Question

A collection of neuron cell bodies located outside the CNS is called a. a tract. b. a nerve. c. a nucleus. d. a ganglion.

Short answer

A collection of neuron cell bodies located outside the CNS is called a ganglion.

Step-by-step solution

Understand the terms

To answer this question correctly, we need to understand the meaning of each term provided in the options: a. A tract is a bundle of nerve fibers (axons) within the CNS. b. A nerve is a bundle of nerve fibers (axons) outside the CNS. c. A nucleus is a group of neuron cell bodies within the CNS. d. A ganglion is a group of neuron cell bodies outside the CNS.

Select the correct term

Now that we have defined each term, we can answer the question by selecting the term that best describes a collection of neuron cell bodies located outside the CNS. Based on the definitions, the correct answer is: d. a ganglion.

Key concepts

Central Nervous System

The central nervous system (CNS) is a vital part of the body's overall nervous system. It acts as the central hub for processing information and dictates how the body responds to various stimuli. The CNS primarily consists of the brain and spinal cord, with the brain serving as the coordination center for processing thoughts, emotions, and decisions, whereas the spinal cord acts as the relay station for sending signals to and from the brain to different parts of the body.

Understanding the CNS is fundamental when studying how the human body processes sensory information and initiates motor responses. Neurons in the CNS are organized into complex networks that enable functions like memory, learning, and voluntary movement. A nucleus, as mentioned in the textbook exercise, refers to a group of neuron cell bodies within the CNS that process specific types of information, such as visual or auditory signals.

Ganglion

A ganglion, which is the correct answer to the textbook exercise, is a collection of neuron cell bodies located outside the CNS. These clusters of neurons serve as mini processing centers and play a critical role in the peripheral nervous system (PNS). Ganglia (plural for ganglion) perform several functions, such as relaying sensory information to the CNS and transmitting motor commands from the CNS to the muscles.

Ganglia are not to be confused with nuclei. While both are groups of neuron cell bodies, nuclei are found within the CNS, while ganglia are found within the PNS. Examples of ganglia include the dorsal root ganglia, which contain the cell bodies of sensory neurons, and autonomic ganglia, which are involved in involuntary functions like heart rate and digestion.

Neural Pathways

Neural pathways are essentially the highways of the nervous system, consisting of bundles of axons that transmit electrical impulses between neurons. They enable communication between different regions of the CNS and PNS, facilitating complex functions such as reflex actions, sensory perception, and controlled movement.

In the context of the exercise, it's important to differentiate between a tract and a nerve, as they represent different types of neural pathways. A tract refers to a bundle of axons within the CNS that connects different parts of the brain or spinal cord. In contrast, a nerve is a bundle of axons outside the CNS, such as those found in the PNS, that connect the CNS with various parts of the body. Understanding these pathways is key to grasping how neuronal signals are organized and directed throughout the body to execute intricate tasks and respond to the environment.