Midbrain

As long as you understand the general function and location you are going to do fine MidBrain
Activation . The cerebellum is connected to the brain stem. The space between the dura and the
arachnoid is known as the subdural space. Many collaterals enter the red nucleus and other fibers are
said to run to the superior colliculus. Drawing of the different cortices sulci and gyri and midsagittal
drawing emphasizes the limbic lobe . The medulla oblongata joins the spinal cord at the foramen
magnum. The medulla is located directly above the spinal cord and controls many vital autonomic
functions such as heart rate breathing and blood pressure. Landmark structures include the head of the
caudate nucleus the anterior limb of the internal capsule the globus pallidus and putamen . The
hippocampus is also located in the temporal lobe which is why this portion of the brain is also heavily
associated with the formation of memories. For descriptive purposes each cerebral hemisphere can be
divided into six lobes.
These nerve fibers are highly developed and able to analyze both motor and sensory information. The
Midbrain contains a number of structures including the superior colliculi which is involved in vision;
the inferior colliculi which are involved in hearing; and the grey matter red nucleus substantia nigra
and ventral region which are all important for the control of movement. The fibers of the medial
lemniscus take origin in the gracile and cuneate nuclei of the medulla oblongata and as internal
arcuate fibers they cross to the opposite side in the sensory decussation MidBrain Activation . Many
fibers either terminate in or send off collaterals to the gray matter of the medulla the pons and the
midbrain. It coordinates subconscious movements such as balance and coordinated movement. These
nuclei are important in the control of movement. The interbrain located at the centre of the cerebrum
links and consolidates the functions of each part of the brain. The corpora quadrigemina are arranged
in pairs and are separated from one another by a crucial sulcus. The frontal lobe is the portion which is
rostral to the central sulcus and above the lateral fissure and it occupies the anterior one third of the
hemispheres . In some cases a device can be placed in the brain to stimulate the areas related to
movement and help control symptoms but this is usually only recommended for patients who dont
respond to medications.
Mesencephalon is continuous with the diencephalon rostrally and with the pons caudally MidBrain
Activation For Adults . The great bulk of the fibers however enter the ventrolateral portion of the
thalamus give off collaterals to the posterior semilunar nucleus and then terminate in the principal
sensory nucleus of the thalamus. It receives many terminals and collaterals from the superior
cerebellar peduncle also collaterals from the ventral longitudinal bundle from Guddens bundle and the
median lemniscus. The temporopontine fibers are lateral to the cerebrospinal fibers; they originate in
the temporal lobe and end in the nuclei pontis. Its the center for vomiting coughing and hiccupping.
The top of the Midbrain is called the tectum or tectal area MidBrain Activation For Adults . These
fibers from the superior colliculus probably pass into the ventral longitudinal bundle. The Midbrain
is the smallest region of the brain that acts as a sort of relay station for auditory and visual
information. The basal ganglia works along with the motor areas of the cortex and cerebellum for
planning and coordinating certain voluntary movements. The cerebellum is involved in movement and
coordination walking posture reflexes eye and head movement.
Thicker medially than laterally it reaches from the oculomotor sulcus to the lateral sulcus and extends
from the upper surface of the pons to the subthalamic region; its medial part is traversed by the fibers
of the oculomotor nerve as these stream forward to reach the oculomotor sulcus. Deficits in this area
have been linked with Huntingdons disease and Parkinsons disease. The ventricles connect with each
other and produce cerebrospinal fluid which is a clear shockabsorbing liquid that is constantly
moving. The diencephalon consists of a complex collection of nuclei lying symmetrically on either
side of the midline MidBrain Activation . Still deeper is the stratum opticum containing large
multipolar nerve cells separated by numerous fine nerve fibers. The tectum is the dorsal or roof part of
the Midbrain and controls visual and auditory reflexes. The base of the Midbrain consists of the
cerebral peduncle which contain nerve fibers descending from the cerebral cortex MidBrain
Activation For Adults . CN IV is the trochlear nerve. The brain and the spinal cord arise in early
development from the neural tube which expands in the front of the embryo to form the three primary

