The dorsal portion of the diencephalon comprises three major parts: the epithalamus, the dorsal thalamus (known as the motor thalamus), and the ventral thalamus. The epithalamus consists of the pineal body, the habenular nuclei, the stria medullaris, and the associated paraventricular nuclei. All of these nuclei play key roles in limbic functions. The dorsal and ventral thalamus comprises many nuclear groups that receive inputs from several brain structures and transmits afferent signals to specific areas of the cerebral cortex, except for the RTN which projects only to other thalamic nuclei and brainstem {Jones, 2002, Thalamic organization and function after Cajal;Jones, 2007, The Thalamus}. In general, most thalamic nuclei can be classified …show more content…
However, the multimodal-association nuclei have widespread cortical connections, with association areas in the frontal, parietal, and temporal lobes. Unlike modality-specific nuclei, they do not receive inputs form one dominant subcortical structure but are rather innervated by many different afferent inputs that have significant weight {Smith, 2003, The Thalamus}. Consistent with such a pattern of innervation, the functions of association nuclei are not precise and modality-specific, but are related to higher cognitive functions such as language, learning, and sensorimotor processing {Smith, 2003, The Thalamus}. Lastly, the nonspecific or diffusely projecting nuclei comprise the intralaminar and midline thalamic nuclei that provide widespread cortical projections and innervate the striatum {Jones, 2007, The …show more content…
The reticular nucleus surrounds the entire extent of the dorsal thalamus and unlike all other thalamic nuclei, does not provide inputs to the cortex, but instead innervates other thalamic nuclei and the brainstem. The dorsal thalamus is divided into anterior, medial, ventrolateral, and posterior nuclear groups by a band of myelinated fibers, the internal medullary lamina of the thalamus. The anterior nuclear group forms a rostral swelling that protrudes from the dorsal surface of the rostral thalamus. It is separated from other thalamic nuclei by a myelinated capsule. The lateral nuclear group comprises two main nuclear masses, and the ventral nuclear mass, which extends throughout the entire rostrocaudal extent of the thalamus, is divisible into separate nuclei: the ventral posterior nucleus, medial geniculate nucleus, and dorsal lateral geniculate nucleus caudally; the ventral lateral nucleus at intermediate levels; and the ventral anterior nucleus rostrally. The lateral nuclear mass, also known as the dorsal-tier thalamic nuclei, located dorsal to the ventral nuclear mass also comprises three major nuclei: the pulvinar, the lateral posterior nucleus, located at an intermediate level, and the lateral dorsal nucleus, the most rostral component of this nuclear mass {Smith, 2003, The Thalamus}. The medial nuclear
Cardiomyopathy, by definition, means the weakening of the heart muscle. The heart is operated by a striated muscle that relies on the autonomic nervous system to function. Cardiomyopathy is diagnosed in four different ways based on what caused the illness and exactly what part of the heart is weakened. The four main types of cardiomyopathy are dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, and arrhythmogenic right ventricular dysplasia. One other category of cardiomyopathy that is diagnosed is “unclassified cardiomyopathy.” Unclassified cardiomyopathy is the weakening of the heart that does not fit into the main four categories.
Action potentials are started at one end of the node, flow passively through the myelinated axon, and pop out the other side to jump to the next node. This jumping of action potentials is called saltatory.
Rowland, L. P., ed. Merritt’s Textbook of Neurology. 7th ed. Lea and Febiger. Philadelphia: 1984.
Kanske, P., Heissler, J., Schönfelder, S., Forneck, J., & Wessa, M. (2013). Neural correlates of
Wessinger, C.M., Clapham, E. (2009) Cognitive Neuroscience: An Overview , Encylopedia of Neuroscience. 12(4) 1117-1122.
