instance_of hand
Invertebrates are animals that neither possess nor develop a vertebral ___MASK72___ ( commonly known as a " backbone " or " spine "), derived from the notochord . This includes all animals apart from the subphylum Vertebrata . Familiar examples of invertebrates include insects ; crabs , lobsters and their ___MASK20___ ; snails , clams , octopuses and their ___MASK20___ ; starfish , ___MASK9___ - urchins and their ___MASK20___ ; and worms . The knee ___MASK91___ joins the thigh with the leg and consists of two articulations : one between the femur and tibia ( tibiofemoral ___MASK91___ ), and one between the femur and patella ( patellofemoral ___MASK91___ ). It is the largest ___MASK91___ in the ___MASK8___ . The knee is a modified hinge ___MASK91___ , which permits flexion and extension as well as slight internal and external rotation . The knee ___MASK91___ is vulnerable to injury and to the development of osteoarthritis . A forelimb is an anterior ___MASK82___ ( arm , leg , or similar appendage ) on a terrestrial vertebrate ' s body . For quadrupeds , the term foreleg is often used instead . ( A forearm however is the ___MASK64___ of the arm or forelimb between the elbow and the wrist .) A hand ( Latin manus ) is a prehensile , multi - fingered ___MASK32___ located at the end of the forearm or forelimb of primates such as humans , chimpanzees , monkeys , and lemurs . A few other vertebrates such as the koala ( which has two opposable thumbs on each `` hand '' and fingerprints remarkably similar to human fingerprints ) are often described as having `` hands '' instead of paws on their ___MASK52___ limbs . The raccoon is usually described as having `` hands '' though opposable thumbs are lacking . Fingers contain some of the densest areas of nerve endings on the body , are the richest source of tactile feedback , and have the greatest positioning capability of the body ; thus the sense of touch is intimately associated with hands . Like other paired organs ( eyes , feet , legs ) each hand is dominantly controlled by the opposing brain hemisphere , so that handedness -- the preferred hand choice for single - handed activities such as writing with a pencil , reflects individual brain functioning . Some evolutionary anatomists use the term hand to refer to the appendage of digits on the forelimb more generally -- for example , in the context of whether the three digits of the bird hand involved the same homologous loss of two digits as in the dinosaur hand . The human hand has five fingers and 27 bones , not including the sesamoid bone , the number of which varies between people , 14 of which are the phalanges ( proximal , intermediate and distal ) of the fingers . The metacarpal bones connect the fingers and the carpal bones of the wrist . Each human hand has five metacarpals and eight carpal bones . Among humans , the hands play an important function in body language and sign language . Procyon , also designated Alpha Canis Minoris (  Canis Minoris , abbreviated Alpha CMi ,  CMi ), is the brightest ___MASK92___ in the constellation of Canis Minor . To the naked eye , it appears to be a ___MASK38___ ___MASK92___ , the eighth - brightest in the night sky with a visual apparent magnitude of 0 . 34 . It is a binary ___MASK92___ system , consisting of a white main - sequence ___MASK92___ of spectral type F5 IV  V , named Procyon A , and a faint white dwarf companion of spectral type DQZ , named Procyon B . Animals are multicellular , eukaryotic organisms of the kingdom Animalia ( also called Metazoa ). The ___MASK78___ kingdom emerged as a basal ___MASK58___ within Apoikozoa as a sister of the choanoflagellates . Sponges are the most basal ___MASK58___ of animals . Animals are motile , meaning they can move spontaneously and independently at some point in their lives . Their body ___MASK77___ eventually becomes fixed as they develop , although some undergo a process of metamorphosis later in their lives . All animals are heterotrophs : they must ingest other organisms or their products for sustenance . ___MASK23___ is the branch of biology concerned with the study of the structure of organisms and their parts . ___MASK23___ is inherently tied to embryology , comparative ___MASK23___ , evolutionary biology , and phylogeny , as these are the processes by which ___MASK23___ is generated over immediate ( embryology ) and long ( evolution ) timescales . Human ___MASK23___ is one of the basic essential