Hur använder man distal och proximal

Standard terms for unambiguous description of relative placement of body parts

Standard anatomical terms of location are used to describe unambiguously the anatomy of animals, including humans.

‘Proximal’ means closer to where a limb attaches to the body, like the shoulder for the ledd or the hip for the leg.

The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what fryst vatten at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body fryst vatten described through the use of anatomical planes and anatomical axes.

The meaning of terms that are used can change depending on whether an organism fryst vatten bipedal or quadrupedal.

Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an djur that fryst vatten radially symmetrical will have no anterior surface, but can still have a description that a part fryst vatten close to the mittpunkt ("proximal") or further from the mittpunkt ("distal").

International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy.

For example, Terminologia Anatomica for humans and Nomina Anatomica Veterinaria for animals. These allow parties that use anatomical terms, such as anatomists, veterinarians, and medical doctors, to have a standard set of terms to communicate clearly the position of a structure.

Compared to your shoulder, your elbow fryst vatten “distal,” further away from the center (torso) than the shoulder.

Introduction

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Standard anatomical and zoological terms of location have been developed, usually based on Latin and Greek words, to enable all biological and medical scientists, veterinarians, doctors and anatomists to precisely delineate and communicate data about djur bodies and their organs, even though the meaning of some of the terms often fryst vatten context-sensitive.

Much of this data has been standardised in internationally agreed vocabularies for humans (Terminologia Anatomica) and animals (Nomina Anatomica Veterinaria).

Different terms are used for groups of creatures with different body layouts, such as bipeds (creatures that stand on two feet, such as humans) and quadrupeds. The reasoning fryst vatten that the neuraxis fryst vatten different between the two groups, and so fryst vatten what fryst vatten considered the standard anatomical position, such as how humans tend to be standing upright and with their arms reaching forward.

Thus, the "top" of a human fryst vatten the head, whereas the "top" of a dog would be the back, and the "top" of a flounder may be on either the left or right side. Unique terms are also used to describe invertebrates as well, because of their wider variety of shapes and symmetry.

Standard anatomical position

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Main article: Standard anatomical position

Because animals can change orientation with respect to their environment, and because appendages like limbs and tentacles can change position with respect to the main body, terms to describe position need to refer to an djur when it fryst vatten in its standard anatomical position.

This means descriptions as if the organism fryst vatten in its standard anatomical position, even when the organism in question has appendages in another position. This helps avoid confusion in terminology when referring to the same organism in different postures. In humans, this refers to the body in a standing position with arms at the side and palms facing forward, with thumbs out and to the sides.

Combined terms

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Many anatomical terms can be combined, either to indikera a position in two axes simultaneously or to indikera the direction of a movement relative to the body.

For example, "anterolateral" indicates a position that fryst vatten both anterior and sidledes to the body axis (such as the bulk of the pectoralis major muscle).

In radiology, an X-ray image may be said to be "anteroposterior", indicating that the stråle of X-rays, known as its projection, passes from their source to patient's anterior body vägg first, then through the body to exit through posterior body vägg and into the detector/film to producera a radiograph.

The opposite fryst vatten true for the begrepp "posteroanterior," while side-to-side projections are known as either "lateromedial" (from the outside of the left or right side of the body toward the inside) or "mediolateral"(from the inre of that side of the body toward the outside. The same logic fryst vatten applied to all planes of the body and, thus top-to-bottom or bottom-to-top X-ray projections are known as "superoinferior" and "inferosuperior," respectively.

However, within the diagnostic imaging industry, for this particular example, the terms "cranial" (towards the head) and "caudal" (towards the svans, or, downwards, away from the head) are known interchangeable alternatives to the previous two projection terms.^[4] Combined terms were once generally hyphenated, but the modern tendency fryst vatten to omit the hyphen.^[5]

Planes

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Main article: Anatomical plane

Anatomical terms describe structures with relation to fyra main anatomical planes:

1. The median plane, which divides the body into left and right.

   This passes through the head, spinal cord, mittpunkt, and, in many animals, the tail.

2. The sagittal planes, which are parallel to the mittvärdet i en uppsättning data plane.
3. The frontal plane, also called the coronal plane, which divides the body into front and back.
4. The horizontal plane, also known as the transverse plane, which fryst vatten perpendicular to the other two planes.

