The Brain | Part 13 | Discovery Channel Body Atlas
Summary
TLDRThis script delves into the marvel of the human brain, the organ of consciousness and thought, highlighting its evolution, complexity, and functions. It explores how the brain enables learning, perception, and abstract thinking, shaping our experiences and knowledge. From the intricate network of neurons to the brain's growth and development, the script paints a picture of the brain as a pinnacle of evolution, a mysterious yet powerful organ that underpins our very existence.
Takeaways
- 🧠 The human brain is an organ of immense complexity, controlling every move we make and enabling us to learn from birth.
- 🤔 It is the pinnacle of evolution, the only object aware of its own existence, and the center of intelligence with senses that pick out sounds and touches.
- 🔬 The brain's power lies in its billions of microscopic nerve cells, which create an intricate network of connections, far more complex than a computer chip.
- 🚀 Humans dominate the world not by strength or speed but by the development of the brain, which allows us to think in abstract symbols and accumulate knowledge.
- 💡 The brain requires a continuous supply of energy, with over a pint of blood flowing through it every minute, highlighting its sensitivity to oxygen deprivation.
- 🌱 The nervous system is one of the first parts of the body to form, with the brain developing rapidly in the womb, producing a quarter of a million nerves every minute.
- 👶 The wiring of the brain is shaped by experience, with the brain growing rapidly as it coordinates the body and learns skills like language through repetition and reinforcement.
- 🧬 The brain's structure changes as we learn, with the process of relearning and skill acquisition actually rewiring the brain, making humans remarkably flexible learners.
- 🧬📈 The front brain, which has reached its maximum complexity in humans, is responsible for our thinking and decision-making processes.
- 🦈🐠🐦🐇 Despite its complexity, the human brain retains its ancient fishy brain for basic life functions, with the cerebellum playing a key role in balance.
- 🧬🧠 The evolution of the human brain is marked by an increase in size and complexity, with the modern human brain reaching its present size 130,000 years ago but taking longer to reach mental capacity.
- 🧠🌐 The brain's cortex, with its crumpled surface, allows for a large surface area to be packed into a small volume, enhancing our thinking power beyond other animals.
- 🤲 The brain devotes a disproportionate amount of nerve cells to sensitive and finely controlled body parts, such as the lips and hands, reflecting their importance in expression and manipulation.
- 👁️👂👃 Our senses are deeply interconnected, with each sense stimulating specific regions of the brain and contributing to our seamless perception of the world.
- 🗣️ Language has a profound impact on the way we think, organizing our thoughts and enabling us to communicate complex ideas and emotions.
- 🔄 The brain's ability to learn and remember involves the formation of new connections, with memories becoming more ingrained through repetition.
Q & A
What is the human brain's role in our ability to learn?
-The human brain, with its 14 billion cells, forms a complex network that enables us to learn from the moment we're born, providing insight and creativity.
How does the brain's structure contribute to its function as the center of intelligence?
-The brain's structure, with its billions of microscopic nerve cells and trillions of connections, allows for complex intelligence operations, processing sensory information and enabling abstract thinking.
What is the significance of the brain's blood supply in maintaining its function?
-The brain requires a continuous supply of oxygen and sugar for energy. Over a pint of blood flows through the brain every minute, and a lack of oxygen can lead to rapid nerve cell death and permanent damage.
How does the brain's development during early life influence our cognitive abilities?
-The brain's development in the womb and early childhood is crucial for cognitive abilities. It produces a quarter of a million nerves every minute during the first four months, shaping the wiring of the brain through experience and learning.
What is the role of the cerebellum in the body's balance and coordination?
-The cerebellum, a primitive part of the brain, is responsible for maintaining balance and coordinating movement. Its complexity in humans may be due to the challenges of balancing on two legs.
How does the brain's structure adapt as we learn new skills or knowledge?
-As we learn, the brain rewires itself by strengthening the connections used for new knowledge or skills. This process of reconnection makes humans remarkably flexible in learning.
What evolutionary changes in the brain have contributed to human intelligence?
-The front brain has evolved to be the largest part, contributing to higher intelligence. Over millions of years, the human brain has increased in size and complexity, enhancing cognitive abilities.
How does the brain process sensory information from different parts of the body?
