A&P2 Combo with Circle of Willis and 4 others

Cranial nerve II: Optic The nasal retinal fields (temporal visual fields) however, are carried back on the optic nerve and ________ at the optic chiasm and then travel _________ back to the visual cortex.

Do Cross; contralaterally

Cranial Nerve III: Oculomotor There is also an accessory parasympathetic nucleus called the _________ found just behind the oculomotor nucleus whose axons travel with _______ and synapse in the ciliary ganglion to constrict the iris (constrictor pupilae muscle). The oculomotor nerve is also responsible for eye reflexes including the _________.

Edinger-Westphal nucleus; CN III; pupillary reflex, accommodation and convergence.

Cranial Nerves VII.

Facial nerve

Cranial Nerves IX.

Glossopharangeal nerve

Cranial Nerves XII.

Hypoglossal nerve

Cranial nerve II: Optic What is the result if there is a lesion in the optic chiasm?

If the optic chiasm is lesioned then it will disrupt the fibers that are crossing over, specifically the nasal retinal field or temporal visual field information. This results in what is called bitemporal hemianopia.

Cranial nerve II: Optic What is the result if there is lesion of the optic nerve on the right?

If the optic nerve is lesioned on the right then the person will be blind in the right eye (all or partial depending on how bad the lesion is-total or partial.

Cranial Nerve II : Optic What is the result if there is a lesion in the right optic radiations?

If the optic radiations are lesioned on the right, then it will also disrupt the temporal visual field (nasal retinal field) of the left eye and the nasal visual field (temporal retinal field) of the right eye and results in left homonymous hemianopia.

Cranial nerve II: Optic What is the result if there is a lesion of the left optic tract?

If the optic tract on the left is lesioned then it will disrupt the nasal visual field (temporal retinal field) of the left eye and the temporal visual field (nasal retinal field) of the right eye. This results in, what is called homonymous hemianopia; specifically, right homonymous hemianopia. In other words you would not be able to see to the right on either eye.

Diencephalon - Thalamus Fibers from the thalamic nuclei travel to the cerebral cortex via the _________ . The internal capsule funnels the ___________ fibers to their destinations. The internal capsule is ________. Ascending fibers then radiate out from the internal capsule and are called the _______

Internal Capsule; corticospinal, corticobulbar, corticothalamic and thalamocortical; white matter; cornea radiata

Diencephalon - Subthalamus Subthalamus:

It is bounded by the thalamus above and the internal capsule below. It contains the subthalamic nuclei which are important motor nuclei. Lesions of this structure result in hemiballismus (a motor disorder characterized by rapid, flailing movements of one side of the body). This is considered a basal ganglia nucleus. In lab you may see this structure on a good coronal section.

Contents of the Diencephalon

Thalamus, hypothalamus

Cytoarchitectural Mapping: (see page 14 in your textbook)

The brain can be divided or mapped out into functional sections. The most widely used map was devised by Brodmann who designated 52 cortical areas related to function. The function was determined through electrical stimulation, surgical ablation and degeneration studies. The important areas that we would like you to know are listed below by where you can find them in the lobes.

what if CN III is damaged?

- Because CN III innervates the medial rectus muscle, if it is lesioned then the eye will deviate laterally because the lateral rectus is unopposed (lateral rectus is innervated by the abducens nerve CN VI). This deviation of the eye can cause the symptom of Diplopia (double vision). - Because CN III also innervates the levator palpabrae muscle the eyelid on the lesioned side will droop down called Ptosis. - Horner's Syndrome: this is a syndrome that can occur with damage of the cervical sympathetic nerve trunk. It can result from a lung tumor or from an anesthetic mishap. It results in an ipsilateral small pupil, an ipsilateral ptosis and ipsilateral anhidrosis (absence of sweating which occurs without the sympathetic innervation to the sweat glands) of the face and neck. This occurs because the parasympathetic fibers are working in CN III and now go unopposed.

