PROCESS OF THE MAXILLA

The maxillary body emerge four major processes; the palatine process, zygomatic and alveolar we have already described and frontal process (ascending process). The frontal process is a bony plate, with two faces, lateral and medial, which continues superiorly to the edge maxillary anterior up to the frontal bone. The side face is covered by a vertical ridge, anterior lacrimal crest, which extends up the ridge orbital. The ridge divides this face on a part above, arranged under the skin, and a rear portion, orbital. In the latter is a groove which is continuous below the nasolacrimal duct. The medial part of the outer wall nostrils and presents a small transverse ridge where the front end of the articulated means turbinate ethmoid (ethmoid crest) and lower other similar (crest conchal) for the inferior turbinate. Bordes. By its forward edge the frontal process articulates with the nasal bone. The trailing edge (edge ​​tear) It articulates with the lacrimal bone. The upper edge is articulated the nasal edge of the front.

MUSCLE CONTRACTION

The concept of shrinkage is different considering the isolated muscle fiber or the whole muscle belly. In the case of muscle fiber contraction is It is shortening its active and depends on the stimulation of the contractile machinery of the muscle fiber by the action the nerve stimulation. However, the contraction of a muscle belly in full does not necessarily mean that is shortened, and even if it is subjected to resistance forces, the muscle belly can be extended. This is because the muscles are divided into functional units, called motor units, which they are formed by all muscle fibers which they are innervated by the same motor neuron. Importantly, the distribution of fibers motor unit does not match the set fascicles by intramuscular connective tissue. When a motor neuron fires all fibers contract innervated by its axon, but not others. Thus, in the muscles contract synchronously different units motor, that is, that, at a given moment, in a muscle there is a variable number of motor units in contraction and relaxation other. The amount of contraction of a muscle it depends on the number of units motor are activated and frequency of stimuli motor neuron emitting fibers. The action of Muscle considered as a whole (shortened, lengthened or maintain their size) will depend on the number of units motor which are contracting at all times, regarding the resistance to which is subjected the whole muscle belly.

VASCULARIZATION OF MUSCLES

Each muscle belly receives one or more own arteries accompanying veins, lymphatics and nerves. Typically, an artery is larger caliber and called the main artery. Point vessel access is usually the central or belly ends, and usually by the deep surface of the muscle. Knowledge of the pattern of vascular pedicle input to the muscles of considerable importance plastic surgery, because it is a key factor in performing muscle grafts. Inside the muscle belly arteries accompanied veins branch into tissue thickness intramuscular connective (perimysium) and arranged with Under the direction of muscle fibers, establishing numerous anastomosis. Capillary ramifications arteries are arranged at the level of endomysium and around muscle fibers forming a capillary frame is more abundant in red muscle fibers. Vascularity of tendons is much scarcer the muscle belly. The vessels entering the tendon from the muscle belly and direct branches that address tendon. Within the tendon, vascular ramifications They are arranged aligned with the fiber material extracellular.

The lymphatic drainage of the muscles begins in perimysium and accompanying blood vessels. An important aspect of capillary blood and irrigation Muscle is its great adaptability to functional needs. During the activity of a muscle, can increase its capillary vascularization fibers up to 700 times in relation to the situation rest. This regulatory effect of blood flow It seems to be enhanced by the existence of anastomosis arteriovenous that, at rest, facilitate flow into the veins without passing through the capillary bed. The irrigation deficiency causes fatigue and muscle cramps (Painful spasms).

INNERVATION OF THE JOINTS

The joints are innervated so finely branches Sensory peripheral nerves, such as nerve vegetative. The sensory innervation of the joints of the peripheral nerves and tension and collects information on stretching the fibrous capsule and ligaments. In Generally, the origin of the sensory nerves of each joint It corresponds to nerve trunks that innervate the muscles acting on the joint. Has been noted, in addition, the areas of the joint being tightened under the action of muscles is innervated by branches from trunks innervating antagonistic muscles of that action. This peculiar topographic distribution of sensory and motor nerves it is very suggestive the establishment of local reflex arcs adapt the muscle activity to tension caused in the joint. Innervation of joints by vegetative nerves reaches the joint accompanying vessels blood. The role of this innervation is not fully clarified, but within its functions may include as follows: 1) collect some information afferent Overvoltage and pain information; 2) regulate synovial fluid production through its action on the vessels; and 3) have a trophic effect on tissues joint. Vegetative nerve joint use  a variety of neurotransmitters, among them They include various neuropeptides such as neurokinin A (NKA), substance P (SP), neuropeptide Y (NPY), and related neuropeptide calcitonin gene (CGRP).