-The brain processes sensory information through specific regions of the cortex dedicated to different senses. It integrates these responses to create a seamless perception of the world.
What is the significance of the brain's two hemispheres in interpreting the world?
-The two hemispheres of the brain interpret the world differently; the left hemisphere thinks in words, while the right hemisphere thinks in images and feelings, exchanging information through a dense band at the base of the brain.
How does the brain's sensory cortex represent different parts of the body in terms of sensitivity?
-The sensory cortex represents different parts of the body based on their sensitivity. Highly sensitive areas like the lips and hands are represented as larger in the brain's view, indicating their importance in sensation and control.
What is the process of memory formation and retrieval in the brain?
-Memory formation involves short-term memory and long-term memory. The brain selectively stores important information and forges new connections between nerves. Retrieval of memories is still a mystery, but it involves the reactivation of these dispersed connections.
Outlines
🧠 The Marvel of the Human Brain
This paragraph delves into the complexity and function of the human brain, highlighting its role as the control center for our actions and thoughts. It underscores the brain's capacity to learn and adapt from birth, facilitated by its 14 billion cells and intricate network. The brain is portrayed as an organ of immense power, enabling us to perceive our environment through our senses and process information through the spinal cord. The script also touches on the brain's evolution, its energy requirements, and the significance of its microscopic nerve cells, which, through electrical signals, allow for abstract thinking and knowledge accumulation across generations.
🌱 The Development and Flexibility of the Nervous System
The second paragraph explores the development of the nervous system, starting from its initial formation three weeks after fertilization. It details the rapid growth of the brain and the production of nerves, emphasizing the brain's ability to create new pathways and adapt through learning. The paragraph also discusses the importance of experience in shaping the brain's connections and the remarkable plasticity of the human brain, which allows for the acquisition of new skills and knowledge. The evolution of the brain from our earliest ancestors to modern humans is briefly traced, illustrating the enlargement of the front brain and its significance in cognitive advancement.
🦴 The Ancient yet Essential Brain Functions
This section examines the ancient parts of the brain that perform vital functions, such as maintaining heartbeat and respiration, and the cerebellum's role in balance. It points out that despite the complexity of the human brain, we still possess these primitive regions that contribute to our basic survival. The paragraph also discusses the evolution of the brain's size and complexity, from the early Australopithecus to Homo erectus, and the significance of the brain's geometry in accommodating the increasing number of nerve cells without enlarging the skull. The unique capabilities of the human cortex in decision-making, interpretation, and understanding are highlighted.
🤲 The Brain's Control Over Movement and Sensation
The fourth paragraph focuses on the brain's control over the body's movements and sensations. It explains how the brain's hemispheres are responsible for opposite sides of the body and how the sensory cortex processes different types of sensory input. The paragraph describes the brain's representation of the body, with highly sensitive areas such as the lips and hands receiving a disproportionate amount of nerve cells. It also discusses the development of motor skills, starting with facial expressions and progressing to fine motor control in the hands, which has been crucial for human evolution and cultural achievements.
🌐 The Integration of Senses and Memory Formation
The final paragraph discusses the integration of our senses and the brain's role in memory formation. It describes how the senses work together to create a cohesive perception of the world, despite our limited understanding of the underlying neural pathways. The paragraph also delves into the process of memory, from short-term to long-term, and how repetition strengthens these memories by forming new neural connections. The discussion concludes with the brain's remarkable capabilities, its role in language, and its potential for self-improvement, emphasizing the brain as a powerful and mysterious organ that drives human intelligence and consciousness.
Mindmap
Keywords
💡Brain
💡Nerve Cells
💡Consciousness
💡Evolution
💡Neural Connections
💡Cortex
💡Hemispheres
💡Sensory Cortex
💡Memory
💡Language
💡Cerebellum
Highlights
The human brain controls 14 billion cells, forming an almost infinitely complex network.
Brain's tranquil folds are the busiest organ, providing insight and creativity.
The brain is the pinnacle of evolution and the only object aware of its own existence.
Brain's intelligence is centered around sensory inputs from eyes, ears, and skin.
The spinal cord acts as the body's information superhighway, routing sensory signals.
The brain is key to human success, enabling abstract thinking and knowledge accumulation.
Brain's 3 pounds of tissue contain billions of microscopic nerve cells for complex operations.
