Exam 8: Neurons: the Matter of the Mind

You might have been accidentally exposed to an insecticide while working in a citrus grove. What symptoms of poisoning would you watch for?

________ is a neurotransmitter released at every neuromuscular junction (the junction of a motor neuron and a skeletal muscle cell), where it triggers contraction of voluntary (skeletal) muscles.

Muscle cells that are not exercised will atrophy, or shrink in size. Lou Gehrig's disease affects nervous tissue but also causes muscle atrophy. What type of nerve cell must be affected to cause this muscle-wasting condition?

________ is the name of the cell that wraps around the axon, forming the myelin sheath.

Which of the following is a chemical signal that diffuses across the gap between adjacent neurons to convey a message to the next cell?

A new drug interferes with the function of the dendrites of a neuron. What will happen to this neuron?

Prior to their release, where are the special chemicals called neurotransmitters stored in a neuron?

Match each definition to the correct term -Association neurons that are located between the sensory and motor neurons, where they integrate or interpret the sensory signals.

Multiple sclerosis is a disease in which the myelin sheath is destroyed. What will happen to nerve conduction speed in affected neurons?

The combined effects of inhibitory and excitatory effects on a postsynaptic cell will decide whether that cell generates an action potential. This principle is called ________.

Prescription drugs such as Prozac help maintain higher levels of serotonin in the brain. What effect will this have on an individual?

A neuron's membrane that maintains a charge difference across its surface in which the inside is more negative than the outside is called ________.

If a drug had the side effect of destroying dopamine-producing neurons, what effect would this have on a person?

During an action potential, the ________ ions rush into the axon.

Some nerves are myelinated, and others are not. Myelinated nerves send signals faster than unmyelinated neurons. Draw two neurons of equal length, and wrap segments of myelin along one. Be careful to leave spaces for the nodes of Ranvier. Now, measure the exposed axons of each, and total up the distance. Describe why the myelinated neurons send signals faster.