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Distal Phalanges

Distal phalanges

Distal phalanges (single distal phalanx) are bones found in the limbs of most vertebrate skeletons. In humans, they are the finger bones located furthest from the shoulder joint, and the toe bones located furthest from the hip. They have a corresponding location in the limbs of most other vertebrates, including the fins of whales and the wings of birds. They are also usually conical. Very often, distal phalanges are tipped with claws. In primates, they are covered by a protective nail. Animals which walk digitigrade (such as dogs) tread upon them, and humans commonly use them to push buttons, pinch, and hold small objects.

Distal

In human and zoological anatomy (sometimes called zootomy), several terms are used to describe the location of organs and other structures in the body of bilateral animals. These terms are listed and explained here. In some cases, the terminology in human anatomy may differ from that in general anatomy.
The anatomical position holds more relevant information on relations and terms of location for human anatomy.

Directions

anatomical position

General usage

Animals typically have one end with a head and mouth, with the opposite end often having the anus and tail. The head end is the cranial end; the tail end is the caudal end. Within the head itself, rostral refers to the direction toward the end of the nose, and caudal is still used to refer to the tail direction. The surface or side of the body normally oriented upwards, away from the pull of gravity, is the dorsal side; the opposite side, typically the one closest to the ground when walking on all legs, swimming or flying, is the ventral side. For example: in vertebrates, the spine or nerve chord is located on the dorsal side of the organism. A cow's udder is on the ventral side. A dolphin's dorsal fin is, unsurprisingly, on the dorsal side. On the limbs or other appendages, a point closer to the main body is "proximal"; a point farther away is "distal". The right and left side (sometimes in Latin: dexter - right, and sinister - left) are given as viewed from the animal that is described.

Usage in human anatomy

In human anatomy, the body and its parts are always described using the assumption that the body is in anatomical position (main article), i.e. standing upright. Portions of the body which are closer to the head end are "superior" ("upper"); those which are farther away are "inferior" ("lower") -- superior corresponds to cranial, and inferior to caudal. Objects near the front are "anterior"; those near the rear are "posterior" -- these correspond respectively to "ventral" and "dorsal". The terms "anterior" and "posterior" should not be used when referring to most animals however, and are particularly incorrect for quadrupeds. In this case, rostral/cranial and caudal are more appropriate. Please visit the anatomical position page for more information for terminology for human anatomy.

Relative directions

Structures near the midline are called medial and those near the sides of animals are called lateral. Therefore, medial structures are closer to the midsagittal plane, lateral structures are further from the midsagittal plane. Structures in the midline of the body are median. For example, your cheeks are lateral to your nose and the tip of the nose is in the median line. Ipsilateral means on the same side, contralateral means on the other side and bilateral means on both sides. Structures that are close to the center of the body are proximal or central, while ones far removed are distal or peripheral. For example, the hands are at the distal end of the arms, while the shoulders are at the proximal ends. These terms can also be used relatively to organs, for example the proximal end of the urethra is attached to the bladder. Structures on or closer to the body´s surface are superficial (or external) and those further inside are profound or deep (or internal). When speaking of inner organs, visceral means close to or attached to the organ, while parietal is more distant. For example, the visceral pleura is attached to the lung and the parietal pleura is attached to the chest wall.

Relative directions in the limbs

In the limbs of most animals, the terms cranial and caudal are used in the regions proximal to the carpus (the wrist, in the forelimb) and the tarsus (the ankle in the hindlimb). Objects and surfaces closer to or facing towards the head are cranial; those facing away or further from the head are caudal. This usage is not common in human anatomy, however. Distal to the carpal joint, the term dorsal replaces cranial and palmar replaces caudal. Similarly, distal to the tarsal joint the term dorsal replaces cranial and plantar replaces caudal. For example, the top of a dog's paw is its dorsal surface; the underside, either the palmar (on the forelimb) or the plantar (on the hindlimb) surface. The sides of the forearm are named after its bones: Structures closer to the radius are radial, and structures closer to the ulna are ulnar. Similarly, in the lower leg, structures near the tibia (shinbone) are tibial and structures near the fibula are fibular (or peroneal). Volar, a term which refers to both the palm and the sole, is sometimes used as a synonym for "palmar".

Planes

General usage

Three basic reference planes are used in zoological anatomy. The sagittal plane divides the body into left and right portions. A coronal plane divides the body into dorsal and ventral portions. A transverse plane divides the body into cranial and caudal portions.

Usage in human anatomy

Sometimes the orientation of certain planes need to be distinguished, for instance in medical imaging techniques such as CT scans, MRI scans or PET scans. One imagines a human in anatomical position (standing, arms hanging down with palms to the front) and an X-Y-Z coordinate system with the X-Y plane parallel to the ground, the X-axis going front and back, the Y-axis passing left and right, and the Z-axis going up and down.
- A transverse (also known as axial or horizontal) plane is an X-Y plane, parallel to the ground, which (in humans) separates the superior from the inferior, or put another way, the head from the feet.
- A coronal (also known as frontal) plane is an Y-Z plane, perpendicular to the ground, which (in humans) separates the anterior from the posterior, the front from the back, the ventral from the dorsal.
- A sagittal plane is an X-Z plane, perpendicular to the ground and to the coronal plane, which separates left from right. The midsagittal plane is the specific sagittal plane that is exactly in the middle of the body.