10 trillion brain connections outnumber the stars in the Milky Way by a hundred times.
Brain requires a continuous supply of oxygen and sugar for its active nerve cells.
Brain's energy supply is 10 watts, a fraction of a computer's needs.
Nerve cells can create new pathways, unlike programmed electrical currents in computers.
The nervous system begins forming just 3 weeks after human egg fertilization.
Brain's structure changes as we learn, rewiring itself with new knowledge and skills.
The front brain's complexity in humans is unmatched, facilitating abstract thought.
Primitive brain regions like the cerebellum maintain vital functions and balance.
Evolution of the human brain is marked by changes in skull size and complexity.
The human brain's cortex, with its crumpled surface, allows for advanced cognitive functions.
The brain's two hemispheres interpret the world differently, with the left thinking in words and the right in images.
The brain selectively stores information, prioritizing what seems important for survival.
Memories are ingrained through repetition, changing the brain's structure.
The human brain is a powerful and mysterious organ, with scientists still exploring its full capabilities.
Transcripts
it controls every move we make it's 14
billion cells connect a network of
almost infinite complexity which enables
us to learn from the moment we're born
these tranquil folds are the busiest
organ in the body constantly providing
us with insight and creativity
probe the secrets of our mind as we
explore the human brain next on body
atlas
[Music]
I think therefore I am this is the home
of all human thought and of our
consciousness the human brain is the
pinnacle of evolution the only object
aware of its own existence it's also the
center of a complex intelligence
gathering operation that employs the
clear window of the eyes senses to pick
out the sounds and sweet airs that
surround us organs of touch crowding
into the sensitive folds of the lips and
every inch of the skin they alert us to
a warm wind or the chill of snow the
lightest touch or a stab of pain these
signals are routed along the bodies
information superhighway the spinal cord
this bundle of delicate nerves is
protected by a spiky suit of armor the
backbone
[Music]
it leads upwards to the bony helmet of
the skull encasing one small organ that
can encompass the whole world outside
[Music]
Brian and his classmates take this jewel
in their crowns for granted
unlike the bodies other organs we can't
easily feel or monitor the brains
ceaseless activity but it's the key to
human success we've come to dominate the
world not by strength or speed but by
the development of this one special
organ we can think in abstract symbols
like language and math and build up
knowledge from generation to generation
the power of the brain isn't evident at
first sight looking like an oversized
walnut it's 3 pounds of soft watery
tissue the brain secret lies in its
billions of microscopic nerve cells when
we think minut electrical signals flash
between these nerves it's similar to the
electric currents that flow between the
tiny transistors in the computer chip
when it makes a calculation but the
network of nerves is far more complex
the 10 trillion connections in one brain
outnumber the stars in the Milky Way a
hundred times over the active nerve
cells need a generous supply of energy
this network of blood vessels brings in
oxygen and sugar the brain's fuel over a
pint of blood flows through the brain
every minute
and a continuous supply of blood is
essential nerves die rapidly when oxygen
is cut off after just a few seconds some
cells begin to shut down we lose
consciousness after a couple of minutes
the brain suffers permanent damage
[Music]
Bryan's brain requires an energy supply
of 10 watts only a fraction of the
computer's needs like the Machine his
nerve center is wired into a wider
Network electrical energy constantly
conveys signals along the spinal cord to
and from the brain but in close-up nerve
cells are very different from electrical
wires there are many gaps for the
signals to jump providing thousands of
alternative routes and living nerve
cells can link up to their neighbors
creating yet more new pathways
unlike the programmed root of electric
currents in the computer the nervous
system is one of the first parts of the
body to form only 3 weeks after a human
egg has been fertilized some of the
cells develop into a distinct swelling
which becomes the brain and spinal cord
[Music]
over the next two months the nervous
system develops at an amazing speed
during this time the brain turns out a
quarter of a million nerves every single
minute these cells move through the
tissues of the body to their final
destinations here a new arrival is
putting out feelers to connect with its
neighbors over the first four months of
the womb the baby's brain produces all
the nerve cells it'll ever have
[Music]
at the same time
bones highlighted in red start to form
they protect the vulnerable network of
nerves
[Music]
the top of the skull is made of eight
separate bones allowing the brain to
grow inside five months before birth 14
billion brain cells are in place yet
even at birth vital connections between
these cells are missing compared to