SKIN INNERVATION

The skin is richly innervated by sensory nerve fibers vegetative fibers and profusely branching through the layers of the dermis (dermal nerve plexus). The sensory fibers (afferent) are part of the and cutaneous nerves are peripheral extensions of the sensory neurons of the dorsal root ganglia or some cranial ganglia. These fibers originate from receivers skin as free nerve endings or specific sensory corpuscles. Reflect the sensibility General skin (pressure, touch, pain, temperature). also they originate, by nerve endings free, in hair follicles and blood vessels. The fibers of the hair follicle and run along the surface inside pods covering the hair root and contact with it on certain points. Vegetative fibers are postganglionic sympathetic. They come from the chain ganglia latero vertebral and reach the skin with cutaneous nerves or surrounding the cutaneous arteries. Innervate blood vessels, glands sweat and erector muscles of hairs. In the nerve terminal norepinephrine is released, except in the case of the sweat glands, where neurotransmitter is acetylcholine. The sebaceous glands They are not innervated; its activity is regulated by hormones androgenic, especially di hydro testosterone.

NOMENCLATURE

Studying anatomy is learning a new language with a very extensive vocabulary, and also learn to sort and relate correctly the words of this vocabulary, Or, in other words, learn to "make grammatical sentences and syntactically correct. " Most anatomical terms come from Greek and Latin. As in other natural sciences, anatomical nomenclature is written in Latin. Nevertheless, as national languages ​​have replaced Latin in the language of science, the terms Latinos anatomical structures have been translated into the vernacular (Castilian, English, German, French). The anatomical language requires clarity and precision, and be as universal as possible. In the late nineteenth century there were more 30 000 anatomical terms to define structures body; Many of these words were repeats or different names that were given the same structure in different countries, or they were not properly verified data. The unification and clarifying the anatomical language It required the development of a single nomenclature (Payroll Anatomical). The first attempt at unification anatomical language was held in 1895 in the city of Basel (Basel anatomical Payroll). Since then, Payroll has always been in constant review and improvement. Payroll anatomical Jena (1935) and anatomical Payroll Paris (1955) accounted Notable changes. In recent years, the Federal Committee on Anatomical Terminology (FCAT), constituted in Rio de Janeiro in 1989, he has made new adaptations of the nomenclature. In this work we have used the Anglicized version 2001 of the Anatomical Payroll approved by the FCAT. Without But we must be very aware that doctors not very interested in these changes and continue to use past terms consecrated by use. Thus, in some cases, it is important to include next to the name Official other terms commonly used, we even eponyms.

ORGANIZATION OF THE HUMAN BODY

The human body, like any other metazoan, It is made of cells. The cell is the structural unit essentials of living organisms. In the human body more than 250 cell types are known which represent a very small part of the millions of cell types that make up all living beings planet. These structural elements are not isolated but closely to build inter-agency alive. Between the cells and the whole organism no intermediate levels of organization: tissues, organs and systems and devices. Tissues are sets of cells which develop a particular function. There are four basic types tissue: epithelial, connective, muscular and nervous; Y of them there are specialized forms. Thus, within the tissue connective can be distinguished adipose, cartilage, bone and blood. One feature of connective tissue cells is well consists in largely by another structural element called extracellular matrix. The extracellular matrix consists fibers and ground substance or amorphous matrix. The fibers are composed of different proteins; stand including several varieties of collagen (fibers collagen and reticulin fibers), fibrillins (microfibrils) and elastin (elastic fibers). The amorphous matrix contains liquid tissue (water, salts and small molecules) and, primarily, glycosaminoglycans, proteoglycans and various glycoproteins. Bodies are formed by different types of tissue. Are well defined anatomical units

exercising at least a function. Thus, esophagus leads food into the stomach, kidney shaped urine but also it produces substances that regulate the pressure blood and liver is an organ with multiple functions metabolic. The organs are associated with appliances and systems perform complex functions. An apparatus or system It can be defined as a combination of parts to service a complex function, for example, digestion. There is a tendency in the current anatomical terminology to exclude the term device. However, in this work both terms are maintained. In the apparatus, organs They are anatomically well defined, with limits accurate. In systems, the concept of organ is more diffuse and macroscopic structures are hardly separable, for the cellular and molecular elements that are no defined barriers or they overlap throughout the body. Thus, it is easy delimit the urinary organs, but in the immune system can not be separate bodies immune lymphoid cells isolated, and the system nervous is, ultimately, a very complex cellular network that invades the whole organism so diffuse. Equipment and systems that make up the human body They are: 1) The skin and its annexes (integumentary system), 2) musculoskeletal system, consisting of bones and cartilage (system Skeleton), joints (articular system) muscles (muscular system), 3) the digestive system, 4) respiratory, 5) urinary tract, 6) the device player or genital, 7) the endocrine system, 8) the immune system, 9) the circulatory system, which encompasses the cardiovascular system and the lymphatic system, 10) the nervous system. The organs do not constitute a system or standalone device. They are receivers that capture and transform information from the outside world form part of a continuum with the nervous system. All systems work in a coordinated and structurally They can only be separated as a method study to understand the overall unit is being alive. Underlying these levels of organization of the body They are human molecules. The cells are formed molecules, producing molecules and interact by molecules. Proteins are the main molecules of which it depends on the structural organization and functional living things. Themselves have their own and specific spatial organization (anatomy). And the structure protein is specified by genes, which they are fragments of the DNA molecule, whose organization space is essential for its function again. The genes thus contain in coded form, the information the structure of the organism, its cell types, their functions, their number and spatial position of organization in tissues and organs, as well as signals for development grow and die.