What is a premaxilla?
Definition of premaxilla : either of a pair of bones of the upper jaw of vertebrates between and in front of the maxillae.
What is the function of the premaxilla?
Lateral Surface of the Skull. The premaxilla carries the incisors, the roots of which extend far back into the bone all the way to the maxilla. The lateral edges of the nasal bone can be seen above the premaxilla and the zygomatic plate and anteorbital bar of the maxilla are obvious.
What is premaxilla in fish?
Premaxilla – A pair of premaxillae forms the anterior part of the upper jaw. Both premaxillae and maxillae form the upper gape of the mouth in ancestral teleosts such as ladyfish (Elopidae), bonefish (Albulidae), eels (Anguilliformes and Saccopharyngiformes), sardines (Clupeidae) and anchovies (Engraulidae).
Which are the structures derived from premaxilla?
Premaxillary-maxillary suture in an adult’s skull. We can distinguish three parts in the premaxilla: » the alveolar part with facial process, » the palatine process, » and the Stenonianus process, which goes along with the cartilage of the nasal septum and the vomer.
What is the alveolar process?
The alveolar process is the horizontal portion of the maxilla that holds the tooth roots. b. Alveoli for the tooth roots are present all along the alveolar process, except where these have been resorbed following the loss of teeth.
Where is sphenoid bone?
skull
An unpaired bone located in the cranium (or skull), the sphenoid bone, also known as the “wasp bone,” is located in the middle and toward the front of the skull, just in front of the occipital bone.
Why do fish have scales?
Scales protect fish, much like a suit of armor. All fish have a slimy covering of mucus. This substance allows the fish to swim through the water with very little drag and also makes it difficult for other organism to attach to the fish.
Is shark jaw bone?
Are Sharks Jaws Made Of Bone? A shark jaw is not used to chew food because a shark gulps food down in huge chunks. Because the shark’s skeleton contains no bone, but only cartilage, areas requiring extra strength and support, like the jaw, need special adaptations.
What is the main function of the alveoli?
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.
Why is it called alveolar process?
The alveolar process is the lining of the tooth socket and also known as the alveolus. While the alveolar process is made from compact bone, it can also be called the cribriform plate because it contains holes where Volkmann canals pass from the alveolar bone into the PDL.
Why is the sphenoid bone so important?
Sphenoid bone has many essential functions. It helps form the base and lateral sides of the skull in combination with the orbital floor. Its many articulations with other bones give the skull rigidity. It is an attachment site for many of the muscles of mastication.