Difference between Brain and Spinal Cord: Definition and Explanation

The brain and the spinal cord are the major components that constitute the nervous system. The difference between brain and spinal cord is not that difficult to differentiate as both of them possess different structures each with its own functions. Both of them play an important role in sensing and sending commands to all parts of the human body. Brain is located inside the skull and controls most of the activities of the body. Whereas, spinal cord is a tube-like structure and it begins from the end of the brain and ends at the bottom of the backbone. Let’s discuss the difference between brain and spinal cord in detail along with some important questions.

Read Also: Human Brain Diagram with Detailed Explanation

Key Terms: Brain, Spinal Cord, Function of Brain, Function of Spinal Cord

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Brain

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The brain is packed inside the skull and is responsible for some of the major functions of the human body. It is also called the center of learning. The human brain is approximately 1-1.5 Kg in weight. It mainly consists of neurons. Recent researches suggest that it has about 86 billion to 100 billion neurons. It is highly responsible for functions like thinking, movements, problem-solving thought processes, interpretation, and many more.

Brain

Check Important Notes for Spinal Cord Diagram: Detailed Illustration

The brain mainly is composed of two types of tissues.

1. Grey Matter, which consists of cells that make up the bulk of the brain.
2. White Matter, which is primarily composed of axons, connects various areas of grey area together.

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Structure and Functions of the Brain

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The Human brain is mainly made up of 3 parts.

Forebrain

This is the largest part of the human brain. It is located on the anterior side. It is responsible for reproductive functions along with emotions, hunger, sleep, and body hemostasis. It is also the largest part of all vertebrate brains.

Its parts include: -

• Cerebrum: It is the largest part composed of two hemispheres joined by the corpus callosum. It consists of four lobes, namely,

1. The frontal lobe, which is responsible for speech, planning, problem-solving, movements, etc.
2. The parietal lobe, which helps in movements and perception of stimuli.
3. The occipital lobe, which is associated with optical functions.
4. The temporal lobe, which is related to memory and speech.

• Hypothalamus: It is a small yet essential part located just below the thalamus. It mainly controls:

1. Appetite
2. Hemostasis
3. Mood and emotions
4. Sense of taste and smell
5. Coordinating messages from the autonomous system
6. And many more.

• Thalamus: It is also a small structure located just above the brain stem. It is related to relaying the sensory information and motor information for movement and coordination.

It is found in the limbic system which is responsible for the formation of new memories and storing past ones.

Forebrain

Midbrain

This is the smallest part of the brain located in the central region.

It comprises of: -

• Tectum: It is a small part present in the dorsal part of the midbrain. It is mainly responsible for relaying information from the ears to the cerebrum. And is also responsible for reflex movement in the head, neck, and eye muscles.
• Tegmentum: It is present within the brainstem. It is a complex structure with various components, responsible mainly for sleep, arousal, attention, and different reflexes.

Hindbrain

This is the most important part of the human brain mainly responsible for human survival. It is responsible for functions like breathing, learning, sleep, and heart rate.

It consists of: -

• Cerebellum: It is the second-largest part located in the posterior portion. Its main functions include:

1. Senses equilibrium
2. Coordinates eye movement
3. Maintains body balanced during running, swimming, riding, etc.
4. Predicts the future position of the body during particular movements.

• Medulla: It is also a small structure present in the lowest region of the brain. It is responsible for autonomic functions such as breathing, digestion. It helps maintain posture and reflexes.
• Pons: It is the primary part of the brain stem present between the midbrain and medulla oblongata. Its main functions are:

1. Maintains sleep cycles
2. Regulates respiration
3. Involved in senses like taste, hearing, etc.

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Spinal Cord

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The spinal cord is a tube-like structure that begins with the brain and ends at the end of the backbone. It is made up of nerves that are mainly responsible for information transmission from the brain to other parts of the body. It arises from the medulla oblongata. In adults, it is usually 40cm long and 2cm wide.

Spinal Cord

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Structure and Functions of Spinal Cord

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The spinal cord is divided into 5 parts, these segments individually give rise to a number of spinal nerves. There are 8 pairs of cervical, 5 lumbar, 12 thoracics, 5 sacral, and 1 coccygeal pair of spinal nerves. They are:

1. Sacral cord: Sacral represents the sacrum, which is a bony plate present in the base of the vertebral column. There are namely 4 sacral nerves (S1-S4).
2. Lumbar cord: Lumbar represents the lower back. There are namely 5 lumbar nerves rising from here (L1-L5).
3. Thoracic cord: Thoracic represents the chest. There are namely 12 thoracic nerves rising from here (T1-T12).
4. Cervical cord: The cervical represents the neck. There are 8 cervical nerves emerging from here (C1-C8).
5. Coccygeal: Coccygeal represents the tailbone. It has one coccygeal nerve rising from here.

Structure and Functions of Spinal Cord

The spinal cord carries sensory information from each and every part of the body to the Central Nervous system.

Three layers of meninges cover the spinal cord:

1. Dura matter
2. Arachnoid matter
3. Pia matter

The spinal cord is responsible for the following functions:

1. Linking the PNS and the brain.
2. Maintaining and controlling flexible movements.
3. Providing structural support and improving the body posture.
4. Coordinate reflexes.
5. Myelin present in the white matter of the spinal cord acts as an insulator.

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Difference Between Brain and Spinal Cord

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The major difference between brain and spinal cord are tabulated below:

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Things To Remember

• The brain is packed inside the skull and weighs about 1-1.5kg.
• The brain is responsible for bodily functions like breathing, memory storage, thinking, problem-solving, digestion, movement.
• The spinal cord is protected by the vertebral column. It is 40 cm long and 2cm wide.
• The spinal cord is a tube-like structure arising from the medulla oblongata.
• The spinal cord is responsible for relaying and transmitting information from the brain to other parts of the body and vice versa.
• Injury to the brain can lead to memory loss, loss of sensory functions, irregularity in bodily functions.
• Injury to the spinal cord leads to loss of muscular function and reflex functions.