The ribs of the second vertebra are not represented.
The odontoid process of the second vertebra is pig-like: and the tibia and fibula and radius and ulna are severally distinct.
ancient vertebra) by Dr R.
They include the mandible of a mastodon and a portion of a vertebra of a large fish, both found in the Lower Madison Valley; the skull and other parts of a dog (Mesocyon drummondanus), found near Drummond, Granite county; the skull of a Poatrephes paludicola, found near New Chicago,.
In anatomy, it is, among other uses, applied to the second cervical vertebra, and in botany itmeans the stem.
Odontoid process of second vertebra semi-cylindrical; skull with a sagittal crest; and the condyle of the lower jaw rounded.
Sometimes the pad is reduced to a ventral semi-ring or meniscus; it retains its largest almost original shape and size in the second vertebra, the axis or epistropheus, where it forms a separately ossifying piece which connects, and coossifies with, the odontoid process (the centrum of the atlas) and the centrum of the second vertebra.
From both birds and reptiles the class is distinguished, so far at any rate as existing forms are concerned, by the following features: the absence of a nucleus in the red corpuscles of the blood, which are nearly always circular in outline; the free suspension of the lungs in a thoracic cavity, separated from the abdominal cavity by a muscular partition, or diaphragm, which is the chief agent in inflating the lungs in respiration; the aorta, or main artery, forming but a single arch after leaving the heart, which curves over the left terminal division of the windpipe, or bronchus; the presence of more or fewer hairs on the skin and the absence of feathers; the greater development of the bridge, or commissure, connecting the two halves of the brain, which usually forms a complete corpus callosum, or displays an unusually large size of its anterior portion; the presence of a fully developed larynx at the upper end of the trachea or windpipe, accompanied by the absence of a syrinx, or expansion, near the lower end of the same; the circumstance that each half of the lower jaw (except perhaps at a very early stage of development) consists of a single piece articulating posteriorly with the squamosal element of the skull without the intervention of a separate quadrate bone; the absence of prefrontal bones in the skull; the presence of a pair of lateral knobs, or condyles (in place of a single median one), on the occipital aspect of the skull for articulation with the first vertebra; and, lastly, the very obvious character of the female being provided with milk-glands, by the secretion of which the young (produced, except in the very lowest group, alive and not by means of externally hatched eggs) are nourished for some time after birth.
Later those pads fuse with the anterior end of the centrum of the vertebra to which they belong; where the vertebral column is rendered inflexible, the disks are ossified with the centra and all trace of them is lost.
B, Caudal vertebra of Archegosaurus.
Odontoid process of second vertebra in the form of a crescent, hollow above.
The genus Rana may be defined as firmisternal Ecaudata with cylindrical transverse processes to the sacral vertebra, teeth in the upper jaw and on the vomer, a protrusible tongue which is free and forked behind, a horizontal pupil and more or less webbed toes.
This plan of structure, apparently evolved out of the rhachitomous type by suppression of the pleurocentra and the downward extension of the neural arch, leads to that characteristic of frogs in which, as development shows, the vertebra is formed wholly or for the greater part by the neural arch (14).
In some genera this coccyx is fused with the ninth vertebra, and contributes to the FIG.
(I) Cervical vertebrae, or those between the skull and the first vertebra which is connected with the sternum by a pair of complete ribs.
- A cervical vertebra from the middle of the neck of a Fowl; natural size.
Some authors have held that the bone on which the occipital condyles have been found most developed in some labyrinthodonts (2) represents a large basi-occipital bearing two knobs for the articulation with the first vertebra, whilst the skull of the batrachians of the present day has lost the basi-occipital, and the condyles are furnished by the exoccipitals.
- A, Dorsal vertebra of Hylonomus (side view and front view).
B, Dorsal vertebra of Branchiosaurus (side view and front view).
All agree, however, in having each vertebra formed of at least two pieces, the suture between which persists throughout life.
