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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Anatomical terminology | 3/4 | https://en.wikipedia.org/wiki/Anatomical_terminology | reference | science, encyclopedia | 2026-05-05T07:26:04.798609+00:00 | kb-cron |
Anterior and posterior, which describe structures at the front (anterior) and back (posterior) of the body. For example, the toes are anterior to the heel, and the popliteus is posterior to the patella. Superior and inferior, which describe a position above (superior) or below (inferior) another part of the body. For example, the orbits are superior to the oris, and the pelvis is inferior to the abdomen. Proximal and distal, which describe a position that is closer to (proximal) or farther from (distal) the trunk of the body. For example, the shoulder is proximal to the arm, and the foot is distal to the knee. Superficial and deep, which describe structures that are closer to (superficial) or farther from (deep) the surface of the body. For example, the skin is superficial to the bones, and the brain is deep to the skull. Sometimes profound is used synonymously with deep. Medial and lateral, which describe a position that is closer to (medial) or farther from (lateral) the midline of the body. For example, the shoulders are lateral to the heart, and the umbilicus is medial to the hips. The medial side of the left knee is the side toward the opposite knee. Radial and ulnar, which describe only structures at or distal to the elbow and may be used interchangeably with medial and lateral in that particular area because they are less confusing. Examples: The thumb is on the radial side of the hand (the same as saying the lateral side); the ulnar side of the wrist is the side toward the little finger (medial side). Dorsal and ventral, which describe structures derived from the back (dorsal) or front (ventral) such as in the embryo, before limb rotation. Rostral and caudal, which describe structures close to (rostral) or farther from (caudal) the nose. For example, the eyes are rostral to the back of the skull, and the tailbone is caudal to the chest. Cranial and caudal, which describe structures close to the top of the skull (cranial), and towards the bottom of the body (caudal). Occasionally, sinister for left, and dexter for right are used. Paired, referring to a structure that is present on both sides of the body. For example, the hands are paired structures.
=== Axes === Each locational term above can define the direction of a vector, and pairs of them can define axes, that is, lines of orientation. For example, blood can be said to flow in a proximal or distal direction, and anteroposterior, mediolateral, and inferosuperior axes are lines along which the body extends, like the X, Y, and Z axes of a Cartesian coordinate system. An axis can be projected to a corresponding plane.
=== Planes ===
Anatomy is often described in planes, referring to two-dimensional sections of the body. A section is a two-dimensional surface of a three-dimensional structure that has been cut. A plane is an imaginary two-dimensional surface that passes through the body. Three planes are commonly referred to in anatomy and medicine:
The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane, or less commonly a longitudinal section. The frontal plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The frontal plane is often referred to as a coronal plane, following Latin corona, which means "crown". The transverse plane is the plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.
== Functional state == Anatomical terms may be used to describe the functional state of an organ:
Anastomoses refers to the connection between two structures previously branched out, such as blood vessels or leaf veins. Patent, meaning a structure such as an artery or vein that abnormally remains open, such as a patent ductus arteriosus, referring to the ductus arteriosus which normally becomes ligamentum arteriosum within three weeks of birth. Something that is patent may also refer to a channel such as a blood vessel, section of bowel, collecting system or duct that is not occluded and remains open to free flow. Such obstructions may include a calculus (i.e. a kidney stone or gallstone), plaque (like that encountered in vital arteries such as coronary arteries and cerebral arteries), or another unspecified obstruction, such as a mass or bowel obstruction. A plexus refers to a net-like arrangement of a nerve.
=== Anatomical variation ===
The term anatomical variation is used to refer to a difference in anatomical structures that is not regarded as a disorder. Many structures vary slightly between people, for example muscles that attach in slightly different places. For example, the presence or absence of the palmaris longus tendon. Anatomical variation is unlike congenital anomalies, which are considered a disorder.
== Movement ==
Joints, especially synovial joints allow the body a tremendous range of movements. Each movement at a synovial joint results from the contraction or relaxation of the muscles that are attached to the bones on either side of the articulation. The type of movement that can be produced at a synovial joint is determined by its structural type. Movement types are generally paired, with one being the opposite of the other. Body movements are always described in relation to the anatomical position of the body: upright stance, with upper limbs to the side of body and palms facing forward.
=== General motion === Terms describing motion in general include: