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Module 23 Lesson 1 Progress Check

Prompt

Read pgs. 619-624 then answer the "Check Your Progress" questions (p624 #1, 3, 7).

Response

  1. Relate the structure of a neuron to its function.

    The structure of a neuron is intricately linked to its function of transmitting information. Dendrites, with their branching structure, are well-suited for receiving signals from other neurons. The cell body, containing vital cellular components, integrates these signals. The axon, a long projection, is designed for transmitting signals over distances, with the myelin sheath (when present) enhancing signal speed and efficiency. Finally, axon terminals at the neuron's end facilitate the release of neurotransmitters, essential for communication with the next neuron.

  2. Infer why energy is necessary to counteract the diffusion of \(\text{Na}^+\) and \(\text{K}^+\) ions across the cell plasma membrane of a neuron.

    Energy is necessary to counteract the diffusion of Na⁺ and K⁺ ions across a neuron's plasma membrane due to the nature of the sodium-potassium pump. This pump actively transports \(\text{Na}^+\) ions out of the neuron and \(\text{K}^+\) ions into it, against their respective concentration gradients. This action is crucial for maintaining the neuron's resting potential and for the generation of action potentials. Since this process moves ions against their natural diffusion gradients, it requires the input of energy in the form of ATP.

  3. Identify and describe the mechanism by which electrical impulse go from one neuron to the next neuron.

    Electrical impulses travel from one neuron to another through a process known as synaptic transmission. When an electrical impulse reaches a neuron's axon terminal, it prompts the release of neurotransmitters into the synaptic cleft. These neurotransmitters then bind to receptors on the next neuron, either exciting or inhibiting it. This mechanism effectively converts the electrical signal into a chemical form and back into an electrical signal in the subsequent neuron, thereby continuing the transmission of information across the neural network.