what is the probable reason why the 3 heads of traceps extansor famoris are regarded as distinct muscle?
491754
Don't really understand your question.  Triceps extensor femoris?
522460
There are three:\nepidermis\ndermis\nsubcutaneous fat
560885
You would think that the pecking itself or the usage pattern of (as it were) of the pecker would be enough to identify not only the sub-species but the individual, however, there is not scientific evidence to show that this is the case. \n\nIt is possible through the use of photgraphs of the peckers to identfy even beyond the sub-species to the invidual (there are a few famous cases of this).
1154782
good looking, well defined, calf muscles. the kind that flex when a man walks. Then, broad shoulders leading down to those guns that lead down to well shaped hands and fingers with clean,clipped nails. but I have followed a man in the mall because of his calf muscles. I don't know what sport he did but daahamm!!!!!
728283
The male and female reproductive "tracts" are homologous.  This means that they're similar in structure and evolutionary origin, but are different in function.
722335
i would say it's the shape of the pelvic bone.  gives stability to their body shape and movement.
214165
Homology (=common origin) can be tested using criteria at various levels: anatomical, embryological/developmental, genetic...\nThe forelimbs of all mammals arise from the same cell types and embryological layers, they appear as limb buds in all mammalian embryos, they're related to the same structures (shoulder girdle, same muscles, blood vessels and nerves), and they're coded for by the same genes (especially the homeotic genes that signal for general developmental patterns). They're formed by the same bones (the bones of the hand are the ones most modified, but they're still recognizable).\nVariations of the basic pattern represent adaptations, but the simple anatomical homology allows you to recognize the bones if you see the skeleton of any of these arms and hands. Or of any other tetrapod for that matter.\n\nWhale forelimb:\nhttp://www.uvm.edu/~jdecher/Hyperphalangy.GIF\nCat forelimb:\nhttp://www.csus.edu/indiv/l/lancasterw/bio168/LABS%20BIO168-03/Lab3-post%20cranial%20BIO168-03_files/image010.jpg\nBat forelimb:\nhttp://www.batworld.org/book/images/skeleton-pg106.gif\nHuman forelimb:\nhttp://staticfiles.sabc.co.za/VCMStaticProdStage/EDUCATION/Schools/Beyond%20The%20Classroom/Ideas%20Library/Theme%20Pictures/Human%20Body%20-%20Skeleton/Arm_c.jpg\n\nPlease see the link for more on homology:
693273
http://en.wikipedia.org/wiki/Parelaphostrongylus_tenuis\n\nMorphology\n\nRoundworms are triploblastic protostomes with a complete digestive system. Roundworms have no circulatory or respiratory systems so they use diffusion to breathe and for circulation of substances around their body. They are thin and are round in cross section, though they are actually bilaterally symmetric. Nematodes are one of the simplest animal groups to have a complete digestive system, with a separate orifice for food intake and waste excretion, a pattern followed by all subsequent, more complex animals. The body cavity is a pseudocoel (persistent blastula), which lacks the muscles of coelomate animals used to force food down the digestive tract. Nematodes thus depend on internal/external pressures and body movement to move food through their digestive tracts. The mouth is often surrounded by various flaps or projections used in feeding and sensation. The portion of the body past the anus or cloaca is called the "tail." The epidermis secretes a layered cuticle made of keratin that protects the body from drying out, from digestive juices, or from other harsh environments, as well as in some forms sporting projections such as cilia that aid in locomotion. Although this cuticle allows movement and shape changes via a hydrostatic skeletal system, it is very inelastic so does not allow the volume of the worm to increase. Therefore, as the worm grows, it has to moult and form new cuticles. The cuticles don't allow volume to increase so as to keep hydrostatic pressure inside the organism very high. For this reason, the roundworms do not possess circular muscles (just longitudinal ones) as they're not required. This hydrostatic pressure is the reason the roundworms are round.\nMost free-living nematodes are microscopic, though a few parasitic forms can grow to several meters in length. There are no circular muscles, so the body can only undulate from side to side. Contact with solid objects is necessary for locomotion; its thrashing motions vary from mostly to completely ineffective at swimming.\nRoundworms generally eat bacteria, algae, fungi and protozoans, although some are filter feeders. Excretion is through a separate excretory pore.\nReproduction is usually sexual. Males are usually smaller than females (often very much smaller) and often have a characteristically bent tail for holding the female for copulation. During copulation, one or more chitinized spicules move out of the cloaca and are inserted into genital pore of the female. Amoeboid sperm crawl along the spicule into the female worm.\nEggs may be embryonated or unembryonated when passed by the female, meaning that their fertilized eggs may not yet be developed. In free-living roundworms, the eggs hatch into larva, which eventually grow into adults; in parasitic roundworms, the life cycle is often much more complicated.\nRoundworms have a simple nervous system, with a main nerve cord running along the ventral side. Sensory structures at the anterior end are called amphids, while sensory structures at the posterior end are called phasmids.\n\nhttp://en.wikipedia.org/wiki/Nematode\n\n\nHope that helps!