Cranial Nerves VI.

Abducens nerve This is the third nerve involved in extraocular eye movements. This is also a MOTOR nerve that innervates the lateral rectus muscle (moving the eye laterally). The abducens nuclei are found in the pons beneath the floor of the fourth ventricle near the facial collulicus. The abducens nerve exits near the base of the pons at the pontomedullary junction (groove between the pons and the medulla) and goes through the area of the cavernous sinus and then exits through the superior orbital fissure to then innervate the lateral rectus muscle of the eye. If this nerve is damaged it results in difficulty turning the eye outward leading to medial strabismus (Esotropia) or diplopia.

Cranial Nerves XI.

Accessory nerve

Accommodation and Convergence Reflex:

Accommodation allows you to change the shape of your lens and restrict how much light enters the eye (pupil constriction). Convergence helps you move your eyes (medially) so that you can focus properly on objects that are near.

Diencephalon - Hypothalamus Hypothalamus:

The hypothalamus is the most ventral and anterior portion of the diencephalon. It is subdivided into 10 nuclei with important homeostatic control. For example, the mammillary bodies serve to integrate our emotional states with homeostatic activity.

Corneal Reflex:

This reflex results in the quick closure of the eye to a stimulus like cotton being touched to the cornea. It involves both CN V and CN VII. Afferent information from the cornea is carried on the ophthalmic division of the trigeminal nerve to the trigeminal sensory nuclei (the spinal nucleus) and synapse. From here the signal is carried by internuncial neurons through the medial longitudinal fasciculus to the motor nucleus of the CN VII (facial). CN VII then innervates the orbicularis oculi muscle causing a blink. See the picture below that traces out the pathway for this reflex as page 518 of your text.

Diencephalon - Epithalamus Epithalamus:

This structure is located next to the roof of the third ventricle. It consists of the habenular nuclei and the pineal gland and the posterior commissure. The habenular nuclei receive input from the olfactory and limbic systems which are projected to the autonomic nervous system. It is part of the circuitry where basic emotions and smell influence visceral function. (You know those feelings and memory that are evoked when you smell something from you childhood—like baking cookies or perhaps a certain flower smell reminds you of a certain person that gave them to you). The pineal gland is an endocrine gland that inhibits gonadal function and delays the onset of puberty. In later life it calcifies and is used as a midline landmark in X-rays, MRI, CT scans.

Posterior cerebral artery Blood supply to MEDIAL and INFERIOR SURFACES of TEMPORAL AND OCCIPITAL LOBES as well as THALAMUS and HYPOTHALAMUS. Part of WATERSHED AREA. Occlusions: VISUAL and PERCEPTION DEFICITS such as HOMONYMOUS HEMIANOPIA or FIELD CUTS, MEMORY LOSS. THALAMIC SYNDROME: CONTRALATERAL HEMIANESTESIA, HEMICHOREA AND CENTRAL PAIN, DEEP LANCINATING PAIN felt in SOFT TISSUE and BONES. High suicide rate.

What is the name of the artery labeled 6?

Superior cerebellar artery - supply SUPERIOR PORTIONS of the CEREBELLUM, MIDBRAIN, and PONS.

What is the name of the artery labeled 7?

Basilar artery

What is the name of the artery labeled 8?

Anterior inferior cerebellar artery (AICA) - feeds ANTERIOR INFERIOR PORTIONS OF CEREBELLUM.

What is the name of the artery labeled 9?

How does the pupillary reflex happen?

When the light hits your eye (retina) it is carried back on (CN II) the optic nerve to the optic chiasm back to the optic track and superior colliculus where some fibers head to the pretectal nucleus and synapse. From here the signal is sent to the Edinger-Westphal nucleus and synapses while the signal also branches and continues through the posterior commissure to the other side's pretectal nucleus and Edinger-Westphal nucleus. From here, preganglionic parasympathetic axons head down each CN III to the ciliary ganglion and synapse. From here postganglionic fibers head down the ciliary nerves to synapse and constrict the pupils via the constrictor pupilae muscle of the iris. Thus, we have a direct response and the consensual response (because the fibers crossed over through the posterior commissure to the other side).