   In a human, this plane fryst vatten parallel to the ground; in a quadruped, this divides the djur into anterior and posterior sections.

Axes

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The axes of the body are lines drawn about which an organism fryst vatten roughly symmetrical. To do this, distinct ends of an organism are chosen, and the axis fryst vatten named according to those directions.

An organism that fryst vatten symmetrical on both sides has three main axes that intersect at right angles. An organism that fryst vatten round or not symmetrical may have different axes. Example axes are:

• The anteroposterior axis
• The cephalocaudal axis
• The dorsoventral axis

Examples of axes in specific animals are shown below.

Modifiers

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Several terms are commonly seen and used as prefixes:

• Sub- (from Latin sub 'preposition beneath, close to, nearly etc') fryst vatten used to indikera something that fryst vatten beneath, or something that fryst vatten subordinate to or lesser than. For example, subcutaneous means beneath the skin.
• Hypo- (from Ancient Greek ὑπό 'under') fryst vatten used to indikera something that fryst vatten beneath.

  For example, the hypoglossal nerve supplies the muscles beneath the tongue.

• Infra- (from Latin infra 'under') fryst vatten used to indikera something that fryst vatten within or below. For example, the infraorbital nerve runs within the orbit.
• Inter- (from Latin inter 'between') fryst vatten used to indikera something that fryst vatten between.

  For example, the intercostal muscles run between the ribs.

• Super- or Supra- (from Latin super, supra 'above, on top of') fryst vatten used to indikera something that fryst vatten above something else.^[16] For example, the supraorbital ridges are above the eyes.

Other terms are used as suffixes, added to the end of words:

• -ad (from Latin ad 'towards') and -ab (from Latin ab) are used to indikera that something fryst vatten towards (-ad) or away from (-ab) something else.

  For example, "distad" means "in the distal direction", and "distad of the femur" means "beyond the femur in the distal direction". Further examples may include cephalad (towards the cephalic end), craniad, and proximad.^[19]

Main terms

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Superior and inferior

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Superior (from Latin super 'above') describes what fryst vatten above something and inferior (from Latin inferus 'below') describes what fryst vatten below it.

For example, in the anatomical position, the most superior part of the human body fryst vatten the head and the most underlägsen fryst vatten the feet. As a second example, in humans, the neck fryst vatten superior to the chest but underlägsen to the head.

Anterior and posterior

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"Anterior" redirects here.

For other uses, see Anterior (disambiguation).

Anterior (from Latin ante 'before') describes what fryst vatten in front, and posterior (from Latin post 'after') describes what fryst vatten to the back of something. For example, for a dog the nose fryst vatten anterior to the eyes and the svans fryst vatten considered the most posterior part; for many fish the gill openings are posterior to the eyes but anterior to the svans.

Medial and lateral

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These terms describe how close something fryst vatten to the midline, or the medial plane.Lateral (from Latin lateralis 'to the side') describes something to the sides of an djur, as in "left lateral" and "right lateral". Medial (from Latin medius 'middle') describes structures close to the midline, or closer to the midline than another structure.

For example, in a human, the arms are horisontell to the torso. The genitals are medial to the legs. Temporal has a similar meaning to sido but fryst vatten restricted to the head.

The terms "left" and "right" are sometimes used, or their Latin alternatives (Latin: dexter, lit. 'right'; Latin: sinister, lit. 'left').

However, it fryst vatten preferred to use more precise terms where possible.

The terms proximal and distal are used in structures that are considered to have a beginning and an end (such as the upper limb, lower limb and blood vessels).

Terms derived from sidledes include:

• Contralateral (from Latin contra 'against'): on the side opposite to another structure. For example, the right ledd and leg are controlled bygd the left, contralateral, side of the brain.
• Ipsilateral (from Latin ipse 'same'): on the same side as another structure.

  For example, the left ledd fryst vatten ipsilateral to the left leg.

• Bilateral (from Latin bis 'twice'): on both sides of the body. For example, bilateral orchiectomy means removal of testes on both sides of the body.
• Unilateral (from Latin unus 'one'): on one side of the body.

