Problem 42 - Objective Biology for NEET

Question

In spiral cord of humans, the grey matter is shaped. (a) Circular (b) Irregular (c) Butterfly (d) None of these

Step-by-Step Solution

Answer

The correct answer is (c) Butterfly.

Step 1: Understanding the Spinal Cord

The first step to answer this exercise is to understand the basic organization of the spinal cord. Grey matter is located in the center of the spinal cord and sends information throughout the body. It contains cell bodies, dendrites, and the axons of the neurons.

Step 2: Identifying Grey Matter Shape

The next step is to identify the shape of grey matter within the spinal cord. This requires recall of specific details about the anatomy of the spinal cord, learned in anatomy or biology classes. In this case, grey matter is organized in the spinal cord in a specific pattern.

Step 3: Selecting the Correct Answer

The final step is to select the correct answer from the options provided. Grey matter is shaped like a butterfly (option c), and not circular, irregular or none of these shapes.

Key Concepts

Grey Matter Structure

The grey matter in the spinal cord forms a unique structure that plays a crucial role in the nervous system. When you think about the spinal cord's anatomy, grey matter is like the central hub. It sits in the middle of the spinal cord and has a distinctive shape. Imagine a butterfly's silhouette within the cross-section of the spinal cord—this is how grey matter appears. This butterfly shape is not just for aesthetics; it separates specific nerve pathways.

Grey matter is composed of:

• Neuronal cell bodies
• Dendrites
• Unmyelinated axons

These elements work together to process information in a refined manner. It is essential in muscle control and sensory perception, linking directly with neurons to manage functions effectively.

Neurons in Spinal Cord

Neurons are the essential cell units in the spinal cord and perform a variety of functions. They are the primary processors and messengers of information within the nervous system. If we delve into the spinal cord's internal workings, we find that neurons are categorized based on their roles.

In the spinal cord, you mainly find:

• Interneurons
• Motor neurons
• Sensory neurons

Interneurons primarily reside in the grey matter and are crucial for reflex actions and integrating sensory inputs. Motor neurons project from the grey matter to muscles, facilitating movement. Sensory neurons help in perceiving touch, pressure, and pain, linking sensory information to the brain.

Central Nervous System

The central nervous system (CNS) is a complex network that includes the brain and spinal cord. The CNS serves as the body's command center, interpreting signals from all over and coordinating actions. Its components work together seamlessly to ensure the body functions properly. The spinal cord, being a part of the CNS, acts as a key communication pathway.

The spinal cord's functions include:

• Relaying messages between the brain and the body
• Hosting reflex arcs for quick reactions
• Facilitating motor control

Understanding the CNS helps in grasping how signals such as touch, temperature, and pain are managed. By processing these signals efficiently, the CNS allows for immediate responses, as well as complex, learned movements.