User:UnderEducatedGeezer/sandbox

SANDBOX SUB-PAGE(S): sample of how to 'ping' someone:
 * User:UnderEducatedGeezer/sandbox/Neural Signal Movement
 * User:UnderEducatedGeezer/sandbox/Passport (PBS Streaming)
 * User:UnderEducatedGeezer/sandbox/List of PBS Passport available programs
 * User:UnderEducatedGeezer/sandbox/Regeneration of the corneal epithelium
 * User:UnderEducatedGeezer/sandbox/Suspects - Season 1
 * User:UnderEducatedGeezer/sandbox/Mesaxon
 * User:UnderEducatedGeezer/sandbox/Modus_TV
 * User:UnderEducatedGeezer/sandbox/Tissue
 * User:UnderEducatedGeezer/sandbox/StarWars
 * User:UnderEducatedGeezer/sandbox/DNA

A neuroscience joke: Any brain simple enough to understand would be too simple to understand.

= The Mind (as Brain functioning)= The mind is the human brain functioning. Every aspect of the mind derives from the brain functioning. Every mind is different from every other mind, although there can be general similarities between various minds, and differences can be both from nature, and from nurture, and from a combination of the two.

the brain is made up of neurons (and glia) which have the following characteristics: (memory changes might relate to which input signals at a synapse have repeatedly contributed to firing the neuron (can't find reference for this)).
 * neurons have many connections with other neurons (via synapses)
 * neurons will fire if they receive sufficient inputs
 * neurons can remember, via physical changes within one or more of:
 * the pre-synaptic neuron (more vesicles?),
 * the synapse itself, (more 'caging' synaptic adhesion molecules?),
 * the post-synaptic neuron (more receptor sites?) ;

The many connections that neurons make with other neurons allow that:
 * networks and circuits of neurons can form.
 * memories of events, actions, & information can be stored

Mind-as-Brain functions in relation to:
 * pathways among neurons along synapses and weighted synapses
 * frequency of firings
 * diffusion of neurotransmitters both to connected and nearby receptors

Cognitive Processes
Cognitive processes are complex neural processes in the brain, which derive from sub-conscious associations among memories of experiences. They occur in the conscious, sub-conscious, and unconscious (sleeping) mind, and sub-conscious processes may actually create the conscious mind. --
 * Sensation
 * Memory
 * Association
 * Perception
 * Experience
 * Thought
 * Mood
 * Learning
 * Actions
 * Motor Activity
 * Character
 * Getting Things Done
 * Values
 * Aptitudes
 * Assumptions
 * Observation
 * Organizing
 * Attention
 * Interests
 * Awareness
 * Wakefulness
 * Consciousness
 * Cohesion
 * Responsibility
 * Intention
 * Contemplation
 * Desires
 * Dreams
 * Imagination
 * Personality
 * Problem Solving
 * Behavior
 * Coordinating
 * Interacting
 * Empathy
 * Working
 * Categorizing
 * Assembling
 * Listing
 * Prioritizing
 * Multi-tasking
 * Surviving
 * Gestalting
 * Working
 * Confidence
 * Socializing
 * Coordinating
 * World View
 * Going for it
 * Considering Consequences
 * Similarity

---

Thoughts
Probably every human being has thoughts. Thoughts are probably verbal for most people, but can probably also be variably visual, aural, kinesthetic, etc. Thoughts can just occur to a person, or be consciously directed. Thoughts are momentary, in that they come, and then go, and are to some degree then forgotten. Thoughts can to varying degrees leave traces of their passing behind in, and by changing, the synapses through which they passed. Thoughts derive at least in part from memories of previous thoughts. Thoughts which recur strengthen the traces which manifested them.

Thoughts which just occur derive from subconscious associations.

Subconscious Associations
Sub-conscious associations are the firings of neurons between sets of neurons configuring memories, along pathways among variously weighted synapses. Large numbers of sub-conscious associations are probably occurring at every moment of life, and each individual one can be a contributor to the firing of one or another one. [How do SCA occasion or transform into conscious thoughts?]

Perception
Perception is an association between a current sensory input (or set of sensory inputs) and a memory of a similar sensory input sufficient to occasion a recognition of the object, event, circumstance, action, state-of-being, etc which presented the original sensory input in the first place.

Understanding
Understanding is a mind state in which a person or entity has a large set of relevant knowledge which "stands-under" some concept, action, situation, event, etc, which knowledge adequately explains the function of the concept or the dynamics of the action or event, and allows for effective actions to be taken in relation to the concept. For instance, to 'understand' exponents, it's useful to know that exponents are just multiplication, and that multiplication is just addition, and that addition is just counting.

=The Brain= The brain is the principle organ of the Central Nervous System. Its functioning allows for sensing and interacting with the environment, & gives rise to the human mind. On average it is about 1 1/3 quarts in size, & weighs about 3 pounds. Its outer surface is heavily convoluted with looping ridges & valleys, called gyri & sulci. It is composed of neurons and glia helper cells, with some hollow spaces (ventricles) filled with cerebrospinal fluid, as well as blood vessels, with 3 layers of protective covering (meninges) over its surface. Different portions of the brain have either a greyish or a white color, with grey matter being comprised of closely packed neural cell bodies, very many dendrites and short axons, whereas white matter is comprised of longer myelinated axons. The surface of the brain, comprised of grey matter, is not smoothly round like a balloon, but is instead heavily convoluted by furrows into valleys & gyrating ridges all over its surface, which increases the total surface area, and thus the amount of grey matter. The largest division separates the left & right hemispheres, joined from within by the corpus calosum, with each hemispheres surface being covered with gyri & smaller sulci over both the outermost & medial surfaces. This surface, to a depth of only about 1/10 of an inch, is the cerebral cortex, where surprisingly all of the higher functions of the brain occur. There are also groupings of masses of grey matter within white matter tracts, called nuclei.

