Human brain

Main thing

The human brain is the central organ of the human nervous system, responsible for processing, integrating, and coordinating information from the sense organs and making decisions to control the rest of the body. It consists of several key parts:

• Cerebrum: The largest part, divided into two hemispheres and four lobes (frontal, parietal, temporal, and occipital). Each lobe has specific functions, such as vision, movement, and reasoning.

• Brainstem: Controls vital functions like heart rate and breathing.

• Cerebellum: Coordinates movement and balance.

• Gray Matter: The outer layer of the brain, composed mainly of neuron cell bodies.

• White Matter: The inner layer of the brain, composed mainly of myelinated axons that connect different parts of gray matter.

The brain is built from neurons, which are nerve cells that transmit information through electrical and chemical signals. It is a part of the central nervous system (CNS), which also includes the spinal cord. The CNS is responsible for integrating sensory information and responding accordingly.

Terms

• Nervous System: The network of nerve cells and fibers that transmits nerve impulses between parts of the body.

• CNS (Central Nervous System): The part of the nervous system consisting of the brain and spinal cord.

An analogy

Think of the human brain as a supercomputer. Just as a computer processes data, runs programs, and controls peripherals, the brain processes sensory information, runs cognitive functions, and controls the body's movements. For example, when you type on a keyboard, the computer processes your keystrokes and displays text on the screen. Similarly, when you touch a hot surface, your brain processes the sensation and prompts you to withdraw your hand.

A main misconception

A common misconception is that humans only use 10% of their brains. In reality, virtually all parts of the brain have known functions, and brain imaging shows that much of the brain is active even when at rest. For example, even simple tasks like walking or talking involve multiple brain regions working together.

The history

1. Ancient Egypt (c. 3000 BCE): Early understanding of the brain's importance, but the heart was considered the seat of intelligence.

2. Ancient Greece (c. 400 BCE): Hippocrates and later Galen recognized the brain's role in sensation and intelligence.

3. Renaissance (14th-17th centuries): Advances in anatomy and dissection led to better understanding of brain structure.

4. 19th Century: Discovery of neurons and the development of neuroanatomy.

5. 20th Century: Advances in brain imaging techniques like MRI and CT scans.

6. 21st Century: Ongoing research in neuroscience, brain mapping, and understanding brain functions.

Three cases how to use it right now

1. Studying for exams: Understanding how the brain processes and stores information can help you develop better study habits. For example, knowing that the hippocampus is involved in memory formation can encourage you to use techniques that enhance hippocampal activity, such as spaced repetition.

2. Seeking advice from older individuals: Young people can benefit from the knowledge that their brains are not fully developed until around age 25. This understanding can encourage them to seek advice and guidance from older, more experienced individuals who have fully developed prefrontal cortices, which are crucial for decision-making and impulse control.

3. Enhancing physical performance: Understanding the role of the cerebellum in coordinating movement can help you improve your physical skills. For instance, athletes can use this knowledge to refine their motor skills through targeted practice and exercises.

Interesting facts

• The human brain contains approximately 86 billion neurons.

• The brain generates about 23 watts of electrical power, enough to power a small light bulb.

• The brain is about 60% fat, making it one of the fattiest organs in the body.

• The brain triples in size during the first year of life and reaches full maturity at about age 25.

• The brain can process information as fast as 120 meters per second.