots Spinal Cord

This is a higher magnification photographic image of the cervical region of the spinal cord. Most of the attached roots are the motor ventral roots, coming from the ventral horn of the spinal cord discussed with Figure 4 a few of the dorsal sensory roots can be seen, which enter the cord in the dorsal horn. These roots exit the vertebral canal and carry a sleeve of arachnoid-dura with them for a very short distance, as they head for the intervertebral spaces see Figure 1 . The somewhat tortuous...

Pain modulation system

Pain, both physical and psychic, is recognized by the nervous system at multiple levels. Localization of pain, knowing which parts of the limbs and body wall are involved, requires the cortex of the postcentral gyrus SI SII is also likely involved in the perception of pain discussed with Figure 36 . There is good evidence that some conscious perception of pain occurs at the thalamic level. We have a built-in system for dampening the influences of pain from the spinal cord level the descending...

Voluntarynonvoluntary motor control

Red Nucleus

The red nucleus is a prominent nucleus of the midbrain. It gets its name from a reddish color seen in fresh dissections of the brain, presumably due to its high vascularity. The nucleus see Figure 48, Figure 51B, and Figure 65A has two portions, a small-celled upper division and a portion with large neurons more ventrally located. The rubro-spinal pathway originates, at least in humans, from the larger cells. The red nucleus receives its input from the motor areas of the cerebral cortex and...

Brainstem and diencephalon ventral photographic view

Glossopharyngeal Nerve

This specimen has been obtained by isolating the brainstem and cerebellum along with the diencephalon from the remainder of the brain. It is the same specimen as in the previous diagrammatic illustration see Figure 6 . The three parts of the brainstem can be differentiated on this ventral view from above downward The midbrain region has the two large pillars anteriorly called the cerebral peduncles. These contain fibers descending from the cerebral cortex to the spinal cord cortico-spinal...

Cerebral cortex dorsal photographic view

Abnormal Brain Mri Images Frontal Lobe

When people talk about the brain, they are generally referring to the cerebral hemispheres, also called the cerebrum. The brain of higher apes and humans is dominated by the cerebral hemispheres. The outer layer, the cerebral cortex, with its billions of neurons and its vast interconnections, is responsible for sensory perception, movement, language, thinking, memory, consciousness, and certain aspects of emotion. In short, we need the intact cerebral hemispheres to adapt to our ever-changing...

Direct voluntary pathway

Pyramidal System

The cortico-spinal tract, a direct pathway linking the cortex with the spinal cord, is the most important one for voluntary motor movements in humans. This pathway originates mostly from the motor areas of the cerebral cortex, areas 4 and 6 see Figure 14A, Figure 17, and Figure 60 discussed in Section B, Part III, Introduction and with Figure 48 . The well-myelinated axons descend through the white matter of the hemispheres, through the posterior limb of the internal capsule see Figure 26,...

Horizontal section of hemispheres photographic view

Brain Horizontal Section

In this photograph, the brain has been sectioned in the horizontal plane. From the dorsolateral view the small figure on the upper left , the level of the section is just above the lateral fissure and at a slight angle downward from front to back. Using the medial view of the brain the figure on the upper right , the plane of section goes through the anterior horn of the lateral ventricle, the thalamus and the occipital lobe. This brain section exposes the white matter of the hemispheres, the...

Thalamus nuclei

Internal Medullary Lamina

In order to lay the groundwork for understanding the functional organization of the sensory and motor pathways in Section B , it is necessary to have a familiarity with the nuclei of the thalamus, their organization, and names. There are two ways of dividing up the nuclei of the thalamus, namely, topographically and functionally. A. Topographically, the thalamus is subdivided by bands of white matter into a number of component parts. The main white matter band that runs within the thalamus is...

Figure 67 midmedulla photographic view

Inferior Cerebellar Peduncle

This is a photographic image, enlarged, at the middle level of the medulla, with the cerebellum attached. This specimen shows the principal identifying features of the medulla, the pyramids ventrally on either side of the mid-line and the more laterally placed inferior olivary nucleus, with its scalloped borders. Between the olivary nuclei, on either side of the mid-line, are two dense structures, the medial lemniscus. The other dense tract that is recognizable in this specimen is the inferior...