Diencephalon - Nuclei of the Thalamus Medial Geniculate nucleus is

a specific thalamic nuclei for the integration and relay of auditory information

Diencephalon - Nuclei of the Thalamus Reticular Nucleus is information about how awake you are

a subcortical nuclei that integrates and relays There are two other subcortical nuclei

If the optic radiations are lesioned on the right, then it will __________

also disrupt the temporal visual field (nasal retinal field) of the left eye and the nasal visual field (temporal retinal field) of the right eye and results in left homonymous hemianopia.

Diencephalon - Nuclei of the Thalamus Lateral Dorsal nucleus is

an association nuclei providing information to the limbic lobe about touch

Diencephalon - Nuclei of the Thalamus Lateral Posterior nucleus is

an association nuclei relaying pain information

Diencephalon - Nuclei of the Thalamus Pulvinar is

an association nuclei that integrates and relays other types of sensations such as movement and proprioception

Diencephalon - Epithalamus The pineal gland is

an endocrine gland that inhibits gonadal function and delays the onset of puberty. In later life it calcifies and is used as a midline landmark in X-rays, MRI, CT scans.

Cranial nerve II: Optic On essence half of what you see out of one eye is send __________ while the other half goes __________ . So, let's see how this will affect us when there is a lesion

back to the ipsilateral visual cortex ; to the contralateral visual cortex.

If the optic nerve is lesioned on the right then the person will ___________

be blind in the right eye (all or partial depending on how bad the lesion is-total or partial.

Pupillary Reflex (it takes two cranial nerves to accomplish the light reflex; CN II and III): When you shine a light into your eye ___________ So, if I shine a light into your right eye your _________ known as the _________ and your left pupil will ______; known at the .

both of your pupils will constrict; direct light reflex; constrict; consensual light reflex

posterior communicating artery

common site of aneuryms, lesions cause CN III palsies

Cerebrum: Telencephalon Cerebral Cortex:

composed of a gray mantle which surrounds a center of white matter fiber pathways, the ventricular system and the diencephalon. The folds in the cerebral hemispheres substantially increase the surface area of the cerebral cortex. These folds or convolutions are called gyri and the intervening grooves are called sulci. Fissures are the clefts (large sulci) that separate large components of the brain. The sulci and fissures divide the brain into 4 lobes seen on the lateral surface and 1 lobe on the medial surface:

The motor nuclei of the cranial nerves receive input from the cortex via the _________ . These tracts begin in the cerebral cortex and synapse in the _______. The cranial nerves also contribute to the _________ nervous system. The "big players" in this cranial outflow of the parasympathetic system are CN's _________ . More on this as we discuss each CN.

corticobulbar tracts; branistem; parasympathetic; III, VII, IX, X

The olfactory nerve travels through the ________ When CN 1 is lost it doesn't come back. You can get along with only one side working, you will still be able to smell but if the lesion is bilateral you will lose the ability to smell (anosmia).

cribiform plate

If the optic chiasm is lesioned then it will __________ , specifically the ______ or ________ . This results in what is called __________.

disrupt the fibers that are crossing over; nasal retinal field or temporal visual field information; bitemporal hemianopia.

If the optic tract on the left is lesioned then it will _________. This results in, what is called __________. In other words __________

disrupt the nasal visual field (temporal retinal field) of the left eye and the temporal visual field (nasal retinal field) of the right eye.; homonymous hemianopia; specifically, right homonymous hemianopia.; you would not be able to see to the right on either eye.

lateral striate

divisions of MCA; supply internal capsule, caudate, putamen, globus pallidus. infarct causes pure motor hemiparesis

Diencephalon - Subthalamus Lesions of thsubthalamic nuclei of the subthalamus structure result in ___________.

hemiballismus (a motor disorder characterized by rapid, flailing movements of one side of the body).