sciences of medicine . The upper ___MASK82___ or upper extremity is the region in a vertebrate animal extending from the deltoid region to the hand , including the arm , axilla and shoulder . Mammals are any vertebrates within the ___MASK19___ Mammalia ( from Latin " mamma " " breast "), a ___MASK58___ of endothermic amniotes distinguished from reptiles and birds by the possession of a neocortex ( a region of the ___MASK66___ ), hair , three middle ear bones and mammary glands . The sister group of mammals may be the extinct " Haldanodon ." The mammals represent the only living Synapsida , which together with the Sauropsida form the Amniota ___MASK58___ . The mammals consist of the Yinotheria including monotrema and the Theriiformes including the theria . The Hominini is a taxonomical ___MASK57___ of the subfamily Homininae ; it comprises three subtribes : Hominina , with its one ___MASK7___ " Homo "; Australopithecina , comprising at least three extinct genera ( see inset at bottom right ); and Panina , with its one ___MASK7___ " Pan ", the chimpanzees ( see the evolutionary ___MASK6___ below ). Members of the human clade , that is , the Hominina , including " Homo " and those species of the australopithecines that arose " after " the split from the chimpanzees , are called homininans . Not all homininans are directly related to the emergence of early " Homo ". A modern cladogram is given by In ___MASK80___ ___MASK23___ , the wrist is variously defined as 1 ) the carpus or carpal bones , the complex of eight bones forming the proximal skeletal segment of the hand ; ( 2 ) the wrist joint or radiocarpal joint , the joint between the radius and the carpus ; and ( 3 ) the ___MASK70___ surrounding the carpus including the distal parts of the bones of the forearm and the proximal parts of the metacarpus or ___MASK49___ metacarpal bones and the series of joints between these bones , thus referred to as " wrist joints ". This region also includes the carpal tunnel , the anatomical snuff box , the flexor retinaculum , and the extensor retinaculum . ___MASK11___ refers variously to the collected myths of a group of ___MASK88___ or to the study of such myths . Myths are the stories ___MASK88___ ___MASK81___ to explain nature , history and customs . Vertebrates comprise all ___MASK85___ of animals within the subphylum Vertebrata ( chordates with backbones ). Vertebrates represent the overwhelming majority of the phylum Chordata , with currently about 64 , 000 ___MASK85___ described . Vertebrates include the jawless ___MASK42___ and the jawed vertebrates , which include the cartilaginous ___MASK42___ ( sharks and rays ) and the bony ___MASK42___ . ___MASK10___ is used in ___MASK5___ to the hair of animals , usually mammals , particularly those with extensive body hair coverage that is generally soft and thick , as opposed to the stiffer bristles on most pigs . The term " pelage " first known use in English c . 1828 ( French , from Middle French , from " poil " hair , from Old French " peilss ", from Latin " pilus ",) is sometimes used to refer to the body hair of an animal as a complete coat . " ___MASK10___ " is also used to refer to animal pelts which have been processed into leather with the hair still attached . The words " fur " or " furry " are also used , more casually , to refer to hair - like growths or formations , particularly when the subject being referred to exhibits a dense coat of ___MASK37___ , soft " hairs ." If layered , rather than grown as a ___MASK38___ coat , it may consist of short down hairs , long guard hairs , and , in some cases , medium awn hairs . Mammals with reduced amounts of fur are often called " naked ", as with the naked mole - rat , or " hairless ", as with hairless dogs . The raccoon ( or , " Procyon lotor "), sometimes spelled racoon , also known as the common raccoon , North American raccoon , northern raccoon and colloquially as coon , is a medium - sized mammal native to North America . The raccoon is the largest of the procyonid ___MASK53___ , having a body length of and a body weight of . Its grayish coat mostly consists of dense underfur which insulates it against cold weather . Two of the raccoon ' s most distinctive features are its extremely dexterous ___MASK52___ paws and its facial mask , which are themes in the mythology of several Native American ethnic groups . Raccoons are noted for their intelligence , with studies showing that they are able to remember the