Noncortical structures

Stria Terminalis

The term limbic system is the concept now used to include those parts of the brain that are associated with the functional definition of the limbic system. This is an overall diagram focusing on the noncortical components of the limbic system, both core and extended. These structures are found in the forebrain, the dienceph-alon, and also in the midbrain. Each of the structures, including the connections, will be discussed in greater detail in subsequent illustrations when this diagram,...

Visual pathway

Optic Radiation

The visual image exists in the outside world, and is designated the visual field there is a visual field for each eye. This image is projected onto the retina, where it is now termed the retinal field. Because of the lens of the eye, the visual information from the upper visual field is seen in the lower retina and likewise for the lower visual field . The visual fields are also divided into temporal lateral and nasal medial portions. The temporal visual field of one eye is projected onto the...

Mr angiogram mra

Cerebral Angiogram Labeled

Recent advances in technology have allowed for a visualization of the major blood vessels supplying the brain, notably the arterial circle of Willis. This investigation does not require an invasive procedure described with the next illustration , although an injection intravenously of a contrast substance called gadolinium maybe used discussed with Figure 28B . Although the quality of such images cannot match the detail seen after an angiogram of select blood vessels shown in the next...

Cranial nerve nuclei motor

Brainstem With Cranial Nerves

The cranial nerves are peripheral nerves that supply the head region, except for the olfactory CN I and optic CN II nerves. Each cranial nerve is unique and may have one or more functional components, either sensory, motor, or both, and some also have an autonomic parasympathetic component. There are two kinds of motor functions 1. The motor supply to the muscles derived from somites, including CN III, IV, VI, and XII, and to the muscles derived from the branchial arches, called branchiomotor,...

Figure 67a upper medulla crosssection

Anterior Ventral Cochlear Nucleus

This section has the characteristic features of the medullary region, namely the pyramids anteriorly with the inferior olivary nucleus situated just laterally and behind. The cortico-spinal voluntary motor fibers from areas 4 and 6 go through the white matter of the hemispheres, funnel via the internal capsule posterior limb , continue through the cerebral peduncles of the midbrain and the pontine region, and emerge as a distinct bundle in the medulla within the pyramids. The cortico-spinal...

Figure 67c lower medulla crosssection

Area Postrema Anatomy Pictures

The medulla seems significantly smaller in size at this level, approaching the size of the spinal cord below. The section is still easily recognized as medullary because of the presence of the pyramids anteriorly the cortico-spinal tract and the adjacent inferior olivary nucleus. The tegmentum contains the cranial nerve nuclei, the reticular formation and the other tracts. The nuclei of CN X and CN XII, as well as the descending nucleus and tract of V, are present as before as in the...

Midpons crosssection

Pons Histology

This section is taken through the level of the attachment of the trigeminal nerve. Anteriorly, the pontine nuclei and the bundles of cortico-spinal fibers are easily recognized. The pontine cells nuclei and their axons, which cross and then become the middle cerebellar peduncle, are particularly numerous at this level see Figure 55 . The cor-tico-spinal fibers are seen as distinct bundles that are widely dispersed among the pontine nuclei at this level see Figure 45 and Figure 48 . The...

Medial forebrain bundle

Medial Longitudinal Bundle

Knowledge of this bundle of fibers is necessary if one is to understand the circuitry of the limbic system and how the limbic system influences the activity of the nervous system. The medial forebrain bundle MFB connects the sep-tal region with the hypothalamus and extends into the limbic midbrain it is a two-way pathway. Part of its course is through the lateral part of the hypothalamus where the fibers become somewhat dispersed as illustrated . There are further connections to nuclei in the...

Figure 65b lower midbrain crosssection

Inferior Colliculus

This cross-section includes the cerebral peduncles, still located anteriorly and the substantia nigra located immediately behind these fibers. The unique feature in the lower midbrain is the decussation crossing of the superior cer-ebellar peduncles, which occupies the central area of the section this identifies the section as the inferior collicular level. Posteriorly the aqueduct is surrounded by the peri-aqueductal gray, and behind the aqueduct is the inferior colliculus. Often, the...

