Machina Biology
Despite how extremely advanced the sciences at play in a Machina's body are, they do not possess many separate organ systems. In basic terms, a Machina's body consists of her Core in the center of her chest to provide power from matter reactions, her brain and her horns for thinking and networking, her various power conduits such as her spine, her breasts to create M2 Nanomachines, and her sex organs. These are the universal systems found in all Machina; both anatomically simple yet so scientifically advanced it is almost fantastical.
Machinium
Whilst humans are based on carbon and other elements, Machina are made of Machinium. Machinium is a group of ultra-dense polymer superalloys which vary in their chemical compositions. The reason for this variation is because Machinium always has M2 Nanomachines embedded in it which alter the chemical composition of a given amount of Machinium in order to adapt to new needs, particularly stresses. As an example, if a Machina is hit with a heat-based weapon, the M2 Nanomachines in her body will learn as they repair her, and alter her casing's chemical composition to become more heat-resistant. Embedded M2 Nanomachines also carry out repairs and growth, so Machinium appears to be a living metal and is often referred to as 'biometal'.
A Machina's body is almost entirely comprised of Machinium. A Machina's face and other soft parts of her 'skin' casing are a softer form of Machinium that feels like plush rubber, yet hardens in response to impacts. Elsewhere on the Machina's body there may be semi-hard armour that is again a variant of Machinium which can flex somewhat but has a higher ability to harden in response to impacts. Actual armour plate is Machinium too, much more capable of withstanding damage yet its ability to feel things is much more dull than elsewhere. Internally, a Machina's bones are made of hardened Machinium, while her soft tissues and cell-structures are made of softer Machinium. This means a Machina's body is extremely dense and possesses a very large mass for their size, which is handled by the Anti-Inertia Systems outlined below.
In order for Machinium to adapt to new stresses, grow, and heal, it must be supplied by a circulation system. Blood flows through all M2-Based Life-Forms for this reason. The blood is comprised of a fluid medium, raw materials, and free M2 Nanomachines. The circulating M2 Nanomachines supply power from their bodies to the embedded M2 Nanomachines, as well as carrying materials with them to where they are needed. Without power supply to the embedded M2 Nanomachines, Machinium will break down over time, becoming inert liquid metal alloy and deactivated M2 Nanomachines. For this reason, a sample of a Machina must be studied quickly before it begins disintegrating into simple monomers.
Core
In place of the heart and lungs of a human is a Machina's Core. The Core is the organ system responsible for supplying the Machina's body with useful materials and power. Anything the Machina eats, drinks, or breathes in travels to the first part of the Core; the Matter-Shredder, located at the top-center of her chest cavity. M2 Nanomachines and Machinium are immediately filtered out and enter the Machina's bloodstream. Next, matter is separated first into separate molecules, then into atoms if necessary. Useful molecules and atoms are again diverted into the bloodstream. Anything not deemed useful at the end of this process enters the twin Mass-Reactors, located where the lungs would be. There, matter is converted almost 1:1 into energy to power the Machina's body. Leftover subatomic particles are taken to smaller organs attached to the Mass-Reactors where they can be fused together to make atoms and molecules the Machina needs but cannot find elsewhere. Due to the extremely complex mathematics involved in these reactions, a Larva is needed for the Core to operate at full output. This Core Larva monitors all the Core's processes and performs the unfathomable calculations necessary to maintain the reactions in the Core.
In the lower-center of the Core is the center of the Machina's circulatory system. The organs there pump the Machina's blood around her body and monitor the raw materials in the blood to ensure supply from the Core is sufficient. Incoming blood goes through the pumps, collects power and materials from the Core, then travels around the body before returning. Notably, the circulation systems do not feature a heartbeat. As the pump organs develop around the human heart, the heart will stop beating, which can be significant moment in a Machina's early development.
Power Systems
The energy produced by the Machina's Core is supplied to all her cells by her power circuitry. These begin as large conduits exiting the Core area, such as the Machina's spine or the various pipes that are somewhat embedded into her body's exterior, before branching off and becoming progressively smaller, similar to blood vessels. The circuitry of a Machina supplies constant power to all her cells and tissues, and is complimented by the ability of the M2 Nanomachines in her blood, who are able to supply bursts of power to areas where it is needed. These power circuits usually run alongside the paths of blood vessels, and similarly they almost always have nerve circuits running alongside them.
Anti-Inertia System
A Machina is extremely dense, due to being made of Machinium. A Category 3 Machina standing the usual height of 200 cm and with average Equipment will have a mass of approximately 15 metric tonnes, yet she will only have a weight of 150 kg. This is because of the Anti-Inertia Systems that all Machina possess. A Machina's spine transmits massive amounts of power along its length. It has been adapted to create a field with some of this power that reduces the inertia of the Machina and cause her to weigh approximately 100x less than her mass. This way, the Machina is neither crushed under her own weight nor does she casually crush her environment with her basic movements. As the field is tied to the power being transmitted along the length of her spine, these systems cannot be deactivated by the Machina even if she wanted to.
Brain
Yes
Horns
Yes
Breasts
Yes
Sex Organs
Yes
Fluids
Yes
Equipment
Yes
Thrones
Yes
Interactions with Larvae
Yes
Machina Mortality
Yes