Question

________ is a reduced response to an ongoing stimulus. a. Propagation b. Perception c. Sensory adaptation d. Synaptic integration

Short answer

The correct answer is c. Sensory adaptation.

Step-by-step solution

Understand the Terminology

First, let's understand what each of the given terms means: - **Propagation** refers to the spread or movement of something, like an electrical impulse in neurons. - **Perception** involves interpreting sensory information to make sense of the environment. - **Sensory adaptation** is the process where sensory receptors become less responsive to a constant stimulus. - **Synaptic integration** is the process by which multiple synaptic potentials combine within one postsynaptic neuron.

Analyze the Definition

The definition provided in the question is "a reduced response to an ongoing stimulus." This means that when a stimulus continues to be present, the response to that stimulus decreases over time.

Match Definition to Terms

Reviewing the terms and their meanings: - **Propagation** doesn't fit, as it involves spreading rather than reducing response. - **Perception** is about understanding sensory input, not about response reduction. - **Sensory adaptation** perfectly matches, as it describes the decrease in sensitivity to a constant stimulus. - **Synaptic integration** involves combining signals, not reducing response.

Select the Correct Answer

Based on the analysis, **Sensory adaptation (c)** is a reduced response to an ongoing stimulus. It fits the definition explicitly provided in the exercise.

Key concepts

Propagation

Propagation refers to the transmission or spreading of something. In neural context, it's the movement of electrical impulses along the neurons. These impulses are the way your brain communicates with the rest of your body. Think of it like a relay race, where each neuron passes the baton, or in this case, the electric signal to the next neuron.

Understanding propagation is crucial because it allows the nervous system to function quickly and efficiently, transferring messages at incredible speeds. This speed is vital for reflexes and rapid responses to stimuli, ensuring organisms can react to their environments promptly and appropriately.

Propagation relies on both chemical and electrical changes within neurons. Neurons have channels that open and close, allowing ions like sodium and potassium to move in and out of cell, generating an action potential. This action potential is a swift voltage change that travels along the neuron, creating the propagation of the nerve impulse.

• Voltage-gated channels: These proteins regulate ion flow and are crucial for nerve impulse travel.
• Myelin sheath: A fatty layer that covers neurons, speeding up signal transmission.
• Nodes of Ranvier: Gaps in myelin where ion exchange occurs, helping propagate the action potential efficiently.

Perception

Perception is the stage of processing that follows sensory reception and sensation. It's about how our brains make sense of the sensory information we receive. Imagine perception as a little scientist in your brain, gathering data from your senses and working to understand and interpret it.

When you touch a hot stove, your skin's sensory receptors feel the heat. However, your perception is what recognizes this as burning and tells you to pull your hand away. Basically, it's how we interpret and interact with the world using our senses.

Perception allows us to experience the world, helping to inform our actions and decisions. It involves several steps:

• Selection: Choosing which stimuli to pay attention to.
• Organization: Arranging sensory information into meaningful patterns.
• Interpretation: Understanding and making sense of those patterns.

For effective perception, our brains must combine information from multiple senses, a process known as sensory integration, leading to a coherent view of our surroundings.

Synaptic Integration

Synaptic Integration is like a complex decision-making process within a neuron, determining whether or not to pass on a signal to the next neuron. Be aware that neurons are bombarded with thousands of inputs from other neurons. Each of these connections is known as a synapse, and not all inputs are equally significant.

When synaptic integration occurs, a neuron combines all the incoming signals to create a net input, deciding whether the threshold for an action potential is reached. This can be seen as a vote, with each synaptic input casting its influence. If enough inputs agree to trigger a signal, the neuron will "fire," sending an action potential down its axon.

Here's how synaptic integration works:

• Excitatory signals: Encourage the neuron to fire by bringing the membrane potential closer to the threshold.
• Inhibitory signals: Discourage firing by moving the membrane potential further away from the threshold.
• Spatial integration: Combines signals arriving at different locations on the neuron at the same time.
• Temporal integration: Combines signals arriving at the same location on the neuron but at slightly different times.

Through synaptic integration, the nervous system can perform complex processing, allowing for intricate behaviors and responses.