Amygdala location and function

Kluver Bucy Syndrome Treatment

This diagram, which is the same as Figure 71, highlights a functional portion of the limbic system the amygdala and its pathways, the stria terminalis and the ventral amygdalofugal pathway. The septal region and functionally connected portions of the midbrain and medulla are also marked. The amygdala amygdaloid nucleus is a subcortical nuclear structure located in the temporal lobe in humans see Figure 25 and Figure 29 . As a subcortical nucleus of the forebrain, it belongs by definition with...

Cerebellar efferents

Human Red Nucleus Connections

This is again a dorsal view of the diencephalon, brainstem, and cerebellum, with the deep cerebellar intracerebellar nuclei. The cerebellar tissue has been removed in the midline, revealing the fourth ventricle as in Figure 10 the three cerebellar peduncles are also visualized from this posterior perspective see Figure 10 . The output from the cerebellum will be described, following the functional divisions of the cerebellum Vestibulocerebellum Efferents from the fasti-gial nuclei go to...

Basal ganglia orientation

There are large collections of gray matter within the hemispheres, belonging to the forebrain, in addition to the white matter and the ventricles already described. These neuronal groups are collectively called the basal ganglia. Oftentimes the term striatum is used for the basal ganglia, but this term is not always used with neuroanatomical precision. Our understanding of the functional role of the basal ganglia is derived largely from disease states affecting these neurons. In general, humans...

Lower illustration photographic view

Primary Visual Cortex

This is a higher magnification of the medial aspect of the brain shown in Figure 17 . The interthalamic adhesion, fibers joining the thalamus of each side across the midline, has been cut see Figure 6, not labeled . The optic chiasm is seen anteriorly posteriorly, the tip of the pulv-inar can be seen. The midbrain includes areas where fibers of the visual system synapse. Fibers emerge from the pulvinar, the visually related association nucleus of the thalamus see Figure 12 and Figure 63 and...

Figure 66c lower pons crosssection

Anterolateral System Caudal Pons

This section is very complex because of the number of nuclei related to the cranial nerves located in the tegmental portion, including CN V, VI, VII, and VIII. Some of the tracts are shifting in position or forming. Anteriorly, the pontine nuclei have all but disappeared, and the fibers of the cortico-spinal tract are regrouping into a more compact bundle, which will become the pyramids in the medulla below . CN V The fibers of the trigeminal nerve carrying pain and temperature, that entered at...

Vestibular nuclei and eye movements

Lateral Vestibular Spinal Tract

The vestibular system carries information about our position in relation to gravity and changes in that position. The sensory system is located in the inner ear and consists of three semicircular canals and other sensory organs in a bony and membranous labyrinth. There is a peripheral ganglion the spiral ganglion , and the central processes of these cells, CN VIII, enter the brainstem at the cere-bellar-pontine angle, just above the cerebellar flocculus see Figure 6, Figure 7, and Figure 8B ....

Limbic system synthesis

After studying the structures and connections of the limbic system in some detail a synthesis of the anatomical information with the notion of an emotional part of the brain seems appropriate. It is not easy to understand how the limbic system is responsible for the reactions required by the definition of emotion proposed in the Introduction to this section. The key structures of the limbic system are the limbic lobe the cortical regions, including the hippocam-pal formation and the...

Extended limbic lobe

Limbic Lobe

Other areas of the brain are now known to be involved in limbic functions and are included in the functional aspects of the limbic system. This includes large parts of the prefrontal cortex, particularly cortical areas lying above the orbit, the orbitofrontal cortex not labeled , as well as the cortex on the medial aspect of the frontal lobe to be discussed with Figure 77B . F Frontal lobe P Parietal lobe T Temporal lobe O Occipital lobe FIGURE 70B Limbic Lobe 2 Cingulum Bundle photograph

Internal capsule photographic view with overlay

Choroid Fissure

One of the most important sets of branches of the middle cerebral artery is found within the lateral fissure this artery has been dissected in Figure 58 . These are known as the striate arteries, also called lenticulostriate arteries see Figure 59B . These branches supply most of the internal structures of the hemispheres, including the internal capsule and the basal ganglia discussed with Figure 26 see also Figure 27 and Figure 29 . In this illustration, a coronal section of the brain see...

Cerebral hemispheres medial photographic view

Cingulate Sulcus

This view of the brain sectioned in the midline mid-sagittal plane is probably the most important view for understanding the gross anatomy of the hemispheres, the diencephalon, the brainstem, and the ventricles. The section has divided the corpus callosum, gone in between the thalamus of each hemisphere through the third ventricle , and passed through all parts of the brainstem. The medial aspects of the lobes of the brain are now in view. The central fissure does extend onto this part of the...

