Claw

The claw (Latin unguis, plural ungues; Latin ungula "claw, claw, hoof, horse"; Latin ungulatus " with claws, provided with hooves "; Latin unguiculus " little nails, nail " Unguicula ) is a solid, mostly curved structure at the end members of the extremities of many animals as protection and to touch.

In many vertebrates ( reptiles, birds, mammals ) she is a grown from callus formation of the toes and fingers ( front toes). Characteristic fundamental component of the claws of the vertebrates is the structural protein keratin, formed by keratinocytes. The bony basis of the claw, the distal finger or phalanx ( distal phalanx ), also referred to as claw bone (os unguiculare ).

The claws on the tarsi of the arthropods are developments of the exoskeleton, its main component is sclerotin with a lower proportion of chitin. There are analogous organs to the claws of vertebrates.

Mammals

The claw- bearing mammals may be referred to as unguiculata in contrast to the Ungulata ( ungulates ), but the term unguiculata is hardly common. The claw is one of the skin appendages and is the nail of humans and apes, and the hoof and claw of ungulates homologous. On the border to normal skin covers the claw back a deeply retracted fold ( Vallum, vallum unguis, nail fold ). In this depression, the dermis has fine villi, their Epidermisüberzug the main part of the horn wall forms (known as coronary horn ). In the wall region of the dermis is the finest papers to find that ensure the anchoring of the claw shoe. At the small rounded sole with a soft horn is formed.

Retraction: The claws of most cats are concealed in a pocket under the skin when they are not needed (not in cheetahs ); an elastic ligament ( dorsal longum ) pulls the claw back passively. An auxiliary ligament ( dorsal breve ) ensures that the claw is laterally past the middle phalanx (claw mechanism ). By train the deep flexor tendon, the claws can be extended. Through this mechanism, the cats claws are spared when running and stay sharp. In addition, cats sharpen their claws by removing the lateral, superficial layers of the hoof wall by constantly.

In contrast, the claws are rubbed with most other claw- bearing mammals while running. For many pets, the abrasion of the claws is less than the length of growth. The claws have to be trimmed regularly.

See also: Wolf claw, claw plaster

Most birds have claws on the toes only. Only the Hoatzin bird carries as a junior in addition claws on its wings.

Birds use their claws to find a firm grip while landing or holding on to trees. Many birds use their claws to hold nesting material or food ( in flight ) or to divide pieces of food, some put their claws in order to catch prey, capture or kill.

Pet birds claws regular cutting is often required because the wear in the cage is too low.

Arthropod

The claws of the arthropods are often called claws. Most claw carrying agents can be found at the end member ( pretarsus ) of the foot ( tarsus ) a pair of claws ( also referred to as unguis ). Rare, only one claw is formed.

Spiders: Spiders In the expression of Tarsus as Trionycha ( Three Kraller or three -claw spinning) or Dionycha ( Two Kraller or two- claws - spiders) of crucial importance and note on different ways of life is. The Dreikrallern include most network be built types. Two Kraller other hand, have held the middle claw setae and are mostly active hunting species like the jumping spiders. However, the classification of spiders in three Kraller and two Kraller not correspond to the taxonomy.

Single Documents

• Anatomy (vertebrates )
• Anatomy (eddy lots)