Anatomical terminology is a form of scientific terminology used by anatomists and health professionals such as doctors. Anatomical terminology uses many unique terms and prefixes deriving from Ancient Greek and Latin; these terms can be confusing to those unfamiliar with them, but can be more precise, reducing ambiguity and errors. Since these anatomical terms are not used in everyday conversation, their meanings are less to change, less to be misinterpreted. To illustrate how inexact day-to-day language can be: a scar "above the wrist" could be located on the forearm two or three inches away from the hand or at the base of the hand. By using precise anatomical terminology such ambiguity is eliminated. An international standard for anatomical terminology, Terminologia Anatomica has been created. Anatomical terminology has quite regular morphology, the same prefixes and suffixes are used to add meanings to different roots; the root of a term refers to an organ or tissue. For example, the Latin names of structures such as musculus biceps brachii can be split up and refer to, musculus for muscle, biceps for "two-headed", brachii as in the brachial region of the arm.
The first word describes what is being spoken about, the second describes it, the third points to location. When describing the position of anatomical structures, structures may be described according to the anatomical landmark they are near; these landmarks may include structures, such as the umbilicus or sternum, or anatomical lines, such as the midclavicular line from the centre of the clavicle. The cephalon or cephalic region refers to the head; this area is further differentiated into the cranium, frons, auris, nasus and mentum. The neck area is called cervical region. Examples of structures named according to this include the frontalis muscle, submental lymph nodes, buccal membrane and orbicularis oculi muscle. Sometimes, unique terminology is used to reduce confusion in different parts of the body. For example, different terms are used when it comes to the skull in compliance with its embryonic origin and its tilted position compared to in other animals. Here, Rostral refers to proximity to the front of the nose, is used when describing the skull.
Different terminology is used in the arms, in part to reduce ambiguity as to what the "front", "back", "inner" and "outer" surfaces are. For this reason, the terms below are used: Radial referring to the radius bone, seen laterally in the standard anatomical position. Ulnar referring to the ulna bone, medially positioned when in the standard anatomical position. Other terms are used to describe the movement and actions of the hands and feet, other structures such as the eye. International morphological terminology is used by the colleges of medicine and dentistry and other areas of the health sciences, it facilitates communication and exchanges between scientists from different countries of the world and it is used daily in the fields of research and medical care. The international morphological terminology refers to morphological sciences as a biological sciences' branch. In this field, the form and structure are examined as well as the changes or developments in the organism, it is functional.
It covers the gross anatomy and the microscopic of living beings. It involves the anatomy of the adult, it includes comparative anatomy between different species. The vocabulary is extensive and complex, requires a systematic presentation. Within the international field, a group of experts reviews and discusses the morphological terms of the structures of the human body, forming today's Terminology Committee from the International Federation of Associations of Anatomists, it deals with the anatomical and embryologic terminology. In the Latin American field, there are meetings called Iberian Latin American Symposium Terminology, where a group of experts of the Pan American Association of Anatomy that speak Spanish and Portuguese and studies the international morphological terminology; the current international standard for human anatomical terminology is based on the Terminologia Anatomica. It was developed by the Federative Committee on Anatomical Terminology and the International Federation of Associations of Anatomists and was released in 1998.
It supersedes Nomina Anatomica. Terminologia Anatomica contains terminology for about 7500 human gross anatomical structures. For microanatomy, known as histology, a similar standard exists in Terminologia Histologica, for embryology, the study of development, a standard exists in Terminologia Embryologica; these standards specify accepted names that can be used to refer to histological and embryological structures in journal articles and other areas. As of September 2016, two sections of the Terminologia Anatomica, including central nervous system and peripheral nervous system, were merged to form the Terminologia Neuroanatomica; the Terminologia Anatomica has been perceived with a considerable criticism regarding its content including coverage and spelling mistakes and errors. Anatomical terminology is chosen to highlight the relative location of body structures. For instance, an anatomist might describe one band of tissue as "inferior to" another or a physician might describe a tumor as "superficial to" a deeper body structure.
Anatomical terms used to describe location
Anatomical terms of location
Standard anatomical terms of location deal unambiguously with the anatomy of animals, including humans. All vertebrates have the same basic body plan – they are bilaterally symmetrical in early embryonic stages and bilaterally symmetrical in adulthood; that is, they have mirror-image left and right halves if divided down the middle. For these reasons, the basic directional terms can be considered to be those used in vertebrates. By extension, the same terms are used for many other organisms as well. While these terms are standardized within specific fields of biology, there are unavoidable, sometimes dramatic, differences between some disciplines. For example, differences in terminology remain a problem that, to some extent, still separates the terminology of human anatomy from that used in the study of various other zoological categories. Standardized anatomical and zoological terms of location have been developed based on Latin and Greek words, to enable all biological and medical scientists to delineate and communicate information about animal bodies and their component organs though the meaning of some of the terms is context-sensitive.
