Human Body

The refers to the physical body that makes up a human being and the general structure shared between them.
Given its role in magic and esper abilities, as well as various fields of science and technology, the human body, its mechanisms and its components have numerous connections to various subjects on both the Magic Side and the Science Side.
==Principles==
Due to the mechanisms which magic and esper abilities generally operate under, with elements of both tied to the connection between the microcosm and the macrocosm, the human body and mind plays a key role in the supernatural powers and phenomena brought about by them, with one's inner world being used to influence the outside world. For magic, methods of changing the flow of life force within one's body (such as altered breathing) are used to refine the magical power that fuels many spells. For esper abilities, changes induced in the body and mind through various means are used to cultivate the Personal Reality needed for the ability and the two also affect the output. For both forms of supernatural power, the mind plays a key role in directing the phenomena they produce, along with the movements of the body, and both also affect the limits on the power that can be wielded or exerted.
===General===
File:Toaru Kagaku no Railgun T E22 12m 36s.png|Depiction of organs (heart, lungs, liver, stomach and intestines)
File:Toaru Kagaku no Accelerator E03 18m 07s.png|Residual thoughts manifested in the vague shape of a human brain.
File:Human body glimpses.jpg|Observational glimpses of the skeleton and muscles under the skin.
The basic anatomical shape of a human body consists of a central vertical torso, a head and neck on top, two arms connected either side of the upper torso and two legs connected either side of the lower torso. A bony skeleton acts as the base frame which supports the body, containing and surrounded by a variety of muscles, organs, blood vessels, nerves and more, with the skin forming the outermost layer.
Notable body parts include:
Name 	Type 	Location	Details
Brain 	Organ	Head 	A critical organ housed within the skull that acts as the center of the nervous system and controls most activities of the body, receiving and processing information received from sensory organs and sending instructions via neural signals to the rest of the body.
Heart 	Organ	Torso 	A critical muscular organ at the middle of the chest and the core of the circulatory system, which pumps blood through the body's blood vessels, carrying oxygen and nutrients to its intended destinations throughout the body, while carrying metabolic waste away to other locations for disposal.
Eyes 	Organ	Head 	A pair of optical organs that provide organisms with vision/sight. They collect light from the surrounding environment, regulate and focus it through an assembly of lenses to form an image, and convert that image into electrical signals which are then transmitted through neural pathways to the brain.
Lungs 	Organ	Torso 	A pair of organs located in the middle of the chest, above and one on each side of the heart, and the core of the respiratory system. Filling with and emptying of air with inhalation and exhalation, the lungs perform a gas exchange, extracting oxygen from the air and transferring it into the bloodstream while also releasing carbon dioxide from the bloodstream into the air. In addition to the breathing process, they also provide the airflow necessary for vocal sounds.
Stomach 	Organ	Torso 	A hollow organ in the digestive system, located in the upper left quadrant of the abdomen, where food is deposited after being swallowed, and where the gastic phase of digestion takes place, through chemical breakdown with aid from digestive enzymes and gastric acid secreted by the stomach.
Liver 	Organ	Torso 	An organ in the digestive system, located in the upper right quadrant of the abdomen, which performs important functions such as detoxification and the synthesis of proteins, bile and other biochemicals supporting digestion and growth. It has a partial degree of regenerative capacity.
Intestines	Organ	Torso 	A pair of organs in the digestive system and the gastrointestinal tract; the small intestine and the large intestine, the second roughly surrounding the vertical outline of the first, both located in the lower half of the abdomen. The small intestine is located after the stomach and is where most nutrients are absorbed from digested food. The large intestine is located after the small intestine, and is where water is absorbed, with waste products deposited at the end before removal via excretion.
Kidneys 	Organ	Torso 	A pair of bean-shaped organs of the urinary system, located in the bottom of the torso, either side of the bladder. They are involved in the control of the volume and concentrations of various body fluids and chemicals, the filtration of blood, and the removal of toxins, with filtrated urine being transferred to the bladder.
Bladder 	Organ	Torso 	A hollow organ of the urinary stem, located at the bottom of the torso, that stores urine from the kidneys prior to disposal via urination.
