Brain

1. 1. The frontal lobe is behind the forehead. It's mainly for moving, talking, planning, motivation, emotion, and social judgment.

   2. Behind, is the parietal lobe. It's mainly with sensory functions of the somatosensory category, like touch, stretch, pain, temperature, and movements.

   3. The temporal lobe is separated from the first two lobes by the lateral sulcus and is related to hearing, learning, visual memory, and language. Without this, we wouldn't be able to recognize others we have met.

   4. The insular lobe is on the inside

   5. The occipital lobe gives our sight, the brain's visual processing center, despite being at the back of the brain.

The cerebrum also has two cerebral hemispheres/halves divided by a deep groove called the longitudinal fissure. The two halves control their respective opposite sides. 

E.g. the right half controls the left nostril and the right side looks controls the right arm

Each half has folds called gyri divided by grooves called sulci. The central landmark is the central sulci. Although looking the same, it's proved that the two hemispheres are different, which is called brain function laterization. Such as, the broca's and Wernicke's are mostly in the left hemisphere of right-handed peoples. Humans have developed larger cerebrum to do all the thinking and thoughts than other animals. It has four major lobes.

Quiz

Brainstem

The brainstem is located at the base. It's continuous to the spinal cord and houses all nerve connections among parts of the central nervous system. It's in charge of our automatic actions, like breathing.

Hypothalamus

Under the thalamus, is the hypothalamus (In Greek, "hypo" means under) links the nervous to the endocrine system via the pituitary gland and contains nuclei involved in the body temperature's regulation, hunger, and water intake, sleep and wake cycle, memory and emotional behaviour. Despite its size, it's one of most crucial part of the brain.

Note: Ironically, its name suggests that it's under the thalamus with its Greek prefix, "hypo".

Epithalamus

Pituitary gland

The pituitary gland is controlled by the hypothalamus and is the endocrine gland controlling all other endocrine glands

Pineal gland

The pineal gland (In Greek, "mela" means black/dark) releases hormones called melatonin that help us to sleep better by calming the brain in the dark. Higher brightness decrease the amount of melatonin, thus making the brain harder to sleep

Auditory cortex

Hearing music activates many parts of the brain, like the auditory cortex, the thalamus, and the superior parietal cortex. These same areas are also associated with pattern recognition and helping the brain decide which inputs to pay attention to and which to ignore. The areas that process music, in other words, are designed to seek out patterns and look for familiarity. This makes sense. Music, after all, is complicated. The numerous tones, pitches, overlapping melodies, and competing sounds inside almost any song— or anyone

speaking on a busy street, for that matter— is so overwhelming that, without our brain’s ability to focus on some sounds and ignore others, everything would seem like a cacophony of noise.

Basal ganglia

Basal ganglia is a group of nuclei in the cerebral hemispheres and near the base of the forebrain, under the cerebral cortex. Basal ganglia have many roles, from motor control, to cognition, and emotion regulation, and are responsible for our habits.

They're made of many structures, like globus pallidus and subthalamic nucleus.

It usually sniffed the corners but couldn't find the sweet despite smelling it. It would turn to the right but turn left without obvious reason. 

But their head told something different. While it appeared relaxed as it walked in the maze, its basal ganglia worked furiously. Its brain exploded with activity each time it touched a wall, with constant information circulating. Its brain activity would decrease. 

It no longer needed to scratch and smelling ceased and only needed to recall the quickest path to the sweet. 

A week later, the structure to the memory stopped and it could sprint in the maze that it hardly needed to think. Its brain worked less.

This process of the brain converting a sequence of actions into an automatic routine is called “chunking,” and it’s at the root of how habits form. There are dozens or hundreds of behavioral chunks that we rely on per day. 

Some are simple: We automatically put toothpaste on our toothbrush to brush our teeth. 

Some like getting dressed or making lunch are more complex.

But some nowadays are done with hardly any thought, occurring by habit. As soon as a habit is about to occur, our basal ganglia is involved, finding the habit stored in our brains related to the habit. Once the habit unfolds, our gray matter is free to quiet itself or chase other thoughts. 

Habits

Habits are delicate but powerful and never really fade and are encoded in the brain's structures, which is a huge advantage, as it would be terrible to relearn how to drive something every break. The issue is that the brain can’t differentiate between bad and good habits, which is always lurking if one has one.

This is why it’s so hard to create exercise habits. Once a routine of eating is developed, rather than running, these patterns remain inside our minds. 

And once someone creates a new pattern, studies have demonstrated, going for a jog or ignoring the doughnuts becomes as automatic as any other habit. 

Basal ganglia that are damaged by injury or disease can become mentally paralyzed, causing issues to performe basic actions, like eating or writing, and losing the ability to ignore insignificant details. 

For instance, a study found that those with basal ganglia injuries can't recognize facial expressions, including fear and disgust as they don't know which part of the face to focus. 

Without a basal ganglia, all habits are lost. 

Nervous System

As the name suggests, it is comprised of nerves, skinny tiny wires transmitting electrical signals to and from our brain, like blood vessels circulating. We have about 6 billion inches of nerves in total.

When the brain functions, it generally sends signals to the spinal cord. 

• Peripheral Nerves are nerves made of different fibers that aren’t in the brain or spinal cord and get signals from everywhere in the body. It controls all of our movements.

There are many types of cells, one of them are neurons, which is what the brain is comprised of. Not all cells are small, like an austrich egg is a single cell.

Different humans brains

• ADHD is a condition that some of us have, standing for attention deficit hyperactivity disorder, making those with ADHD to concentrate, remember things, and still. Many very successful people have ADHD, like Justin Timberlake (singer), Simone Biles (Olympic gold medalist), and Walt Disney.  

• Autism makes it harder to make friends, understand how other feels, or might not understand jokes very well. Although, they can be clever in many subjects. 

• Epilepsy is those with seizures; they fall, fidget, stop, and stare for a moment. Although, seizures don’t occur constantly. For some, once a month. Overall, it’s brain's neurons get overexcited and send signals at the wrong time, which can be stopped by consuming medicines.

• fidget: make small movements

• Dyslexia refers to those with trouble with reading and writing. Sometimes assistance is needed at school and is generally not involved with intelligence but affects the brain which processes the letters it sees and turns into words. These include some of the most successful people: John Lennon of the Beatles, Steve Spielberg, and George Washington. Not to be confused with other conditions starting with “dys” and ending with “ia”. 

• Dyscalculia refers to those struggling to read.

• Dyspraxia refers to those with affected coordination, the way all muscles work together. 

Quiz

Frontoparietal cortex

The frontoparietal network (FPN), mostly also known as the central executive network (CEN) or, specifically, the lateral frontoparietal network (L-FPN), is a large brain network mainly made of the dorsolateral prefrontal cortex and posterior parietal cortex, around the intraparietal sulcus. It's involves sustained attention, complex problem-solving, and working memory.

The FPN is one of three networks in the so-called triple-network model, along with the salience network and the default mode network (DMN). The salience network facilitates switching between the FPN and DMN.

Disabilities and Syndromes