Relative motions

Flexion means approximating adjacent parts of the body (usually at a joint) and extension means separating them. For example, the legs are flexed at the knee joints when sitting down, and extended when standing up. Generally, flexion produces an acute angle between adjacent parts, with its vertex at the joint, and extension produces an obtuse angle. One exception to this rule is in the ankle joint where moving the foot such that the toes move upwards is dorsiflexion and moving the foot such that the toes move downwards is plantar flexion. Adduction means moving a part of the body toward or past its median line or toward the long axis of a limb. Abduction means moving a part of the body away from its median line or away from the long axis of a limb. For example, adducting the thighs brings the legs together, and abducting the thighs spreads the legs apart. Similarly, adducting the fingers or vocal folds brings them into contact with one another, and abducting the fingers or vocal folds spreads them apart. Rotation means moving a part about its long axis, for example, in turning the neck. Supination means rotation of the forearm such that the palm of the hand faces forward or upward, and pronation means rotation of the forearm such that the palm of the hand faces backward or downward; the forearm with the hand is supinated or pronated at the elbow. Similar movements may be accomplished at the ankle, where supination results in the foot tipping inward relative to its long axis, and pronation results in the foot tipping outward; overpronation may contribute to the condition flatfoot. Circumduction refers to the circular movement of a joint or other organ, such as the wrist or the eye. An anterograde motion is in the normal direction of flow, while retrograde means reversed flow. For example, passage of food from the mouth to the stomach is in an anterograde direction, and gastric reflux is in a retrograde direction. Inversion is a turning towards the medial plane, while eversion is turning away from the medial plane.

Vertebrate

Conodonta
Hyperoartia
:Petromyzontidae (lampreys)
Pteraspidomorphi (early jawless fish)
Thelodonti
Anaspida
Cephalaspidomorphi (early jawless fish)
:Galeaspida
:Pituriaspida
:Osteostraci
Gnathostomata (jawed vertebrates)
:Placodermi
:Chondrichthyes (cartilaginous fish)
:Acanthodii
:Osteichthyes (bony fish)
::Actinopterygii (ray-finned fish)
::Sarcopterygii (lobe-finned fish)
:::Actinistia (coelacanths)
:::Dipnoi (lungfish)
:::Tetrapoda ::::Amphibia
::::Amniota
:::::Sauropsida/(Reptiles)
::::::Aves (Birds)
:::::Synapsida
::::::Mammalia Vertebrata is a subphylum of chordates, specifically, those with backbones or spinal columns. Vertebrates started to evolve about 530 million years ago during the Cambrian explosion, which is part of the Cambrian period (first known vertebrate is Myllokunmingia). The bones of the spinal column (or vertebral column) are called vertebrae. Vertebrata is the largest subphylum of chordates, and contains most animals with which people are generally familiar (except insects). Fish (including lampreys, but traditionally not hagfish, though this is now disputed), amphibians, reptiles, birds, and mammals (including humans) are vertebrates. Additional characteristics of the subphylum are a muscular system that mostly consists of paired masses, as well as a central nervous system which is partly located inside the backbone. The internal skeleton which defines vertebrates consists of cartilage or bone, or in some cases both. The skeleton provides support to the organism during the period of growth. For this reason vertebrates can achieve larger sizes than invertebrates, and on average vertebrates are in fact larger. The skeleton of most vertebrates, that is excluding the most primitive ones, consists of a skull, the vertebral column and two pairs of limbs. In some forms of vertebrates, one or both of these pairs of limbs may be absent, such as in snakes or whales. These limbs have been lost in the course of evolution. The skull is thought to have facilitated the development of intelligence as it protects vital organs such as the brain, the eyes and the ears. The protection of these organs is also thought to have positively influenced the development of high responsiveness to the environment often found in vertebrates. Both the vertebral column and the limbs support the body of the vertebrate overall. This support facilitates movement. Movement is normally achieved with muscles that are attached directly to the bones or cartilages. The contour of the body of a vertebrate is formed by the muscles. A skin covers the inner parts of a vertebrate's body. The skin sometimes acts as a structure for protective features, such as horny scales or fur. Feathers are also attached to the skin. The trunk of a vertebrate is hollow and houses the internal organs. The heart and the respiratory organs are protected in the trunk. The heart is located behind the gills, or where there are lungs, in between the lungs. The central nervous system of a vertebrate consists of the brain and the spinal cord. Both of these are characterized by being hollow. In lower vertebrates the brain mostly controls the functioning of the sense organs. In higher vertebrates the size of the brain relative to the size of the body is larger. This larger brain enables more intensive exchange of information between the different parts of the brain. The nerves from the spinal cord, which lies behind the brain, extend to the skin, the inner organs and the muscles. Some nerves are directly connected to the brain, linking the brain with the ears and lungs. Vertebrates have been traced back to the ostracoderms of the Silurian Period (444 million to 409 million years ago) and the conodonts, a group of eel-like vertebrates characterized by multiple pairs of bony toothplates. All vertebrates have: the ability to form bones; paired, specialised sensory organs and a brain.

