1. Levels:

In the dimension model it's assumed that each step in a fundamental chain can develop to secondary whole dimension chains and so on, thus to "level chains".

Levels in accordance with a dimensional chain - a "level chain":

Fig L-1-29-1

In physical and geometrical quantities:
   

Fig L-2-29-2

Steps in a dimension chain in direction outwards as progressive design and differentiation, could be written: 4 = 3 + 1, 3 = 2 + 1, 2 = 1 + 1…
Applied to the organism:
4. Systems →> organs + "infrastructure": canals, streams, communication
3: Organs/cavities →> tissues layers + channels, transport routes
2: Tissues →> cells + cell projections and produced extracellular fibers.
1: Cell level with cell projections as structures or translated into motions in dimension degree (d-degree) step 1-0/00, designed in many ways at different levels.
  The development takes the opposite way.

Links between steps according to the loop model:

      Fig L-3
    Fig L-4-29-3

2. Systems:

Nutrition and a sensory/motor system as mutually opposed vector fields from V- and A-poles (see Embryology) are both bi-directional in themselves, illustrated here as superimposed:

Inward/outward directions of vector fields (d-degree 4):
a) Nervous system: sensory nerves inwards, motor nerves outwards.
      (From ectoderm.)
b) Nutrition system: digestive organs inwards; blood system for distribution outwards.
      (From mostly endoderm.)
      Fig L-5-30-1

Real neurons are found first in Diploblastica, multicellular organisms with sooner 2.5 layers (see Evolution) but even unicellular organisms have sensitivity for light and excitation.

Nutrition system and nervous system are interwoven in such a fact that the same peptides can be both digestive enzymes and neurotransmitters in the nervous system.
   However, the two systems operate mainly with chemical versus the electrical one. In the dimension chain of physical quantities mass and charge has been interpreted as a relation d-degree 3 to d-degree 2. The neural system operates primarily with charge over the surface of the cell membrane (d-degree 2), the nutrition system with molecules representing what can be regarded as mass in this context, in the interior of the cell (d-degree 3).
   Hence, we can see the two systems meeting from opposite poles in d-degree step 3 - 2
       

Fig L-6-30-3

Systems —> Organs:
Regarded as vector fields of d-degree 4 in our model, both primary systems develop a growing complexity of double-directed infrastructures (of d-degree 1 on a macro-scale). The vector fields get expressed in d-degree steps ... ← 2←1←0/00. Cf. 0 and 00 are "outer poles" or partial structures of d-degree 4. Constructions get stepwise substantiated as from field lines, from motional pathways to linear strings and canals etceteras...
   (From steps 5 → 4 → 3 the steps 2 ← 1 ← 0/00 may be said to follow as debranched d-degrees meeting in opposite direction according to the loop version of the model, see figure L-3 above.)

Polarization of directions within the two systems:

Fig L-7

- An essential part of body mass (d-degree 3) is made up of muscles and supporting tissues as skeleton and so in, mostly from mesoderm, the 3rd , middle tissue layer.
   It could be mentioned here too that muscles need innervation to develop.
   

3. Organs individualized:

Individual organs in relation to the "vector systems" could be compared with word classes in relation to syntax in languages.
   The stepwise synthesis from lower d-degrees 3← 2← 1← 0/00 can be referred to the integrating force from 0-pole (cf. Exogastrulation), while the individualization of centralized organs from the field level can be suspected as an effect of the polarizing force of anticenter, the 00-pole.

Organs, from the main "vector systems":
(The border between main "systems", "organs" and "tissues" can be discussed.)
   

Fig L-8

Origin of the systems, approximate positions in blastula stage of an embryo:

Fig L-9-31-3

With the assumed secondary developments of dimension chains within each step of a basic chain, the individual organs as more or less "tied off" and centered units (like organelles in single cells) could perhaps be imagined as expressions for such secondary evolutions designed in zstep d-degree 3 to 2. The principle illustrated with the unpaired organs from the nutrition system:

Fig L-10-33-3

(Tonsils, thyroid and parathyroid glands and others in the gullet wall not included.)

The animal pole and nervous system doesn't show a similar row of secondary individualized units apart from the spinal cord and brain. Cf. again Exogastrulation in file Embryology,

Nutrition →> Blood system:
The nutrition system develops a primarily "radial" distribution system outwards, the blood system. A branched forefront of the intestine can replace a blood circulation in primitive species.
   In the embryo of less primitive species the blood channels develop from archenteron as a dorsal and a ventral aorta, along the F-B-axis. Blood is also in lower chordates produced by the spleen, which in turn is derived from the intestine. And lungs in the blood system develop from the gut.
   One example of the loop version of the model (see figure 3 above) with debranched degrees from higher d-degrees meeting 'the other way around' could be how blood later gets produced in skeleton bones; skeleton as supportive tissue interpreted as of lower d-degrees, see below about tissue levels.

Fig L-11-33-2

Nervous system →> Muscles:
Development of muscles requires the nervous system (at least striated muscles of vertebrates). Muscles atrophy if they are not innervated. (The nervous system from the 00-pole in our application of the dimension model, should as a first polarizing force appropriately act as a differentiating factor.)
   In the skin bag of "2.5"-layer species (Diploblastica) sensory nerve cells and muscle cells are differentiated adjacent to each other with parallelly running threads in a layer of the skin bag, muscle filaments inside nerve fibers (figure Ez p. 62).
   It's perhaps noteworthy that these primary muscles act circularly contracting and that the active force of muscles is convergent, geometrical features derived from anticenter, the 00-pole in our model.