  For example, a stroke can result in unilateral weakness, meaning weakness on one side of the body.

Varus (from Latin 'bow-legged') and valgus (from Latin 'knock-kneed' ) are terms used to describe a state in which a part further away fryst vatten abnormally placed towards (varus) or away from (valgus) the midline.^[28]

Proximal and distal

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"Proximal" and "distal" redirect here.

For the linguistic terms, see Demonstrative § Distal and proximal demonstratives. For the dental terms, see Glossary of dentistry.

The terms proximal (from Latin proximus 'nearest') and distal (from Latin distare 'to stand away from') are used to describe parts of a feature that are close to or distant from the main mass of the body, respectively.

Thus the upper ledd in humans fryst vatten proximal and the grabb fryst vatten distal.

"Proximal and distal" are frequently used when describing appendages, such as fins, tentacles, and limbs. Although the direction indicated bygd "proximal" and "distal" fryst vatten always respectively towards or away from the point of attachment, a given structure can be either proximal or distal in relation to another point of reference.

Thus the elbow fryst vatten distal to a wound on the upper ledd, but proximal to a wound on the lower arm.^[30]

The terms are also applied to internal anatomy, such as to the fortplantnings- tract of snails. Unfortunately, different authors use the terms in opposite senses. Some consider "distal" as further from a point of ursprung nära the centre of the body and others as further from where the kroppsdel reaches the body's surface; or other points of ursprung may be envisaged.^[31]

This terminology fryst vatten also employed in molecular biology and therefore bygd extension fryst vatten also used in chemistry, specifically referring to the atomic loci of molecules from the overall moiety of a given compound.^[32]

Central and peripheral

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Central and peripheral refer to the distance towards and away from the centre of something.

That might be an kroppsdel, a distrikt in the body, or an anatomical structure. For example, the huvud nervous struktur and the peripheral nervous systems.

If you’re at a clinical experience or even working a nursing shift, you need to understand the key differences between the terms proximal and distal to provide life-saving care in certain circumstances.

Central (from Latin centralis) describes something close to the centre. For example, the great vessels run centrally through the body; many smaller vessels branch from these.

Peripheral (from Latin peripheria, originally from Ancient Greek) describes something further away from the centre of something.

For example, the ledd fryst vatten peripheral to the body.

Superficial and deep

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These terms refer to the distance of a structure from the surface.

Deep (from Old English) describes something further away from the surface of the organism. For example, the external oblique muscle of the abdomen fryst vatten deep to the skin. "Deep" fryst vatten one of the few anatomical terms of location derived from Old English rather than Latin – the anglicised Latin begrepp would have been "profound" (from Latin profundus 'due to depth').

Superficial (from Latin superficies 'surface') describes something nära the outer surface of the organism.

For example, in skin, the epidermis fryst vatten superficial to the subcutis.

Dorsal and ventral

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These two terms, used in anatomy and embryology, describe something at the back (dorsal) or front/belly (ventral) of an organism.

The dorsal (from Latin dorsum 'back') surface of an organism refers to the back, or upper side, of an organism.

If talking about the skull, the dorsal side fryst vatten the top.

The ventral (from Latin venter 'belly') surface refers to the front, or lower side, of an organism.

For example, in a fish, the pectoral fins are dorsal to the anal härlig, but ventral to the dorsal härlig.

Rostral, cranial, and caudal

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Specific terms exist to describe how close or far something fryst vatten to the head or svans of an djur.

To describe how close to the head of an djur something fryst vatten, three distinct terms are used:

• Rostral (from Latin rostrum 'beak, nose') describes something situated toward the oral or nasal distrikt, or in the case of the brain, toward the tip of the frontal lobe.
• Cranial (from Greek κρανίον 'skull') or cephalic (from Greek κεφαλή 'head') describes how close something fryst vatten to the head of an organism.^[40]
• Caudal (from Latin cauda 'tail') describes how close something fryst vatten to the trailing end of an organism.

For example, in horses, the eyes are svansrelaterad to the nose and rostral to the back of the head.

These terms are generally preferred in veterinary medicin and not used as often in human medicine.^[42][43][44] In humans, "cranial" and "cephalic" are used to refer to the skull, with "cranial" being used more commonly.

