Problem 25 - Anatomy and Physiology of Animals

Question

The cells responsible for the transmission of the nerve impulse are ___________. a. neurons b. oligodendrocytes C. astrocytes d. microglia

Step-by-Step Solution

Answer

The correct answer is a. neurons.

Step 1: Understanding the Question

The question is asking us to identify the type of cell that is responsible for transmitting nerve impulses within the nervous system. We are provided with multiple options to choose from.

Step 2: Analyzing Each Option

- Option a: Neurons - Neurons are specialized cells that transmit nerve impulses through electrical and chemical signals. - Option b: Oligodendrocytes - These cells insulate nerve fibers in the central nervous system by forming a myelin sheath, but they do not transmit nerve impulses. - Option c: Astrocytes - These are supportive glial cells involved in maintaining the blood-brain barrier and providing nutrients to neurons, but not in directly transmitting impulses. - Option d: Microglia - These are the immune cells of the brain that act as macrophages to clean up debris, not transmitters of nerve impulses.

Step 3: Selecting the Correct Option

After analyzing each option, we find that neurons are the cells responsible for the transmission of nerve impulses. They are the main contributors in relaying signals across different parts of the body.

Key Concepts

Nerve Impulse Transmission

In the nervous system, nerve impulses are essential for communication between neurons. These impulses are a combination of electrical and chemical signals that allow neurons to transmit information rapidly. This transmission begins when a neuron receives a stimulus, causing a change in the electrical charge across its membrane. This electrical change, called an action potential, travels along the neuron’s axon. When the action potential reaches the end of the axon, neurotransmitters are released. These chemical messengers cross the synaptic gap to the adjacent neuron, perpetuating the impulse. This intricate process allows the brain to coordinate complex tasks like movement, sensation, and thought processing.

Nervous System

The nervous system is a complex network responsible for coordinating the body’s actions and sensory information. It consists of two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS, comprising the brain and spinal cord, is the command center for processing information and making decisions. The PNS connects the CNS to the rest of the body, transmitting sensory input and motor output.

• Central Nervous System: Interprets and processes information.
• Peripheral Nervous System: Extends to limbs and organs for functional communication.

This system relies on various types of cells to maintain homeostasis and ensure effective communication throughout the body.

Cell Types in Nervous System

The nervous system is composed of various cell types, each with unique roles. The four primary types include:

• Neurons: These are the primary cells responsible for transmitting nerve impulses. They have specialized structures like dendrites and axons to facilitate communication.
• Oligodendrocytes: Found in the CNS, they form the myelin sheath providing insulation and increasing conduction speed of neural impulses.
• Astrocytes: These star-shaped cells support neurons by maintaining the blood-brain barrier, regulating nutrients, and repairing the brain and spinal cord after injuries.
• Microglia: Act as the immune defense in the CNS, cleaning up debris, dead cells, and protecting neurons from pathogens.

Understanding the roles of these cells is crucial for comprehending how the nervous system functions harmoniously.