Human Nervous System Structure and Functions Explained

The Spinal Bulb

The spinal bulb (medulla oblongata) is an extension of the spinal cord. It consists of grey matter surrounded by white matter. There are neural pathways that carry information, and these pathways cross; thus, the right side of the brain receives information from the left side of the body, and the left side of the brain receives information from the right side of the body.

Functions of the Spinal Bulb and Hypothalamus

It performs different functions, including:

• Regulating the process of sleep.
• Regulating visual and auditory reflexes.
• Regulating blood pressure.
• Coordinating communication between the cerebrum and other parts of the brain.

It contains an important part called the hypothalamus, which controls the pituitary gland, which in turn secretes regulatory hormones to the rest of the glands.

The Cerebellum: The Tree of Life

The cerebellum is found at the back of the brain and looks like a tree with branches; it is often called the "tree of life." It receives information for balance sent by the inner ear and coordinates motor impulses sent by the cerebrum, which is crucial when using several muscles at the same time (coordination).

The Cerebrum and Its Functions

The cerebrum is the largest part of the brain. It has white matter (axons) inside and grey matter (neuron cell bodies) outside. This grey matter forms the cortex, which has many ridges called gyri. A large fissure separates the cerebrum into two hemispheres, which are connected by the corpus callosum.

The cerebrum generally performs these functions:

• Controlling higher nerve functions like memory, reasoning, intelligence, consciousness, and will.

The Peripheral Nervous System (PNS)

The peripheral nervous system connects all of the receptors and effectors in the body to the central nervous system. It is made up of nerves, which are groups of several axons surrounded by different layers of connective tissue.

The Somatic Nervous System

The somatic nervous system connects the sensory receptors of the sensory organs to the central nervous system, and the central nervous system to the skeletal muscles. It fulfills the following functions:

• It receives information from external stimuli.
• It transmits signals for voluntary muscle contractions.

There are 12 pairs of cranial nerves that emerge from the brain, and 31 pairs of spinal nerves that emerge from the spine.

The Autonomic Nervous System

The autonomic nervous system regulates and controls involuntary body functions. It is divided into two parts: the sympathetic nervous system and the parasympathetic nervous system. Their functions are opposite; the sympathetic system controls the organs to work under stress, and the parasympathetic system controls them during rest.

Healthy Habits for Your Nervous System

To maintain a healthy nervous system, practice these habits:

• Keep a regular timetable with duties, resting time, and leisure activities.
• Do not consume drugs, tobacco, or alcohol because they seriously damage your nervous system.