The diencephalon is located _________ and is surrounded by the ________ except for a small ventral surface.

immediately cranial to the midbrain , cerebral hemispheres

PICA

infarct causes Wallenberg's syndrome (nystagmus, ipsilateral ataxia, nausea, vomiting, Horner's syndrome)

basilar artery

infarct causes locked-in syndrome

Diencephalon - Nuclei of the Thalamus Ventral Anterior and Ventral Lateral nuclei are

integration and relay nuclei for motor control

The cranial nerves carry sensory information, motor information or both to the head, face and neck regions. When a cranial nerve is lesioned it usually results in _________.

ipsilateral signs.

Diencephalon - Nuclei of the Thalamus Lateral Geniculate nucleus

is a specific thalamic nuclei for integration and relay of visual information

Diencephalon - Nuclei of the Thalamus Ventral posterior nucleus

is divided into the VPM (ventral posteriomedial) and the VPL (ventral posteriorlateral). The VPM receives sensory input from the face and head. The VPL receives sensory input from the body. Lesions that destroy this nuclei results in contralateral hemianesthesia specific to the area from which the nuclei was receiving input.

middle cerebral artery

lateral aspect of brain, inc. trunk-arm-face area of motor and sensory cortices, Broca's and Wernicke's areas

anterior cerebral artery

medial surface of brain, inc. leg-foot area of motor and sensory cortices

anterior communicating artery

most common site of aneuryms, lesions may cause visual field defects

Cranial Nerve III: Oculomotor This nerve carries __________ and is involved in __________ and works along with CN's IV (trochlear) and VI (abducens). The oculomotor nucleus is found in the ________ at the level of the _________ . The nerve exits and travels ventrally through the __________ and goes through the area of the ________ before heading through the __________ and to the _____.

motor information only; extraoccular eye movement; midbrain; superior colliculi (pretectal area); cerebral peduncle ; cavernous sinus; superior orbital fissure; eye

Lesions to the Trigeminal nerve can affect . . . .

motor, sensory or both components. Damage to the motor nerve may result in some weakness in chewing and a jaw deviation to the affected side. Damage to the sensory nerve can cause a loss of sensation to the head, face and oral cavity.

Cranial nerve II: Optic When you look at an object you are using both eyes and the image is projected onto your retina. What comes in from the temporal visual fields (objects to the far right and left) "reflect" and stimulate the rods and cones of the _______. What you see in front of you, in the nasal visual fields stimulates the rods and cones of the _______. The temporal retinal fields (what you see if the nasal visual fields) signals are carried back on the optic nerve and _______ at the optic chiasm but are carried ________ in the optic tract back to the visual cortex.

nasal retinal fields; temporal retinal fields; do not cross; ipsilaterally

posterior cerebral artery

visual cortex

Cerebrum: Telencephalon Temporal Lobe:

- Integrates memory - Receives stimuli from senses of hearing, taste and smell - Has visual fibers located deep in the lobe (for visual processing and perception)

Cerebrum: Telencephalon Occipital Lobe:

- Integrates visual stimuli

Diencephalon - Thalamus Major Functions of the Thalamus:

- Integration and relay of sensory information (except olfaction) - Integration and relay of motor control information from the cerebellum and the basal ganglia to the motor cortex - Gating of passage of sensory and motor information - Transmit states of consciousness from brainstem to cortex

Cranial Nerve III: Oculomotor The oculomotor nerve innervates the:

- Levator palpebrae (to lift up the eyebrow) - Superior rectus (move eye up and medially) - Medial rectus (moves eye medially) - Inferior rectus (moves eye downward and medially) - Inferior oblique (moves eye up and laterally)

