Difference between Brain and Spinal Cord: Function, Anatomy and Structure

Introduction — Brain and Spinal Cord in the CNS

The human brain is the command centre for the nervous system of human beings, receiving signals from the sensory organs, sending motor signals out to the musculature, and regulating critical functions within the body. It follows then, that the brain works in close partnership with the spinal cord to comprise the central nervous system, intervening in most integration and coordination of body systems.

The brain, together with the spinal cord, controls higher functions of thought and action along with the maintenance functions of the body, those that allow a person to stay alive. These higher functions are integrated rather seamlessly, as anyone who experiences the repositioning of a body part can attest to. Understanding the structure and functions of the brain is very crucial in the understanding of issues related to neurology and further in the way of treating them.

What Is the Human Brain?

The brain is a complex organ which serves as the centre of the nervous system in controlling most of the activities in the body. It can be grossly divided into several major parts.

Major Functions

• It involves thinking, reasoning, the formation of memory, problem-solving, and receiving and understanding the language and producing it.

• The brain processes and receives information about the sense organs from the environment, which includes visions, audition, and tactile sense i.e. touching, and gustation.

• It is responsible for the coordination of highly learned voluntary muscle movements in all parts of the body, to allow systemic activities and for goal-directed interaction with the environment.

• It coordinates the exact involuntary actions of breathing, heartbeat, digestion, and other hormone secretions to guarantee body homeostasis and allow for body stability in all aspects.

Major Parts of the Brain

• Cerebrum: the brain's largest division harbouring higher cognitive functions like thought, learning, and decision-making.

• Cerebellum: Located at the back of the brain, it performs the very important function of coordinating all voluntary movements and maintaining balance.

• Brainstem: the part that connects the brain and the spinal cord. It consists of the midbrain, pons, and medulla oblongata.

• It, therefore, regulates the most basic physiologic activities of the body since it is highly involved in the following general functions respiration, cardiac activities, and sleep.

What Is the Human Brain?

The spinal cord is the cylindrical bundle of nerve fibres, which extend from the brainstem downwards via the vertebral column and assort as follows:

Regions of the Spinal Cord

• Cervical: In the region above the neck, controlling the functioning of the upper limb and a part of the neck.

• Thoracic: In the upper and mid–back controls the functioning of the trunk muscles and some parts of the abdominal organs.

• Lumbar: In the lower back, controls the act of the lower limbs and lower abdomen functioning.

• Sacral Region: Situated at the pelvic region controls all the functioning of the bowels, bladder, and sexual functions.

Functions of the Spinal Cord

• It relays sensory information (such as pain, touch, and temperature) and motor commands (commands for muscle movement) to and from the brain.

• The spinal cord coordinates simple reflexes, as the patellar reflex, and complex reflex arcs that require many segments of the cord.

• These functions allow the acting of stimuli with no direct involvement of the body acting upon stemming from the brain.

Brain vs Spinal Cord — Key Differences

The difference between brain and spinal cord is discussed in the table below:

Brain and Spinal Cord — Combined Roles in Neural Control

The brain and spinal cord work together as the central nervous system (CNS), coordinating signals, processing information, and regulating all major body functions.

• They enable rapid communication between different parts of the body and ensure smooth, integrated neural responses.

• They play essential roles in behaviour, posture, sensation, and overall survival by interpreting stimuli and generating appropriate actions.

• They help the body adapt to environmental changes through reflexes, learning, and higher-order processing.

Brain vs Spinal Cord NEET MCQs (With Answers & Explanations)

Important questions asked in NEET from this topic are:

• Anatomy of brain and spinal cord

• Functions of brain and spinal cord

• Brain vs Spinal cord

Practice Questions for NEET

Q1. The spinal cord extends from the foramen magnum at the base of the skull to the L1/L2 vertebra where it terminates as the

1. Conus medullaris (medullary cone)

2. Coccygeal vertebra

3. Epiduramater

4. Choroid plexus

Correct answer: 1) Conus medullaris (medullary cone)

Explanation:

The spinal cord, an essential component of the central nervous system, originates from the foramen magnum, a significant aperture situated at the skull's base, and extends down to the L1/L2 vertebral levels. It does not stretch throughout the vertebral column's entirety, but rather concludes at this point, transforming into the conus medullaris. Following the conus medullaris, the cauda equina, a collection of spinal nerve fibres, descends within the vertebral canal.

Hence, the correct answer is option 1. Conus medullaris (medullary cone).

Q2. The number of pairs of thoracic spinal nerves is

1. 31

2. 12

3. 5

4. 8

Correct answer: 2) 12

Explanation:

There are 8 pairs of cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pair of spinal nerves (a total of 31 pairs).

Hence, the correct answer is option 2) 12.

Q3. Identify the following statements.

1) The neural canal is the channel for the spinal cord to pass through.

2) The gray matter extends from the brain to the inside of the spinal cord and white matter covers the surroundings of the spinal cord.

1. Statement 1 is false.

2. Statement 2 is true.

3. Statements 1 and 2 are true

4. Statements 1 and 2 are false.

Correct answer: 3) Statements 1 and 2 are true

Explanation:

Both are true of the spinal cord:
The spinal cord is a long, cylindrical structure running from the back of the brain down to the lower part of the back and through the neural canal. It is an extremely important linkage between the central and peripheral nervous system.
The sensory neurons transmit impulses through the spinal cord. It is the portion that contains grey matter as horn-like projections and white matter surrounding it. Grey matter includes the cell bodies of neurons while white matter consists of myelinated axons connecting to other parts of the nervous system.
The spinal cord carries out the reception of sensory input and coordination of reflexes.

Hence the correct answer is option 3) Statements 1 and 2 are true.

Also Read:

• MCQs on Spinal Cord

• Sympathetic Nervous System

• Central Nervous System

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