However, in tracking we also refer to the larger palm pad behind the toes as the metacarpal pad Cats and dogs are a great example of digitigrade locomotion. Unguligrade: The animals that have this form of locomotion are called ungulates, and include all hooved animals.
Ungulates walk on the very tip of their toes and are protected by a hard hoof called an unguis. Unguligrade -- running with only the unguis or hooves touching the ground ungulates. Volant -- true flight bats only. Use the skeletal material provided in lab to learn the following bones and structures of the cat skeleton.
Cranium Axis Floating Rib. Cervical Vertebrae True Rib. Thoracic Vertebrae False Rib. Lumbar Vertebrae Xiphoid Process.
Sacrum Ilium Ischium Caudal Vertebrae Fibula Calcaneus Phalanges Metatarsals Tarsals Glenoid Fossa. Head of Femur Femur Tibia Finally, fibrous bands dorsoscapular ligament between thoracolumbar deep fascia and the scapula assist the serratus ventralis muscle in supporting the trunk. Hind limb specializations: Cranially the fibularis peroneus tertius tendon and caudally the superficial digital flexor tendon constitute two fibrous cords that mechanically link stifle and hock joints.
The fibrous cords reciprocal apparatus keep the two joints synchronized even during conditions of neuromuscular fatigue. To facilitate standing, the stifle joint can be locked to preclude its collapse under body weight by hooking a loop of patellar tendons around an enlarged medial ridge of the femoral trochlea.
This locking mechanism allows a horse to rest one hind limb at a time. A quadruped gait walk, trot, pace, canter, gallop refers to a characteristic pattern of ground contact made by all four limbs during one stride. The fastest gait is the gallop. It is a four beat gait in which no more that one limb makes ground contact at a time. Transverse Gallop: The four beats are: left hind, right hind, left fore, right fore, followed by suspension prior to the next left hind beat.
This pattern is a right lead , which quadrupeds favor when circling to the right. The alternative is a left lead the lead is indicated by the last forelimb that contacts the ground prior the suspension. Quadrupeds can switch leads within a stride. Both carnivores and ungulates employ the transverse gallop readily recognizable since the hind limb two beat pattern is repeated by the forelimbs prior to suspension. Rotary Gallop: Carnivores also employ a rotary gallop, which is their fastest but most tiring gait due to the extent of epaxial and abdominal muscle invovolvement.
Among perissodactyls, rhinos and tapirs have three or four toes, but the center one 3 is enlarged and bears much of the weight a condition termed mesaxonic. In horses , the 3rd metapodial is very long, similar in length to the other main limb elements.
The other toes are lost or reduced to the point of being slivers of bones that fuse with the 3rd. Among the much more diverse artiodactyls, pigs , peccaries and hippos have moderately long metapodials, which are unfused.
The third and fourth metapodials, however, are larger than the others and bear most of the weight paraxonic. In camels , the third and fourth metapodials are very long and fused for most of their length, although the distal ends remain separate.
Fusion is complete in bovids and cervids , and the resulting bone is called a cannon bone. Other digits are much reduced or lost. Lengthening and fusion of metapodials is also associated with ricochetal locomotion. Kangaroos , for example, have a very long fourth digit, especially the metatarsal.
The fifth digit is also important, but smaller than the fourth. The second and third digits are fused for most of their length syndactylous , except the claws, which remain separate and are used for grooming. The first toe is lost. Another example is provided by some ricochetal dipodid rodents. In these species, the 3 central metatarsals are not only elongated but fused, forming a distinctive cannon bone.
A third and very common means of lengthening stride is to include the scapula as part of the limb, allowing it to swing forward and back with each stride.
In cursorial mammals that use their scapulae in this fashion, the clavicle which would restrict the movement of the scapula is much reduced or lost. It is easy to watch the scapula in a cat move with each stride as the animal walks or runs. Another way of lengthening the stride involves flexing the spine. This is associated with a bounding or galloping form of locomotion. When the animal pushes off with its hind feet, it extends its back.
Contact with the ground by the hind legs prevents the rear part of the animal from moving backward, and the increase in body length becomes part of the forward stride.
Yet another means of lengthening the stride is to increase the distance traveled by the animal when its feet are off of the ground. This is determined by the animal's gait, or the sequence and manner by which it moves its feet when running. Afinal means of lengthening the stride has to do with the mechanics of muscle action. A muscle can move a joint through a wider angle the closer it inserts to the joint.
The second general means of increasing speed is to increase stride rate. Mammals have approached this problem in a number of ways; here, we will mention only a few conspicuous ones.
Hildebrand's excellent and thorough discussion of the biomechanics of motion by mammals should be consulted for more a more detailed treatment of the subject. Muscles acting on bones behave as simple force-and-lever systems.
Muscles inserted close to joints not only move the joint through a wider angle, but they make the bones on which they insert move faster. In doing so, however, they must exert more force than a muscle inserted farther away from the joint.
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