How Our Brain Works: A Brief Overview

STARLOG.COM      The Brain 

How Our Brain Works: A Brief Overview

Sophia Xu
Updated: September. 26, 2023 

The brain is the most complex organ in our body. It controls our thoughts, emotions, behavior, movement and sensation. It also regulates many vital functions such as breathing, heartbeat, blood pressure and temperature. But how does the brain work? What are the main parts of the brain and what do they do?

Main Parts of the Brain and Their Functions

The brain can be divided into three basic units: the forebrain, the midbrain and the hindbrain1.

• The forebrain is the largest and most developed part of the brain. It consists of two hemispheres (left and right) that are connected by a bundle of nerve fibers called the corpus callosum. The forebrain contains the cerebral cortex, which is the outer layer of gray matter that covers the inner core of white matter. The cerebral cortex is responsible for higher cognitive functions such as language, reasoning, memory, learning, perception and voluntary movement. The forebrain also contains other structures such as the thalamus, hypothalamus, pituitary gland and limbic system that are involved in sensory processing, emotion, motivation, hormone secretion and homeostasis23.
• The midbrain is a small part of the brain that connects the forebrain and the hindbrain. It contains structures such as the tectum and the tegmentum that are involved in vision, hearing, eye movement and body movement. The midbrain also plays a role in arousal, attention, reward and pain3.
• The hindbrain is the lower part of the brain that connects the brainstem and the cerebellum. It includes the upper part of the spinal cord, which carries signals between the brain and the rest of the body. The brainstem consists of three parts: the medulla oblongata, the pons and the midbrain. The brainstem controls vital functions such as breathing, heartbeat, blood pressure and swallowing. It also regulates sleep, wakefulness and reflexes13. The cerebellum is a wrinkled ball of tissue that lies at the back of the brainstem. It coordinates balance, posture, movement and motor learning13.

How the Brain Communicates

The brain communicates with itself and with the rest of the body through a network of nerve cells called neurons. Each neuron consists of a cell body, an axon and many dendrites. The cell body contains the nucleus and other organelles that support the cell’s function. The axon is a long projection that carries electrical impulses away from the cell body to other neurons or target cells. The dendrites are short branches that receive signals from other neurons or sensory receptors.

Neurons communicate with each other through specialized junctions called synapses. At a synapse, an electrical impulse travels along an axon until it reaches a terminal button at its end. The terminal button releases chemical messengers called neurotransmitters into a small gap called the synaptic cleft. The neurotransmitters bind to receptors on the membrane of another neuron or target cell, causing it to either fire an electrical impulse or inhibit its firing.

The brain contains billions of neurons that form intricate patterns of connections called neural circuits. These circuits enable different parts of the brain to work together to process information and coordinate actions.

How We Learn and Remember

One of the most amazing abilities of our brain is to learn from experience and store information for future use. This process involves changes in the structure and function of neurons and synapses.

When we encounter something new or important, our brain activates certain neural circuits that encode the information into short-term memory. Short-term memory is limited in capacity and duration. It can hold about 7 items for about 20 seconds. To transfer information from short-term memory to long-term memory, we need to repeat it or associate it with something meaningful.

Long-term memory is unlimited in capacity and duration. It can store information for days, months or years. Long-term memory is divided into two types: declarative memory and procedural memory.

• Declarative memory is memory for facts and events that can be consciously recalled and verbally expressed. For example, we use declarative memory to remember our name, birthday, phone number or what we did yesterday.
• Procedural memory is memory for skills and habits that can be unconsciously performed without verbal explanation. For example, we use procedural memory to ride a bike, play an instrument or tie our shoelaces.