Neurology Lab 1

Front 1

The proliferative zone of the neural tube's ependymal lining is demarcated into two regions by the __. What are these two regions?

Back 1

Sulcus limitans. Dorsal alar plate (sensory) and a ventral basal plate (motor).

Front 2

By the fifth week of gestation, the embryonic nervous system has differentiated into four major parts. Name these parts.

Back 2

Prosencephalon (forebrain), mesencephalon (midbrain), rhombencephalon (hindbrain), and the embryonic spinal cord.

Front 3

The lumen of the embryonic neural tube will expand and change shape to form large spaces, called __, that are filled with __.

Back 3

Ventricles; CSF.

Front 4

The rostral limits of the original neural tube are represented by the __.

Back 4

Lamina terminalis.

Front 5

The cerebral hemispheres are separated from one another on the midline by the __.

Back 5

Longitudinal fissure.

Front 6

The visible part of the cerebral hemisphere is called the __, which consists of a thin (~1.5 to 2.5 mm) sheet of neurons and underlying axons.

Back 6

Cerebral cortex.

Front 7

The cerebral hemispheres of the adult brain exhibit numerous rounded convolutions or __ separated by fissures or __.

Back 7

Gyri; sulci.

Front 8

A __ demarcates the frontal lobe anteriorly from the parietal lobe.

Back 8

Central (Rolandic) sulcus.

Front 9

A __ divides the parietal lobe from the occipital lobe posteriorly.

Back 9

Parieto-occipital sulcus.

Front 10

A large __ separates the temporal lobe ventrally from the rest of the cerebral cortex.

Back 10

Lateral sulcus or Sylvian fissure.

Front 11

Buried within the lateral sulcus is a fifth major lobe called the __.

Back 11

Insula (island of Reil).

Front 12

Functionally, the cerebral cortex can be divided into three kinds of areas. Name these areas.

Back 12

(1) Primary sensory areas. Neurons from these areas receive information from visual, auditory, vestibular, somatosensory, gustatory, and olfactory receptors in the periphery. (2) Areas of motor control. Neurons here are involved with the initiation of movements. (3) Associative or integrative areas. Nuerons here are involved in so-called "higher" processes such as language, learning and memory, and sensorimotor integration.

Front 13

The __ lobe has a major role in initiating voluntary movements.

Back 13

Frontal lobe.

Front 14

The __ lobe is important for processing visual information.

Back 14

Occipital lobe.

Front 15

Within a cortical hemisphere, short and long fiber tracts interconnect areas performing interrelated functions, for example vision (__ lobe) and eye movement (__ lobe). Also, regions within the left and right hemispheres are interconnected by a thick band of horizontally running axons called the __.

Back 15

Occipital lobe; frontal lobe. Corpus callosum.

Front 16

The anterior part of the lateral surface of the frontal lobe is divided into three longitudinal strips oriented from rostral to caudal, called the __. On the inferior surface of the brain are the __ gyri of the frontal lobe, so named because they are located just above the skull's bony orbits.

Back 16

Superior, middle, and inferior frontal gyri. This part of the frontal lobe serves diverse high level motor, cognitive, and emotional functions. Damage to it can result in a condition known as frontal-lobe syndrome, where the patient shows deficits in eye movements and striking changes in personality. The patient may become impulsive and flippant, and display a loss of social decorum. Orbital gyri.

Front 17

A functional area of major importance in the frontal lobe is the __, which runs across the lateral posterior part of the frontal lobe from medial to lateral. This part of the cortex is called the __ cortex because it controls voluntary movements of the contralateral body.

Back 17

Precentral gyrus. Somatosensory cortex. Neurons here give rise to the corticospinal tract*, which contains axons that project to motoneurons in the spinal cord; the motoneurons in turn innervate muscles. Medial regions of the precentral gyrus control movements of the leg, whereas progressively more lateral parts of the gyrus control movements of the trunk, arm, and face. Thus, the precentral gyrus contains a functional map of the contralateral body and is described as being topographically organized.

Front 18

In the left hemisphere of most individuals, the part of the inferior frontal gyrus just anterior to the precentral gyrus has a special motor-related function. This is __ , a part of the brain that is critically involved with the motor components of speech.

Back 18

Broca's area. Patients with damage here have difficulty producing words, and their speech may be hesitant and non-fluent.

Front 19

Language deficits are broadly termed __.

Back 19

Aphasias.

Front 20

The parietal lobe is bounded anteriorly by the __. The first gyrus behind this is the __.

