Anatomy | Human anatomy | Organs | What constitutes the human body

Anatomy as a science



Name of Science "anatomy" (humans, animals, plants) is derived from the Greek word "anatemno" - cut, dismember, dissect, and its essence is to study the structure organisms and organisms organs by method autopsy of tissues. This science refers to the biological sciences, united under the term "morphology" (from the Greek. Tohriho - form, logos - teaching).

Morphology (a term coined German poet and scientist Goethe in 1817) is not limited to stating the information on the form and structure of the various parts of the body (normal, abnormal, ugly, etc.) obtained at different teaching levels (macroscopic, microscopic, cellular, molecular etc.). It also clarifies the organs evolution and the whole organism under the influence of various factors (functional, climatic -heohrafichnyh etc.). It must be admitted that the priority of anatomy was very large in the historical birth of many morphological sciences. In the late XIX - early XX centuries the morphology developed its section - evolutionary morphology which aims to study organisms and some organs in ontogeny and phylogeny.

Human anatomy as an independent science for a long time (until the XIX century) remained as descriptive in most cases (arose as descriptive anatomy), that it was limited to only describing, naming and classification of organs and systems. In the Renaissance, and all subsequent days up to now world science was enriched by discoveries that explain not only certain phenomena but also reasons of their occurrence and development. In search of truth, scientists were increasingly go beyond the individual sciences. In other words, there was a process of intensive interpenetration of different disciplines.

Splanchnology (SPLANCHNOLOGIA) - the science of internals



The internals - the internal organs that lie in body cavities (mouth, cavity of neck, chest, abdominal, pelvic) and provide the metabolic processes in the organism with the external environment. The internals are combined into organs systems (digestive, respiratory, urogenital).

Development of internals

After 3th week of fetal development, as a result of end of gastrulation are formed three germ layers (ectoderm, mesoderm, endoderm) and axial complex of germs. Mesoderm is divided into:
- dorsal
- intermediate
- ventral.

Development of the human organism



Development of the human organism - ontogenesis - is divided into two periods: prenatal (intrauterine) and postnatal (extrauterine). Utero period lasts from the moment of fertilization and to the birth of a child and also consists of two phases: embryonic (first 2 months) and fetal (3 to 9 months). At the moment of fertilization male germ cell - spermatozoon (sperm) - penetrates into the female sex cell - ovule (oocyte), causing appears a zygote. Fertilization usually occurs in the fallopian tube. Zygote (single-celled embryo) has all the properties of both gametes.

1st week of embryonic development - is crushing, in which one of the cells formed many cells - blastomeres that form multicellular blastula. Crushing lasts 3-4 days in the fallopian tube, and then continues in the uterus. By the end of the 1st week formed a bubble - blastocyst, which consists of internal group of cells - Embryoblast and peripheral group of cells - the trophoblast (lines the surface of Embryoblast). Between embryoblast trophoblast and a cavity filled with mesenchyme. The embryo begins to take root in the mucous membrane of the uterus (implantation). Trophoblast cells secrete the enzyme, loosening the surface layer of the endometrium and give outgrowths - villi and turn into villous membrane - chorion. From the chorion and endometrium neighboring to it developing placenta. From embryoblast formes the embryo.

Cells, tissues, organs, organs systems and organs apparatus

Cells, tissues, organs, organs systems and organs apparatus


Cell (cellula) is a microscopic formation, elementary particle of a living organism, but is a complex system that contains the nucleus and cytoplasm. The sizes of the cells are from a few micrometers to 200 micrometers. Cell shape is different (spherical, spindle-shaped, flat, cubic, prismatic, cylindrical, star-shaped, with spikes). Cell structure is difficult. Externally, every cell has a membrane - cytolemma (plasmolema). Cytolemma - is a semi-permeable membrane through which performes the transport of substances and the interaction of cells with neighboring cells and intercellular substance. In the cell is contained nucleus, which is involved in protein synthesis and keeps genetic information. The core is covered with shell - cariolema. The core filled nucleoplasm (carioplasma), which have 1-2 nucleolus and chromatin. Around the core is placed cytoplasm. The composition of the cytoplasm included cytosol, organelles and cytoplasmic inclusions. Cytosol - is free of organelles substance of cytoplasm semi-liquid, semi-transparent, is involved in the metabolism. Organelles - constant part of cells that perform specific functions.

Organelles include:
- Mitochondria - the energy cell organelles are involved in the processes of oxidation, phosphorylation;
- Internal mesh apparatus (lamellar complex or Golgi apparatus), which consists of vesicles, plates, tubes, synthesize polysaccharides is involved in removing of products of its life to outside of the cell;
- Cytoplasmic (endoplasmic) grid - formed by tubes and plates. Non-granular cytoplasmic grid involved in the metabolism of lipids and polysaccharides. Granular cytoplasmic grid contains spherical granules - ribosomes and their clusters - polysomes (polyribosomes). Granular cytoplasmic grid is involved in protein synthesis. Cytoplasmic inclusion - is the accumulation of various substances (protein, fat, pigment and others creations).

The organism and its integrity



Organism (from the Greek. Organon - organ) is defined as any whole alive plant or animal, including the man. The main properties of the organism are: constant exchange of substances and energy (internal and with the environment), self-renewal, movement, reactivity, self-development and growth , heredity and variability, adaptability to conditions of existence. The more complex the structure of the body, the better it retains constant internal environment (homeostasis (body temperature, blood biochemical composition, etc)) regardless of environmental conditions. For human, unlike animals, external factors of the leading importance attaches to socio-economic conditions.

The evolution of the animals occurred by increase in the level of life organization: molecular, cytoplasmic (unicellular protozoa), cell (sponge), tissue organisms (coelenterates), higher animals (with complex of organs). Evolution included two opposite processes: differentiation or division of the body for tissues, organs, systems of organs(with appropriate and the simultaneous distribution and specialization of functions) and integration, or combining of pieces into an integral organism, sealed humoral and neural connections. The highest organisms, including man, preferably is inherent a system level of performance. The presence other levels of functioning is not disputed but they have a subordinate character.

Man in Nature



Modern man in the classification system of animal organisms belongs to the type of chordates (Chordata), a subtype of vertebrates (Vertebrata), the class of mammals (Mammalia), a number of primates (Primates), friendly of people (Hominidae), kind of man (Homo), species Homo sapiens (Homo sapiens). The human body keeps a general structure, inherent in all vertebrates: bilateral symmetry, the prevalence of paired organs, the presence of the axial skeleton, saving some (relic) signs of segments (metamerism), better detected in primitive form. These and many other features (reduced state of smell saved some rudiments of caudal vertebrae, the presence of the rudiments of the third eyelid, etc.) testify to ways the evolution past zoological ancestors.

The main morphological features of the human body compared to other primates body include: functional forelimbs (in human upper limb - arm), high growth and differentiation of the mantle (cortex) of the brain, a significant weakening of the jaw apparatus, equal number of teeth, lack of overall hair , upright posture, prolonged childhood and so on. Modern man owns expressive language, interconnected with abstract thinking (development of the second signal system). However, the main distinguishing feature between man and animal is that people - a social being, the main condition and formation of life is socially useful labor, is closely associated with the emergence of society.