Cerebrum: Telencephalon The major sulci and fissures include:

- Longitudinal cerebral fissure - Lateral sulcus - Central sulcus - Parieto-occipital sulcus - Calcarine sulcus

Cerebrum: Telencephalon Frontal Lobe:

- Personality - Behavior - Higher intellectual function - Primary voluntary motor area

Diencephalon - Hypothalamus Major Functions of the Hypothalamus:

- Regulation of the ANS - Cardiovascular regulation - Temperature regulation - Energy metabolism regulation - Fluid balance regulation - Sleep cycle regulation

Cerebrum: Telencephalon Parietal Lobe:

- responsible for perception of general sensation - Involved with spatial perceptions and inter-relationships - Interacts with the motor area

Cranial Nerves There are _______ of cranial nerves. These nerves are considered _________ and part of the ________. However, their associated nuclei are part of the ________.

12 pairs; lower motor neurons; peripheral nervous system; central nervous system

Cranial Nerves III.

Oculomotor nerve This nerve carries MOTOR information only and is involved in extraocular eye movement and works along with CN's IV (trochlear) and VI (abducens). The oculomotor nucleus is found in the midbrain at the level of the superior colliculi (pretectal area). The nerve exits and travels ventrally through the cerebral peduncle and goes through the area of the cavernous sinus before heading through the superior orbital fissure and to the eye. The oculomotor nerve innervates the: Levator palpebrae (to lift up the eyebrow); Superior rectus (move eye up and medially); Medial rectus (moves eye medially) Inferior rectus (moves eye downward and medially); Inferior oblique (moves eye up and laterally)

Cranial Nerves I.

Olfactory nerve Sensory information-smell- from the nose (mucous membrane) is carried on the olfactory nerve to the olfactory bulb then down the olfactory tract to the olfactory cortex found in the hippocampus. The olfactory nerve travels through the cribiform plate. When CN 1 is lost it doesn't come back. You can get along with only one side working, you will still be able to smell but if the lesion is bilateral you will lose the ability to smell (anosmia).

Cranial Nerves II.

Optic nerve This cranial nerve carries sensory information for vision. The receptors of the eyes (the rods and cones) send information down the optic nerve back through the optic canal in the skull then to the optic chiasm where half of each eyes fibers cross over and then travel back through the optic tract and synapse in the lateral Geniculate bodies (on the thalamus). Some fibers actually go to the pretectal nucleus and the superior colliculus which is important for light reflexes. From the Geniculate the information continues back via the optic radiations to the visual cortex in the occipital lobe (area 17). When you look at an object you are using both eyes and the image is projected onto your retina. What comes in from the temporal visual fields (objects to the far right and left) "reflect" and stimulate the rods and cones of the nasal retinal fields. What you see in front of you, in the nasal visual fields stimulates the rods and cones of the temporal retinal fields. The temporal retinal fields (what you see if the nasal visual fields) signals are carried back on the optic nerve and DO NOT CROSS at the optic chiasm but are carried ipsilaterally in the optic tract back to the visual cortex. The nasal retinal fields (temporal visual fields) however, are carried back on the optic nerve and DO CROSS at the optic chiasm and then travel contralaterally back to the visual cortex. So in essence half of what you see out of one eye is send back to the ipsilateral visual cortex while the other half goes to the contralateral visual cortex. So, let's see how this will affect us when there is a lesion.

trigeminal neuralgia.

This causes pain in the distribution of the trigeminal nerve usually the maxillary and or mandibular divisions. The pain is described as intense, burning, stabbing or like electric shocks. It may be due to irritation of the nerve or a tumor or multiple sclerosis.

Diencephalon - Nuclei of the Thalamus THALAMUS:

This is a large ovoid mass that makes up most of the diencephalon (80%). It is subdivided into 12 nuclei that have specific relay functions and connections with the cortex or subcortical structures.

