Introductory Concepts and Imaging Techniques
LEARNING OBJECTIVES
To understand the difference between systematic, regional, and clinical anatomy.
Have a thorough knowledge of proper anatomical terminology. This will include terms that are associated with location and direction.
Have a thorough knowledge of anatomical planes and axes in order to interpret radiological images.
Have an understanding of the integumentary system that includes its functions and the five layers of the epidermis. Associated structures such as the dermis, nails, and glands will also be looked at along with clinical correlates such as surgical incisions and types of burns.
Have an understanding of the skeletal system that involves bones, cartilage, and articulating joints. Types of bones, cartilage, and joints will be presented along with formation of bones and clinical correlates related to this system such as osteoporosis and bone fracture healing.
Have an understanding of the muscular system and the three different types of muscles. This section examines the micro- and macrostructure of muscles along with contraction and movements produced by them. Clinical correlates would include muscular dystrophy and fibromyalgia.
Have an understanding of the circulatory system that includes its functions, tunic layers, and types of blood vessels. This would also include a look at the lymphatic system and the specific structures associated with it. Clinical correlates will include a look at peripheral arterial disease, varicose veins, and the possible routes or pathways of cancer spreading.
Have an understanding of the nervous system and the multiple parts of it. This would include the difference between the central and peripheral nervous systems as well as the difference between somatic and visceral innervation. A look at the micro- and macrostructure of neurons will be preceded by a look at the specific type of nerve fibers that pass through larger peripheral nerves. A closer look at the autonomic nervous system and its paired visceral sensory fibers will conclude this section.
Introduce a brief synopsis of all other systems located in the body. These details will be presented during later chapters.
Have a general understanding of the clinical imaging techniques used in today's medical field.
I.1 Studying Human Anatomy
There are three different approaches to studying human anatomy. These include a systematic, regional, or clinical (applied) anatomy approach. This text will focus on the clinical or applied anatomy approach that encompasses both regional and systematic approaches to studying human anatomy. The anatomical sciences are divided and studied as gross, microscopic (histology), development (embryology), and neuroanatomy with all aspects being touched upon in this text.
I.1.1 Systematic Anatomy
When organizing the body into organ systems that work together and carry out complex functions, this is known as the systematic approach to studying anatomy. For example, when the muscular system is active during exercise, it is not only the muscles that are functioning in this complex system. The heart and vessels of the cardiovascular system supply blood to the muscles. Within this blood, oxygen derived from the lungs of the respiratory system and glucose derived from the digestion of food from the digestive system supply the muscles with energy. Nerves of the nervous system are responsible for activating and turning off opposing muscles so that we have fluid movements. The basis of most of the systematic anatomy will be mentioned in this chapter but are relatable to almost all other chapters.
I.1.2 Regional Anatomy
When organizing the body into parts or regions, such as thorax or pelvis, this is the regional approach to studying anatomy. The body is divided into parts: head, neck, back, thorax, abdomen, pelvis/perineum, paired upper limbs, and paired lower limbs. The term "trunk" refers to the back, thorax, abdomen, and pelvis/perineum. The one thing to remember is that regions cannot only be thought of as just an isolated part of the body. The region is continuous or adjacent to other parts of the body being studied; thus, major neurovasculature bridging adjacent regions must be understood.
When a physician investigates the body for possible trauma or pathology, surface anatomy will be essential in understanding specific regional anatomy. Surface anatomy provides the treating physician landmarks of structures that are palpable under the skin and gives them a baseline of information to begin their diagnosis or further exploration (Fig. I.1). When a patient arrives to the emergency room with a gunshot to the upper left quadrant of the abdomen, the ER physician must know what organs were at risk of damage due to the bullet traveling through that region of the abdomen.
Fig. I.1 (a) Surface contours and palpable bony prominences of the face and neck, anterior view. (b) Surface contours and palpable bony prominences of the trunk and upper and lower limbs in the female, anterior view. (From Schuenke M, Schulte E, Schumacher U. THIEME Atlas of Anatomy. General Anatomy and Musculoskeletal System. Illustrations by Voll M and Wesker K. 3rd ed. New York: Thieme Medical Publishers; 2020.)
Fig. I.1 (continued) (c) Surface contours and palpable bony prominences of the trunk and upper and lower limbs in the male, posterior view. (d) Surface contours and palpable bony prominences of the face and neck, posterior view. (From Schuenke M, Schulte E, Schumacher U. THIEME Atlas of Anatomy. General Anatomy and Musculoskeletal System. Illustrations by Voll M and Wesker K. 3rd ed. New York: Thieme Medical Publishers; 2020.)
I.1.3 Clinical Anatomy
When systematic and regional anatomy is applied together and emphasis is on both structure and function, this is known as clinical anatomy. This is important in health care practice covering all fields such as medicine and the allied health sciences. Emphasis is placed on clinical application. This text emphasizes and bridges the four major areas of the anatomical sciences (gross anatomy, histology, embryology, and neuroanatomy) to better understand clinical practice. Gross, histology, and embryology will be the focus until near the end of the text when neuroanatomy is isolated and focus is on components of both the central and peripheral nervous systems.
I.2 Anatomical Terminology and Position
In anatomy there is no need for translation because it has an international vocabulary that is the foundation of all medical terminology or nomenclature. All health professionals are able to communicate whether they are from clinical practice or basic sciences. Anatomical terms are mainly derived from Latin or Greek but many of these terms can provide a structure's location, size, shape, or function. Eponyms are the names of structures derived from the people who generally discovered them and are no longer listed as official anatomical terminology but are still seen in clinical practice. This text will mention the more common eponyms when appropriate. This standard was established during the Terminologia Anatomica: International Anatomical Terminology(Federative Committee on Anatomical Terminology or FCAT). It was released in 1998 and supersedes the previous standard, Nomina Anatomica.
All descriptions of the human body are expressed in terms of anatomical position. This is to ensure all clinical or scientific descriptions of the human body are not ambiguous. Anatomical position is a reference posture in which the human body is:
Standing erect with the legs slightly spread apart.
Upper limbs by the sides.
Palms of the hands, toes of the feet, and head are facing forward.
I.3 Anatomical Variation
The anatomy described in written texts and atlases is the observation of what is seen in most individuals. The most common pattern of structures is generally what is reported in these texts. Anatomical variation must be expected when a student is dissecting. Neurovasculature has a general theme with smaller veins varying the most, followed by arteries and then finally nerves.
I.4 Terms of Location and Direction
Location and directional terms used in the medical field will refer to the body in anatomical position. A list of terms describing the head, neck, trunk, and limb location and directions are listed in Table I.1 (Fig. I.2).
Table I.1 Terms of location and direction
Head, neck, and trunk
Superior (cranial)
Pertaining to, or located toward the head
Inferior (caudal)
Pertaining to, or located toward the feet
Anterior (ventral)
Located toward the front
Posterior (dorsal)
Located toward the back
Medial
Toward the median plane
Lateral
Away from the median plane or toward the side
Superficial
Near the surface
Intermediate
Between the superficial and deep...