other animals the newborn human brain
has a long way to go to reach its full
potential the wiring of the brain is
shaped by experience as parents and
teachers pass on thousands of years of
accumulated knowledge it's expanding
network of connections makes the brain
grow rapidly with signals from the eyes
and ears hands and feet the brain begins
to coordinate the young body by
repeating its successes a child learns
hand-eye coordination the skill of
balancing on two legs and even something
as complicated as language by the age of
two some children can speak 2,000 words
as we learn we actually change the
structure of the brain all parts of the
brain are connected by these bundles of
nerve fibers Criss crossing the interior
like telephone lines
each time we repeat an action or a word
the connection we're using becomes
stronger so as we achieve new knowledge
and skills we literally rewire our
brains these reconnections make humans
remarkably flexible in what we can learn
it's one reason for our success as a
species the rewiring takes place within
the front brain it's the part of our
brain that thinks the front brain has
reached its maximum complexity in humans
after billions of years of evolution
the brain of our earliest ancestors the
fish has only a very small front region
the fringe on the left the main bulge
deals with sight the fish's most
important sense the front brain grew
rapidly as our ancestors became
amphibians by the time reptiles evolved
it was the largest part of the brain in
a bird the front brain has enlarged
further a bird is smarter than a reptile
in the first mammals the growth of the
front brain and intelligence continued
until in humans the crinkled surface of
the front brain seems to have taken over
entirely but hidden inside and below we
still have our ancient fishy brain
carrying out its age-old functions these
nether regions of the brain keep our
hearts beating and our lungs breathing
the cauliflower shaped cerebellum keeps
our bodies in balance the human
cerebellum is the most complex in the
animal kingdom possibly because it's
more difficult to balance on two legs
than on four
this early part of the brain has a
primitive beauty all its own
[Music]
without the cerebellum we'd have to
concentrate on standing upright and
taking every step from its primitive
base upwards the human brain has
successive layers of intricate
connections and staggering complexity in
these layers is hidden everything that
makes us individuals emotions memories
aspirations and thoughts the human brain
has reached its present complexity in
size in only five million years since
the human lineage split from the
chimpanzee the story of the brains
evolution is revealed by changes in the
skull a modern chimpanzee has a brain
only slightly smaller than one of our
possible ancestors Australopithecus
africanus who lived 3 million years ago
2 million years ago a larger brained
early human emerged these people made
the first tools
[Music]
dating back half a million years this
human skull housed a brain twice as
large as the early Australopithecus Homo
erectus had mastered the art of using
fire the human brain reached its present
size a hundred and thirty thousand years
ago but it took another hundred thousand
years to reach a mental capacity similar
to ours a child from 35,000 years ago
could easily learn all the skills needed
to survive in present-day society the
human characteristics that evolve them
self-expression and curiosity are still
the cornerstones of society today the
number of nerve cells in the brain has
multiplied immensely over the past few
million years the brain was in danger of
outgrowing the skull but it was saved by
a clever piece of geometry the cells we
use to think lie on the surface of the
brain in a layer just 1/8 of an inch
thick the cortex and a large surface can
be stuffed into a small volume by
crumpling it up like a sheet of paper
the cortex has crumpled into fissures
and grooves if we smoothed out the
crinkles the cortex would be the size of
a pillowcase
with these intricate folds we far
outdistanced the thinking power of even
the largest animal brain the nerve cells
in the cortex do everything that unique
to humans to make decisions to voice
opinions to interpret what we see and
hear and to understand it the crumpled
cortex forms two distinct hemispheres
each filled with bundles of nerves the
two halves have different ways of
interpreting the world the left
hemisphere thinks in words while the
right half thinks in images and feelings
the nerves exchange information through
a dense band at the base of the brain
every point in the right hemisphere is
connected to an exact mirror image point
in the left hemisphere
if the word water appears here in the
left hemisphere then just here the right
hemisphere has an image of water to
prevent any argument within the brain
one hemisphere almost always the left
makes the ultimate decisions when it
comes to controlling the muscles each
hemisphere is responsible for one side
of the body all the way from the feet
and legs to the hands and eyes but the
lines of command cross over the left
side of the body is connected to the
brains right hemisphere while sensations
from the right side of your body
and up in the left hemisphere the most