External links

- [http://tolweb.org/tree?group=Amniota&contgroup=Terrestrial_vertebrates Tree of Life]
- [http://reference.allrefer.com/encyclopedia/categories/vertz.html Vertebrate Zoology] Category:Chordates ko:척추동물 ms:Vertebrata ja:脊椎動物 simple:Vertebrate th:สัตว์มีกระดูกสันหลัง

Skeleton

In biology, the skeleton or skeletal system is the biological system providing support in living organisms. (By extension, non-biological outline structures such as gantries or buildings may also acquire skeletons.) Skeletal systems are commonly divided into three types - external (an exoskeleton), internal (an endoskeleton), and fluid based (a hydrostatic skeleton), though hydrostatic skeletal systems may be classified separately from the other two since they lack hardened support structures. Large external skeletal systems support proportionally less weight than endoskeletons of the same size, and thus many larger animals, such as the vertebrates, have internal skeletal systems. Examples of exoskeletons are found in arthropods, shellfish, and some insects: the skeleton forms a hard shell-like covering protecting the internal organs. The phyla arthropoda and mollusca both have exoskeletons. Since exoskeletons necessarily limit growth, phyla with exoskeletons have come up with various solutions. Most molluscs have calcareous shells and as they grow, the diameter of the shell is enlarged without altering its shape. On the other hand, arthropods shed their exoskeletons to grow, a process known as molting (or ecdysis). During molting the arthropod breaks down their old exoskeleton and then regenerates a new one which they then harden through various processes (such as calcification or sclerotization). An internal skeletal system consists of rigid structures within the body, moved by the muscular system. If the structures are mineralized or ossified, as they are in humans and other mammals, they are referred to as bones. Cartilage is another common component of skeletal systems, supporting and supplementing the skeleton. The human ear and nose are shaped by cartilage. Some organisms have a skeleton consisting entirely of cartilage and without any calcified bones at all, for example sharks. The bones or other rigid structures are connected by ligaments and connected to the muscular system via tendons. Hydrostatic skeletons are similar to a water-filled balloon. Located internally in cnidarians (coral, jellyfish, etc.) and annelids (leeches), among others, these animals can move by contracting the muscles surrounding the fluid-filled pouch, creating pressure within the pouch that causes movement. Animals such as earthworms use their hydrostatic skeletons to change their body shape as they move forward from long and skinny to short and stumpy.

Fin

A fin is a surface used to produce lift and thrust or to steer while traveling in water, air, or other fluid media. The first use of the word was for the limbs of fish, but has been extended to include other animal limbs and man made devices. The foremost use of fins is to ensure the directional stability of an object moving through a fluid such as water or air and may be seen in the use of fletching on arrows and fins at the rear of some missiles, rockets, self-propelled torpedoes, and kinetic energy penetrators. Fins have also been used on automobiles of the late 1950's and early 1960's, promoted then as adding aerodynamic stability but now more realistically evaluated as a rather flamboyant style, particularly in American automobiles of this period. Moving fins may be used to propel an object through lateral thrust (see mechanics). Examples of fin use:
- Propellers usually have a number of fins that work to translate torquing force to lateral thrust, thus propelling a ship. These are also called blades. In the case of high power application it is important to avoid cavitation, caused by excessive negative pressure, as this can cause noise, a loss of power, and damage to the propeller.
- For scuba divers' fins, see swimfin.
- In surfing, a skeg is a stabilizing fin located at the rear of the surfboard. A skeg has the effect of keeping the board moving forward in a controlled manner.
- Constructions of the same purpose as fins (producing thrust, but working in gaseous media) instead are usually called wings or stabilizers with aerodynamics as the governing science. The exception to this is the vertical surface of an aircraft to which the rudder is attached - this is still usually called a fin but is (more formally) called a vertical stabilizer.

Wing

:For some other uses of the word "wing" please see Wing (disambiguation). Wing (disambiguation).]] Wing (disambiguation) A wing is a surface used to produce an aerodynamic force normal to the direction of motion by travelling in air or another gaseous medium, facilitating flight. It is a specific form of airfoil. The first use of the word was for the foremost limbs of birds, but has been extended to include other animal limbs and man-made devices. A wing is an extremely efficient device for generating lift. Its aerodynamic quality, expressed as a Lift-to-drag ratio, can be up to 60 on some gliders and even more. This means that a significantly smaller thrust force can be applied to propel the wing through the air in order to obtain a specified lift.

Use

The most common use of wings is to fly by deflecting air downwards to produce lift, but upside-down wings are also commonly used as a way to produce downforce and hold objects to the ground (for example racing cars). A sailing boat moves by using its sails as wings to produce lift (in the horizontal plane) from the force of the wind.

Artificial wings

Terms used to describe aeroplane wings

Image:Aircraft wing flaps small dsc06830.jpg|Flaps partially deployed Image:Aircraft wing flaps full dsc06835.jpg|Full flaps Image:Aircraft wing flaps full airbrakes dsc06838.jpg|Full flaps, with airbrakes and spoilers deployed for ground braking
- Leading edge: the front edge of the wing
- Trailing edge: the back edge of the wing
- Span: distance from wing tip to wing tip
- Chord: distance from wing leading edge to wing trailing edge, usually measured parallel to the long axis of the fuselage
- Aspect ratio: ratio of span to standard mean chord
- Aerofoil (or Airfoil in US English): the shape of the top and bottom surfaces when viewed as cross sections cut from leading edge to trailing edge.
- Sweep angle: the angle between the perpendicular to the design centreline of the wing in the wing plane, and either the leading edge or 1/4 chord line.
- Twist: gradual change of the airfoil (aerodynamic twist) and/or angle of incidence of the wing cross-sections (geometrical twist) along the span.

Design features

Aeroplane wings may feature some of the following:
- A rounded (rarely sharp) leading edge cross-section
- A sharp trailing edge cross-section
- Leading-edge devices such as slats, slots, or extensions
- Trailing-edge devices such as flaps
- Ailerons (usually near the wingtips) to provide roll control
- Spoilers on the upper surface to disrupt lift and additional roll control
- Vortex generators to help prevent flow separation
- Wing fences to keep flow attached to the wing
- Dihedral, or a positive wing angle to the horizontal. This gives inherent stability in roll. Anhedral, or a negative wing angle to the horizontal, has a destabilising effect
- Folding wings allow more aircarft to be carried in the confined space of the hangar of an aircraft carrier.