The vertebrates and Craniata share a substantial heritage and common structure, so many of the same terms are used for location. To avoid ambiguities this terminology is based on the anatomy of each animal in a standard way. For humans, one type of vertebrate, anatomical terms may differ from other forms of vertebrates. For one reason, this is because humans have a different neuraxis and, unlike animals that rest on four limbs, humans are considered when describing anatomy as being in the standard anatomical position, thus what is on "top" of a human is the head, whereas the "top" of a dog may be its back, the "top" of a flounder could refer to either its left or its right side. For invertebrates, standard application of locational terminology becomes difficult or debatable at best when the differences in morphology are so radical that common concepts are not homologous and do not refer to common concepts. For example, many species are not bilaterally symmetrical. In these species, terminology depends on their type of symmetry.
Because animals can change orientation with respect to their environment, because appendages like limbs and tentacles can change position with respect to the main body, positional descriptive terms need to refer to the animal as in its standard anatomical position. All descriptions are with respect to the organism in its standard anatomical position when the organism in question has appendages in another position; this helps avoid confusion in terminology. In humans, this refers to the body in a standing position with arms at the side and palms facing forward. While the universal vertebrate terminology used in veterinary medicine would work in human medicine, the human terms are thought to be too well established to be worth changing. Many anatomical terms can be combined, either to indicate a position in two axes or to indicate the direction of a movement relative to the body. For example, "anterolateral" indicates a position, both anterior and lateral to the body axis. In radiology, an X-ray image may be said to be "anteroposterior", indicating that the beam of X-rays pass from their source to patient's anterior body wall through the body to exit through posterior body wall.
There is no definite limit to the contexts in which terms may be modified to qualify each other in such combinations. The modifier term is truncated and an "o" or an "i" is added in prefixing it to the qualified term. For example, a view of an animal from an aspect at once dorsal and lateral might be called a "dorsolateral" view. Again, in describing the morphology of an organ or habitus of an animal such as many of the Platyhelminthes, one might speak of it as "dorsiventrally" flattened as opposed to bilaterally flattened animals such as ocean sunfish. Where desirable three or more terms may be agglutinated or concatenated, as in "anteriodorsolateral"; such terms sometimes used to be hyphenated. There is however little basis for any strict rule to interfere with choice of convenience in such usage. Three basic reference planes are used to describe location; the sagittal plane is a plane parallel to the sagittal suture. All other sagittal planes are parallel to it, it is known as a "longitudinal plane".
The plane is perpendicular to the ground. The median plane or midsagittal plane is in the midline of the body, divides the body into left and right portions; this passes through the head, spinal cord, and, in many animals, the tail. The term "median plane" can refer to the midsagittal plane of other structures, such as a digit; the frontal plane or coronal plane divides the body into ventral portions. For post-embryonic humans a coronal plane is vertical and a transverse plane is horizontal, but for embryos and quadrupeds a coronal plane is horizontal and a transverse plane is vertical. A longitudinal plane is any plane perpendicular to the transverse plane; the coronal plane and the sagittal plane are examples of longitudinal planes. A transverse plane known as a cross-section, divides the body into cranial and caudal portions. In human anatomy: A transverse plane is an X-Z plane, parallel to the ground, which s
A gubernaculum in classical references describes a ship's rudder or steering oar. Gubernaculum, like cornucopia, is a Latin word; the English word government is related to it. The Old English word governail and the Scots word gouernaill are both derived from it; the ancient rudder's different parts were distinguished by the following names: the handle. The famous ship Tessarakonteres or Forty is said to have had four rudders. In the Bible, Paul's ship, shipwrecked on Malta, had its rudders cut loose. Various gods such as Tritons and Venus have been shown with a gubernaculum, it is most associated with Fortuna since, along with the cornucopia, it is an item that she is depicted as holding. The corresponding Greek god Tyche is regularly shown with a gubernaculum. There are abundant depictions of Fortuna holding the gubernaculum on coins, in paintings, on altars and statues or statuettes. Fortuna is depicted on around 1000 different Roman coins holding a gubernaculum. A sandstone statuette of Fortuna, the Roman god of luck, fortune was found at Castlecary and can now be found at the Hunterian Museum in Glasgow, Scotland.