Back 20

Central sulcus. Postcentral gyrus. The postcentral gyrus contains somatosensory cortex, so called because neurons here receive information from somatic sensory receptors in skin and from proprioceptive sensory receptors in muscles and joints. Like the motor cortex, somatosensory cortex is topographically organized; again, the contralateral leg is represented medially whereas the contralateral face is represented laterally. Because adjacent parts of the contralateral body project to adjacent areas of the somatic cortex, it is said to be "somototopically" organized.

Front 21

Behind the postcentral gyrus, the parietal lobe is divided into an inferior and a superior lobule by the __.

Back 21

Intraparietal sulcus.

Front 22

The __ is important for our forming a mental image of how the outside world is spatially organized and where our body is located within it.

Back 22

Posterior parietal cortex. A patient with damage to the posterior parietal cortex may be unaware that one half of her/his world exists and may sometimes even fail to recognize that the contralateral side of the body belongs to them.

Front 23

The most important function of the occipital lobe is the processing of visual information. On the medial surface note the prominent and deep __ that runs from rostral to caudal and separates the occipital lobe into an inferior part (__) and a superior part (__).

Back 23

Calcarine fissure (or sulcus). Lingual gyrus (inferior); cuneus gyrus (superior). This latter area of cortex is also referred to as the calcarine cortex; it processes images arising from the contralateral half of the visual world.

Front 24

The temporal cortex continues into the lateral sulcus where its dorsal surface contains the __, which comprises the primary auditory receiving area.

Back 24

Transverse temporal gyri of Heschl.

Front 25

In the left hemisphere of most individuals, the posterior part of the superior temporal gyrus and nearby regions of the inferior parietal lobe are involved with comprehending language. This region is called __ and has a function closely related to that of Broca's area in the frontal lobe.

Back 25

Wernicke's area.

Front 26

On the inferior surface of the temporal lobe, the collateral sulcus separates the occipitotemporal gyri from the __ and the __.

Back 26

Parahippocampal gyrus and the uncus. The uncus and the anterior part of the parahippocampal gyrus are part of the primary olfactory cortex*.

Front 27

The __ is thought to be infvoled with gustatory and visceral sensations, among other things.

Back 27

Insula.

Front 28

An important set of telencephalic structures is the basal ganglia, which are important in controlling movement. However, unlike the somatomotor cortex, which projects to the spinal cord, the basal ganglia only control movements indirectly, by modulating cortical motor output. The basal ganglia are located deep within the cerebral hemispheres and underlie the cerebral cortex immediately adjacent to the insula. Name the structures of the basal ganglia.

Back 28

Caudate, putamen, globus pallidus. The caudate nucleus is an arc-shaped structure that begins as a large swelling (head) in the lateral wall of the anterior part of the lateral ventricle. As it arches dorsally and laterally, it becomes thinner and more laterally its tail lies in the roof of the temporal horn of the lateral ventricle. The lenticular nucleus consists of the putamen and globus pallidus.

Front 29

The __, another basal ganglia structure, lies beneath the cerebral cortex and just lateral to the uncus, at the tip of the temporal horn of the lateral ventricle. It is involved in emotional expression.

Back 29

Amygdala.

Front 30

The __ consists of paired egg-shaped structures lying within the cerebral hemispheres. It means "antechamber" and is so named because virtually all information passing to the cerebral cortex first synapses or relays on cells here.

Back 30

Thalamus. Axons reach the cortex by means of the internal capsule*, which also contains axons descending from the cerebral cortex. The thalamus consists of a number of nuclear groups; each nucleus has a different function and is linked with particular parts of the cerebral cortex. The ventral posterolateral nucleus is a somatosensory relay nucleus to the postcentral gyrus. The medial and lateral geniculate nuclei are the main sensory relays for auditory and visual information, respectively. Axons in the optic tract (optic nerve --> optic chiasm --> optic tract) terminate in the lateral geniculate nucleus.

Front 31

The __ lies inferior to the thalamus. It can be identified by locating the __ bodies.

Back 31

Hypothalamus. Mammillary bodies (associated with hypothalamic nuclear groups). The hypothalamus functions as a regulatory center for many important autonomic functions such as osmotic regulation, feeding, endocrine control, etc.

Front 32

The ventral two-thirds of the mesencephalon constitute the __. They appear to support the cerebral hemispheres. The hollow area between and medial to these structures is called the __. Immediately beneath them is the __, which consist of massive bundles of axons that arise from the cerebral cortex and project caudally through the brainstem and into the spinal cord.

