Dr.Kaan Yücel Introduction to anatomy & Terminology in anatomy

INTRODUCTIONTO ANATOMY

TERMINOLOGY IN ANATOMY

18. 09.2012

Kaan Yücel

M.D., Ph.D.

1. 1. DEFINITION OF ANATOMY

The following two years, you will have your anatomy class. I think starting these two years with a definition of anatomy would be wise. Besides, I love etymology (the science dealing with the origins of the words). In the exams, however, you will not be responsible on my etymology interest. But you should know the origin of the word anatomy. If you are like me;enjoy etymology; here is a neat online source:

The word “anatomy” is derived from “anatomia, anatome” which has a Latin and Ancient Greek origin. The prefix “ana-“means “up", where “temnein, tome” means "to cut." As a result, anatomy means “cutting up, cutting through”. The name of the technique became the name of the discipline throughout the history.

The term human anatomy comprises a consideration of the various structures which make up the human organism. In a restricted sense it deals merely with the parts which form the fully developed individual and which can be rendered evident to the naked eye by various methods of dissection. As you see, the difference between two major parts of morphology (morph- Ancient Greek, shape, figure) histology and anatomy is the way you investigate the human body. In histology (the world of tissues and cells), the human body is investigated under a microscope, but in anatomy by the naked eye.

1.2. Types of anatomy

The three main approaches to studying anatomy are regional, systemic, and clinical (or applied), reflecting the body's organization and the priorities and purposes for studying it. Be careful! In medicine, you should also know the synoynms of the words: in this example clinical anatomy and applied anatomy are the same (The same story for regional anatomy and topographical anatomy).

In systematic anatomy, various structures may be separately considered. On the other hand, in topographical or regional anatomy, the organs and tissues may be studied in relation to one another.

1.2.1.Regional Anatomy

Regional anatomy (topographical anatomy) considers the organization of the human body as major parts or segments: a main body, consisting of the head, neck, and trunk (subdivided into thorax, abdomen, back, and pelvis/perineum), and paired upper limbs and lower limbs. All the major parts may be further subdivided into areas and regions.

Regional anatomy is the method of studying the body's structure by focusing attention on a specific part (e.g., the head), area (the face), or region (the orbital or eye region); examining the arrangement and relationships of the various systemic structures (muscles, nerves, arteries, etc.) within it; and then usually continuing to study adjacent regions in an ordered sequence.

Surface anatomy is an essential part of the study of regional anatomy. Surface anatomy provides knowledge of what lies under the skin and what structures are perceptible to touch (palpable) in the living body at rest and in action. The aim of this method is to visualize (recall distinct mental images of) structures that confer contour to the surface or are palpable beneath it and, in clinical practice, to distinguish any unusual or abnormal findings. In short, surface anatomy requires a thorough understanding of the anatomy of the structures beneath the surface.

1.2.2. Systematic Anatomy

Systematic Anatomy.—The various systems of which the human body is composed are grouped under the following headings:

Osteology—the bony system or skeleton.

Syndesmology—the articulations or joints.

Myology—the muscles. With the description of the muscles it is convenient to include that of the fasciæ which are so intimately connected with them.

Angiology—the vascular system, comprising the heart, bloodvessels, lymphatic vessels, and lymph glands.

Neurology—the nervous system. The organs of sense may be included in this system.

Splanchnology—the visceral system.

Topographically the viscera form two groups, viz., the thoracic viscera and the abdomino-pelvic viscera. The heart, a thoracic viscus, is best considered with the vascular system. The rest of the viscera may be grouped according to their functions: (a) the respiratory apparatus; (b) the digestive apparatus; and (c) the urogenital apparatus.

1.2.3.Clinical Anatomy

Clinical (applied) anatomy emphasizes aspects of bodily structure and function important in the practice of medicine, dentistry, and the allied health sciences. It incorporates the regional and systemic approaches to studying anatomy and stresses clinical application.

Clinical anatomy often involves inverting or reversing the thought process typically followed when studying regional or systemic anatomy. For example, instead of thinking, “The action of this muscle is to … ,” clinical anatomy asks, “How would the absence of this muscle's activity be manifest?” Instead of noting, “The … nerve provides innervation to this area of skin,” clinical anatomy asks, “Numbness in this area indicates a lesion of which nerve?”

Clinical anatomy is exciting to learn because of its role in solving clinical problems.

1.3. The importance of learning anatomy as a future medical doctor

  • To understandbodily function and how bothstructure and function are modified bydisease.
  • To interpret the images that are produced by the sophisticated imaging techniques, such as CT, MRI, DTI.
  • To understand the pathway fortargeting therapy to a specific site
  • To examine the patient properly
  • To communicate with the colleagues properly

1.4. WAYS OF LEARNING ANATOMY

Cadaver:(Merriam Webster dictionary) from Latin, from cadere'to fall'.A dead body; especially: one intended for dissection.

Dissection: (Oxford dictionary) from Latin dissectus, past participle of dissecare to cut apart, from dis- + secare to cut. The action of dissecting a body or plant to study its internal parts.