In mythology the rudder, which the goddess can steer, represents control of the changeable fortunes of life. Plato used the metaphor of turning the Ship of State with a rudder. In the Biblical book of James, the author compares the tongue with a ship's rudder which, though physically small, makes great boasts
Development of the reproductive system
The development of the reproductive system is a part of prenatal development, concerns the sex organs. It is a part of the stages of sexual differentiation; because its location, to a large extent, overlaps the urinary system, the development of them can be described together as the development of the urinary and reproductive organs. The reproductive organs are developed from the intermediate mesoderm; the permanent organs of the adult are preceded by a set of structures which are purely embryonic, which with the exception of the ducts disappear entirely before the end of fetal life. These embryonic structures are the paramesonephric ducts; the mesonephric duct remains as the duct in males, the paramesonephric duct as that of the female. The mesonephric duct originates from a part of the pronephric duct. In the outer part of the intermediate mesoderm under the ectoderm, in the region from the fifth cervical segment to the third thoracic segment, a series of short evaginations from each segment grows dorsally and extends caudally, fusing successively from before backward to form the pronephric duct.
This continues to grow caudally. Thus, the mesonephric duct remains after the atrophy of the pronephros duct. In the male the duct persists, forms the tube of the epididymis, the vas deferens and the ejaculatory duct, while the seminal vesicle arises during the third month as a lateral diverticulum from its hinder end. A large part of the head end of the mesonephros disappears. In the female the mesonephric bodies and ducts atrophy; the nonfunctional remains of the mesonephric tubules are represented by the epoophoron, the paroöphoron, two small collections of rudimentary blind tubules which are situated in the mesosalpinx. The lower part of the mesonephric duct disappears, while the upper part persists as the longitudinal duct of the epoöphoron, called Gartner's duct. There are developments of other tissues from the mesonephric duct that persist, e.g. the development of the suspensory ligament of the ovary. Shortly after the formation of the mesonephric ducts a second pair of ducts is developed.
Each arises on the lateral aspect of the corresponding mesonephric duct as a tubular invagination of the cells lining the abdominal cavity. The orifice of the invagination remains open, undergoes enlargement and modification to form the abdominal ostium of the fallopian tube; the ducts pass backward lateral to the mesonephric ducts, but toward the posterior end of the embryo they cross to the medial side of these ducts, thus come to lie side by side between and behind the latter—the four ducts forming what is termed the common genital cord, to distinguish it from the genital cords of the germinal epithelium seen in this article. The mesonephric ducts end in an epithelial elevation, the sinus tubercle, on the ventral part of the cloaca between the orifices of the mesonephric ducts. At a stage the sinus tubercle opens in the middle, connecting the paramesonephric ducts with the cloaca. In the male the paramesonephric ducts atrophy, but traces of their anterior ends are represented by the appendix of testis of the male), while their terminal fused portions form the prostatic utricle in the floor of the prostatic urethra.
This is due to the production of Anti-Müllerian hormone by the Sertoli cells of the testes. In the female the paramesonephric ducts undergo further development; the portions which lie in the genital cord fuse to form the vagina. This fusion of the paramesonephric ducts begins in the third month, the septum formed by their fused medial walls disappears from below upward; the parts outside this cord remain separate, each forms the corresponding Fallopian tube. The ostium of the fallopian tube remains from the anterior extremity of the original tubular invagination from the abdominal cavity. About the fifth month a ring-like constriction marks the position of the cervix of the uterus, after the sixth month the walls of the uterus begin to thicken. For a time the vagina is represented by a solid rod of epithelial cells. A ring-like outgrowth of this epithelium occurs at the lower end of the uterus and marks the future vaginal fornix. At about the fifth or sixth month the lumen of the vagina is produced by the breaking down of the central cells of the epithelium.
The hymen represents the remains of the sinus tubercle. The gonads are the precursors of the testes in ovaries in females, they develop from the mesothelial layer of the peritoneum. The ovary is differentiated into a central part, the medulla of ovary, covered by a surface layer, the germinal epithelium; the immature ova originate from cells from the dorsal endoderm of the yolk sac. Once they have reached the gonadal ridge they are called oogonia. Development proceeds and the oogonia become surrounded by a layer of connective tissue cells. In this way, the rudiments of the ovarian follicles are formed; the embryological origin of granulosa cells, on the other hand, remains controversial. Just as in the male, there is a gubernaculum in the female, which pulls it downward, albeit not as much as in males; the gubernaculum becomes the proper ovarian ligament and the round ligament of the uterus. The periphery of the testes are converted into the tunica albuginea. Cords of the
The ovarian ligament is a fibrous ligament that connects the ovary to the lateral surface of the uterus. This ligament should not be confused with the suspensory ligament of the ovary, which extends from the ovary in the other direction; the ovarian ligament is composed of fibrous tissue. The ligament runs in the broad ligament of the uterus, a fold of peritoneum rather than a fibrous ligament, it is located in the parametrium. Embryologically, each ovary is connected to a band of the gubernaculum; this strip of mesoderm remains in connection with the ovary throughout its development, spans this distance by attachment within the labium majus. During the latter parts of urogenital development, the gubernaculum forms a long fibrous band of connective tissue stretching from the ovary to the uterus, continuing into the labium majus; this connective tissue span, the remnant of the gubernaculum is separated into two parts anatomically in the adult. Suspensory ligament of the ovary uterine tube broad ligament of the uterus Anatomy photo:43:03-0203 at the SUNY Downstate Medical Center - "The Female Pelvis: The Broad Ligament" Anatomy image:9781 at the SUNY Downstate Medical Center pelvis at The Anatomy Lesson by Wesley Norman figures/chapter_35/35-2.