In others, which represent the perichordal type, the greater share of the formation of the whole vertebra falls to the (paired) dorsal cartilage, but there is in addition a narrow ventral or hypochordal cartilage which fuses with the dorsal or becomes connected with it by calcified tissue; the notochord is thus completely surrounded by a thick sheath in tadpoles with imperfectly developed limbs.
either to the vertebra anterior (procoelous type) or posterior (opisthocoelous type) to it, if not remaining as an independent, intervertebral, ossified sphere, as we sometimes find in specimens of Pelobatidae.
In the Ecaudata, the form of the transverse processes of the sacral vertebra varies very considerably, and has afforded important characters to the systematist.
occipital condyles that form a joint with the first cervical vertebra of the neck.
A conventional X-ray, often the first imaging technique used, looks for broken bones or an injured vertebra.
These genera attained the Colophiuran grade in respect of external plating, but it is unlikely that they or their ancestors had acquired even the Streptophiuran type of vertebra.
In the Caudata and Apoda, cartilage often persists between the vertebrae; this cartilage may become imperfectly separated into a cup-and-ball portion, the cup belonging to the posterior end of the vertebra.
articular facets, or the whole vertebra.
caudal vertebra was found.
The foramen magnum is flanked by two large knobs or occipital condyles that form a joint with the first cervical vertebra of the neck.
Post mortem examination revealed cause of death to be bowel perforation by a sharp sawn section of ox vertebra.
The arch of the vertebra features a small knob or prominence, called an anterior tubercle.
Karl Muggeridge, who fell this morning, has fractured the 12th vertebra and the second lumbar.
The Atlas vertebra meets with the occipital condyles which flank the foramen magnum in the basilar part of the occipital bone of the skull.
The Chi Machine can adjust the whole spine all the way up to the cervical vertebra.
Also in 1996, another caudal vertebra was found.
It is the only vertebra in the spine which has no vertebra in the spine which has no vertebral body.
He concisely cites (p. 238) no fewer than eight other characters of more or less value as peculiar to the Carinate Division, the first of which is that the feathers have their barbs furnished with hooks, in consequence of which the barbs, including those of the wing-quills, cling closely together; while among the rest may be mentioned the position of the furcula and coracoids, 4 which keep the wing-bones apart; the limitation of the number of the lumbar vertebra to fifteen, and of the carpals to two; as well as the divergent direction of the iliac bones - the corresponding characters peculiar to the Ratite Division being the disconnected condition of the barbs of the feathers, through the absence of any hooks whereby they might cohere; the non-existence of the furcula, and the coalescence of the coracoids with the scapulae (or, as he expressed it, the extension of the scapulae to supply the place of the coracoids, which he thought were wanting); the lumbar vertebrae being twenty and the carpals three in number; and the parallelism of the iliac bones.
When limbs are present, one vertebra, rarely two a.,.r (fig.
The atlas vertebra meets with the occipital condyles which flank the foramen magnum in the basilar part of the occipital bone of the skull.
It is the only vertebra in the spine which has no vertebral body.
A conventional x-ray, often the first imaging technique used, looks for broken bones or an injured vertebra.
Spondylolisthesis. Spondylolisthesis is the medical term for a forward slippage of one vertebra on the one below it.
If the slippage is more than 30 degrees, the slipped vertebra may require surgical realignment.
To achieve fusion, the involved vertebra are first exposed and then scraped to promote regrowth.
In rare cases, congenital torticollis can also be a symptom of other congenital disorders including abnormalities of the neck vertebra such as spina bifida or Arnold-Chiari syndrome.
Torticollis can also be caused at an older age by fracture or dislocation of the neck vertebra or juvenile rheumatoid arthritis.
It is a deformity of the thoracic spine (in the chest area, the vertebra to which ribs are attached) caused by abnormal centers of bone development at the intervertebral joints (physes).
Keep your core muscles engaged, and slowly lift each vertebra from the floor, until you reach a bridge position.
This places all of the stress of your upper body on a few vertebra in your lower back.
This creates stress and tension on the vertebra of the upper neck, which can lead to injury.
The word usage examples above have been gathered from various sources to reflect current and historial usage. They do not represent the opinions of YourDictionary.com.