Wing types

- Swept wings are wings that are bent back at some angle, instead of sticking straight out from the fuselage.
- Forward-swept wings are high performance wings that are bent forward, the reverse of a traditional swept wing. Forward swept wings are also used in some two seat gliders.
- Elliptical wings (technically wings with an elliptical lift distribution) are theoretically optimum for efficiency at subsonic speeds.
- Delta wings have reasonable performance at subsonic and supersonic speeds and are good at high angles of attack.
- Waveriders are efficient supersonic wings that take advantage of shock waves.
- Rogallo wings are two hollow half-cones of fabric, one of the simplest wings to construct.
- Swing-wings (or variable geometry wings) are able to move in flight to give the benefits of dihedral and delta wing. Although they were originally proposed by German aerodynamicists during the 1940s, they are currently only found on some military aircraft such as the Grumman F-14, Panavia Tornado, General Dynamics F-111, B-1 Lancer, Tupolev Tu-160, MiG-23 and Sukhoi Su-24.
- Ring wings are optimally loaded closed lifting surfaces with higher aerodynamic efficiency than planar wings having the same aspect-ratios. Other non planar wing systems display an aerodynamic efficiency intermediate between ring wings and planar wings. Ring wing

Science of wings

The science behind how wings work can be complex and is one of the principal applications of the science of aerodynamics. However at the simplest level, both the upper and lower surfaces of a wing produces lift by deflecting air downward, which propels the flying body upward with an equal and opposite force (see Newton's Third Law). The air is deflected downwards because of Bernoulli's principle. This relates the pressure of air to its local velocity. If the velocity of the air changes as it flows around an object, such as a wing, the pressure of the air also changes. The shape and the angle of attack of the wing causes the air to flow faster above the wing than below, and so the pressure above the wing is less than below the wing. This pressure difference causes a force, called lift that acts at right angles to the air-flow. The science of wings applies in other areas beyond conventional fixed-wing aircraft, including:
- Helicopters which use a rotating wing with a variable pitch or angle to provide a directional force
- The space shuttle which uses its wings only for lift during its descent
- Formula One cars which use upside-down wings to give cars greater adhesion at high speeds
- Sailing boats which use sails as vertical wings with variable fullness and direction to move across water. Structures with the same purpose as wings, but designed to operate in liquid media, are generally called fins or hydroplanes, with hydrodynamics as the governing science. Applications arise in craft such as hydrofoils and submarines. Interestingly sailing boats use both fins and wings.

Evolution of wings in animals

Biologists believe that animal wings evolved at least four separate times, an example of convergent evolution. Insect wings are believed to have evolved about 300 million years ago, pterosaur wings about 225 million years ago, bird wings about 150 million years ago, and bat wings about 55 million years ago. Wings in these groups are analogous structures because they evolved independently rather than being passed from a common ancestor. See also flight.

External links

- [http://www.av8n.com/how/ An Excellent treatment of why and how wings generate lift]
- [http://www.npr.org/templates/story/story.php?storyId=3875411 Demystifying the Science of Flight] - Audio segment on NPR's Talk of the Nation Science Friday
- [http://www.grc.nasa.gov/WWW/K-12/airplane/short.html NASA's explanations and simulations]
- [http://aerodyn.org/Wings/ Advanced Topics in Aerodynamics] Wings for all speeds
- [http://www.nurseminerva.co.uk/adapt/evolutio.htm Evolution of flight] in animals
- [http://jef.raskincenter.org/published/coanda_effect.html Explanation invoking Coanda Effect] Category:Aerospace engineering Category:Aerodynamics Category:Aircraft components ja:翼

Cone (geometry)

Suppose

V

is a real (or complex) vector space with a subset

C

. If

\lambda C \subset C

for any real

\lambda >0

, then

C

is a cone. If the origin belongs to a cone, then the cone is called pointed. Otherwise, the cone is called blunt. A pointed cone is salient, if it contains no 1-dimensional vector subspace of

V

. If

C-x_0

is a cone for some

x_0 \in V

, then

C

is a cone with vertex at

x_0

. A proper cone is a cone

C \subset \R^n

that satisfies the following:
-

C

is convex;
-

C

is closed;
-

C

is solid, meaning it has nonempty interior;
-

C

is pointed, meaning

x, -x\in C\Rightarrow x=0

. A proper cone

C

induces a partial ordering "<=" on

\R^n

: :

a <= b\Leftrightarrow b-a\in C

Examples

#In

\R^1

, the set

x>0

is a salient blunt cone. #Suppose

x\in \R^n

. Then for any

\varepsilon>0

, the set

C=\bigcup \

is an open cone. If

|x| < \varepsilon

, then

C=\R^n

. Here,

B_x(\varepsilon)

is the open ball at

x

with radius

\varepsilon

Properties

#The union and intersection of a collection of cones is a cone. #A set

C

in a real (or complex) vector space is a convex cone if and only if #:

\lambda C \subset C,

for all

\lambda>0,

C+C\subset  C.

#For a convex pointed cone

C

, the set

C\cap (-C)

is the largest vector subspace contained in

C

. #A pointed convex cone

C

is salient if and only if

C\cap (-C)=\.