HTM: Basic Human Anatomy at Dartmouth Medical School
The labia majora are two prominent longitudinal cutaneous folds that extend downward and backward from the mons pubis to the perineum. Together with the labia minora they form the labia of the vulva; the labia majora are homologous to the male scrotum. Labia majora is the Latin plural for big lips; the Latin term labium/labia is used in anatomy for a number of paired parallel structures, but in English it is applied to two pairs of parts of female external genitals —labia majora and labia minora. Labia majora are known as the outer lips, while labia minora, which run alongside between them, are referred to as the inner lips. Traditionally, to avoid confusion with other lip-like structures of the body, the labia of female genitals were termed by anatomists in Latin as labia majora pudendi. Embryologically, they develop from labioscrotal folds, it means that they develop in the female foetus from the same sexually undifferentiated anatomical structure as the scrotum, the sac of skin below the penis in males.
The same process of sex differentiation concerns other male and female reproductive organs, with some organs of both sexes developing similar, yet not identical and functions. But other male and female sex organs become different and unique, like the internal female genitalia; the scrotum and labia majora develop to have crucial differences. Like the scrotum, labia majora after puberty may become of a darker color than the skin outside them, also grow pubic hair on their external surface. But, during sexual differentiation of the foetus, labioscrotal folds in the males fuse longitudinally in the middle, forming a sack for male gonads to descend into it from the pelvis, while in the females these folds do not fuse, forming the two labia majora and the pudendal cleft between them. Female gonads do not descend from the pelvis, thus the structure of labia majora may seem simpler and of lesser significance for functioning of the female body as a whole than the scrotum with testicles for males; the ridge or groove remaining of the fusion can be traced on the scrotum.
In some cases of intersex with disorders of sex development male/female genitalia may look ambiguous for either gender with phallus too small for a typical penis yet too big for a clitoris, with external urethral opening in an atypical location, with labia/scrotum or fused but without descended gonads in them. Undescended testicles, may occur in otherwise healthy male infants; the labia majora constitute the lateral boundaries of the pudendal cleft, which contains the labia minora, interlabial sulci, clitoral hood, clitoral glans, frenulum clitoridis, the Hart's Line, the vulval vestibule, which contains the external openings of the urethra and the vagina. Each labium majus has two surfaces, an outer and covered with strong, pubic hair; the labia majora are covered with squamous epithelium. Between the two there is a considerable quantity of areolar tissue, a tissue resembling the dartos tunic of the scrotum, besides vessels and glands; the labia majora are thicker in front, form the anterior labial commissure where they meet below the mons pubis.
Posteriorly, they are not joined, but appear to become lost in the neighboring integument, ending close to, nearly parallel to, each other. Together with the connecting skin between them, they form another commissure the posterior labial commissure, the posterior boundary of the pudendum; the interval between the posterior commissure and the anus, from 2.5 to 3 cm in length, constitutes the perineum. The anterior region of the perineum is known as the urogenital triangle which separates it from the anal region. Between the labia majora and the inner thighs are the labiocrural folds. Between the labia majora and labia minora are the interlabial sulci. Labia majora atrophy after menopause; the fat pad of the labia majora can be used as a graft as a so-called "Martius labial fat pad graft", can be used, for example, in urethrolysis. Femalia Labia Labia minora Labia pride Labia Majora Medical Definition
Gubernaculum (nematode anatomy)
In nematodes, the gubernaculum is a hardened or sclerotized structure in the wall that guides the protrusion of the spicule during copulation. For example, in Caenorhabditis elegans, spicules serve to open and dilate the vagina of the female and the gubernaculum is a grooved plate in which the spicules move; the shape and size of the gubernaculum are important characters for the systematics of nematodes