Welcome back to another video on Critically Selected, where we discuss educational topics
on anything and everything! Our topic for today is the human brain and how we actually have
three brains instead of just one! No wonder, we Homo-sapiens are so smart.
Yo I am drinking this glass of bleach to cure coronavirus.
well, at least some of us! But before we begin to dissect our brains, make sure to
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Without further ado, let’s dive right into our brains!
The human brain is a very complex organ weighing about 3 pounds on average.
It controls most of the activities of the human body and gives rise to every aspect of our
humanity. It allows us to do many things such as think, feel, breathe, move, and a lot more.
It is made up of soft tissue, which includes gray and white matter,
containing the nerve cells, non-neuronal cells, and small blood vessels.
So, mostly it is composed of water and large amounts of fats and looks like a pink sponge.
The human brain evolved over a very long-time inheriting brain structure from earlier animals
and building upon these structures. So, modern humans actually have 3 brains layered on top
of each other starting with the Hindbrain or the reptilian brain, then the Midbrain or the
mammalian brain, and finally, the Forebrain or the human brain. Each of these 3 brains has assisted
animals with survival over millions of years and encourage our well-being by working together.
They each have their unique way in which they try to ensure survival. Let’s take a look at
the functions of each of these 3 brains and how they have aided animals over millions of years.
The hindbrain is the most primitive part of our brain and is responsible for our basic
life functions such as heartbeat, digestion, arousal, balance, and coordination. It is
made up of smaller parts some of which include, Medulla Oblongata, Pons, Reticular Formation,
Cerebellum, and brainstem. The medulla controls many vital autonomic functions such as heart rate,
breathing, digestion, and blood pressure. Pons helps coordinate movement on each side of the body
by relaying information between the cerebellum and the cerebrum. The reticular formation is a
neural network located in the medulla that helps control functions such as sleep and
attention. Damaging this area is what results in a coma. The Cerebellum is involved in the
coordination of motor movements as well as basic features of memory and learning. And finally,
the brainstem is an extension of the spinal cord and aids in sending and receiving information.
Together, these parts make up our reptilian brain which seeks survival by reacting to threats.
The midbrain, which is located in the middle brain transmits
signals from the hindbrain to the forebrain and helps process information relating to our senses.
It is associated with behaviors such as fight or flight response, feeding,
and reproduction. This part of our brain is also made up of smaller parts including Striatum,
Thalamus, Hypothalamus, Amygdala, and Hippocampus. The striatum which is also called the striate body
is responsible for controlling smooth body movements. Thalamus serves as a switchboard
that relays movement and sensory information to the appropriate area of the brain for processing.
It is essentially a relay station which takes in sensory information and then passes it on to
the cerebral cortex. This sensory information, however, does not include the sense of smell.
The sense of smell is regulated by the Olfactory bulb located near the front of the brain.
Hypothalamus regulates hunger, thirst, fight or flight response, sex drive, body temperature,
and circadian rhythms. It also helps to maintain homeostasis. The amygdala,
which is shaped like an almond, is associated with emotions such as fear and aggression.
And finally, the hippocampus controls the formation of new explicit memories and contains
the largest concentration of acetylcholine, the absence of which causes Alzheimer’s disease.
Together, these parts make up our mammalian brain which seeks survival through social bonds.
The forebrain or the Cerebrum is the most complex and includes brain structures to help
regulate emotions, hunger, the formation of long-term memories, growth hormones,
and smell. It is the outer layer of the brain and is the last part to evolve.
It is the biggest part of the brain and makes up about 85 % of the brain's weight.
Its surface has a lot of wrinkles and cracks. The cerebrum is the thinking part of the brain.
It controls our muscles and makes them move when we want them to. This part of the brain is unique
to humans as it is solely responsible for our thinking, and our use of logic. We also use this
part of the brain when we are trying to draw pictures or solve tough mathematical problems.
The cerebrum has two halves. Some scientists think that the right half helps us think about
things like music, colors, or shapes whereas the left half helps us think logically and controls
our speech. Furthermore, the right side of the cerebrum controls the left side of our body and
the left half controls the right side. Apart from this, the Cerebrum is also divided into smaller
parts called Lobes. These include the frontal lobe, the parietal lobe, the temporal lobe,
the occipital lobe. The frontal lobe is located at the front of the brain and is associated with
reasoning, motor skills, higher-level cognition, and expressive language. At the back of the
frontal lobe lies the motor cortex. This area of the brain receives information to carry out body
movements. The parietal lobe is located in the middle section of the brain and is associated with
processing tactile sensory information such as pressure, touch, and pain. A portion of the brain
known as the somatosensory cortex is located in this lobe and is essential to the processing
of the body's senses. The temporal lobe is located on the bottom section of the brain.
This lobe is also the location of the primary auditory cortex, which is important for
interpreting sounds and the language we hear. The hippocampus, which is also part of the
Midbrain, is also located in the temporal lobe, which is why this portion of the
brain is also heavily associated with the formation of memories. The occipital lobe
is located at the back portion of the brain and is associated with vision. Together,
these parts or lobes make up our human brain which seeks survival by learning from experience.
Our 3 brains work together for our well-being
using past experiences to build social bonds and avoid any kind of harm.
Since the reptilian brain and the mammalian brain do not speak the same language as the human brain,
they release neurochemicals into the body which we experience as emotions. Chemicals such as
serotonin, oxytocin, dopamine, and endorphin are released when the brain sees positive
things that assist in survival. On the other hand, cortisol is released if the brain sees
negative things that conflict with survival. We experience this as anxiety or panic.
The brain is made up of millions and millions of nerve cells called neurons. Almost all of them are
there when you are born but they are not connected with each other. When we learn new things,
the brain starts to create pathways between neurons. As time goes on, things become easier
and we don't have to think about doing these things, they happen automatically. The human
brain is an amazing organ that puzzles us all even in this day in age. Perhaps in the future,
we will be able to better understand and appreciate it and all its complexities.
This brings us to the end of this video! If you liked this video,
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