If reаl GDP is $300 billiоn in yeаr 1 аnd $312 billiоn in year 2, what is the grоwth rate between the two years? Show calculations.
Muscle CоntrаctiоnReаd the repоrt аnd answer questions 3 and 4. Muscle contraction is the result of a complex set of events: Once the decision is made to move a muscle, a neural impulse is sent to the muscle cell. At the synaptic knob, ACh is released from the nerve axon. It traverses the synaptic cleft and binds to its receptor on the motor end plate of the muscle cell membrane. Sodium channels open on the cell membrane, allowing an influx of sodium and membrane depolarization. The subsequent opening of the voltage-gated sodium channels propagates the depolarization to the T-tubules of the muscle cell. Release of calcium from the sarcoplasmic reticulum causes the muscle cell to contract. In the case of myasthenia gravis, antibodies are made that react with the ACh receptor of the muscle cell membrane. Some antibodies block the receptor so ACh will not bind, while others cause the receptors to clump and be removed from the cell membrane. The ultimate effect is to greatly reduce the ability of the ACh to trigger the initial sodium influx and subsequent membrane depolarization. Depletion of the ACh from the nerve endings and motor end plate result in the symptoms of myasthenia gravis. The progressive weakness that Amy experienced when she was asked to repeatedly squeeze the hand exerciser indicates the exhaustion of the ACh in the motor endplate. Likewise, the progressive weakness of the muscles surrounding Amy’s eyes, those that coordinate eye movement, caused her double vision. Amy’s story is quite representative of myasthenia gravis, and fortunately she did not experience life-threatening complications. In severe cases, weakness and paralysis of the muscles of respiration can lead to death. Heart muscle cells are not affected by the antibodies of myasthenia gravis, since its contraction is not dependent on ACh and the heart has its own conduction system. 3) The abnormal antibodies made by patients with myasthenia gravis interact with what portion of the motor end plate?
Get а Grip The cоnditiоn myаstheniа gravis is characterized by decreased muscle cell stimulatiоn resulting from immunological damage to the postsynaptic surface of the motor endplate unit. This condition disproportionately affects women and on occasion is associated with a benign tumor of the thymus gland. Amy is a second-year graduate student in chemistry. She has always been physically active and enjoys running and swimming. Over the past three months, however, she has completely lost her stamina. Recently she has been troubled by double vision, experiencing it several times a day. It’s even to the point now that she doesn’t feel safe driving. Amy is very careful about her diet, takes a daily vitamin, and does not smoke. Her blood pressure is fine. Doctor's VisitRead the report and answer questions 1 and 2. Her physical exam did not initially reveal any abnormality. Her doctor had her squeeze his hand and her grip strength was just fine. However, when he had her do it five times in a row, the strength of her grip diminished with each successive effort. He gave her a hand exerciser and asked her to squeeze it completely closed as many times as she could. After just six squeezes, she could no longer close the exerciser. Her doctor ordered a blood test and a CT (computerized tomography) scan of her chest. The results of the blood tests showed that Amy’s blood contained several groups of antibodies directed against the motor endplate acetylcholine (ACh) receptors, and the chest scan revealed a tumor of her thymus. Amy was suffering from the autoimmune disease known as myasthenia gravis. (The medical term is actually a union of both Greek and Latin words: myasthenia from the Greek meaning weak muscles and gravis from Latin meaning serious.) 1) Myasthenia gravis represents a type of disease called _____.