References

-
- Category:geometry

Claw

:This article relates to the claw in anatomy. For the 1927 Hollywood motion picture directed by Sidney Olcott, see Claw. A claw is a curved pointed growth found at the end of a toe or finger, or in arthropods, of the tarsus. The claws of arthropods are sometimes called pincers. In tetrapods, claws are made of keratin, and consist of two layers. The unguis is the harder external layer which consists of keratin fibers perpendicular to the direction of growth arranged in layers at an oblique angle; and the subunguis is the softer, flaky underside layer whose grain is parallel to the direction of growth. The claw grows outward from the nail matrix at the base of the unguis, and the subunguis grows thicker while travelling across the nail bed. The unguis grows outward faster than the subunguis to produce a curve, and the thinner sides of the claw wear away faster than their thicker middle, producing a more or less sharp point. Tetrapods use their claws in many ways, commonly to grasp or kill prey, to dig, and to climb and hang. A nail is homologous to a claw, but is flatter and has a curved edge instead of a point. A nail that is big enough to walk on is called a hoof. A talon is the claw of a bird of prey. Every so often, the growth of claws stops and restarts, as does hair. In hair, this results in the hair falling out and being replaced by a new one; in claws, this results in an abscission layer, and the old segment breaks off. This process takes several months for human thumbnails; cats are often seen working old unguis layers off on wood or on boards made for the purpose. Many predators have retractile (retractable) claws that can partially hide inside the animal's limb.

External links

- [http://www.ratbehavior.org/claws.htm Rat's Claws], also explains much about mammalian claws in general. Category:zootomy th:กีบ (เล็บเท้าสัตว์)

Primate

:For the ecclesiastical use of this term, see primate (religion) A primate is any member of the biological order Primates, the group that contains all lemurs, monkeys, apes, and humans. The English singular primate is a back-formation from the Latin name Primates, which itself was the plural of the Latin primas ("one of the first, excellent, noble"). Colin Groves lists about 350 species of primates in Primate Taxonomy. All primates have five fingers (pentadactyly), a generalized dental pattern, and a primitive (unspecialized) body plan. Another distinguishing feature of primates is fingernails. Opposing thumbs are also a characteristic primate feature, but are not limited to this order; opossums, for example, also have opposing thumbs. In primates, the combination of opposing thumbs, short fingernails (rather than claws) and long, inward-closing fingers is a relic of the ancestral practice of brachiating through trees. Forward-facing color binocular vision was also useful for the brachiating ancestors of humans, particularly for finding and collecting food. All primates, even those that lack the features typical of other primates (like lorises), share eye orbit characteristics, such as a postorbital bar, that distinguish them from other taxonomic orders. __TOC__

Relative sizes

As the table below illustrates, in many primate species, the males are larger than the females. However this picture is incomplete. All but one of these are Old World species, and in this group the mating system is usually polygynous; sexual dimorphism is expected with this kind of social structure. As the table shows, sexual dimorphism is much less in the marmosets (New World) than in the other species listed, and this is characteristic of marmosets and tamarins in comparison with the Old World monkeys and apes. This is because marmosets and tamarins generally form pair bonds.

Classification and evolution

Close relations

The Primate order lies in a tight clustering of related orders (the Euarchontoglires) within the Eutheria, a subclass of Mammalia. Recent molecular genetic research on primates, flying lemurs, and tree shrews has shown that the two species of flying lemur (Dermoptera) are more closely related to the primates than the tree shrews of the order Scandentia, even though the tree shrews were at one time considered primates. These three orders make up the Euarchonta clade. This clade combines with the Glires clade (made up of the Rodentia and Lagomorpha) to form the Euarchontoglires clade. Variously, both Euarchonta and Euarchontoglires are ranked as superorders. Also, some scientists consider Dermoptera a suborder of Primates and call the "true" primates the suborder Euprimates. Euarchontoglires |--Glires | |--rodents (Rodentia) | |--rabbits, hares, pikas (Lagomorpha) \--Euarchonta |--tree shrews (Scandentia) \--N.N. |--flying lemurs (Dermoptera) \--N.N. |--Plesiadapiformes (extinct) \--primates (Primates)

Classification

In older classifications, the Primates were divided into two superfamilies: Prosimii and Anthropoidea. The Prosimii included all of the prosimians: all of Strepsirrhini plus the tarsiers. The Anthropoidea contained all of the simians. In modern, cladistic reckonings, the Primate order is also a true clade. The suborder Strepsirrhini, the "wet-nosed" primates, split off from the primitive primate line about 63 million years ago. The seven strepsirhine families are the four related lemur families and the three remaining families that include the lorises, the Aye-aye, the galagos, and the pottos. Some classification schemes wrap the Lepilemuridae into the Lemuridae and the Galagidae into the Lorisidae, yielding a three-two family split instead of the four-three split as presented here. Other lineages of lower primates inhabited Earth. During the Eocene, most of the northern continents were dominated by two dominant groups, the adapids and the omomyids. The former is considered a member of Strepsirrhini, but it does not have a tooth comb like modern lemurs. The latter was related closely to tarsiers, monkeys, and apes. Adapids survived until 10 mya; omomyids on the other hand perished 20 million years earlier. The Aye-aye is difficult to place in Strepsirrhini. Its family, Daubentoniidae, could be a lemuriform primate and its ancestors split from lemur line more recently than the lemurs and lorises split, about 50 mya. Otherwise it is sister to all of the other strepsirrhines, in which case in evolved away from the main strepsirrhine line between 50 and 63 mya. The suborder Haplorrhini, the "dry-nosed" primates, is composed of two sister clades. The prosimian tarsiers in family Tarsiidae (monotypic in its own infraorder Tarsiiformes), represent the most primitive division at about 58 mya. The Simiiformes contain the two unranked clades the New World monkeys in one, and the Old World monkeys, humans and the other apes in the other. This division happened about 40 mya. However about 30 mya, three groups split from the main haplorrhine lineage. One group stayed in Asia and are closest in kin to the "dawn monkey" Eosimias. The second stayed in Africa, where they developed into the Old World monkeys. The third rafted to South America to become the New World monkeys. Mysteriously the aboriginal Asian Haplorrhini vanished from record once Africa collided with Eurasia 24 mya. Apes and monkeys spread into Europe and Asia. Close behind came lorises and tarsiers, also African castaways. The first hominid fossils were discovered in Northern Africa and date back 7 mya. Modern humans did not appear until 0.2 mya, eventually becoming the most prevalent primate and mammal on Earth.