Discriminative touch pain temperature

Lateral Medullary Syndrome

The sensory fibers include the modalities discriminative touch as well as pain and temperature. The sensory input comes from the face, particularly from the lips, all the mucous membranes inside the mouth, the conjunctiva of the eye, and the teeth. The fiber sizes and degree of myeli-nation are similar to the sensory inputs below the neck. The cell bodies of these fibers are found in the trigeminal ganglion inside the skull. The fibers enter the brainstem along the middle cere-bellar peduncle...

Phineas gage

Phineas Gage

Phineas Gage has become a legendary figure in the annals of the history of the brain. In brief, Gage was working on the construction of a railway in the 1800s, when an untimely explosion drove a steel peg through his brain. The steel peg is said to have penetrated the orbit and the frontal lobes, much like the surgical procedure described above, emerging through the skull. He survived and lived on his personality changes, which have been well documented, subsequent to this accident concur with...

Spinal cord crosssectional views upper diagram

Dorsal Root

The upper diagram is a cross-section through the spinal cord at the C8 level, the eighth cervical segmental level of the spinal cord not the vertebral level, see Figure 1 . The gray matter is said to be arranged in the shape of a butterfly or somewhat like the letter H . The gray matter of the spinal cord contains a variety of cell groups i.e. nuclei , which subserve different functions. Although it is rather difficult to visualize, these groups are continuous longitudinally throughout the...

Spinal cord cauda equina photograph

Conus Medullaris Syndrome

This is a higher magnification photographic image of the lowermost region of the spinal cord, the sacral region. The tapered end of the spinal cord is called the conus med-ullaris, and this lower portion of the cord corresponds approximately to the sacral segments. The collection of dorsal and ventral nerve roots, below the level of the termination of the cord, is collectively called the cauda equina. These roots, which belong to the lumbar and sacral segments of the spinal cord, fill the...

Cortical structures

Mid Brain With Fornix

The limbic lobe refers to cortical areas of the limbic system. These cortical areas, which were given the name limbic, form a border limbus around the inner structures of the diencephalon and midbrain see Figure 17 and Figure 70B . The core cortical areas include the hippoc-ampal formation, the parahippocampal gyrus, and the cin-gulate gyrus. There are a number of cortical areas located in the most medial also called mesial aspects of the temporal lobe in humans that form part of this limbus....

Figure 66a upper pons crosssection

Trochlear Nerve Pathway

This level is presented mainly to allow an understanding of the transition of midbrain to pons. This particular section is taken at the uppermost pontine level, where the trochlear nerve, CN IV, exits below the inferior collicu-lus, see Figure 7 . This is the only cranial nerve that exits posteriorly its fibers cross decussate before exiting see Figure 48 . Anteriorly, the pontine nuclei are beginning to be found. Cortico-pontine fibers will be terminating in the pontine nuclei. From these...

Limbic structures and the lateral ventricle

Stria Terminalis

The temporal lobe is a more recent addition in the evolution of the hemispheres and develops later in the formation of the brain. During the development of the temporal lobe, a number of structures migrate into it the lateral ventricle, the hippocampal formation, the caudate nucleus, as well as various tracts, the fornix and stria terminalis. The lateral ventricle and associated structures form a crescent in the shape of a reverse letter C see Figure OL and Figure 20A . These relationships are...

Basal ganglia circuitry

Globus Pallidus

This is the same view of the basal ganglia as shown previously see Figure 24 , with the head of the caudate nucleus removed. The illustration includes the two other parts of the basal ganglia as a functional system the subthalamic nucleus and the substantia nigra. The subthalamic nucleus S is situated in a small region below the level of the thalamus. The substantia nigra SN is a flattened nucleus located in the midbrain region. It is composed of two parts see Figure 65A . The pars compacta has...

Sensory nuclei and ascending tracts

Spinal Nucleus Trigeminal

This diagrammatic presentation of the internal structures of the brainstem is shown from the dorsal perspective as in Figure 10 and Figure 36 . The information concerning the various structures will be presented in an abbreviated manner, as most of the major points have been reviewed previously. The orientation of the cervical spinal cord representation should be noted. Dorsal column-medial lemniscus discriminative touch, joint position, and vibration and its nuclei Anterolateral system pain...

