superior, inferior, cranial, caudal, external, internal, superficial, deep, palmar, dorsal, plantar ANATOMICAL TERMINOLOGIES Anatomical position ● Reference position in anatomy: The person is standing upright, with the arms hanging by the side, palms facing forward, and thumbs pointing away from the body. The feet are slightly parallel, and toes oriented to the front. Directional terms and relations ● Anterior In front of or front Posterior ● Ventral ● Anatomical planes ● Imaginary planes that intersect the body, ● creating slices of various organs and structures. Main anatomical planes: Mid-sagittal/median, sagittal, frontal (coronal), transverse (axial) ● ● ● Mid-sagittal/median - vertical plane passing through the centre of the body (midline) that cuts it longitudinally into right and left halves. Sagittal - arbitrary vertical plane passing through the body parallel to the midline, slicing it longitudinally into right and left parts. To aid your understanding, imagine that you are slicing an apple - each slide is a sagittal plane. Frontal (coronal) - vertical plane at right angle to the sagittal plane that divides the body into anterior (front) and posterior (back) portions. Transverse (axial) - horizontal plane at right angles to the sagittal and frontal planes, slicing the body into a superior (upper) and inferior (lower) portions. The obtained cuts are transverse or axial views. Towards the front of the body Dorsal ● Towards the back of the body Distal ● Away or farthest away from the trunk or the point origin of the body part Proximal ● FOUR MAJOR PLANES ● In behind of or behind Closer or towards the trunk or the point of origin of the body part Median ● Midline of the body Medial ● Towards the median Lateral ● Away from median Superior ● Towards the top of the head Inferior ● Towards the feet Cranial ● Towards the head Caudal ● Towards the tail External ● Towards the surface, superficial Internal ● Away from the surface, deep Superficial ● Nearer to the surface Deep ● Directional terms ● ● Anatomical terms used to describe the position and relation between various structures. Main directional terms: Anterior, posterior, ventral, dorsal, proximal, distal, median, medial, lateral, Farther from the surface Palmar ● Anterior hand or palm of hand (palmar) Dorsal (of hand) ● Posterior surface of hand (dorsum) ● Moving backwards (tongue, mandible) Protraction ● Moving forwards and laterally simultaneously Rectraction ● Moving backwards and medially simultaneously Depression ● Moving downwards Elevation Body planes and directional terms Movements ● ● ● Changing the position of a body part around a certain axis and in one of the anatomical planes. When describing joint movements, two factors are included: ★ Axis, or fulcrum, around which the specific part moves ★ Plane of the movement Main types of movements: Flexion, extension, abduction, adduction, lateral rotation, medial rotation, circumduction, pronation, supination, inversion, eversion ● Medial (internal) rotation ● Decreasing the angle between two structures ● ● ● Flexion of the plantar (underside) part of the foot Dorsiflexion ● Flexion of the dorsum (top) part of the foot ● Moving away from the midline Adduction ● Moving towards the midline Protrusion ● Moving straight ahead or forwards (tongue, mandible) Retrusion Side (lateral flexion) or forward (anterior flexion) bending Extension (trunk) ● Bending backwards Pronation ● Medial rotation of the radius, resulting in the palm of the hand facing posteriorly (if in anatomical position) or inferiorly (if elbow is flexed) Supination ● Lateral rotation of the radius, resulting in the palm of the hand facing anteriorly (if in anatomical position) or superiorly (if elbow is flexed) Circumduction ● Combined movement starting with flexion, then abduction, extension, and ending with adduction Deviation ● Abduction ● Twisting motion towards or away from the midline (left or right) Flexion (trunk) Increasing the angle between two structures Plantarflexion Spiral movement away from the midline Rotation (trunk) Extension ● Spiral movement towards the midline Lateral (external) rotation Movement terms Flexion ● Moving upwards Movement of the wrist join towards the rafdial or ulnar sides (radial deviation, ulnar deviation) Opposition ● Touching the pad of any of your fingers from the thumb of the same hand Reposition ● Separating the pad of any of your fingers from the thumb of the same hand Inversion ● Plantar side of the foot is rotated towards the median plane Eversion ● Plantar side of the foot is rotated away from the median plane Anatomical regions ● ● Areas of the human body defined by the landmarks provided by evident structures that are easily palpable or visible. Main regions: Head, neck, thorax, abdomen, pelvis, upper extremity, lower extremity The human body is divided into regions. The main ones in the human body are the head, neck, thorax, abdomen, pelvis, together with the upper and lower extremities. The upper limb is divided into shoulder, arm, elbow, forearm, wrist, and hand. The lower limb consists of the hip, gluteal, thigh, knee, leg, ankle, and foot. All of the anatomical regions are defined by precise landmarks making them universally accepted terms that every healthcare professional instantly recognizes and understands. Generally speaking, these landmarks are provided by evident structures that are easily palpable or visible. This is known as surface anatomy. On the trunk (thorax and abdomen) there are several lines and surface landmarks, as follows: anterior/posterior median lines, sternal line, parasternal line, midclavicular line, anterior/middle/posterior axillary lines, paravertebral line, scapular line, ribs, sternum, vertebral spinous processes, clavicle, and pectoral muscles. These imaginary lines intersect at various points, creating particular regions between them. These are named: ● Presternal region ● Infraclavicular fossa ● Clavipectoral triangle ● Deltoid region ● Axillary region ● Pectoral region ● Inframammary region ● Vertebral region ● Suprascapular region ● ● ● ● ● ● ● ● Scapular region Interscapular region Lateral pectoral region Infrascapular region Lumbar triangle Sacral region Gluteal region Anal region The head and neck also consist of regions. They are not formed by precise planes, but they are named according to the anatomical structures contained within them. Therefore, the terms are easy to understand: frontal, orbital, infraorbital, nasal, oral, mental, sternocleidomastoid, lateral cervical, posterocervical, buccal, parotideomasseteric, infratemporal, zygomatic, temporal, occipital, and parietal regions. In addition, there are submandibular, submental, carotid, and muscular triangles, supraclavicular, jugular, and retromandibular fossae. Similar to the head and neck, the extremities are divided into regions according to their anatomical contents. Regions in the upper limb are named scapular, axillary, deltoid, brachial (anterior, posterior), cubital (anterior, posterior), antebrachial (anterior, posterior), carpal (anterior, posterior), palmar, and dorsal regions. Regions of the upper limb (anterior and posterior views) The regions of the lower limb are the following: femoral triangle, gluteal, femoral (anterior, posterior), genicular (anterior, posterior), popliteal, crural (anterior, posterior), lateral retromalleolar, dorsal, plantar, and calcaneal regions. Regions of the lower limb (anterior and posterior views) Abdominopelvic Region Regarding the abdominal regions, we’ll look at them separately because they are a favourite exam question and crucial clinical topic. Two approaches are used in medical practice. The simpler one takes advantage of a horizontal and vertical axis crossing at right angles directly on the umbilicus. This results in the formation of four abdominal quadrants called right upper (RQQ), left upper (LUQ), right lower (RLQ), and left lower (LLQ) quadrants. The second one involves four planes: two vertical lines running through the middle of the clavicles and middle of the inguinal ligaments, and two horizontal axes. One of which passes directly subcostally, while the second traverses the iliac tubercles. The intersection of these planes forms 9 abdominal regions; the right hypochondriac, epigastric, left hypochondriac, left lumbar, umbilical, right lumbar, right iliac, hypogastric, and left iliac regions. Cavities of the human body (anterior view) Regions of the thorax and abdomen (anterior and posterior views) Body Cavities Many anatomical structures are housed inside open fluid filled spaces, or cavities, located throughout the body. The most important ones are located axially, meaning inside the skull, vertebral column, thorax, and abdomen. What’s the importance of such spaces? Cavities compartmentalise the body, they also protect and lubricate organs; reducing friction during organ movement. The human body has two cavitary groups anterior and posterior. The latter is composed of two cavities called the cranial cavity and vertebral canal, which are continuous with each other and contain the central nervous system (brain plus spinal cord). It is filled with cerebrospinal fluid which bathes the central nervous system The larger anterior cavitary group is composed of several smaller cavities called the thoracic and abdominopelvic cavities. The former is composed out of the superior, anterior, middle, and posterior mediastinal cavities, as well as the two pleural cavities. The latter is subdivided into the abdominal and pelvic cavities. The thoracic and abdominal cavities are separated by the diaphragm. Each of these spaces is home to the typical neurovasculature structures and organs specific to each respective region. The pericardial cavity, sitting within the mediastinum, deserves a special mention because it contains the heart. Synovial joint One set of structures making these actions a daily reality are joints, which are the union of two or more bones. There are many types of joints classified according to many criteria, one example being synovial joints. Also known as diarthrosis, a synovial joint is a potential space containing synovial fluid that separates two bones. It is the most flexible out of all types, allowing a great degree of motion and joint movements. The bone ends are covered with cartilage. There are six main types of synovial joints: ● Pivot joint ● Ball and socket joint ● Condyloid joint ● Saddle joint ● Hinge joint ● Plane joint Almost every major joint in the human body is synovial in nature, including the shoulder, elbow, hip, knee, and ankle joints. Brain anatomy Housed within the cranium, more specifically the cranial cavity, the brain consists of folds (gyri), grooves (sulci), and clefts (fissures). It is composed of several parts, such as: ● ● ● ● ● Cerebral hemispheres (cerebral cortex) Diencephalon Brainstem Cerebellum Ventricles Several lobes of the brain (parietal, occipital, temporal, frontal, and insular) form the cerebral hemispheres, each one having several distinct roles. For example, the frontal lobe function includes motor function, problem solving, memory, language, judgement, and many more. The brainstem is the vegetative and most primitive part, consisting of the midbrain, pons, and medulla oblongata. Here’s a brain diagram illustrating its various parts: Overview of the brain (lateral and sagittal views) What about the cerebellum function? This structure is unique in terms of structure and roles, being involved in balance and movement coordination, to name a few. The ventricles are part of an entire system called the ventricular system of the brain that is involved in the production and drainage of the cerebrospinal fluid within the central nervous system. In terms of directional terms, axes, and planes, the brain is quite special. It has neuraxes which are different than the normal body axes. There are two in total called rostral/caudal and ventral/dorsal neuraxes. As you can see, the previous four relation terms are preferred in the brain, but they can change to the normal terms used in other parts of the human body when referring to structures above or below the midbrain.
