The term Embryology, in its widest sense, is applied to the various changes which take place during the growth of an animal from the egg to the adult condition: it is, however, usually restricted to the phenomena which occur before birth. Embryology may be studied from two aspects: that of ontogeny, which deals only with the development of the individual; and that of phylogeny, which concerns itself with the evolutionary history of the animal kingdom.

In vertebrate animals the development of a new being can only take place when a female germ cell or ovum has been fertilized by a male germ cell or spermatozoön. The ovum is a nucleated cell, and all the complicated changes by which the various tissues and organs of the body are formed from it, after it has been fertilized, are the result of two general processes, viz., segmentation and differentiation of cells. Thus, the fertilized ovum undergoes repeated segmentation into a number of cells which at first closely resemble one another, but are, sooner or later, differentiated into two groups:

(1) somatic cells, the function of which is to build up the various tissues of the body;
(2) germinal cells, which become imbedded in the sexual glands—the ovaries in the female and the testes in the male—and are destined for the perpetuation of the species.
   
Having regard to the main purpose of this work, it is impossible, in the space available in this section, to describe fully, or illustrate adequately, all the phenomena which occur in the different stages of the development of the human body. Only the principal facts are given, and the student is referred for further details to one or other of the text-books 1 on human embryology.

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Depending on the cell that is, cytoplasm bears different names, thus:
- liquid phase of cytoplasm is called citosol
- located in the cytoplasm membrane or cortex called ectoplasma
- cytoplasm situated between the cortex and nuclear membrane called endoplasm

In the cytoplasm we find:

- nucleus (the largest organ common to all cells)
- common organic of all cells
- cell-specific organic
- fat cells, glycogen granules, O2, CO2, catabolic, etc..

The cell is morphologic and functional unit of the human body.

The cell is composed from: Membrane, Cytoplasm, Core, Cell Organic (common, specific).

Membrane cell: – Lipo-protein double layer : hydrophilic pole outward, inward hydrophobic pole
- contains protein molecules
- covered glicocalix
- Thickness of 7.5 to 10 nm
- Composition: 55% protein, 25% phospholipids, 13% cholesterol, other lipids and 4% 3% carbohydrate
- Double-layer lipid membrane is fluid
- Proteins and other substances dissolved or floating in the cell membrane thickness, tend to run on every surface / thickness they
- Integral proteins serve as transporters or channels made transmembrane
- Peripheral proteins are attached to proteins and their role full enzyme
- Glicocalixis consists of carbohydrates attached to proteins or molecules (glycoproteins) or membrane lipids (glicolipide)
- May proteoglicanics find related lax the outside cell
- Glicocalixis – give the electro-negative exterior load cell
- Tie cells between them
- Some carbohydrates serve receiver (eg insulin)

Anatomy and Phisology of kidney device

Urogenital device – it is formed from urinary and genital systems. The most part of excretion products are eliminated through an organs system called excretory system

Urinary tract – has 2 kidneys and exit ways of urin: potassium, basins, ureters, bladder and urethra.

Kidneys – secretory organs of urine, have grains and beans are located on both sides of the lumbar spine. Each kidney is surrounded by Celulose-fat layer and coated by a inextensible fibrous capsule located in the renal lodge.

Nefron – kidney anatomical and physiological unit, consisting of glomerule [vascular pole] and urinifer tube [urinary pole]. Nephron number in the two kidneys is valued at 2 million.

Glomeruli – the first element of nephron – consists of a bundle of capillaries resulting from an arterial branches involved, arising from renal artery. Capillaries then unite to form a eferent arteriola which capillarise again around the first portion of the tube urinifer.

Urinifer tube – the second part of the nephron – is presented as a channel of 50 mm long, consisting of the following segments Bowman capsule, proximal tube contorta, Ansa Henle, distal and Tubes contorta tube collectors. Bowman capsule – the form of a cup that surround the glomeruli and is composed of two lamina.

Bowman capsule with glomeruli it contains, is called the particle Malpighi. From Tubes contorta remotely through collector channels and common channels that open in the renal papillae, formed passes urine potassium and hence the basin.

Urinary bladder – Urethra-channel – is a trajectory very short woman, unlike man, that path is long and crosses the prostate, where the possibility of a urethral compresiunii adenoma, prostate, to echo the entire urinary tree.