Reticular formation nuclei

Reticular Formation

In this diagram, the reticular formation is being viewed from the dorsal posterior perspective see Figure 10 and Figure 40 . Various nuclei of the reticular formation, RF, which have a significant known functional role, are depicted, as well as the descending tracts emanating from some of these nuclei. Functionally, there are afferent and efferent nuclei in the reticular formation and groups of neurons that are distinct because of the catecholamine neurotransmitter used, either serotonin or...

Auditory gyri photographic view

Transverse Gyri Heschl

This photographic view of the left hemisphere is shown from the lateral perspective see Figure 14A . The lateral fissure has been opened, and this exposes two gyri, which are oriented transversely. These gyri are the areas of the cortex that receive the incoming auditory sensory information first. They are named the transverse gyri of Heschl as was also shown in the previous illustration , the auditory gyri, areas 41 and 42 see Figure 60 . The lateral fissure forms a complete separation between...

Reticular formation organization

Reticular Activating System

The reticular formation, RF, is the name for a group of neurons found throughout the brainstem. Using the ventral view of the brainstem, the reticular formation occupies the central portion or core area of the brainstem from midbrain to medulla see also brainstem cross-sections in Figure 65-Figure 67 . This collection of neurons is a phylogenetically old set of neurons that functions like a network or reticulum, from which it derives its name. The RF receives afferents from most of the sensory...

White matter lateral dissected view association bundles photograph

Arcuate Fasciculus

The dorsolateral aspect of the brain is being viewed in this photograph see Figure 14A . The lateral fissure has been opened, with the temporal lobe below deep within the lateral fissure is the insula see Figure 14B and Figure 39 . Under the cerebral cortex is the white matter of the brain. It is possible to dissect various fiber bundles not easily using a blunt instrument e.g., a wooden tongue depressor . Some of these, functionally, are the association bundles, fibers that interconnect...

Brainstem and cerebellum dorsal inferior photographic view

Cerebellum Dorsal

This is a photograph of the same specimen as Figure 9A, but the specimen is tilted to reveal the inferior aspect of the cerebellum and the posterior aspect of the medulla. The posterior aspect of the pons is still covered by the cerebellum see Figure 10 . The posterior aspect of the midbrain can no longer be seen. The upper end of the thalamus is still in view. The horizontal fissure of the cerebellum is now clearly seen it is used as an approximate divider between the superior and inferior...

Cerebral cortex dorsolateral photographic view

Angular Gyrus

This is a photographic image of the same brain as shown in the previous illustration, tilted slightly, to show the dorsolateral aspect of the hemispheres. The edge of the other hemisphere with meninges is still in view. It is now possible to identify the sulci and fissures with more certainty. The central fissure often called the fissure of Rolando is seen more completely, dividing the frontal lobe anteriorly from the parietal lobe posteriorly. The deep lateral fissure is clearly visible see...

Sagittal view schematic

Sagittal View The Brainstem Labeled

This is a schematic drawing of the brainstem seen in a midsagittal view see Figure 17 and Figure 18 . This view is being presented because it is one that is commonly used to portray the brainstem. The learner should try to correlate this view with the ventral view shown in the previous diagram. This schematic also will be shown in each of the cross-section diagrams, with the exact level indicated, in order to orient the learner to the plane of section through the brainstem. The location of some...

Special tract

Dorsolateral Fasciculus

The dorsolateral fasciculus, better known as the tract of Lissauer see Figure 32 , carries intersegmental information, particularly relating to pain afferents. The functional aspects of each of these tracts should be reviewed at this time by noting the loss of function that would be found following a lesion of the various pathways. An acute injury to the cord, such as severing of the cord following an accident, will usually result in a complete shutdown of all spinal cord functions, called...

Blood supply

Fasciculus Cuneatus

The anterior spinal artery, the main blood supply to the spinal cord, comes from branches from each of the vertebral arteries that join see Figure 58 it descends in the midline see Figure 2B and supplies the ventral horn and the anterior and lateral group of tracts, including the lateral cortico-spinal pathway. The posterior spinal arteries supply the dorsal horn and the dorsal columns. The blood supply to the spinal cord was reviewed with Figure 2B it is known that this blood supply is...