Elemental Constituents
The elemental constituents of the brain are neurons and glia. The brain also has meninges (the outer coverings of the brain), vasculature (blood vessels), and ventricles (spaces containing cerebrospinal fluid).

Neurons
Neurons are excitable cells found in the central nervous system (brain & spine), the peripheral nervous system (sensation & muscle control), and the enteric nervous system (digestion). Neurons can receive, process, & transmit signals, and a neuron is excitable in that it can 'fire' an action potential when sufficiently stimulated. Neurons make synapses (electro-chemical connections) with one another to provide pathways for the movement of signals between them, and some glia assist in speeding up the movement of signals along longer tracts & nerves.

structure of a neuron
A neuron is comprised of inputs (dendrites), a cell body (Soma), and an output (axon). On the soma, connecting it to the axon, is the axon hillock, & there may also be dendritic spines on the dendrites.

neural signals
Neurons receive, process, and output signals.

movement of neural signals
There are 5 ways neural signals move:
 * 1) chemical synapses (between neurons via neurotransmitters)
 * 2) electrical synapses (between neurons at gap junctions)
 * 3) electrotonic conduction (along dendrites and soma)
 * 4) action potential (along an un-myelinated axon)
 * 5) saltatory conduction (along a myelinated axon)

Neural Signal Movemement
Signals related to sensation, muscle control, and cognition are processed by neurons. Neurons are excitable cells found in the central nervous system, the peripheral nervous system , and the enteric nervous system. A neuron is comprised of inputs (dendrites), a cell body (Soma), and an output (axon). Neurons connect to other neurons and muscle cells at synapses, and some may have inputs at sensory receptors. There may also be dendritic spines on dendrites for receiving signals, and signals, as action potentials, start at the beginning of an axon, the axon hillock. The movement of a signal through a neuron involves being received, processed with regard to other similar signals, and output to either other neurons, muscles, or glands at synapses.

Reception of a Signal at a Synapse
Signals are presented to a neuron at a synapse as chemicals called neurotransmitters, which bind to sites on receptors embedded in the membrane of a neuron.

Neurons receive, process, and output signals.

(a cell which can 'fire' an action potential when sufficiently stimulated) (brain & spine) (sensation & muscle control) (digestion)

Meninges
The meninges are the 3 outer coverings of the brain and the spinal cord. The 3 are the dura mater, the arachnoid mater, and the pia mater.

Dura Mater
The dura is the outermost covering of the brain. It is somewhat thick (how thick?), opaque, grey, flexible, and resistant to tearing, like a bathing cap.

Arachnoid Mater
The arachnoid is the second-most meninges, milky-white, and is thinner than the dura and translucent, somewhat like a 2 or 3 times the thickness of thin plastic wrap. There are a series of string-like structures called trabeculae connecting it to the next innermost layer, the pia, and cerebral-spinal fluid circulates within the sub-arachnoid space.

Pia Mater
The pia is the most innermost layer of meninges, and is transparent and maybe half the thickness of thin plastic wrap. It adheres closely & strongly to the surface of the brain, and follows all gyri and sulci, unlike the other two meninges, which bridge over the sulci, although they do both dive down into the inter-cerebral fissure, as the falx cerebri.

Peduncles
Cerebellar peduncles connect the cerebellum to the brain stem. There are six cerebellar peduncles in total, three on each side:


 * Superior cerebellar peduncle is a paired structure of white matter that connects the cerebellum to the midbrain, comprised mostly of efferent (motor) fibers.
 * Middle cerebellar peduncles connect the cerebellum to the pons and are composed entirely of centripetal (afferent, sensory) fibers.
 * Inferior cerebellar peduncle is a thick rope-like strand that occupies the upper part of the posterior district of the medulla oblongata, comprised of mostly afferent (sensory) fibers.

Brainstem
The brainstem is lowest part of the brain, as an upward continuation of the spinal cord, which connects the spinal cord to the cerebrum, and inter-connects the cerebellum with the cerebrum and spinal cord(?). It's comprised of ascending (afferent) and descending (efferent) tracts of white matter (myelinated neuronal axons), surrounding various masses of grey matter (nuclei), and is covered on the outside, as is the rest of the brain and the spinal cord, with 3 layers of protective tissue called the meninges (dura mater, arachnoid mater, pia mater), and Cerebrospinal fluid is found between the dura mater and arachnoid layers of tissue.

The brainstem is composed of the medulla oblongata, the pons, and the midbrain.

Nuclei
(Describe nuclei in general)

Basal Ganglia
Caudate Nucleus Putamen Globus Pallidus (maybe not part, but Claustrum outside, & inside insula)

Tractology (connections)
Tracts are sets of axons connecting different parts of the brain. Association Tracts connect gyri in the same hemisphere Commissural Tracts connect the two hemispheres Projection Tracts connect higher & lower parts of the brain, and to & from the spinal cord.

Ontogeny
The development of the human brain from fertilized egg. A link to an article titled: "The basics of mammalian brain development": https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989000/ (which might suggest how choroid plexus gets pia into it.)

Other Things of Interest

 * how axon terminals link to capillaries in neurohypophysis
 * Pituicytes
 * reference for above https://jeb.biologists.org/content/jexbio/139/1/67.full.pdf
 * new research? https://www.frontiersin.org/articles/10.3389/fendo.2017.00275/full
 * picture from above https://www.frontiersin.org/files/Articles/294946/fendo-08-00275-HTML/image_m/fendo-08-00275-g011.jpg