Prosection:(Wikipedia) A prosection is the dissection of a cadaver (human or animal) or part of a cadaver by an experienced anatomist in order to demonstrate for students anatomic structure. In a dissection, students learn by doing; in a prosection, students learn by either observing a dissection being performed by an experienced anatomist or examining a specimen that has already been dissected by an experienced anatomist (etymology: Latin pro- "before" + sectio "a cutting

Other materials of learning human anatomy:

Anatomy models

Anatomy atlases (Pictures, drawings)

Videos

Textbooks

Charts & diagrams

Medical dictionaries, etc.

1.6. History of anatomyin the world

The development of anatomy as a science extends from the earliest examinations of sacrificial victims to the sophisticated analyses of the body performed by modern scientists. It has been characterized, over time, by a continually developing understanding of the functions of organs and structures in the body. The field of Human Anatomy has a prestigious history, and is considered to be the most prominent of the biological sciences of the 19th and early 20th centuries. Methods have also improved dramatically, advancing from examination of animals through dissection of cadavers to technologically complex techniques developed in the 20th century.

1.6.1. Ancient anatomy

Egypt

The study of anatomy begins at least as early as 1600 BCE, the date of the Edwin Smith Surgical Papyrus. This treatise shows that the heart, its vessels, liver, spleen, kidneys, hypothalamus, uterus and bladder were recognized, and that the blood vessels were known to emanate from the heart.

Greece

The earliest medical scientist of whose works any great part survives today is Hippocrates, a Greek physician active in the late 5th and early 4th centuries BCE (460 - 377 BCE). His work demonstrates a basic understanding of musculoskeletal structure, and the beginnings of understanding of the function of certain organs, such as the kidneys. Much of his work, however, and much of that of his students and followers later, relies on speculation rather than empirical observation of the body.

In the 4th century BCE, Aristotle and several contemporaries produced a more empirically founded system, based animal dissection. The first use of human cadavers for anatomical research occurred later in the 4th century BCE when Herophilos and Erasistratus gained permission to perform live dissections, or vivisection, on criminals in Alexandria under the auspices of the Ptolemaic dynasty.

Galen

The final major anatomist of ancient times was Galen (of Berga, active in the 2nd century. He compiled much of the knowledge obtained by previous writers, and furthered the inquiry into the function of organs by performing vivisection on animals. Due to a lack of readily available human specimens, discoveries through animal dissection were broadly applied to human anatomy as well. His collection of drawings, based mostly on dog anatomy, became the anatomy textbook for 1500 years.

1.6.2. Early modern anatomy

The works of Galen and Avicenna (Ibn-I Sina), especially The Canon of Medicine which incorporated the teachings of both, were translated into Latin, and the Canon remained the most authoritative text on anatomy in European medical education until the 16th century. The first major development in anatomy in Christian Europe, since the fall of Rome, occurred at Bologna in the 14th to 16th centuries, where a series of authors dissected cadavers and contributed to the accurate description of organs and the identification of their functions. A succession of researchers proceeded to refine the body of anatomical knowledge, giving their names to a number of anatomical structures along the way.Andreas Vesaliusis the first modern anatomist who wrote the first anatomy textbook of the modern times; De humani corporis fabrica (On the Fabric of the Human Body).

1.6.3. 17th and 18th centuries

The study of anatomy flourished in the 17th and 18th centuries. The advent of the printing press facilitated the exchange of ideas. Because the study of anatomy concerned observation and drawings, the popularity of the anatomist was equal to the quality of his drawing talents, and one need not be an expert in Latin to take part. Many famous artists studied anatomy, attended dissections, and published drawings for money, from Michelangelo to Rembrandt. For the first time, prominent universities could teach something about anatomy through drawings, rather than relying on knowledge of Latin.

1.6.4. 19th century anatomy

During the 19th century, anatomists anatomists largely finalized and systematized the descriptive human anatomy of the previous century. The discipline also progressed to establish growing sources of knowledge in histology and developmental biology, not only of humans but also of animals. Extensive research was conducted in more areas of anatomy.

1.7. History of anatomy education in Turkey

Anatomy education commenced as a distinct course at “Tıbhane-i Cerrahhane-i Amire”, the first medical school founded by Sultan Mahmut II in March 14th, 1827. It is possible to explain anatomy education in three periods:

1. Pre-dissection period (1827-1841):

In this period, anatomy education was given theoretically. Anatomy contitutions except bones were being displayed on charts and models which were brought from Europe.

2.Unmedicated cadaver period (1841-1908):

Anatomy experts were appointed from abroad in this period. First one was Dr. Charles Ambroise Bernard from Vienna (1808-1844).After Sultan Abdülmecid has signed the imperical decree allowing dissections with the purpose of education; practical applications on cadavers began initially. Corpses of slaves and captives were used as cadavers for dissection. These corpses had no relations and dissections were made until they began to decay. For this reason, large scale of anatomy education was still given theoretically.

