In vertebrate anatomy, ribs are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the thoracic cavity, enabling the lungs to expand and thus facilitate breathing by expanding the thoracic cavity. They serve to protect the lungs, heart, and other vital organs of the thorax. In some animals, especially snakes, ribs may provide support and protection for the entire body.
The middle ear is the portion of the ear medial to the eardrum, and distal to the oval window of the cochlea.
The ossicles are three irregular bones in the middle ear of humans and other mammals, and are among the smallest bones in the human body. Although the term "ossicle" literally means "tiny bone" and may refer to any small bone throughout the body, it typically refers specifically to the malleus, incus and stapes of the middle ear.
The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate.
In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the condylar process of mandible below; it is from these bones that its name is derived. The joints are unique in their bilateral function, being connected via the mandible.
In vertebrates, the maxilla is the upper fixed bone of the jaw formed from the fusion of two maxillary bones. In humans, 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 jaws are a pair of opposable articulated structures at the entrance of the mouth, typically used for grasping and manipulating food. The term jaws is also broadly applied to the whole of the structures constituting the vault of the mouth and serving to open and close it and is part of the body plan of humans and most animals.
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex.
Fish anatomy is the study of the form or morphology of fish. It can be contrasted with fish physiology, which is the study of how the component parts of fish function together in the living fish. In practice, fish anatomy and fish physiology complement each other, the former dealing with the structure of a fish, its organs or component parts and how they are put together, such as might be observed on the dissecting table or under the microscope, and the latter dealing with how those components function together in living fish.
The quadrate bone is a skull bone in most tetrapods, including amphibians, sauropsids, and early synapsids.
The articular bone is part of the lower jaw of most vertebrates, including most jawed fish, amphibians, birds and various kinds of reptiles, as well as ancestral mammals.
The pharyngeal arches, also known as visceral arches, are transient structures seen in the embryonic development of humans and other vertebrates, that are recognisable precursors for many structures. In fish, the arches support the gills and are known as the branchial arches, or gill arches.
The squamous part of temporal bone, or temporal squama, forms the front and upper part of the temporal bone, and is scale-like, thin, and translucent.
The evolution of mammalian auditory ossicles was an evolutionary process that resulted in the formation of the mammalian middle ear, where the three middle ear bones or ossicles, namely the incus, malleus and stapes, are a defining characteristic of mammals. The event is well-documented and important academically as a demonstration of transitional forms and exaptation, the re-purposing of existing structures during evolution.
The splanchnocranium is the portion of the cranium that is derived from pharyngeal arches. Splanchno indicates to the gut because the face forms around the mouth, which is an end of the gut. The splanchnocranium consists of cartilage and endochondral bone. In mammals, the splanchnocranium comprises the three ear ossicles, as well as the alisphenoid, the styloid process, the hyoid apparatus, and the thyroid cartilage.
Branchial arches or gill arches are a series of paired bony/cartilaginous "loops" behind the throat of fish, which support the fish gills. As chordates, all vertebrate embryos develop pharyngeal arches, though the eventual fate of these arches varies between taxa. In all jawed fish (gnathostomes), the first arch pair develops into the jaw, the second gill arches develop into the hyomandibular complex, and the remaining posterior arches support the gills. In tetrapods, a mostly terrestrial clade evolved from lobe-finned fish, many pharyngeal arch elements are lost, including the gill arches. In amphibians and reptiles, only the oral jaws and a hyoid apparatus remains, and in mammals and birds the hyoid is simplified further to support the tongue and floor of the mouth. In mammals, the first and second pharyngeal arches also give rise to the auditory ossicles.
The hyomandibula, commonly referred to as hyomandibular [bone], is a set of bones that is found in the hyoid region in most fishes. It usually plays a role in suspending the jaws and/or operculum. It is commonly suggested that in tetrapods, the hyomandibula evolved into the columella (stapes).
In jawed vertebrates, the mandible, lower jaw, or jawbone is a bone that makes up the lower – and typically more mobile – component of the mouth.
Most bony fishes have two sets of jaws made mainly of bone. The primary oral jaws open and close the mouth, and a second set of pharyngeal jaws are positioned at the back of the throat. The oral jaws are used to capture and manipulate prey by biting and crushing. The pharyngeal jaws, so-called because they are positioned within the pharynx, are used to further process the food and move it from the mouth to the stomach.
The malleus, or hammer, is a hammer-shaped small bone or ossicle of the middle ear. It connects with the incus, and is attached to the inner surface of the eardrum. The word is Latin for 'hammer' or 'mallet'. It transmits the sound vibrations from the eardrum to the incus (anvil).