Masseter Reflex (Jaw Jerk):

This reflex occurs when you tap the masseter muscle with your reflex hammer; you will see a reflexive contraction. See the picture above that traced the sensory tract for cranial nerve V. The jaw jerk is also represented on that picture. Follow from V3 (the mandibular branch of the cranial nerve): when you tap the jaw it is carried to the Mesencephalic nucleus, then to the motor nucleus of V which would then send signal back out to the jaw for a reflex contraction. You will see that it is also sent to the Principle nucleus of V and then up to the thalamus and sensory cortex so we can then "feel" the tap on the jaw.

Cranial Nerves V.

Trigeminal nerve This is the largest cranial nerve and it is both a motor nerve to the muscle of mastication and a sensory nerve of the face, head, cornea and oral cavity. There are four trigeminal nerve nuclei; one motor and three sensory. The nuclei include the motor nucleus the main or principle sensory nucleus of V, the nucleus of spinal tract of V, and the mesencephalic nucleus of V. The nuclei are found in the pons. The trigeminal nerve leaves the pons and heads to the upper surface of the temporal bone where the sensory portion of the nerve expands and is called the trigeminal ganglion. It then splits into three divisions: the ophthalmic, the maxillary, and the mandibular nerves which then innervate the skin of the face as well as the mucous membranes of the mouth and nose. The ophthalmic division heads up through the cavernous sinus and out of the skull through the superior orbital fissure, the maxillary division exits through the foramen rotundum, and the mandibular division exits out the foramen ovale. Clinically the three divisions are important because of their different distribution to the face. Sensory loss in a particular area (like the chin) can help you determine where a lesion may exist (mandibular branch). The motor portion of the nerve exits from the motor nucleus and follows the mandibular division of the nerve and leaves the skull through the foramen ovale to innervate the muscles of mastication (chewing).

Cranial Nerves IV.

Trochlear nerve This nerve also carries only MOTOR information and is involved in extraocular eye muscle function. The trochlear nuclei are found in the periaquaductal gray at the level of the inferior colliculus. The nerve fibers leave the nucleus and pass around from posterior to the other side of the midbrain wrapping around the cerebral peduncle and into the area of the cavernous sinus. It continues then through the superior orbital fissure and innervates the superior oblique muscle to turn the eye down and lateral. If this nerve is damaged it will result in difficulty moving the eye down or laterally and a vertical, medial strabismus or a vertical diplopia.

Cranial Nerves X.

Vagus

Cranial Nerves VIII.

Vestibulocochlear nerve

How does accommodation and convergence happen?

Well, again we have to "see" the object so CN II is used to get a signal back to the occipital lobe (area 17, 18 19). A signal is sent from the visual cortex to the pretectal area and both Edinger-Westphal nuclei which then send preganglionic fibers down CN III to the ciliary ganglion. From here postganglionic fibers travel to contract the ciliary muscle for pupil constriction as well as lens thickening. Meanwhile the visual cortex sends signals to the frontal eye field. Cortical fibers are then sent from here down through the internal capsule to the oculomotor nuclei. From here signal is carried down CN III to contract the medial rectus muscles. The result of all these events leads to turning of the eye medially while the pupil and lens constrict so that you can focus on the object.

Vertebral artery

What is the name of the artery labeled 10?

Posterior inferior cerebellar artery (PICA)

What is the name of the artery labeled 11?

Anterior spinal artery - supplies ANTERIOR 2/3 of SPINAL CORD.

What is the name of the artery labeled 12?

Anterior communicating artery - connects internal carotid to anterior cerebral arteries.

What is the name of the artery labeled 1?

Anterior cerebral artery - supplies MEDIAL surface of hemispheres around the CORPUS CALLOSUM, FRONTAL and PARIETAL LOBES part of BASAL GANGLIA. Part of WATERSHED AREA. - Occlusions: severe hemiplesia involving CONTRALATERAL LOWER EXTREMITY, some SENSORY LOSS over CONTRALATERAL LOWER EXTREMITY, PERSONALITY CHANGES, URINARY INCONTENANCE, APRAXIA.