 	 	 	
===Magic===
The mechanisms of the human body plays a key role in the use of magic, as the basic method of casting most spells involves refining one's life force into magical power and this is often done by inducing a change in the body's operations, such as through altered breathing. Prologue Chapter 1 Part 8 The limitations of the human body also play a role, at all with restrictions and dangers from exceeding the body's limits accompanying certain types or levels of magic and related power.
File:Christian cross.png|The cross, a symbol that is associated with the human body
File:Blank Tree (Kircher).png|The Sephiroth, a symbol that is associated with the human body
There are a number of symbols which are used to represent the human body as a whole, including the cross and the Sephiroth. Chapter 2 Part 6 Chapter 4 Part 4 Chapter 4 Part 2 There are also numerous symbols corresponding to its individual components, some of which are connected to the symbols used to represent the whole, such as the spheres and channels that make up the Sephiroth. Chapter 3 Part 6
Due to correspondences drawn between specific body parts and certain symbols and stories, those body parts are utilized in certain forms of magic. For example, each of the fingers on one's hand is associated with one of the five elements and can be used to exploit the elemental symbolism. Chapter 4 Part 7 Other spells and stories involve the use of specific body parts as materials. In a number of cases, the microcosmic territory inside one's body can be used in a spell aimed at causing a macrocosmic effect in the outer world.Toaru Majutsu no Index SS: Agnese's Magic Side Work Experience Chapter 8 Part 1Toaru Majutsu no Index SS: Agnese's Magic Side Work Experience Chapter 8 Part 2Toaru Majutsu no Index SS: Agnese's Magic Side Work Experience Chapter 8 Part 3 While skilled practioners can perform powerful magic using just the body and its movements, a weakness of magic relying solely on it is that damage to the user's body will hamper its movements and restrict their ability to use the magic. Prologue
These effects and conditions can also be applied in reverse. Aside from spells that affect specific body parts based on stories used as their foundation, Chapter 1 Part 7 the magical correspondence tied to the human body and its components can be used to affect the insides of one's body, seen with Coronzon and Anna Sprengel using methods derived from the Sephiroth (with its spheres and the channels between them) to cause obstructions in the flow of power and unseen circulations inside a target's body upon physical contact (either striking a blow or being struck a blow). Chapter 1 Part 4 For example, when she affected Accelerator in this way, Coronzon mentioned how an arm is formed from Chesed and Gevurah, and how out of the five fingers controlling the elements, the middle finger controls fire, represented by the red associated with blood, which symbolizes the activity of the heart - in that case, when Accelerator accepted the rebounding force from his punch for measurements, the damage passed from his fist, up his arm to his heart, causing an invisible clog in his chest.
In other cases, magical symbols associated with the human body and its components can be utilized in magic to simulate or reproduce the body. Chapter 3 Part 3 Chapter 3 Part 3
===Science===
The study of the human body falls across several branches of science, including and .
====Espers====
The processes and development of the human body, as well as knowledge about how it works and how to manipulate it, plays a key role in the development of esper abilities, such as in the Power Curriculum Program, with hormones generated during puberty and adolescence considered critical to esper development,Toaru Kagaku no Railgun: PSP SS Part 4 Chapter 2 Part 4 along with the more malleable nature of the human body during its growth period.
The most prominent part of the human body involved with espers and their abilities is the brain, as mental faculties are crucial to the development and usage of their powers. It is critical in the cultivation and maintenance of an esper's Personal Reality, as well as the micro-scale observations that are necessary for an esper to cause macro-scale phenomena, based on . In order for an esper to use their ability, they have to mentally perform the calculations necessary for their ability to produce the desired effect, Chapter 7 Part 4 and mental concentration is needed for both calculation and usage. Chapter 7 Part 4 Between the Lines 1 Chapter 1 Part 1 Chapter 2 Part 21 Chapter 3 Part 7
Disrupting an esper's concentration (be it through pain, exhaustion, surprise, confusion or some other factor), preventing them from completing calculations and using their power, will result in their ability being disrupted, with the principle being utilized in AIM Jammers. Between the Lines 1 Chapter 1 Part 1 Chapter 2 Part 21 Chapter 3 Part 7 Outside of the typical changes in the brain brought about in the Power Curriculum Program, and the modification of thought patterns performed in certain experiments (such as the Dark May Project), direct physical modification of an esper's brain will have a noticeable impact on their ability. Damage to an esper's brain will negatively impact their capacity to use their ability on their own, prominently seen with Accelerator requiring his calculations to be performed externally through the Misaka Network after being shot in the head.
