The Brain 101: Knowing Yourself Inside Out

Scientists and neuro-doctors will both agree that the brain is the most sophisticated organ in the body, as well as the most essential for survival. But how does it work?

The below video does a fantastic job of summing it up!

Basic Brain 101 - 4 Main Brain Parts


Brain Anatomy & Function

The brain is one characteristic that separates the animal kingdom from the plant kingdom. While the human brain begins off looking like any other animal brain in utero, it develops at a rapid speed into something far more unique and complex.

This 3lb mass of lipids and proteins is hard wired with neurons to take in information and process it for us, allowing us to think, feel, breathe, and experience life.

The brain is not limited to just our heads. The nervous system is an extension of our brain that makes this constant neuro-feedback possible, fetching information from everywhere in the body.

Learning how your brain works will give you a better understanding of the processes going on inside your body and allow you to take charge of your health further.

There are four main sections of the brain, each of which takes in either sensory or hormonal input, process it, before sending back information that allows us to act accordingly.

1. Brainstem

This is the first portion of the brain that any neuro-input reaches, and it is also one of the most critical parts of the brain for basic survival!

The brainstem keeps your brain attached to the spinal cord, but more importantly, it serves to regulate vital automatic processes in the body.

These include breathing, our heartbeat, blinking our eyes, sleep, digestion and instant reflexes. As you can see, damage to your brainstem has a high chance of being fatal.

Brainstem

There are three parts that make up the Brainstem, and each of them works together to carry out the above functions:

  1. Midbrain

    Another name for the Midbrain is the mesencephalon, and it sits at the top end of the brainstem [1]Britanica Science – Midbrain.

    This part of the brainstem is responsible for controlling automatic motor movements, such as moving your eyes or contracting your pupils in response to dark or light. It also helps to process audio and visual input, while also sending this type of data to other areas of the brain for further processing.

  2. Pons

    The Pons sorts out sensory information to where it needs to be, sending signals between the cerebrum and cerebellum. It has been described as a “conduction pathway for nerve tracts.” [2]UC San Diego – Cognitive Science

    This part of your brain stem is also serving to help aid the medulla oblongata (below) and contributes to maintaining your circadian rhythm (your state of arousal and when you sleep).

  3. Medulla Oblongata

    The Medulla Oblongata rests underneath the Pons at the bottom of the Brainstem. This is the portion responsible for maintaining functions necessary for survival, such as breathing, your heartbeat, and automatic reflexes.

    It is also involved in regulating autonomic nervous system responses, such as bladder control, swallowing, maintaining posture or facial expressions. In short, the medulla oblongata controls everything you do physically without thinking.

2. Cerebellum
The Cerebellum sits at the back lower end of your brain. The specialized nerve cells found here look like a bit like cauliflower that’s been chopped in half. These are called Purkinje cells. There are five other types of neuronal cells in this portion of the brain, all working together to process information collectively.

This part of the brain is where motor connections are made, making it possible for us to move, play sports, dance or ride a bicycle. The cerebellum is also where motor coordination and muscle memory are developed. It works by integrating and coordinating multiple sensory inputs from other areas of the brain, such as spatial awareness and vision, to allow us to move. [3]PubMed – Structure and function of the cerebellum

If you battle to catch a ball or your sense of timing with sports is off, then you likely have missing connections inside this part of your brain – fear not, for practice makes perfect!

3. Diencephalon
The diencephalon sits almost directly in the center of the brain and is no larger than apricot in size.

This whole portion of the brain helps coordinate all information relating to our five senses by sending signals to where they need to go. Other parts of the diencephalon have vital functions, such as regulating hormones and chemical balances in our bodies.

The diencephalon can be divided into three parts:

  1. Thalamus

    The Thalamus was described in the above video as the ‘router of the brain,’ as it sorts and sends out lots of sensory information to necessary parts. It consists of grey brain matter and many neurons.

    All the five senses (except for smell) get processed here and sent to parts of the Cerebrum. Moreover, the Thalamus also communicates with the Cerebellum to achieve perfect motor control.

  2. Hypothalamus

    The Hypothalamus rests just beneath the Thalamus and is the mediator between different chemical and hormonal balances in the body. A part of this section of our brains crosses the roof of our mouths.

    It makes sure that the body retains a state of homeostasis by moderating temperature, osmoregularity (which is the balance between salts and water), neurochemicals and hormones. These, in turn, regulate the endocrine system, the kidneys, and our metabolism.