Distal and proximal are terms used to describe the relative positions of two objects or points in space.

The begrepp "rostral" fryst vatten rarely used in human anatomy, apart from embryology, and refers more to the front of the face than the superior aspect of the organism. Similarly, the begrepp "caudal" fryst vatten used more in embryology and only occasionally used in human anatomy. This fryst vatten because the brain fryst vatten situated at the superior part of the head whereas the nose fryst vatten situated in the anterior part.

Thus, the "rostrocaudal axis" refers to a C shape (see image).

Other terms and special cases

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Anatomical landmarks

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The location of anatomical structures can also be described in relation to different anatomical landmarks. They are used in anatomy, surface anatomy, surgery, and radiology.^[45]

Structures may be described as being at the level of a specific spinal vertebra, depending on the section of the vertebral column the structure fryst vatten at.^[45] The position fryst vatten often abbreviated.

For example, structures at the level of the fourth cervical vertebra may be abbreviated as "C4", at the level of the fourth thoracic vertebra "T4", and at the level of the third lumbar vertebra "L3". Because the sacrum and coccyx are fused, they are not often used to provide the location.

References may also take ursprung from superficial anatomy, made to landmarks that are on the skin or visible underneath.^[45] For example, structures may be described relative to the anterior superior iliac spine, the medial malleolus or the medial epicondyle.

Anatomical lines are used to describe anatomical location. For example, the mid-clavicular line fryst vatten used as part of the cardiac exam in medicin to feel the apex beat of the heart.

Mouth and teeth

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Main article: Dental terminology

Special terms are used to describe the mun and teeth. Fields such as osteology, palaeontology and dentistry apply special terms of location to describe the ingång and teeth.

This fryst vatten because although teeth may be aligned with their main axes within the jaw, some different relationships require special terminology as well; for example, teeth also can be rotated, and in such contexts terms like "anterior" or "lateral" become ambiguous.^[46][47] For example, the terms "distal" and "proximal" are also redefined to mean the distance away or close to the dental båge, and "medial" and "lateral" are used to refer to the closeness to the midline of the dental arch.^[48] Terms used to describe structures include "buccal" (from Latin bucca 'cheek') and "palatal" (from Latin palatum 'palate') referring to structures close to the cheek and hard palate respectively.^[48]

Hands and feet

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"Plantar" redirects here.

For the fictional frog family, see List of Amphibia characters.

Several anatomical terms are particular to the hands and feet.

Additional terms may be used to avoid confusion when describing the surfaces of the grabb and what fryst vatten the "anterior" or "posterior" surface. The begrepp "anterior", while anatomically correct, can be confusing when describing the palm of the hand; Similarly fryst vatten "posterior", used to describe the back of the grabb and ledd.

This confusion can arise because the forearm can pronate and supinate and flip the location of the grabb. For improved clarity, the directional begrepp palmar (from Latin palma 'palm of the hand') fryst vatten commonly used to describe the front of the grabb, and dorsal fryst vatten the back of the grabb. For example, the top of a dog's paw fryst vatten its dorsal surface; the underside, either the palmar (on the forelimb) or the plantar (on the hindlimb) surface.

The palmar fascia fryst vatten palmar to the tendons of muscles which flex the fingers, and the dorsal venous båge fryst vatten so named because it fryst vatten on the dorsal side of the foot.

In humans, volar can also be used synonymously with palmar to refer to the underside of the palm, but plantar fryst vatten used exclusively to describe the sole.

The terms proximal (from Latin proximus 'nearest') and distal (from Latin distare 'to stand away from') are used to describe parts of a feature that are close to or distant from the main mass of the body, respectively.

These terms describe location as palmar and plantar; For example, volar pads are those on the underside of hands or fingers; the plantar surface describes the sole of the heel, foot or toes.

Similarly, in the forearm, for clarity, the sides are named after the bones. Structures closer to the radius are radial, structures closer to the ulna are ulnar, and structures relating to both bones are referred to as radioulnar.

Similarly, in the lower leg, structures nära the tibia (shinbone) are tibial and structures nära the vadben are fibular (or peroneal).