539604
as you move your muscles, they burn oxygen...blod flow increases to muscled to replace this lost oxygen...
764288
Some muscles have a predominance of one type or another  but most are a composition of both\nGastroc 40% type1\nTriceps 32%\nBiceps 40%\nDeltoid 50%\nSoleus 87%
923862
are you trying to get us to do your homework!!?\n\nwell i will help you lol!\nmuscles always work in pairs because they can only contract and not ..... ? these pairs are known as antagonistic muscles. For the movement to occur, one muscle shortens (contracts) while the other muscle lengthens (relaxes) the muscle that contracts is known as the.....muscle. Muscles which hold the bone in place are known as tendon muscles\n\nsorry I didn't get them all, those were the ones I could do off the top of my head!
264749
*pulling; that's the 1st blank or (contracting and then relaxing)\n\n\nthe 3rd is flexor and 4th is extensor\ndon't know about the 2nd and 5th
112685
Isn't this something they're trying to teach you at school? Think of the origins and insertions of these muscles, and of the movements achieved when each muscle layer contracts. Look at the pictures in any good Comparative Anatomy book and check the difference between the muscles of fishes and tetrapods (hint: new feature- lungs).
801430
There Sach's organ has a stack of electroplaques, which acts somewhat as a stack of battery plates. There evolutionary history is not know to me.
1051548
Masseter, Serratus Anterior, Psoas Major, Iliacus, Gastrocnemius, Soleus, Tibialis Posterior, Deltoid (anterior, middle and posterior), Brachialis, Triceps Brachii (long head, lateral head and medial head), Biceps Brachii (long head and short head), Pronator Quadratus, Scalenes (anterior, middle, posterior, and minimus), Rectus Femoris, Vastus Lateralis, Vastus medius, Vastus intermedius, Biceps Femoris, Semitendinosus, Semimembranosus, Pectoralis Major & Minor, Rectus Abdominis, External & Internal Obliques
238425
Link 1 is the Google search of "largest muscle."\n\nLink 2 (found in Link 1) says "latissimus dorsi."\n\nLink 3 (found in Link 1) says "gluteus maximus." Most of the other links appear to agree with this.\n\nLink 4 says it's the heart.\n\nLink 5 is catbird's other question about this.
175138
The shape of the articular surfaces of the vertebrae give good clues as to the types of movements that they allow. \nFish have amphicelous vertebrae, that is, with both surfaces concave. Fishes have primarily lateral movements of the body axis. \nIn tetrapods, in addition to the main articular surfaces, there are apophyses that restrict dorsoventral movements between adjacent vertebrae. They are called zygapophyses and are situated anterodorsally and posterodorsally in each vertebra.\nIn tetrapods the vertebrae may have one convex surface and one concave surface (complementary), or other shapes. If they have anterior concavity they're called procoelous, and if the concavity is in the posterior surface they're opisthocelous. Amphibians and reptiles have procoelous, opisthocoelous or amphicoelous vertebrae. These type of joints permit much lateral movement (except in frogs that have a shortened vertebrate column, and no tail).\nThe neck vertebrae of birds are heterocoelous: their articular surfaces have the shape of a horse saddle and this allows greater mobility (some birds are able to rotate their heads 180º). \nIn mammals the vertebrae are amphiplatyan, with both surfaces flat; mammals do not move their column laterally, but there is dorsoventral undulation when running. The xenarthrans (armadillos, sloths and giant anteaters) have special additional articulations that make their lumbar area more rigid when they stand on their hindlegs.