Extant primate families

- ORDER PRIMATES
- Suborder Strepsirrhini: non-tarsier prosimians
- Infraorder Lemuriformes
- Superfamily Cheirogaleoidea
-
- Family Cheirogaleidae: dwarf lemurs and mouse-lemurs
- Superfamily Lemuroidea
-
- Family Lemuridae: lemurs
-
- Family Lepilemuridae: sportive lemurs
-
- Family Indridae: woolly lemurs and allies
- Infraorder Chiromyiformes
- Family Daubentoniidae: Aye-aye
- Infraorder Lorisiformes
- Family Lorisidae: lorises, pottos and allies
- Family Galagidae: galagos
- Suborder Haplorrhini: tarsiers, monkeys and apes
- Infraorder Tarsiiformes
- Family Tarsiidae: tarsiers
- Infraorder Simiiformes
- Platyrrhini: New World monkeys
-
- Family Cebidae: marmosets, tamarins, capuchins and squirrel monkeys
-
- Family Aotidae: night monkeys, owl monkeys, douroucoulis
-
- Family Pitheciidae: titis, sakis and uakaris
-
- Family Atelidae: howler, spider and woolly monkeys
- Catarrhini
-
- Superfamily Cercopithecoidea
-
- Family Cercopithecidae: Old World monkeys
-
- Superfamily Hominoidea
-
- Family Hylobatidae: gibbons or "lesser apes"
-
- Family Hominidae: humans and other great apes

Some prehistoric primates

- Adapis, an adapid
- Australopithecus, a hominid
- Branisella, an early New World monkey
- Dryopithecus, an early ape
- Eosimias, an early catarrhine
- Homo antecessor, the first relatives of humans in Europe
- Homo erectus, the first hominin outside Africa
- Homo floresiensis, the smallest near-human species
- Homo neanderthalensis, the Neanderthal Man
- Gigantopithecus, the largest ape
- Godinotia, an adapid
- Megaladapis, a giant lemur
- Notharctus, an adapid
- Plesiopithecus, a relative of lorises and galagos
- Protopithecus, a giant New World monkey
- Sivapithecus, an early ape
- Tielhardina, the earliest haplorrhines
- Victoriapithecus, an early Old World monkey

Primate hybrids

In "The Variation Of Animals And Plants Under Domestication" Charles Darwin noted: "Several members of the family of Lemurs have produced hybrids in the Zoological Gardens." Many gibbons are hard to identify based on fur coloration and are identified either by song or genetics. These morphological ambiguities have led to hybrids in zoos. Zoo gibbons usually come from the black market pet trade in Southeast Asia, which transported gibbons across countries all over the region. As a result, perhaps as much as 95% of zoo gibbons are of unknown geographic origin. As most zoos rely on morphological variation or labels that are impossible to verify to assign species and subspecies names, it is unfortunately common for gibbons to be misidentified and housed together. For example, some collections' supposedly pure breeding pairs were actually mixed pairs or hybrids from previous mixed pairs. The hybrid offspring were sent to other gibbon breeders and led to further hybridization in captive gibbons. Within-genus hybrids also occur in wild gibbons where the ranges overlap (Agile Gibbons and Pileated Gibbons x Lar Gibbons, Agile Gibbons x Müller's Bornean Gibbon, Yellow-cheeked Gibbons x Northern White-cheeked Gibbons). Intergeneric gibbon hybridizations have only occurred in captivity. Silvery Gibbons (Hylobates moloch) and Müller's Bornean Gibbon (H. muelleri) have hybridized with Siamangs (Symphalangus syndactylus) in captivity - a female Siamang produced hybrid "Siabon" offspring on 2 occasions when housed with a male gibbon; only one hybrid survived. Anubis Baboons and Hamadryas Baboons have hybridized in the wild where their ranges meet. A Rheboon is a captive-bred Rhesus Macaque/Hamadryas Baboon hybrid with a baboon-like body shape and macaque-like tail. Different macaque species can interbreed. In "The Variation Of Animals And Plants Under Domestication" Charles Darwin wrote: A Macacus, according to Flourens, bred in Paris; and more than one species of this genus has produced young in London, especially the Macacus rhesus, which everywhere shows a special capacity to breed under confinement. Hybrids have been produced both in Paris and London from this same genus. The Japanese Macaque (Macaca fuscata) has interbred with the introduced Taiwanese Macacque (M. cyclopis) when the latter escaped into the wild from private zoos. Various hybrid monkeys are bred within the pet trade, for example:
- Hybrid capuchin monkeys e.g. Tufted Capuchin (Cebus apella) x Weeper Capuchin (C. olivaceus)
- Liontail Macaque x Pigtail Macaque hybrids
- Rhesus Macaque x Stumptail Macaque hybrids. Among Old World monkeys, natural hybridization is not uncommon. There numerous field reports of hybrid monkeys and detailed studies of zones where species overlap and hybrids occur. Among the great apes, Sumatran and Bornean orangutans are considered separate species with anatomical differences, producing sterile or poorly fertile hybrids. Hybrid orangutans are genetically weaker, with lower survival rates than pure animals.

