What is the smallest bone in the human body?
82957#1
The stapes is the third bone of the three ossicles in the middle ear. The stapes is a stirrup-shaped bone, and the smallest in the human body. It rests on the oval window, to which it is connected by an annular ligament. The stapes is described as having a base, resting on the oval window, as well as a head that articulates with the incus. These are connected by anterior and posterior limbs (). The stapes articulates with the incus through the incudostapedial joint. The stapes is the smallest bone in the human body, and measures roughly 3 x 2.5mm, greater along the head-base span.
Stapes
82957#0
The stapes or stirrup is a bone in the middle ear of humans and other mammals which is involved in the conduction of sound vibrations to the inner ear. The stirrup-shaped small bone is on and transmits these to the oval window, medially. The stapes is the smallest and lightest named bone in the human body, and is so-called because of its resemblance to a stirrup ().
Stapes
4099#2
In the human body at birth, there are over 270 bones, but many of these fuse together during development, leaving a total of 206 separate bones in the adult, not counting numerous small sesamoid bones. The largest bone in the body is the femur or thigh-bone, and the smallest is the stapes in the middle ear.
Bone
2111321#0
The stapedius is the smallest skeletal muscle in the human body. At just over one millimeter in length, its purpose is to stabilize the smallest bone in the body, the stapes.
Stapedius muscle
82940#0
The ossicles (also called auditory ossicles) are three bones in either middle ear that are among the smallest bones in the human body. They serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss. The term "ossicle" literally means "tiny bone". Though the term may refer to any small bone throughout the body, it typically refers to the malleus, incus, and stapes (hammer, anvil, and stirrup) of the middle ear.
Ossicles
27609#18
The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. It serves as a scaffold which supports organs, anchors muscles, and protects organs such as the brain, lungs, heart and spinal cord. Although the teeth do not consist of tissue commonly found in bones, the teeth are usually considered as members of the skeletal system.
The biggest bone in the body is the femur in the upper leg, and the smallest is the stapes bone in the middle ear. In an adult, the skeleton comprises around 14% of the total body weight, and half of this weight is water.
Skeleton
1076169#1
These relatively small snakes rarely exceed 30 cm in length; only "Trilepida macrolepis" and "Leptotyphlops occidentalis" grow larger. The cranium and upper jaws are immobile and no teeth are in the upper jaw. The lower jaw consists of a much elongated quadrate bone, a tiny compound bone, and a relatively larger dentary bone. The body is cylindrical with a blunt head and a short tail. The scales are highly polished. The pheremones they produce protect them from attack by termites. Among these snakes is what is believed to be the world's smallest: "L. carlae" .
Leptotyphlopidae
462691#3
Andreas Vesalius (1514-1564), a Flemish anatomist, was at first a "Galenist" at the University of Paris. When he moved to Italy and entered the University of Padua, he began dissecting human bodies. He studied many details of human anatomy and found that Galen made some anatomical mistakes. For example, Galen wrote that the sternum has seven segments, but Vesalius found it has three segments. Galen wrote that the bone of the arm is the longest bone in the human body, but Vesalius found that the bone of the thigh is actually the longest bone in human body. At age 25 Vesalius realized that the anatomical knowledge of Galen was derived from animal anatomy and therefore Galen had never dissected a human body.
Moulage
242625#0
The trapezoid bone (lesser multangular bone) is a carpal bone in tetrapods, including humans. It is the smallest bone in the distal row of carpal bones that give structure to the palm of the hand. It may be known by its wedge-shaped form, the broad end of the wedge constituting the dorsal, the narrow end the palmar surface; and by its having four articular facets touching each other, and separated by sharp edges. It is homologous with the "second distal carpal" of reptiles and amphibians.
Trapezoid bone
1353433#16
Among non-human primates phylogenesis and style of locomotion appear to play a role in apical tuft size. Suspensory primates and New World monkeys have the smallest apical tufts, while terrestrial quadrupeds and Strepsirrhines have the largest.
A study of the fingertip morphology of four small-bodied New World monkey species, indicated a correlation between increasing small-branch foraging and reduced flexor and extensor tubercles in distal phalanges and broadened distal parts of distal phalanges, coupled with expanded apical pads and developed epidermal ridges. This suggests that widened distal phalanges were developed in arboreal primates, rather than in quadrupedal terrestrial primates.
Phalanx bone