At least one project, the Exterior Project, involved growing a brain from a sample from an esper in order to utilize an ability - in the case of Exterior, a portion of Shokuhou Misaki's cerebral cortex was sampled, cultivated and enlarged with the goal of allowing others to utilize Mental Out.
While the brain is a key component of the system for esper powers, it is not the only bodily factor involved. Chapter 4 Part 2 Between the Lines 3Toaru Majutsu no Index: Shokuhou Misaki Figurine Part 3 The entire physical body is also part of this system and also linked to control of the esper power, Epilogue though the full and exact mechanisms are not well understood. In the experiment known as Produce, aimed at determining the exact location of an esper power within the body, aside from dissection, specific body parts (from limbs to organs to brain parts) were removed from living test subjects. The esper ability remained in the living test subjects despite the specific removals, although its output dropped as the body grew smaller. Researcher Hishigata Mikihiko would eventually conclude that an esper power could only reside in a body containing a soul, and would later apply the findings regarding the connection between body size and power output in reverse, with the idea of reinforcing and expanding the body to strengthen the power being used in the development of the Coffin.
Similarly, it has been shown that, as long as something is considered a part of an esper's body, the esper's ability can be used with it, regardless of where the part is natural or artificial, or whether it is properly attached or detached. Examples include Kuroyoru Umidori using Bomber Lance through her detached cyborg arms, which she considers parts of her body, Chapter 5 Part 1 Chapter 5 Part 11 Kakine Teitoku controlling his Dark Matter even if it was not directly touching his body by no longer distinguishing between his actual body and the parts fabricated from his power, Chapter 4 Part 13 Chapter 5 Part 13 and Rensa changing her internal structure to match that of other espers in order to create an output point and drawn upon their abilities. Chapter 3 Part 8 Coffins also operate on this principle, tricking the brains of dead espers, reanimated with artificial souls, into considering the bigger mechanical bodies their own, resulting in an increased power output.
====Technology====
There are various types of technology which are intended to either affect or replicate the components or functions of the human body in some way, and as such, involve a certain degree of knowledge on how the body functions.
A prominent example is the technology used with cyborgs, where part(s) of an individual's body are replaced with mechanical components (such as a prosthetic limb or artificial organs, sometimes even full-body mechanization),Souyaku Toaru Majutsu no Index SS for the purposes of performing the functions of damaged or lost body parts,Toaru Jihanki no Fanfare or for enhancing one's capabilities. Chapter 3 Part 3
A similar yet different case are androids, a type of humanoid machine built to closely match the shape of the human body. The exact degree may vary but being designed to closely match the shape and structure of a human body, Chapter 2 Part 7 Chapter 3 Part 6 Chapter 4 Part 10 the technology utilized in them may share some of its operational principles with that of an actual human body.
Related but earlier along the development line from cyborgs, are technologies used in life-support machinery that supplement or act as a substitute for the functions of the body and its components to keep a person alive.Souyaku Toaru Majutsu no Index SS There are also the technologies involved in the cloning or cultivation of genetical material, to grow body parts (for purposes such as ), or even whole human bodies, clone or otherwise.
There are certain forms of technology which are meant to interact or interface with the brain and neural system, Chapter 4 Part 15 be it to interfere with or manipulate it (such as with the Testament), or for the brain to communicate with or through, Between the Lines 1 or for the brain to control the technology. Prologue Sub.16 Some of these fall under the category of .
===Other===
Imagine Breaker, in both its current and previous form, has manifested within an individual's right hand, presently that of Kamijou Touma. Chapter 3 Part 13 The similar power World Rejecter manifested within Kamisato Kakeru's right hand in a similar manner. Epilogue Chapter 1 Part 1 Between the Lines 3
During the events surrounding the Ichihanaransai, Fräulein Kreutune developed and was subject to the compulsion of a bodily function meant to acquire information through consuming a human brain (aimed specifically at Last Order in order to acquire the Misaka Network). Epilogue
==External Links==
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==References==
Category:Terminology