What is the name of the artery labeled 2?

Medial cerebral artery - blood supply to LATERAL SURFACES of CEREBRAL HEMISPHERES , FRONTAL, PARIETAL AND TEMPORAL LOBES, INFERIOR SURFACE of FRONTAL and TEMPORAL LOBES. Part of WATERSHED AREA. Occlusions: At Origin: symptoms severe, disabling, possibly fatal. CONTRALATERAL HEMIPLESIA or HEMIPARESIS and HEMIPARESTHESIA involving UPPER EXTREMITY and FACE most severely. HOMONYMOUS HEMIANOPIA (visual problems). TRACTS often involved with MIDDLE CEREBRAL VESSELS (CORTICOSPINAL, CORTICOBULBAR, extra pyramidal) Occluded Left Side: both MOTOR and SENSORY SPEECH PROBLEMS (aphasia). Occluded Right Side: DYSPRAXIA or APRAXIA, NEGLECT SYNDROMES, , DENYAL or NOT RECOGNIZING Existanse of left side of body.

What is the name of the artery labeled 3?

Carotid artery

What is the name of the artery labeled 4?

Posterior communicating artery - connects INTERNAL CAROTID ARTERT to the POSTERIOR CEREBRAL ARTERIES.

What is the name of the artery labeled 5?

Sensory information-smell- from the nose (mucous membrane) is carried on the _______ to the ________then down the _________ to the __________ found in the hippocampus.

olfactory nerve; olfactory bulb; olfactory tract; olfactory cortex

Cranial nerve II: Optic The receptors of the eyes (the rods and cones) send information down the ______ back through the _______ in the skull then to the _______ where half of each eyes fibers cross over and then travel back through the ______ and synapse in the _______ . Some fibers actually go to the _______ and the ________ which is important for light reflexes. From the Geniculate the information continues back via the ______ to the ________ in the occipital lobe (area 17).

optic nerve; optic canal; optic chiasm; optic tract; lateral geniculate bodies on the thalamus; pretectal nucleus; superior colliculus; optic radiations; visual cortex

Diencephalon - Epithalamus The habenular nuclei

receive input from the olfactory and limbic systems which are projected to the autonomic nervous system. It is part of the circuitry where basic emotions and smell influence visceral function. (You know those feelings and memory that are evoked when you smell something from you childhood—like baking cookies or perhaps a certain flower smell reminds you of a certain person that gave them to you).

Cranial nerve II: Optic This cranial nerve carries ________ for ______.

sensory information; vision

Diencephalon - Subthalamus It is bounded by ________ . It contains the ________ which are important motor nuclei. Lesions of this structure result in ___________. This is considered a basal ganglia nucleus. In lab you may see this structure on a good coronal section.

the thalamus above and the internal capsule below; subthalamic nuclei; hemiballismus (a motor disorder characterized by rapid, flailing movements of one side of the body).

The diencephalon is divided by ________ with the _________ connecting the two halves. The diencephalon contains 4 major nuclei and their interconnecting fiber pathways.

the thin third ventricle , massa intermedia (thalamic adhesion)

Horner's Syndrome:

this is a syndrome that can occur with damage of the cervical sympathetic nerve trunk. It can result from a lung tumor or from an anesthetic mishap. It results in an ipsilateral small pupil, an ipsilateral ptosis and ipsilateral anhidrosis (absence of sweating which occurs without the sympathetic innervation to the sweat glands) of the face and neck. This occurs because the parasympathetic fibers are working in CN III and now go unopposed.

Cytoarchitectural Mapping: - Frontal Lobe: Area 4: Precentral Gyrus:

this is the primary motor area and it is somatotopically organized. It sends signals down to the muscle for motor actions