Connections and function

Precommissural Fibers Fornix

In the temporal lobe, the six-layered parahippocampal gyrus provides extensive input to the adjacent hippocam-pal formation. The hippocampal formation also receives input from the amygdala. There are extensive interconnections within the component parts of the hippocampal formation itself. Part of the output of the hippocampal formation is directed back to the parahippocampal gyrus, establishing a strong reciprocal connection. This is analogous to the cortical association pathways described...

Photographic view with midbrain

Medial Eminence Midbrain

This is another brain specimen showing the inferior surface of the brain, in which the brainstem has been sectioned through at the level of the midbrain, removing most of the brainstem and the attached cerebellum. The cut surface of the midbrain is exposed, showing a linear area of brain tissue, which is black in coloration this elongated cluster of cells is the nucleus of the midbrain called the substantia nigra, and consists of neurons with pigment inside the cells discussed with Figure 65 ....

Pain temperature crude touch

Anterolateral Tract

This pathway carries the modalities of pain and temperature and a form of touch sensation called crude or light touch. The sensations of itch and tickle, and other forms of sensation e.g., sexual are likely carried in this system. In the periphery the receptors are usually simply free nerve endings, without any specialization. These incoming fibers sometimes called the first order neuron enter the spinal cord and synapse in the dorsal horn see Figure 4 and Figure 32 . There are many collaterals...

Mlf and associated tracts

Medial Longitudinal Fasciculus

This diagram shows the brainstem from the posterior perspective as in Figure 10 and Figure 40 . Note the orientation of the spinal cord with the ventral horn away from the viewer . The MLF is a tract within the brainstem and upper spinal cord that links the visual world and vestibular events with the movements of the eyes and the neck, as well as linking up the nuclei that are responsible for eye movements. The tract runs from the midbrain level to the upper thoracic level of the spinal cord....

Figure 66 upper pons photographic view

Pontocerebellar Fibers

This is a photographic image, enlarged, of the pontine region, with the cerebellum attached. The section is done at the level of the upper pons, as indicated in the upper images of the ventral view of the brainstem and in the midsagittal view. The unique nucleus present at this level is the locus ceruleus, a small nucleus whose cells have pigment, much like those of the substantia nigra, pars compacta see Figure 65 . As with that nucleus, the pigment is lost during histological processing. The...

Brainstem and cerebellum dorsal photographic view

Cerebral Peduncle

This specimen of the brainstem and diencephalon, with the cerebellum attached, is being viewed from the dorsal or posterior perspective. The third ventricle, the ventricle of the diencephalon, separates the thalamus of one side from that of the other see Figure OA and Figure 20A also Figure 17 and Figure 21, where the brain is separated down the midline in the midsagittal plane . The dienceph-alon is to be discussed with Figure 11. Additional structures of the brainstem are seen from this...

Figure 65 upper midbrain photographic view

Upper Midbrain

This is a photographic image, enlarged, of the sectioned midbrain. As shown in the upper left image, the brainstem was sectioned at the level of the cerebral peduncles the corresponding level is shown on a medial view of the brain, indicating that the section is through the superior colliculus. Many of the structures visible on this gross specimen will be seen in more detail on the histological sections. The distinctive features identifying this section as midbrain are Anteriorly, the outline...

Basal ganglia nuclei lateral view

Lentiform Body

The basal ganglia, from the point of view of strict neu-roanatomy, consist of three major nuclei in each of the hemispheres. The reader is reminded that this illustration has been enlarged from the previous figure, and that these structures are located within the forebrain. The caudate nucleus is anatomically associated with the lateral ventricle and follows its curvature. It is described as having three portions see Figure 25 The head, located deep within the frontal lobe The body, located...

Orientation to diagrams

Cross Section Lower Pons Schematic

The illustrations of the sensory and motor pathways in this section of the atlas are all done in a standard manner On the left side, the CNS is depicted, including spinal cord, brainstem, thalamus, and a coronal section through the hemispheres, with small diagrams of the hemisphere at the top showing the area of the cerebral cortex involved. On the right side, cross-sections X-sections of the brainstem and spinal cord, at standardized levels are depicted the exact levels are indicated by arrows...

