Michael Anderson Dr. Thompson Exsc 224-001 Summer 2016May 16th, 2016Assignment #11. Define resting membrane potential and describe its electrochemical basis.The cell membrane of a resting neuron is polarized, meaning it is more negativelycharged inside of the cell than it is outside of the cell. The degree to which these charges differ is referred to as the cell’s Resting Membrane Potential. The difference in charges iscreated by the ionic makeup of the extracellular and intracellular fluid. Resting Potential is developed and maintained by a complex series of processes. Specialized proteins referred to as Sodium-Potassium pumps studded throughout the membrane of the cell use ATP to pump 3 sodium ions from inside the cell out and 2 potassium ions outside the cell back inside. The works of these pumps result in a high concentration of potassium ions inside the cell and a high concentration of sodium ions outside the cell. There are also specialized membrane proteins called channel proteins that all serve a specific purpose. Nongated Leakage channels allow for either sodium or potassium to diffuse down their concentration gradients. When potassium leaves the cell is contributes it the hyperpolarization of the cell membrane meaning the cells potential becomes more negative. When sodium enters the cell it contributes to the repolarization of the cells membrane and works to counter act the hyperpolarization caused by the outflow of potassium. The leakage channels working together help to maintain the resting potential of the cell at around -70 mV. 2. Compare and contrast graded potentials and action potentialsGraded Potentials and Action Potentials both are changes in membrane potentials.Both are used as a means to convey Impulses from Neuron to Neuron. They both have the capability to cause Depolarizations and Hyper polarizations in membrane potential.Graded potentials are short lived, and localized disruptions in Membrane Potential that are only capable of short transmission before the strength of the disruption is depleted and are typically found in the dendrites and Cell bodies on Neurons, if a graded potential is large enough or frequent enough it can generate enough of a change in membrane potential to generate and Action Potential. Action Potentials cause and carry a much larger disruption in membrane potential down the length of the Axons of Neurons. Strength of the AP doesn’t change like that of a GP, the signal strength is constant down the entire length of the axon. Once the disruption reaches the Axon terminals it causes them to release neurotransmitters. AP cause the depolarization, repolarization and then possibly a hyperpolarization. Summation of AP does not occur as it does in dendrites due to the refractory periods that are found in axons.3. List the major lobes, fissures, and functional areas of the cerebral cortex.The brain is a complex organ composed of various areas and regions all fighting for space in a very compact environment. The brain possesses special structural adaptations to help it save as much space as possible and still carry out its full function. When looking at the brain it is easy to notice multiple ridges, these ridges are called gyri. Between these gyri are shallow crevasses called sulci, these separate the individual gyri. Similar to sulci there are fissures, fissures are deeper crevasses that separate large areas ofthe brain. The Longitudinal Fissure runs down the middle of the brain and separates the left and right hemispheres. The Transverse Cerebral Fissure separates the hemispheres from another structure called the Cerebellum. A structure called the Central Sulcus is found in the frontal portions of the hemispheres and separates the Frontal and Parietal Lobes. The parietal lobe is bordered by the Parieto-Occipital Sulcus which separates it from the Occipital Lobe. The Parietal and Frontal Lobes are also separated from the Temporal Lobe by the Lateral Sulcus. Beneath the Central Sulcus lies the an Interior lobecalled the Insula that rests in the middle of the brain. 4. For the right side of the body, describe and draw the spinocerebellar pathway, dorsal columnmedial lemniscal pathway, spinothalamic pathway, and the lateral (pyramidal) corticospinal pathway. What information is transmitted by each