Legal status

orangutan Human primates are recognized as persons and protected in law by the United Nations Universal Declaration of Human Rights [http://www.un.org/Overview/rights.html] and by all governments, though to varying degrees. Non-human primates are not classified as persons, which means their individual interests have no formal recognition or protection. The status of other apes particularly—as our closest genetic cousins—has generated much debate, particularly through the Great Ape Project [http://www.greatapeproject.org/declaration.html] which argues for their personhood. Thousands of primates are used every year around the world in scientific experiments because of their psychological and physiological similarity to humans. The species most commonly used are chimpanzees, baboons, marmosets, macaques, and African green monkeys. In the European Union, around 10,000 were used in 2004, with 4,799 experiments conducted on 3,073 non-human primates in the UK alone in 2003. [http://www.buav.org/campaigns/primates]. As of 2004, 3,100 non-human great apes were living in captivity in the United States, in zoos, circuses, and laboratories, 1,280 of them being used in experiments. [http://www.greatapeproject.org/news.html]

References

- Primate Taxonomy (Smithsonian Institute Press, 2001), Colin Groves (ISBN 156098872X)
- Primates in Question (Smithsonian Institute Press, 2003), Robert W. Shumaker & Benjamin B. Beck (ISBN 1-58834-176-3)
- Mammal Species of the World, 3rd ed. (The Johns Hopkins University Press, 2005), Don E. Wilson & DeeAnn M. Reeder (ISBN 0801882214)
- [http://primate-brain.org High-Resolution Cytoarchitectural Primate Brain Atlases]
- [http://pin.primate.wisc.edu Primate Info Net]
- [http://www.buav.org/campaigns/primates British Union for the Abolition of Vivisection - Primates]
- [http://www.greatapeproject.org/declaration.html Declaration on Great Apes], Great Ape Project ko:영장류 ja:サル目

Nail (anatomy)

: This article discusses the anatomical nail. For other uses of the term, see nail. nail nail In anatomy, a nail is a horn-like piece at the end of a human or animal finger or toe. See also claw. Fingernails and toenails are composed of:
- the nail matrix or the root of the nail - this is the growing part of the nail still under the skin at the nail's proximal end.
- eponychium or cuticle which is the fold of skin at the proximal end of the nail.
- paronychium which is the fold of skin on the sides of the nail.
- hyponychium which is the attachment between the skin of the finger or toe and the distal end of the nail.
- nail plate which is what we think of when we say nail, the hard and translucent portion, composed of keratin.
- nail bed which is the adherent connective tissue that underlies the nail.
- lunula which is the crescent shaped whitish area of the nail bed. Fingernails require 3 to 6 months to regrow completely. Toenails require 12 to 18 months. Any major illness will cause a groove to form in the nails, marking in time the past medical history of its owner. These are called Beau's lines. Nails grow at an average rate of 0.1 mm/day (1 cm every 100 days) . The average is not constant, though, and actual growth rate is dependent upon age, season, exercise level, and hereditary factors. Nails can become thickened (onychogryphosis), loosened (onycholysis), infected with fungus (onychomycosis) or degenerative (onychodystrophy); for further information see nail diseases.

Care

A manicure or pedicure is a health and cosmetic procedure to groom, trim, and paint the nails. It is accomplished with cuticle scissors, nail scissors, nail clippers, and nail files, among various other tools. To paint the nails, nail lacquer (also known as nail polish or fingernail polish) is manually applied and allowed to dry. In 2003 the first ink nail printer NailJet Pro was released. It allowed individuals to print custom hi-resolution colour images on their nails. In some parts of Asia, similar but larger nail-art printers have been set up near bookstores and other popular destinations of young people. They work much like picture-taking booths. 2003

Fashion and culture

In the late 20th century, artificial nails for women became widely popular. The artificial nails are not a replacement, but an extension for natural nails. There are two main approaches to creating artificial nails—tips and forms. Tips are lightweight plates that are glued on the natural nail. Forms are fit over the nail and then an artificial nail is molded and the form is removed. With both approaches several materials can be used to glue the tips of form artificial nails. One popular material is acryl—a mixture of powder and ethymethacrylate that hardens in 30–40 seconds after application. Acryl can be removed in 20 minutes using a variety of solvents. Another material, gel, hardens under ultraviolet light and is more lasting and more expensive. It can only be removed by cutting it off. Other materials can be used, as well as combinations of them. There are also cheaper flexible tips that can be quickly glued at home without help from a professional. Artificial nails are produced in a variety of colours and can use "special effects" such as contours and sparkles. In some (Asian) cultures men also will grow long fingernails, or only the nail on the little finger, to show that they do not do much manual labor, but instead work in an office setting. Some guitar players, notably classical and fingerstyle players, will purposely grow long nails on one hand. Their longer nails serve as small, easily-maneuverable guitar picks. Care thereof becomes a daily ritual and a mark of pride. Though this attention may seem effeminate, it is a mark of the dedication that accompanies the serious musician.