solution to tasks for up to three years . The diet of the omnivorous raccoon , which is usually nocturnal , consists of about 40 % invertebrates , 33 % plant foods , and 27 % vertebrates . ___MASK43___ is the ___MASK7___ that comprises the species " ___MASK43___ sapiens ", which includes modern humans , as well as several extinct species classified as ancestral to or closely related to modern humans , most notably " ___MASK43___ erectus ". The ___MASK7___ is between 2 and 3 million years old , taken to emerge with the appearance of " ___MASK43___ habilis ". It is derived from the ___MASK7___ " Australopithecus ", which itself had previously split from the lineage of " Pan ", the chimpanzees . Taxonomically , " ___MASK43___ " is the only ___MASK7___ assigned to the subtribe Hominina which , with the subtribes Australopithecina and Panina , comprise the tribe Hominini ( see evolutionary ___MASK6___ below ). All species of the ___MASK7___ " ___MASK43___ " plus those species of the australopithecines that arose " after " the split from " Pan " are called hominins . The ankle , or the talocrural ___MASK27___ , is the ___MASK27___ where the foot and the leg meet . The ankle includes three joints : the ankle ___MASK91___ proper or talocrural ___MASK91___ , the subtalar ___MASK91___ , and the inferior tibiofibular ___MASK91___ . The movements produced at this ___MASK91___ are dorsiflexion and plantarflexion of the foot . In common usage , the term ankle refers exclusively to the ankle ___MASK27___ . In medical terminology , " ankle " ( without qualifiers ) can refer broadly to the ___MASK27___ or specifically to the talocrural ___MASK91___ . Modern ___MASK73___ (" ___MASK43___ sapiens ", primarily ssp . " ___MASK43___ sapiens sapiens ") are the only extant members of Hominina ___MASK57___ ( or human ___MASK57___ ), a branch of the ___MASK57___ Hominini belonging to the ___MASK53___ of great apes . They are characterized by erect posture and bipedal locomotion ; manual dexterity and increased tool use , compared to other animals ; and a general trend toward larger , more complex brains and societies . The ___MASK66___ is an organ that serves as the center of the nervous ___MASK4___ in all vertebrate and most invertebrate animals . The ___MASK66___ is located in the ___MASK55___ , usually close to the sensory organs for senses such as vision . The ___MASK66___ is the most complex organ in a vertebrate ' s body . In a human , the cerebral cortex contains approximately 15  33 billion neurons , each connected by synapses to several thousand other neurons . These neurons communicate with one another by means of long protoplasmic fibers called axons , which carry trains of signal pulses called action potentials to distant parts of the ___MASK66___ or body targeting specific recipient cells . The forearm refers to the ___MASK27___ of the upper ___MASK82___ between the elbow and the wrist . The term forearm is used in ___MASK23___ to distinguish it from the arm , a word which is most often used to describe the entire appendage of the upper ___MASK82___ , but which in ___MASK23___ , technically , means only the ___MASK27___ of the upper arm , whereas the lower " arm " is called the forearm . It is to the ___MASK27___ of the leg that lies between the knee and the ankle joints , the crus . A ___MASK57___ is viewed , developmentally or historically , as a social group existing before the development of , or outside , states . A ___MASK57___ is a group of distinct people , dependent on their land for their livelihood , who are largely self - sufficient , and not integrated into the national ___MASK31___ . It is perhaps the term most readily understood and used by the general public . Stephen Corry , director of Survival International , an organisation dedicated to indigenous rights , defines tribal people as those who "... have followed ways of life for many generations that are largely self - sufficient , and are clearly different from the mainstream and dominant ___MASK31___ ." This definition , however , would not apply in countries in the Middle East such as Iraq , where the entire population is a member of one ___MASK57___ or another , and tribalism itself is dominant and mainstream . A ___MASK2___ is any physical item that can be used to achieve a ___MASK83___ , especially if the item is not consumed in the process . Tool use by humans dates back millions of years , and other animals are also known to employ simple tools .