Dacryon | |
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Medial wall of left orbit. (Dacryon visible but not labeled.) | |
The skull from the front. (Dacryon visible but not labeled. Maxilla is yellow bone in center, frontal bone is light blue bone at top, and lacrimal bone is barely visible pink bone at center. Label for lacrimal bone is at center right.) | |
Anatomical terminology |
The point of junction of the maxillary bone, lacrimal bone, and frontal bone is named the dacryon.
The carpal bones are the eight small bones that make up the wrist that connects the hand to the forearm. The term "carpus" is derived from the Latin carpus and the Greek καρπός (karpós), meaning "wrist". In human anatomy, the main role of the wrist is to facilitate effective positioning of the hand and powerful use of the extensors and flexors of the forearm, and the mobility of individual carpal bones increase the freedom of movements at the wrist.
The human skeleton is the internal framework of the human body. It is composed of around 270 bones at birth – this total decreases to around 206 bones by adulthood after some bones get fused together. The bone mass in the skeleton reaches maximum density around age 21. The human skeleton can be divided into the axial skeleton and the appendicular skeleton. The axial skeleton is formed by the vertebral column, the rib cage, the skull and other associated bones. The appendicular skeleton, which is attached to the axial skeleton, is formed by the shoulder girdle, the pelvic girdle and the bones of the upper and lower limbs.
A joint or articulation is the connection made between bones in the body which link the skeletal system into a functional whole. They are constructed to allow for different degrees and types of movement. Some joints, such as the knee, elbow, and shoulder, are self-lubricating, almost frictionless, and are able to withstand compression and maintain heavy loads while still executing smooth and precise movements. Other joints such as sutures between the bones of the skull permit very little movement in order to protect the brain and the sense organs. The connection between a tooth and the jawbone is also called a joint, and is described as a fibrous joint known as a gomphosis. Joints are classified both structurally and functionally.
In anatomy, a sesamoid bone is a bone embedded within a tendon or a muscle. It is derived from the Latin word sesamum, indicating the small size of most sesamoids. Often, these bones form in response to strain, or can be present as a normal variant. The kneecap is the largest sesamoid bone in the body. Sesamoids act like pulleys, providing a smooth surface for tendons to slide over, increasing the tendon's ability to transmit muscular forces.
In human anatomy, the thigh is the area between the hip (pelvis) and the knee. Anatomically, it is part of the lower limb.
The maxilla in vertebrates is the upper fixed bone of the jaw formed from the fusion of two maxillary bones. The upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible, which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw.
The ethmoid bone is an unpaired bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbits. The cubical bone is lightweight due to a spongy construction. The ethmoid bone is one of the bones that make up the orbit of the eye.
The sphenoid bone is an unpaired bone of the neurocranium. It is situated in the middle of the skull towards the front, in front of the basilar part of the occipital bone. The sphenoid bone is one of the seven bones that articulate to form the orbit. Its shape somewhat resembles that of a butterfly or bat with its wings extended.
The frontal bone is a bone in the human skull. The bone consists of two portions. These are the vertically oriented squamous part, and the horizontally oriented orbital part, making up the bony part of the forehead, part of the bony orbital cavity holding the eye, and part of the bony part of the nose respectively. The name comes from the Latin word frons.
The nasal bones are two small oblong bones, varying in size and form in different individuals; they are placed side by side at the middle and upper part of the face and by their junction, form the bridge of the upper one third of the nose.
The vomer is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms the inferior part of the nasal septum, with the superior part formed by the perpendicular plate of the ethmoid bone. The name is derived from the Latin word for a ploughshare and the shape of the bone.
The metatarsal bones, or metatarsus are a group of five long bones in the foot, located between the tarsal bones of the hind- and mid-foot and the phalanges of the toes. Lacking individual names, the metatarsal bones are numbered from the medial side : the first, second, third, fourth, and fifth metatarsal. The metatarsals are analogous to the metacarpal bones of the hand. The lengths of the metatarsal bones in humans are, in descending order: second, third, fourth, fifth and first.
In humans and many other primates, the calcaneus or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is the point of the hock.
The nasal septum separates the left and right airways of the nasal cavity, dividing the two nostrils.
The talus, talus bone, astragalus, or ankle bone is one of the group of foot bones known as the tarsus. The tarsus forms the lower part of the ankle joint. It transmits the entire weight of the body from the lower legs to the foot.
The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles and it has openings for blood vessels. From its borders, the mastoid part articulates with two other bones.
The crest of the ilium is the superior border of the wing of ilium and the superiolateral margin of the greater pelvis.
The zygomatic processes are three processes (protrusions) from other bones of the skull which each articulate with the zygomatic bone. The three processes are:
The pelvis is either the lower part of the trunk of the human body between the abdomen and the thighs or the skeleton embedded in it.
In the vertebrate spinal column, each vertebra is an irregular bone with a complex structure composed of bone and some hyaline cartilage, the proportions of which vary according to the segment of the backbone and the species of vertebrate.
This article incorporates text in the public domain from page 189 of the 20th edition of Gray's Anatomy (1918)
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