Cerebellum Similarities And Differences

971 Words 4 Pages
The cerebellum, on the other hand, is involved in controlling movements through coordination, precision, and accurate timing of movement. Unlike the basal ganglia, it does not directly initiate or suppress movement but works by influencing movements by modifying activity patterns of the upper motor neurons. The cerebellum receives its input from the spinal cord in form of mossy fibers that project from the pons and spinocerebellar pathways. Mossy fibers contribute the information necessary for the output from the motor cortex and sensory information about the state of the body. In addition, it also receives input from climbing fibers that project from the inferior olive, of which contribute information about the errors in movement. These climbing …show more content…
The input from the cerebral can be quite complex and indirect. Neurons in the pontine nuclei receive projection from the cerebral cortex which then relays information to contralateral cerebellar cortex. The mossy fibers, which are the axons projecting from the pontine nuclei and other sources send excitatory input signals via Acetylcholine. They synapse onto granule cells in the granular layer of the cerebellar cortex. These granule cells give rise to specialized axons known as parallel fibers. Parallel fibers ascend up to the molecular layer of the cerebellar cortex and bifurcate in the molecular later to form T-shape branches which send signal information through excitatory synapses onto the dendrite spines of Purkinje cells. The excitatory input from the parallel fibers to the Purkinje cells occurs via Glutamate release. When the Purkinje cell is excited it sends an inhibitory output via GABA release onto deep cerebellar nuclei causing it to excite and send signals onto its projection to different motor centers in the brainstem and cortex. These projections to the motor cortex allows the cerebellum to access upper motor neurons that are utilized in actions that ultimately control movements. In addition, the peduncles of the brain connect cerebellum to other portions of the brain such as the midbrain, pons, and …show more content…
It occurs when stomach acids or stomach content back flows into your esophagus. Since this backwash substance comes from the stomach it is generally highly acidic and causes irritation of the sensitive lining of the esophagus, ultimately causing gastric reflux. The primary event in GERD is the movement of gastric juice from the stomach into the esophagus. The movement of gastric contents into the esophagus is generally due to a defect in the sphincter mechanism at the esophago-gastric junction. It is thought that there is a weakness in one of the two lower esophageal sphincters that cause the reflux. It is found that although some patients do indeed experience a weak lower esophageal sphincter they also have a weak crural diaphragm, however this mechanism is currently unknown. Currently, there are two possible mechanisms that are thought to cause reflux. One of the mechanisms is low basal sphincter pressure leading to free reflux, mostly occurring while the patient is in supine position. The second mechanism is increased frequency of transient lower esophageal sphincter relaxations with normal or increased resting lower esophageal sphincter pressure leading to reflux during daytime hours while the patient is standing upright. The major mechanism that is thought to cause GERD involves transient spontaneous and inappropriate

Related Documents