Figure 65a upper midbrain crosssection

Midbrain Cross Section

The identifying features of this cross-section of the mid-brain include the cerebral peduncle ventrally, with the substantia nigra posterior to it. The aqueduct is surrounded by the periaqueductal gray. The remainder of the midbrain is the tegmentum, with nuclei and tracts. Dorsally, behind the aqueduct, is a colliculus. The descending fiber systems are segregated within the cerebral peduncles see Figure 45, Figure 46, and Figure 48 . The substantia nigra consists, in fact, of two functionally...

Figure 49a pontine medial reticulospinal tract

Reticulospinal Tract

This tract originates in the pontine reticular formation from two nuclei the upper one is called the oral portion of the pontine reticular nuclei nucleus reticularis pontis oralis , and the lower part is called the caudal portion see Figure 42B . The tract descends to the spinal cord and is located in the medial region of the white matter see Figure 68 and Figure 69 this pathway therefore is called the medial reticulo-spinal tract. Functionally, this pathway exerts its action on the extensor...

Brainstem dorsal view cerebellum removed

Cerebellum Removed

This diagram shows the brainstem from the dorsal perspective, with the cerebellum removed. A similar view of the brainstem is used for some of the later diagrams see Figure 40 and Figure 48 . This dorsal perspective is useful for presenting the combined visualization of many of the cranial nerve nuclei and the various pathways of the brain-stem. The posterior aspect of the midbrain has the superior and inferior colliculi, as previously seen, as well as the emerging fibers of CN IV, the...

Brainstem and diencephalon ventral view

Cerebellar Flocculus

The brainstem is the lowermost part of the brain and is located above the spinal cord. It can be seen by viewing the brain from below see Figure 15A also Figure OA and Figure OL . This specimen has been obtained by dissecting out the brainstem, and cerebellum, along with the diencephalon a photographic view of this specimen is shown in the next illustration Figure 7 . The dienceph-alon will be described subsequently see Figure 11 and Figure 12 . In the human brain, the brainstem is a relatively...

The neural hypothalamus

Stria Medullaris Thalami

This diagram, which is the same as Figure 71, highlights the hypothalamus, one of the core structures of the limbic system, with the prominent mammillary nuclei as part of the hypothalamus. The third ventricle is situated between the two diencephalic parts of the brain, e.g. see Figure 9A and Figure 27 and the hypothalamic tissue of both sides joins together at its inferior portion as the median eminence see next illustration and Figure 15A and Figure 15B . The hypothalamus is usually divided...

Spinal cord mri t2 axial views radiograph

Mri Spinal Root Axial View

MRI views of the spinal cord are shown in the axial plane at the C4 fourth cervical vertebral level the orientation should be noted with anterior ventral at the top. The CSF is bright in these T2-weighted images. The position of the spinal cord can be easily visualized within the vertebral canal, with the surrounding CSF space. The vertebral bodies and lamina are dark the muscles of the neck can be visualized. In both images it is possible to see the butterfly shape of the gray matter of the...

The arterial circle of willis photographic view with overlay

Anterior Inferior Cerebellar Artery

The arterial circle of Willis is a set of arteries interconnecting the two sources of blood supply to the brain, the vertebral and internal carotid arteries. It is located at the base of the brain, surrounding the optic chiasm and the hypothalamus the mammillary nuclei review Figure 15A and Figure 15B . Within the skull, it is situated above the pituitary fossa and gland . The major arteries to the cerebral cortex of the hemispheres are branches of this arterial circle. This illustration is a...

Photographic view with brainstem

Bulb Spinal Cord

This is a photographic view of the same brain seen from below, the inferior view, a view that includes the brainstem and the cerebellum. The medulla and pons, parts of the brainstem can be identified see Figure 6 and Figure 7 , but the midbrain is mostly hidden from view. The cranial nerves are still attached to the brainstem, and some of the arteries to the brain are also present. The frontal lobe occupies the anterior cranial fossa of the skull. The inferior surface of the frontal lobe...

Coronal view mri radiograph

Trigeminal Nerve Coronal Mri

This is a view of the brain similar to the previous brain section, in the coronal plane. The T2 MRI has been adjusted on the viewing screen to invert the displayed image sometimes called an inverted video view . The distinction between the gray matter and the white matter is enhanced with this view the CSF is dark. Note that the tables of the skull are now white, and the bone marrow is dark. The superior sagittal sinus is seen in the midline, at the top of the falx cerebri bright . The cortex...