4. The organism as such and principle of individualization:

The demarcation of the multicellular organism by the skin, the outer ectoderm, and its reproduction capacity through stored genetic information in sex cells could be regarded as primary in relation to development of the vector fields, as 00- and 0-poles respectively in our model. They derive from opposite poles of the first embryo and could perhaps be called the "individualization" system.
   The immune system with thymus, spleen and lymph system is linked with the blood system and implies breaking-down processes as phagocytosis in similarity with the inward directed, digestive phase of the nutrition system.
   Immune system could be seen as an expression of the individualization principle on the deep, underlying level, as a biological defense from inside the genetic heritage, developed through the nutrition system. The skin is an equally essential counterpart of an individual existence, an own(-ed) anticenter and a more mechanical defense.

Fig L-12-31-2

5. Tissue level, 4-5 types:

Biologists talk about 4-5 tissue types, where the liquid one is regarded as the 5th "tissue" (Mf, Kz).

Order of tissues according to their origin during embryo evolution:
   Epithelium: appearing in ecto-, endo-, mesoderm
   Nerve tissue:- from ectoderm
   Muscle tissue: - from mesoderm
   Supporting tissues: connective tissue, cartilage, bone: - from mesoderm
   Body fluids like blood, the 5th "tissue".

The tissue types can be described and ordered after degree of cell contacts and of extracellular substance produced, i.e. different degrees of internal versus external fiber production. It implies a chain of decreasing "density" (in a general sense), in this respect resembling the stepwise transitions in a dimension chain from higher degree of internal structure to more externalized relations and 1-dimensional forms as debranched d-degrees. (Cf. density, according to previous definitions of physical quantities the first "quantity".)

• Epithelium: Dense cell contact. Epithelium dresses all outer and inner surfaces. It represents obviously the fundamental form of 2-dimensional tissue surfaces.
• Nerve tissue: Contacts between cells through their projections via synapses.
  Single tubules of protein fibers within axons and dendrites.
• Muscle tissue: The cells separated by connective tissue, cells = "muscles" almost completely filled with protein fibers.
• Supporting tissues, reticular type: Cells more or less scattered in the extracellular substance. When cell contacts, these are just point-formed contacts between long cell projections. External production of protein fibers as elastin and collagen.
     With such fibers as 1-dimensional threads external 2-dimensional layers are built and 3-dimensional networks of external relations.
• Liquids: No cell contacts. (Blood cells lose also their nuclei.)

Both liquids and external fibers can be classified as secretion products, analogous to "branched off" lower dimensional degrees from higher dimensional steps in the dimension chain.
      Fig L-13

The loop version can illustrate a connection between first tissue type and the last one: epithelium forming glands with liquid secretion.

Fig 14-35-1

It's more doubtful if a similar relation may be found between nervous and connective tissue in next step. However, we have osteoblasts deriving from the area around the neural plate of blastula, among other cells becoming e.g. glial cells. Osteoblasts form connective tissue in bones, often in concentric circles around blood vessels.
   (Perhaps also glial cells as astrocytes in the brain can be regarded as "connective tissue", although not described as such? )

6. Cell contacts:

Cell contacts are classified as follows (Kz) and show up to be clearly 3- to 2- to 1-dimensional (possible to complete with a 0-dimensional one in reticular tissue.):
      Fig L-15-36-1

3-dimensional: Symplasma: nuclei of cells share plasma within the same cell. There are two complementary types representing opposite directions.
a) Plasmodium: Fission: a nucleus is divided into several within a shared cell membrane; example (some?) liver cells. Note outward direction: liver part of the blood system, subsystem to the nutrition system.
b) Syncytium: Fusion of several cells to one within a common membrane; example striated muscle cells. Note inward direction, muscles as subsystem to the Nervous system.

2-dimensional: Wall-to-wall contacts, typical for epithelium.

1-dimensional: Desmosomal junctions: long projections of cells in wall-separated point contact; example reticular tissue.

Hence, contacts as common room, common wall, common creation of "lines" through extensions but only a common "point".
   We may note that in embryo development the first divisions occur within the cell as mentioned in that file, which corresponds to 3a here, plasmodium. Then, in the blastula, we get the wall to wall-contacts. First during later gastrulation and from mesoderm the 3b) type, syncytium appears. It seems to agree with outward and inward (polarizing - synthesizing) directions in our dimension model.

7. Fibers - levels of storage:

It is noteworthy that number of storing levels of extracellular fibers at the final stages in the chain of tissue types are 5 - 4, from the individual molecules to the fiber - as if they corresponded to steps in a chain (Kz p.154, 139, Fb p. 29):
- Collagen: 5 levels: collagen molecule - protofibril - collagen fibril - bundle of collagen fibrils - collagen thread.
- Hair: 5 levels: keratin molecule - protofibril - tonofibril - bark cells - hair.
- Cellulose fiber: 4 levels.
(Cf. chromosomes: 5 storage levels of the double helix of DNA.)

Fig L-16

To 04. Glands