sensitive regions command a
disproportionate number of nerve cells
in the brains feeling Center called the
sensory cortex
[Music]
this weird figure shows how your brain
feels your body to be highly sensitive
parts loom large in the brains view of
the body the lips look huge because
they're extremely sensitive and ideal
for displaying our feelings
[Music]
children instinctively use their lips to
explore the world around them the boss
stimulates the nerves in his lips
sending signals to this very specific
part of the brain a different part of
the sensory cortex lights up when you
touch something with your right index
finger the hand is packed with nerve
endings so we feel it to be much larger
than life the thumb is biggest of all it
can discriminate the finest details by
touch the entire back stimulates fewer
nerve cells in the sensory cortex than
the palm of your hand
[Music]
a second figure shows how much of the
brain is devoted to controlling our
bodies
his largest parts have many nerve cells
in charge of finely tuned muscles the -
distorted figures have much in common
parts of the body sensitive to touch
generally need the finest control from
birth our nerves can feel sensations but
it takes time and patience to control
our muscles properly among the first we
master are the facial muscles a baby can
express emotions with a smile or a frown
from a very early age our facial
expressions acquire more finesse as our
muscles and nervous system become more
mature the expressive lips need fine
control to convey speech and emotions in
the brains view they are enormous the
hands are packed with precision muscles
the huge amount of brain devoted to the
hand has been vital for our evolution
from our clumsy ancestors and it's led
to some of our greatest cultural
achievements to monitor our muscles we
rely on our vigilant sense organs each
is connected to its own region of the
brains cortex
the eyes send signals to the back of the
brain along nerves that cross over on
the way
where we see the world is strangely
farthest from the eyes themselves when
you see something electrical signals
race along these pale nerve bundles they
carry coded messages through the brains
massive hemispheres to the back of the
cortex
this scan shows electrical activity in
the part of the brain where the messages
are received
[Music]
the ear keeps us in touch with every
sound and with messages from our fellow
human beings sounds are amplified and
detected by a natural microphone it
signals more sensibly are analyzed in a
region of the brain right next to the
ear smells are conveyed by invisible
molecules to the back of the nose they
trigger nerves that fire straight into
the depths of the brain where our
emotions reside
that's why smells can trigger long-lost
feelings and other memories hear a sniff
of perfume lights up several parts of
the brain the visual region at the lower
right is recalling of you associated
with the smell
[Music]
the unconscious pathways that link our
senses are still largely unexplored and
we don't understand how the cortex ties
together it's scattered responses to our
different senses to create a seamless
image of the world around us most things
we do involve almost every part of the
brain even something apparently as
simple as answering a question yes we
must hear the words understand them draw
on our memories and then voice the
answer because it reinforces particular
pathways through the brain language has
molded the very way we think this area
organizes our thoughts according to the
rules of grammar it sends signals to the
region which coordinates our breathing
vocal cords tongue and lips to allow us
to speak language helps us to learn new
facts and new ideas but we can't recall
everything we were taught at high school
the brain is selectively choosing what
seems to be important and it stores
information in two stages first is
short-term memory
Samos hear a new word and you can recall
it for a few seconds but it will quickly
fade
unless it's filed in the long term
memory which like choose Desperados
quarry fraud new school versus to retain
what you've learned the brain must build
up permanent new connections between its
nerves the actual structure of the brain
changes subtly each time we commit a new
fad to our long-term memory
new links are forged throughout the
brain but it's still a mystery how we
can recall these dispersed memories at
will
[Music]
with constant repetition memories become
more deeply ingrained the brain can
teach itself by repeating words and
facts mentally remarkably the technique
also works for physical skills the human
brain is our most wonderful and our most
mysterious organ scientists have yet to
learn the function of every fold
increase and how this mass of nerve
cells creates intelligence consciousness
and self-awareness a computer that can
think let alone be aware of itself is
still far off in the realms of science
fiction yet each one of us contains a
far more powerful computer than any
space-age instrument the human brain has
the ingenuity to take us to the farthest
corners of the earth and beyond its
mental reach knows no limit
with our flexible brain we can look
beyond our own world and contemplate the
infinite
[Music]
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