For this experiment, Rana temporaria were utilized since they have two midbrain nuclei that receive impulses since the neurons respond to stimulation of optokinetic pathways. (Cochran). Each of these neurons plays a different role in response types. Examples of such movements in neurons include both upward and downward moving targets from optokinetic perspective. Cells in a specific region have this sensitivity, and can even utilize their stimulation for increasing and decreasing rest rate. Oculomotor neurons were studied because they possess an exclusive upward or downward motion which would make the controls easier to identify and carry out the experiment. (Precht, 1982). Temporal nasal pattern movements are an additional type of neuron that have similar velocity preferences as simple sensory nuclei. To investigate the connectivity between motor and sensory nuclei, the region that they were derived from within the frog was restricted to the pretectum and abducens. A single connection between these areas is suggested through onset latency in antidromically motor neurons, activation of the pretectal cells, horseradish injections which involve labeling the axons, and horseradish injections into the region of abducens which create labeling of cells in pretectal region. (Gaupp, 1896). In this experiment, a length of time of two years and
(Slide 2) What is Cardiomyopathy? If we break down the word we can see “Cardio” which means of the heart, “myo” which means muscle, and “pathy” which means disease, therefore cardiomyopathies are diseases of the heart muscle. (Slide 3) There are 3 main types of cardiomyopathies; hypertrophic, dilated, and restrictive. I will only be discussing dilated cardiomyopathy, which is characterized by the enlargement of the hearts chambers with impaired systolic function. It is estimated that as many as 1 of 500 adults may have this condition. Dilated cardiomyopathy is more common in blacks than in whites and in males than in females. It is the most common form of cardiomyopathy in children and it can occur at any age (CDC).
Arrhythmia I am doing my report on Arrhythmia. It affects the cardiac muscle, the heart. Arrhythmia causes three types of problems. It causes the heart to pump too slowly (bradycardia), it causes the heart to pump too fast (tachycardis), and it causes the heart to skip beats (palipations).
Prevosto, V., & Sommer, M.A. (2013). Cognitive Control of Movement Via the Cerebellar-Recipient Thalamus. Frontiers in Systems Neuroscience, 7, 1-8.
The brain consists of both neurons and glia cells. The neurons, which are cells housed in a cell body called a Soma, have branches which extend from them, referred to as dendrites. From these dendrites extend axons which send and receive impulses, ending at junction points called synapses. It is at these synapse points that the transfer of information takes place.
...owell, E. R., Thompson, P. M., & Toga, A. W. (2004). Mapping changes in the human cortex
Myelin protects and electrically insulates fibers and increases the transmission speed of nerve impulses. Myelin sheaths in PNS are formed by Schwann cells, which indent to receive an axon and then wrap themselves around it in a jellyroll fashion. In CNS, the oligodendrocytes form myelin sheaths. Unlike Schwann cells, oligodendrocytes have multiple flat processes that can coil around as many as 60 axons at a time. In PNS, myelin sheath gaps separate adjacent sections of an axon’s myelin sheath. In CNS, myelin sheaths lack an outer collar of perinuclear cytoplasm because cell extensions do the coiling and cytoplasm is forced back toward the
The cerebrum is the largest part of the brain. It contains all the tools that are responsible the majority of the brains functions. The cerebrum is split up into four sections: frontal lobe, occiptal lobe and pariental lobe. The cerebrum has two sections the right and the left hemisphere that are connected by axons that send messages to and from one another. The matter in this part is made up of cells that carry signals between the nerve cells and the organs that run through the
The SNpc is part of the larger basal ganglia that affects the motor cortex via the thalamus in the central nervous system. The thalamus intrinsically sends tonic inhibitory input to the motor cortex, suppressing motor function. Two pathways in the basal ganglia are capable of influencing this usual thalamic tonic inhibition – the indirect pathway and the direct pathway. The direct pathway flows from the cerebral cortex to the striatum to the internal segment of the globus pallidus, which synapses with the thalamus. The indirect pathway takes a similar route, but first detours from the striatum to the external segment of the globus pallidus, then the subthalamic nucleus, and then back to the internal segment of the globus pallidus. The net effect of the transient cortical activation of the direct pathway is an increase in motor movements, while transient cortical activation of the indirect pathway inhibits motor movements. The SNpc is relevant here because its neurons synapse with those of the striatum, an intermediate of both the direct and indirect pathways. However, the effect of its dopaminergic neurons on the cells of the striatum depends on the type of receptor present on the post-synaptic cells. The cells of the striatum with D1
The Cerebrum is the largest part of the brain , it controls certain fucntions such as perception, imagination , thought ,judgement and decision making . The surface of the Cerebrum (Cerebral cortex) is comprises of six thin layers of neurons , that rest ontop of a large surface of white matter pathways . The cortex is extemerly twisted and coiled to the point that if it is spread out, it might actually take up as much as 2.5 Square feet, and it comprises of 10 billion neurons and about 50 trillion synapses.The furthest part is the frontal lobe and is very important because its responsibility consists of voluntary movement and planning is thought to be the most significant lob for personality and intelligence .Behind the frontal Lobe is the parietal lobe, which includes the somatosensory area which happens to be just be...