Back 32

Cerebral peduncles. Interpeduncular fossa. Crus cerebri. Some of these axons originate in the motor cortex and project through the brainstem and into the spinal cord as the corticospinal tract*, which is the major descending pathway for controlling voluntary movement.

Front 33

The mesencephalon contains a dorsal tectum or roof, consisting of the __, both of which are alar plate derivatives. They can be recognized as two pairs of bumps on the midbrain.

Back 33

Inferior and superior colliculi. The inferior colliculus processes auditory information and relays it to the medial geniculate nucleus of the thalamus. The superior colliculus is involved with reflexive eye movements, and receives input from the optic tract.

Front 34

Beneath the cerebral aqueduct, the tegmentum overlies the cerebral peduncle, and in accordance with its derivation from the basal plate, contains motor nuclei of the __ and __ cranial nerves.

Back 34

Oculomotor (III) and trochlear (IV).

Front 35

The metenceophalon develops into the cerebellum and the __.

Back 35

Pons. Bundles of axons run from medial to lateral, connecting nuclei within the pontine nuclei to the cerebellar hemispheres. The pons also houses cranial nerve nuclei as well as tracts that interconnect higher and lower regions of the neuroaxis.

Front 36

One cranial nerve, the __, is associated with the pons, and three are located at the junction of the pons and the medulla. Name them.

Back 36

Trigeminal (V). The larger bundle of the trigeminal is sensory to the face and the smaller one is motor to the muscles of mastication. Abducens (VI), facial (VII), and vestibulo-cochlear (VIII). The abducens root fibers (motoneurons to the ipsilateral lateral rectus muscle) attach to the brainstem near the midline at the caudal-most part of the pons. The facial nerve emerges at the caudal border of the pons just lateral to the abducens (muscles of facial expression). The vestibulo-cochlear nerve emerges caudal to the pons and lateral to the facial nerve (sensory information about auditory stimuli from the cochlea and head movements encoded by the vestibular part of the labyrinth).

Front 37

The __ is an important motor control and coordinating center. It monitors the accuracy of intended movements by comparing sensory information, for example from the limb muscles, with motor commands originating in the motor cortex, and then sends corrective signals back to the motor cortex via the thalamus. It is attached to the brainstem by 3 large fiber tracts called the __.

Back 37

Cerebellum. Cerebellar peduncles. The superior, middle, and inferior peduncles are bundles of axons that are either inputs to and/or outputs from the cerebellum.

Front 38

Unlike the cerebral hemispheres, the cerebellar hemispheres are continuous at the midline with a structure called the __.

Back 38

Vermis.

Front 39

The myelencephalon develops into the __, which is physically continuous rostrally with the pons and caudally with the spinal cord.

Back 39

Medulla oblongata (medulla). The medulla is an important brainstem center for the control of autonomic functions such as respiration and blood pressure. It contains cranial nerve nuclei whose functions are in many cases life-sustaining. It also contains fiber pathways connecting the upper and lower regions of the brain. Localized damage, caused for example by a vascular problem such as an embolus or a hemorrhage, can create widespread and life-threatening damage.

Front 40

The two prominent bulges on the lateral surface of the medulla are called __. Just medial to the olives are the medullary __.

Back 40

Olives. The olives are motor nuclei that relay information to the cerebellum. The pyramids. These are bundles of motor control axons of the corticospinal tract. Recall, corticospinal tract axons originate from neurons in the somatosensory cortex and project to the contralateral spinal cord. The place where these axons cross or decussate from one side of the brain to the other is at the most caudal end of the medulla (the spinomedullary junction, called the pyramidal decussation*).

Front 41

What cranial nerves are associated with the medulla?

Back 41

The glossopharyngeal (IX) and vagus (X) nerves emerge from the brainstem as a series of rootlets immediately lateral to the olive, the rostral bundles belonging to the glossopharyngeal nerve and the caudal ones to the vagus; these nerves contain afferent and efferent neurons innervating visceral structures. The spinal accessory nerve (XI) is formed by the union of rootlets emerging from the caudal medulla and of rootlets emerging from the spinal cord at upper cervical levels. The cranial component of the accessory nerve innervates the muscles of the larynx, and its spinal component innervates the ipsilateral SCM and trapezius muscles. The hypoglossal nerve (XII) rootlets emerge in the sulcus between the medullary pyramid and the inferior olive on the ventral medulla. This motor nerve innervates the somatic skeletal muscles of the tongue.