3. Medicated cadaver period (1908-present):

In anatomy education by using the method of giving chemical substance through vein, cadavers began to be used initally without decaying in this period. As a result, scale of practice in anatomy education increased considerably.

In this period anatomy education gained new dimensions.Some students were sent to the European countries. These students had the opportunity of studying with the famous anatomists of the time. They not only returned to their homeland with the anatomy knowledge but with investigation and education methods as well. Mazhar Pasha, Prof. Dr. Nurettin Ali Berkol, and Prof. Dr. Zeki Zeren can be considered as the founders of modern anatomy in Turkey. After 1945, the anatomy education demonstrated a rapid development considerably. Today, tens of anatomy departments continue their activities.

Ulucam E, Gokce N, Mesut R. Turkish Anatomy Education From the Foundation of The First Modern School to Today. Journal of the International Society for the History of Islamic Medicine (ISHIM), 2003,2

The full article @

1.8. Anatomical Position

All anatomical descriptions are expressed in relation to one consistent position, ensuring that descriptions are not ambiguous. One must visualize this position in the mind when describing patients (or cadavers), whether they are lying on their sides, supine (recumbent, lying on the back, face upward), or prone (lying on the abdomen, face downward).

Figure 1. Anatomical position

1.9. Anatomical Variations

Anatomy books describe (initially, at least) the structure of the body as it is usually observed in people—that is, the most common pattern. However, occasionally a particular structure demonstrates so much variation within the normal range that the most common pattern is found less than half the time!

In a random group of people, individuals differ from each other in physical appearance. The bones of the skeleton vary not only in their basic shape but also in lesser details of surface structure. A wide variation is found in the size, shape, and form of the attachments of muscles. Similarly, considerable variation exists in the patterns of branching of veins, arteries, and nerves. Veins vary the most and nerves the least. Individual variation must be considered in physical examination, diagnosis, and treatment.

It is important for medical personnel to have a sound knowledge and understanding of the basic anatomic terms. With the aid of a medical dictionary, you will find that understanding anatomic terminology greatly assists you in the learning process.

The accurate use of anatomic terms by medical personnel enables them to communicate with their colleagues both nationally and internationally. Without anatomic terms, one cannot accurately discuss or record the abnormal functions of joints, the actions of muscles, the alteration of position of organs, or the exact location of swellings or tumors.

Anatomical terms are descriptive terms standardized in an international reference guide, Terminologia Anatomica (TA). These terms, in English or Latin, are used worldwide. Colloquial terminology is used by—and to communicate with—lay people. Eponyms are often used in clinical settings but are not recommended because they do not provide anatomical context and are not standardized.

Many anatomical terms have both Latin and Greek equivalents, although some of these are used in English only as roots. Thus the tongue is lingua (L.) and glossa (Gk), and these are the basis of such terms as lingual artery and glossopharyngeal nerve.

Various adjectives, arranged as pairs of opposites, describe the relationship of parts of the body or compare the position of two structures relative to each other.Anatomical directional terms are based on the body in the anatomical position. Four anatomical planes divide the body, and sections divide the planes into visually useful and descriptive parts.

2.1. Terms Related to PosItIon

All descriptions of the human body are based on the assumption that the person is standing erect, with the upper limbs by the sides and the face and palms of the hands directed forward. This is the so-called anatomic position. The various parts of the body are then described in relation to certain imaginary planes.

2.1.1. Anatomical Planes

Anatomical descriptions are based on four imaginary planes (median, sagittal, frontal-coronal, and transverse-axial) that intersect the body in the anatomical position:

The median plane, the vertical plane passing longitudinally through the body, divides the body into right and left halves. The plane defines the midline of the head, neck, and trunk where it intersects the surface of the body. Midline is often erroneously used as a synonym for the median plane.

Sagittal planes are vertical planes passing through the body parallel to the median plane. Parasagittal is commonly used but is unnecessary because any plane parallel to and on either side of the median plane is sagittal by definition. However, a plane parallel and near to the median plane may be referred to as a paramedian plane.

Frontal (coronal) planes are vertical planes passing through the body at right angles to the median plane, dividing the body into anterior (front) and posterior (back) parts.

Transverse planes are horizontal planes passing through the body at right angles to the median and frontal planes, dividing the body into superior (upper) and inferior (lower) parts. Radiologists refer to transverse planes as transaxial, which is commonly shortened to axial planes.

Since the number of sagittal, frontal, and transverse planes is unlimited, a reference point (usually a visible or palpable landmark or vertebral level) is necessary to identify the location or level of the plane, such as a “transverse plane through the umbilicus”.

Anatomists create sections of the body and its parts anatomically, and clinicians create them by planar imaging technologies, such as computerized tomography (CT), to describe and display internal structures.

Figure 2. Anatomical planes

2.1.2. Anatomical terms specific for comparisons made in the anatomical position, or with reference to the anatomical planes:

Superior refers to a structure that is nearer the vertex, the topmost point of the cranium (Mediev. L., skull).

Cranial relates to the cranium and is a useful directional term, meaning toward the head or cranium.