Descending tracts and corticopontine fibers

The descending pathways that have been described are shown, using the somewhat oblique posterior view of the brainstem see Figure 10 and Figure 40 , along with those cranial nerve nuclei that have a motor component. These pathways will be presented in summary form Cortico-spinal tract see Figure 45 These fibers course in the middle third of the cerebral peduncle, are dispersed in the pontine region between the pontine nuclei, and regroup as a compact bundle in the medulla, situated within the...

Mri t1 sagittal view radiograph

Foramen Magnum Location Mri

This radiological image, obtained by magnetic resonance imaging MRI , shows the brain as clearly as the actual brain itself review the NOTE on radiologic imaging with Figure 3 . This is the way the brain will be seen in the clinical setting. The view presented is called a T1-weighted image. Note that the CSF is dark in this image, including the ventricles, the subarachnoid space, and cisterns see Figure 21 . The bones tables of the skull are visible as a dark space, while the bone marrow,...

Spinal cord mri t1 longitudinal view radiograph

Subarachnoid Mri Dog

This is a magnetic resonance image MRI of the vertebral column and spinal cord, viewed in a midsagittal plane. This is called a TI-weighted image, in which the cerebrospinal fluid CSF is dark. The various radiological techniques used to image the nervous system are discussed below. This image is from an adult, in which no pathology was found in the spinal cord radiological examination. Because of the length of the spinal cord, it is being shown in two parts upper and lower. The vertebral...

Horizontal view ct scan radiograph

Tectum Scan

This radiological view of the brain is not in exactly the same horizontal plane as the anatomical specimen shown in the previous illustration. The radiological images of the brain are often done at a slight angle in order to minimize the exposure of the stuctures of the orbit, the retina and the lens, to the potential damaging effects of the x-rays used to generate a CT scan. A CT image shows the skull bones in white and the relationship of the brain to the skull. A piece of the falx cerebri...

Horizontal view t2 mri radiograph

Optic Radiation

This radiograph is a view of the brain taken in the same plane, horizontally, closer to the plane of the brain section see Figure 27 , but a little higher than the previous radiograph. Parameters of the MRI have been adjusted to generate a T2-weighted image see explanation with Figure 3 . In this view, the CSF of the ventricles is white, while the bones of the skull are dark. This MRI shows the brain as if it were an anatomical specimen compare with the previous illustration there is a good...

The amygdala connections

Anterior Commissure

One of the major differences between the amygdala and the other parts of the basal ganglia is that the amygdala is not a homogeneous nuclear structure but is composed of different component parts. These are not usually studied in an introductory course. The amygdala receives a variety of inputs from other parts of the brain, including the adjacent parahippocampal gyrus not illustrated . It receives olfactory input directly via the lateral olfactory stria, see Figure 79 and indirectly from the...

Intracerebellar deep cerebellar nuclei

Cerebellar Nuclei

The brainstem is presented from the anterior perspective, with the cerebellum attached as in Figure 6, Figure 7, Figure 8A, and Figure 8B . This diagram shows the intracerebellar nuclei also called the deep cerebellar nuclei within the cerebellum. There are four pairs of deep cerebellar nuclei the fastigial nucleus, the globose and emboliform nuclei together called the intermediate or interposed nucleus , and the lateral or dentate nucleus. Each belongs to a different functional part of the...

Overview lateral view

Head Body The Caudate

This is the companion diagram to the previous illustration, created to assist the learner in placing the brain and its various divisions in a three-dimensional construct. This is a semi-anatomic view of the brain from the lateral perspective. The front pole of the brain is on the left side of this illustration the posterior pole is on the right side. The structures included are Cerebral hemispheres The extensive cerebral hemisphere of one side is seen, with the top edge of the other hemisphere...

Overview anterior view

Diagram Anterior Cerebral Hemispheres

Constructing a three-dimensional visualization of the brain and its various parts is a challenging task for most people, and this diagram and its companion the next illustration are designed to assist the learner in this task. This is a semi-anatomic representation of the brain and the parts of the CNS. This general diagrammatic view should be consulted as the learner is orienting to the placement of the structures within the brain. These same structures are viewed from the lateral perspective...