    The Pituitary and many other parts of the brain work with the Hypothalamus to achieve this. When the Hypothalamus receives a signal from other corresponding areas of the brain or body, it then starts to send the signals for secreting hormones or neurochemicals called neurotransmitters [4]Britanica – Hypothalamic Regulation Of Hormone Secretion.

  3. Posterior Pituitary Gland

    The Posterior Pituitary Gland works hand in hand with the Hypothalamus to regulate hormones in the body. Nerve endings feed into the Pituitary, which together with the Hypothalamus, processes this information and sends off signals to produce chemicals. This part of the brain helps to regulate growth, development, sensations, weight gain, energy expenditure and primal instincts (such as love or sexual behaviors).

4. Cerebrum

The Cerebrum or Cerebral Cortex is the largest and newest part of the human brain, developing last in our evolution.

It takes up just over 80% of our brain mass and consists of intricate webs of billions of neurons, all embedded in folds of brain tissue. This section of the brain is largely what separates man from other animals.

The Cerebrum helps to coordinate all sensory input and organizes large volumes of information. It is in constant communication with all other parts of the brain, but mainly with the Thalamus and Cerebellum.

There are four different sections of the Cerebral Cortex, each one responsible for processing different portions of the input the brain receives.

  1. Frontal Lobe

    The frontal lobe resides in the front portion of the brain. It deals with executive functions, such as behavior, emotional control, speech, learning, reasoning, judgment, and perception.

    It also plays a crucial role in processing sensory input through a part of it called the motor cortex. This receives information from the Parietal lobe before sending signals out to the intended part of the body.

  2. Parietal Lobe

    The Parietal lobe is responsible for spatial awareness, sensations, and touch. This part of the brain deals with you and how you react to your environment. There is an essential part of the Parietal Lobe called the somatosensory cortex.

    This part takes signals from the body that move up the brainstem, as well as other areas, sending them to this sensory cortex. These signals are then relayed to the motor cortex in the Frontal Lobe, where they then are transmitted back to appropriate regions of the body.

  3. Occipital Lobe

    The occipital lobe is the smallest of all these central Cerebral Cortexes and is only used for one function: interpreting visual input from the eyes. If you damage this part of your brain, you will lose your sight.

  4. Temporal Lobes

    The temporal lobes rest on either side of the brain and coordinate sensory input related to language, hearing, smell and memory.

The Four Main Neurotransmitters
Epinephrine
Also known as Adrenaline and mainly secreted in the adrenal glands when one stresses. This signals other areas of the body to raise cardiac levels as well as blood glucose so that the person can act fast. This gives rise to a ‘fight or flight’ response. Epinephrine is created from the methylation of Norepinephrine [5]Britanica Science – Epinephrine .
Norepinephrine
This neurotransmitter is known as Noradrenaline, and it acts to increase the force of muscle contractions, including the heart and its beat. This uses Tyrosine to produce itself and is eventually broken down to form Epinephrine [6]Britanica Science – Norepinephrine . The body holds small stores of this substance in all the neurons of the Autonomic Nervous System.
Serotonin
This neurotransmitter is made from Tryptophan and is also called 5-hydroxytryptamine. It helps to keep blood vessels constricted and is present in blood clotting platelets, mast cells, the gut and the brain[7]Britanica Science – Serotonin. If levels of Serotonin have been depreciated from the brain, it can link to mood disorders and sleep irregularities.
Acetylcholine
This neurotransmitter is made from acetic acid (vinegar) and choline. It is present in the peripheral nervous system that expands blood vessels, slows heart rate, increases bodily secretions and contracts smooth muscle (such as in the gut and bladder). In other words, this neurotransmitter helps our bodies to function optimally. It also plays a crucial role in memory and learning, and those with Alzheimer’s have significantly reduced quantities in their bodies [8]Britanica Science – Acetylcholine.

There are several other lesser neurotransmitters which are classified as neuropeptides. These work to diminish the production of hormones as well as stimulate their production, thereby maintaining homeostasis.

Extra Minor Parts of the Brain

There are also some extra minor parts of the brain that help coordinate additional input. Here is a brief look at them:

  • Basal Ganglia

    Sits just beneath the Corpus Callosum and is made up of many neuronal tissues. These further aid motor control and hormonal regulation in the body, such as skilled muscle movements, regulation of emotions and our reward pathway via Dopamine. Short-term memory is also stored here.

  • Corpus Callosum

    The Corpus Callosum connects the two hemispheres of the brain together and ensures that all parts of the left and right side are coordinating.

Additional Video - 17 Parts of the Brain




References   [ + ]

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