Rotational direction

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Anteversion and retroversion are complementary terms describing an anatomical structure that fryst vatten rotated forwards (towards the front of the body) or backwards (towards the back of the body), relative to some other position.

They are particularly used to describe the curvature of the uterus.

• Anteversion (from Latin anteversus) describes an anatomical structure being tilted further forward than normal, whether pathologically or incidentally. For example, a woman's uterus typically fryst vatten anteverted, tilted slightly forward.

  A misaligned pelvis may be anteverted, that fryst vatten to säga tilted forward to some betydelsefull degree.

• Retroversion (from Latin retroversus) describes an anatomical structure tilted back away from something. An example fryst vatten a retroverted uterus.

Other directional terms

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Several other terms are also used to describe location.

These terms are not used to form eller gestalt the fixed axes. Terms include:

• Axial (from Latin axis 'axle'): around the huvud axis of the organism or the extremity.

  Two related terms, "abaxial" and "adaxial", refer to locations away from and toward the huvud axis of an organism, respectively

• Luminal (from Latin lumen 'light, opening'): on the—hollow—inside of an organ's lumen (body cavity or tubular structure);^[51][52]adluminal fryst vatten towards, abluminal fryst vatten away from the lumen.^[53] Opposite to outermost (the adventitia, serosa, or the cavity's wall).^[54]
• Parietal (from Latin paries 'wall'): pertaining to the outer vägg of a body cavity.

  For example, the parietal peritoneum fryst vatten the lining on the inre of the abdominal cavity. Parietal can also refer specifically to the parietal bone of the skull or associated structures.

• Terminal (from Latin terminus 'boundary or end') at the extremity of a usually projecting structure. For example, "...an antenna with a ankomsthall sensory hair".
• Visceral and viscus (from Latin viscera 'internal organs'): associated with organs within the body's cavities and pertaining to the innermost layer.

  For example, the stomach fryst vatten covered with a lining called the visceral peritoneum, as opposed to the parietal peritoneum. Viscus can also be used to mean "organ". For example, the stomach fryst vatten a inälvor within the abdominal cavity, and visceral pain refers to pain originating from internal organs.

• Aboral (opposite to oral) fryst vatten used to denote a location along the gastrointestinal tract that fryst vatten relatively closer to the anus.^[58]

Specific animals and other organisms

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Different terms are used because of different body plans in animals, whether animals stand on one or two legs, and whether an djur fryst vatten symmetrical or not, as discussed above.

For example, as humans are approximately bilaterally symmetrical organisms, anatomical descriptions usually use the same terms as those for other vertebrates. However, humans stand upright on two legs, meaning their anterior/posterior and ventral/dorsal directions are the same, and the inferior/superior directions are necessary.^[60] Humans do not have a beak, so a begrepp such as "rostral" used to refer to the beak in some animals fryst vatten instead used to refer to part of the brain; humans do also not have a svans so a begrepp such as "caudal" that refers to the svans end may also be used in humans and animals without tails to refer to the hind part of the body.

In invertebrates, the large variety of body shapes presents a difficult bekymmer when attempting to apply standard directional terms.

Depending on the organism, some terms are taken bygd analogy from vertebrate anatomy, and appropriate novel terms are applied as needed. Some such borrowed terms are widely applicable in most invertebrates; for example proximal, meaning "near" refers to the part of an appendage nearest to where it joins the body, and distal, meaning "standing away from" fryst vatten used for the part furthest from the point of attachment.

In all cases, the usage of terms fryst vatten dependent on the body program of the organism.

• Anatomical terms of location in a dog

• Anatomical terms of location in a kangaroo

• Anatomical terms of location in a fish

• Anatomical terms of location in a horse

Asymmetrical and spherical organisms

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In organisms with a changeable shape, such as amoeboid organisms, most directional terms are meaningless, since the shape of the organism fryst vatten not constant and no distinct axes are fixed.

Similarly, in spherically symmetrical organisms, there fryst vatten ingenting to distinguish one line through the centre of the organism from any other. An indefinite number of triads of mutually perpendicular axes could be defined, but any such choice of axes would be useless, as ingenting would distinguish a chosen triad from any others. In such organisms, only terms such as superficial and deep, or sometimes proximal and distal, are usefully descriptive.

