Essay Database

KEY TERMS Key Terms and Concepts The Control of Movement 1. Muscles and their movements Categories of muscle Smooth Skeletal or striated Cardiac Precise movements: few muscle fibers innervated by each axon Neuromuscular junction Acetylcholine Muscle contraction Antagonistic muscles Flexor Extensor Myasthenia gravis Autoimmune attack on acetylcholine receptors at neuromuscular junctions Progressive weakness and rapid fatigue Depletion of acetylcholine after several action potentials in rapid succession Treatment Drugs that suppress immune system Drugs that inhibit acetylcholinesterase (…

…disease (Huntingtonís chorea) Symptoms Twitches and tremors Writhing movements Impaired ability to learn new movements Extensive brain damage, especially in caudate nucleus, putamen, globus pallidus, and cortex Psychological symptoms: depression, memory impairment, anxiety, hallucinations and delusions, poor judgment, alcoholism, drug abuse, sexual disorders Heredity and presymptomatic testing Autosomal dominant gene on chromosome #4 Extra repetitions of sequence of bases: the more repetitions, the earlier the onset Protein encoded: huntingtin Mutant form: interferes with gene expression