Torture

The whole area of the nail is connected to the finger. Thus, the removal of a nail can be painful. Sometimes this has to be done for medical reasons (for example, if the nail becomes infected or mechanically damaged; this is usually done under anesthesia). Because the procedure is extremely painful, its variations were widely used for torture in the past and are still used occasionally. One variation is pulling the nail off completely with some kind of pliers. It was usually administered together with other methods of torture. Another variation is inserting sharp objects under the nails, including needles and metal nails. If sterile and sufficiently small tools are used, this method will not leave any permanent damage, while still causing excruciating pain.

Myth

It is commonly claimed that nails and hair will continue growing for several days after death. This is a myth; the appearance of growth is actually caused by the retraction of skin as the surrounding tissue dehydrates, making nails and hair more prominent.

Biting

Many people bite their nails. It is considered to be a mildly embarrassing habit in some cultures. It does not break the taboo of cannibalism against eating parts of the human body. Biting one's nails can indicate internal tension or stress. However, biting the nails can result in the transportation of germs that are buried under the surface of the nail into the mouth. In fact, nail salons use tools that potentially affect a human in a similar way. Regarding nail tools such as files, "If they're used on different people, these tools may spread nail fungi, staph bacteria or viruses," warns Rick Lopes, a spokesperson for the California Board of Barbering and Cosmetology. In fact, over 100 bacterial skin infections in 2000 were traced to footbaths in nail salons. Thus, one can see that many pathogens have the ability to "live" inside of a nail, and because of this biting the nails can potentially cause health "issues."

References

# [http://www.aad.org/public/Publications/pamphlets/NailHealth.htm American Academy of Dermatology - Nail Health] # [http://www.imaginail.com ImagiNail Website] # [http://www.diginailart.com Digi Nail Art Website] # Tram Kim Nguyen, [http://www.fitnessmagazine.com/fitness_and_health/070303_germs.jsp "The Truth About Germs"], Fitness Magazine. Accessed 10 April 2005. Category:Integumentary system ja:爪

Digitigrade locomotion

A digitigrade is an animal that stands or walks on its digits, or toes. Digitigrades include walking cats, dogs, and most other mammals, excepting humans, bears, and a few others. They are generally faster and quieter than other types of animals. While humans usually walk with the soles of their feet on the ground (plantigrade locomotion), digitigrade animals walk on their distal and intermediate phalanges. Digitigrade locomotion is responsible for the distinctive hooked shape of dog legs. There are anatomical differences between a plantigrade and digitigrade limb. Digitigrade animals have relatively long carpals and tarsals, and the bones which would correspond to the human ankle are thus set much higher in the limb than in a human. This effectively lengthens the foot, so much so that a digitigrade animal's "hands" and "feet" are often thought to correspond only to what would be the bones of the human toe or finger. Because so little surface area needs to get off the ground, and also because of the added length of the foot, digitigrade locomotion tends to be swift.

Examples of digitigrades

- canidae
- wolf
- dog
- coyote
- felines
- cat
- lion
- hippopotamuses
- elephants

References

- [http://www.cvm.uiuc.edu/petcolumns/showarticle.cfm?id=118 Yes, the Shin Bone Is Connected to the Ankle Bone] Category:Locomotion

Terms for anatomical location

Directions

anatomical position

General usage

Usage in human anatomy

Relative directions

Relative directions in the limbs

Planes

General usage

Usage in human anatomy

Relative motions

Wheelwright, Kentucky

Wheelwright esas urbo en Floyd Komtio, Kentucky. Segun la 2000 kontado, la tota populo di la urbo esis 1,042.

Geografio

2000 Wheelwright jacas a . Segun la Usana Kontado Ministerio, la urbo havas tota areo di 4.5 km² (1.7 mi²). 4.5 km² (1.7 mi²) di qua esas lando e nulo kovresas per aquo.

Demografio

Segun la kontado di 2000 esas 1,042 homi, 203 hemanari, e 146 familii qui rezidas en la urbo. La lojanto-denseso esas 231.2/km² (598.0/mi²). Esas 236 domi kun mezala denseso di 52.4/km² (135.4/mi²). La rasi en la urbo inkludas 63.15% Blanka, 34.74% Nigra o Afrika-usana, 0.00% Indijena amerikana, 0.10% Aziana, 0.00% Pacifika Insulana, 1.25% de altra rasi, e 0.77% de du o plu rasi. 1.73% de la populo esas Hispana o Latina de irga raso. Esas 203 heminari di qua 36.0% havas pueri sub la evo di 18 en la domo, 53.7% esas mariajita e habitas kune, 16.3% havas homina domo-maestro sen spozulo, e 27.6% esas ne-familii. 26.1% de omna hemanari facesas ek individui e 10.3% havas ulu qua habitas sole qua evas 65 yari o plu evoza. La mezala grandeso di hemanari esas 2.53 e la mezala grandeso di familii esas 3.08. La nombro di lojanti e lia evi esas: 13.7% sub la evo di 18, 22.7% de 18 til 24, 43.4% de 25 til 44, 13.6% de 45 til 64, e 6.5% qui evas 65 yari o plus. La mezala evo esas 29 yari. Po 100 homini esas 290.3 homuli. Po 100 homini 18 yari o plus esas 330.1 homuli. La mezala revenuo di hemanaro en la urbo esas $14,808, e la mezala revenuo por familio esas $20,625. Homuli havas mezala revenuo di $30,625 kontre $16,563 por homini. La revenuo per capita por la urbo esas $5,367. 40.0% de la populo e 36.8% de familii esas sub la povreso-lineo. Ek la tota populo, 47.0% di qui sub la evo di 18 e 11.6% de ti qui evas 65 o plus habitas sub la povreso-lineo . Category:Floyd Komtio, Kentucky Category:Urbi en Kentucky

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