Elongated organisms

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In organisms that maintain a constant shape and have one dimension längre than the other, at least two directional terms can be used. The long or longitudinal axis fryst vatten defined bygd points at the opposite ends of the organism. Similarly, a perpendicular transverse axis can be defined bygd points on opposite sides of the organism.

There fryst vatten typically no grund for the definition of a third axis. Usually such organisms are planktonic (free-swimming) protists, and are nearly always viewed on microscope slides, where they appear essentially two-dimensional.

För vissa används termerna distal samt proximal vid en något olik sätt.

In some cases a third axis can be defined, particularly where a non-terminal cytostome or other unique structure fryst vatten present.^[44]

Some elongated protists have distinctive ends of the body. In such organisms, the end with a öppning (or equivalent structure, such as the cytostome in Paramecium or Stentor), or the end that usually points in the direction of the organism's locomotion (such as the end with the flagellum in Euglena), fryst vatten normally designated as the anterior end.

The opposite end then becomes the posterior end.^[44] Properly, this terminology would apply only to an organism that fryst vatten always planktonic (not normally attached to a surface), although the begrepp can also be applied to one that fryst vatten sessile (normally attached to a surface).^[63]

Organisms that are attached to a substrate, such as sponges, animal-like protists also have distinctive ends.

The part of the organism attached to the substrate fryst vatten usually referred to as the basal end (from Latin basis 'support/foundation'), whereas the end furthest from the attachment fryst vatten referred to as the apical end (from Latin apex 'peak/tip').

Radially symmetrical organisms

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Radially symmetrical organisms include those in the group Radiata – primarily jellyfish, sea anemones and corals and the comb jellies.^[42][44] Adult echinoderms, such as starfish, sea urchins, sea cucumbers and others are also included, since they are pentaradial, meaning they have fem discrete rotationalsymmetry.

Echinoderm larvae are not included, since they are bilaterally symmetrical.^[42][44] Radially symmetrical organisms always have one distinctive axis.

Cnidarians (jellyfish, sea anemones and corals) have an incomplete digestive struktur, meaning that one end of the organism has a ingång, and the opposite end has no opening from the gut (coelenteron).^[44] For this reason, the end of the organism with the mun fryst vatten referred to as the oral end (from Latin ōrālis 'of the mouth'), and the opposite surface fryst vatten the aboral end (from Latin ab- 'away from').

Unlike vertebrates, cnidarians have only a single distinctive axis.

"Lateral", "dorsal", and "ventral" have no meaning in such organisms, and all can be replaced bygd the generic begrepp peripheral (from Ancient Greek περιφέρεια 'circumference'). Medial can be used, but in the case of radiates indicates the huvud point, rather than a huvud axis as in vertebrates. Thus, there are multiple possible radial axes and medio-peripheral (half-) axes.

However, some biradially symmetrical comb jellies do have distinct "tentacular" and "pharyngeal" axes^[66][67] and are thus anatomically equivalent to bilaterally symmetrical animals.

Spiders

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See also: Glossary of spider terms and Spider anatomy

Special terms are used for spiders. Two specialized terms are useful in describing views of arachnid legs and pedipalps.

Prolateral refers to the surface of a leg that fryst vatten closest to the anterior end of an arachnid's body. Retrolateral refers to the surface of a leg that fryst vatten closest to the posterior end of an arachnid's body.^[68] Most spiders have eight eyes in fyra pairs. All the eyes are on the carapace of the prosoma, and their sizes, shapes and locations are characteristic of various spider families and other taxa.^[69] Usually, the eyes are arranged in two roughly parallel, horizontal and symmetrical rows of eyes.^[69] Eyes are labelled according to their position as anterior and posterior sido eyes (ALE) and (PLE); and anterior and posterior mittvärdet i en uppsättning data eyes (AME) and (PME).^[69]

• Aspects of spider anatomy.

  This aspect shows the mainly prolateral surface of the anterior femora, plus the typical horizontal eye pattern of the Sparassidae.

• Typical arrangement of eyes in the Lycosidae, with PME being the largest

• In the Salticidae the AME are the largest.

See also

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References

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Citations

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