brain divisions: the pros encephalon mesencephalon and rhomb encephalon . In this space there is a
clear liquid known as the CSF.
The spinal cord is an elongated cylindrical structure lying within the vertebral canal which includes
the central canal and the surrounding gray matter. The forebrain consists of two almost symmetrical
cerebral hemispheres made up of the cerebral cortex the basal ganglia and the limbic system. In other
words I am attempting to simplify a REALLY complex science. The forebrain deals with homeostasis
emotions and conscious actions. The inferior parietal gyrus which is known as Wernickes area is also
important for language and reading skills whereas the superior parietal gyrus is concerned with body
image and spatial orientations. The Cerebrum: The cerebrum or cortex is the largest part of the human
brain associated with higher brain function such as thought and action. Coronal Section through the
MidbrainDiencephalon Junction. This is because we move our hands and lips all the time and both
are very sensitive. The limbic system also screens all sensory messages to the cerebral cortex
MidBrain Activation . There are three structures you should know in the hindbrain.
Additionally facial paralysis due to a pyramidal lesion will not permit voluntary control of the
muscles but these paralyzed muscles will respond to emotional expression. The axons of its larger
cells cross the middle line and are continued downward into the lateral funiculus of the medulla
spinalis as the rubrospinal tract; those of its smaller cells end mainly in the thalamus. The superior
colliculus receives input from the retina and the visual cortex and participates in a variety of visual
reflexes particularly the tracking of objects in the visual field. There are subcortical areas in the
telencephalon like the basal ganglia and the amygdaloid nucleus complex. Because the nuclei of the
vagus nerve are found in the medulla it is a center for circulation and respiration. Many of the signals
our brain receives from our senses are registered in the cerebral cortex. The interior of the brain
consists of myelinated neurons that are referred to as white matter. Midbrain strokes typically affect
an individuals motor and sensory functions including speech vision body movement and sensation.
The occipital lobe is the most caudal part of the brain lies on the tentorium cerebelli and is comprised
of several irregular lateral gyri. On the lateral surface of the cerebral hemisphere there are two major
deep groovessulci the lateral fissure and the central sulci these sulci provide landmarks for
topographical orientation MidBrain Activation For Adults .
Portions of the frontal parietal and temporal lobes which are adjacent to the lateral sulcus and overlie
the insular cortex are known as the operculum.The major brain structures and central nervous system
structures are described below. It consists of fibers from the terminal nuclei of the cochlear division of
the acoustic nerve together with others from the superior olivary and trapezoid nuclei.
TemporalSpeech behavior memory hearing vision smell and emotions. Olfactory Nerve I is the
sensory nerve for the sense of smell Optic Nerve II is the sensory nerve for the receipt of primary
visual stimuli Oculomotor Nerve III innervates 4 of the 6 muscles involved in eye movement is
responsible for elevating the upper eyelid and involved with pupillary constriction Trochlear Nerve IV
is responsible for downward and inward eye movement Trigeminal Nerve V is a mixed nerve which is
involved in sensations of pain temperature and light touch of the entire face scalp nose and mouth and
which innervates the muscles of mastication Abducens Nerve VI is responsible for rotating the eye
laterally Facial Nerve VII is a mixed nerve which: Innervates the muscles of facial expression and is
responsible for closing the eyes smiling whistling showing the teeth wrinkling the nose and brow and
grimacing Controls tearing and salivation Mediates taste to the anterior twothirds of the tongue
Mediates sensation from the skin lining to the external auditory meatus Acoustic Nerve VIII is
involved in the sense of hearing balance and orientation in space Glossopharyngeal Nerve IX is a
mixed nerve which innervates the pharynx taste receptors on the tongue parotid gland and back of the
ear Vagus Nerve X is a mixed nerve which innervates the soft palate pharynx larynx thoracic and
abdominal organs including the heart lungs and viscera and external auditory meatus. Of the efferent
fibers some cross the middle line to the opposite colliculus; many ascend through the superior
brachium and finally reach the cortex of the occipital lobe of the cerebrum; while others after
undergoing decussation form the tectospinal fasciculus which descends through the formatio
reticularis of the Midbrain pons and medulla oblongata into the medulla spinalis where it is found

partly in the anterior funiculus and partly intermingled with the fibers of the rubrospinal tract. What
does that mean? Sensory information is anything you feel using one of your five basic senses. The
medullathe most primitive brain structurecontrols our digestive respiratory and circulatory systems.
The third and fourth cranial nerves originate in the Midbrain. The right hemisphere is concerned with
sensory input auditory and visual awareness creative abilities and spatialtemporal awarenessthat is
what is happening around us moment by moment.

Midbrain

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Midbrain