SKELETAL SYSTEM

Endoskeleton

A skeletal system that is derived from mesodermal tissues such as cartilages and dermis.

Exoskeleton

A skeletal system that has an integumentary origin.

Mesodermal

Referring to mesenchymal cells that give rise to the endoskeleton.

Endochondral Ossification

The process of bone formation from cartilage.

Sesamoid Bones

Bones that form within tendons.

Cranial Structure

The structure of the skull in vertebrates.

Chondrocranium/Neurocranium

The cartilaginous part of the skull that protects the brain and sense organs.

Dermatocranium

The part of the skull derived from the dermis that covers and protects the underside of the chondrocranium.

Dermal Bone Series

The series of bones derived from the dermis that make up different parts of the skull.

Facial Series

The series of bones that form the snout, including the premaxilla, maxilla, and nasal bones.

Orbital Series

The series of bones that surround the eye sockets, including the lacrimal, prefrontal, postfrontal, postorbital, and jugal bones.

Temporal Series

The series of bones located beside the orbit, including the intertemporal, supratemporal, tabular, squamosal, and quadratojugal bones.

Vault Series

The series of bones that cover the brain, including the frontal, parietal, and postparietal bones.

Palatal Series

The series of bones that form the roof of the mouth, including the vomer, palatine, ectopterygoid, pterygoid, and parasphenoid bones.

Mandibular Series

The series of bones that make up the lower jaw, including the lateral, dentary, splenials, angular, strangulation, prearticular, and coronoid bones.

Skull Phylogeny

The evolutionary history and development of the skull in different groups of organisms.

Axial Skeleton

The main components of the skeleton that include the ribs, sternum, and vertebrae.

Vertebral Column

The segmented structure of vertebrae in humans, including the cervical, thoracic, lumbar, sacral, and caudal segments.

Ribs

Bones that protect internal organs and provide muscle attachment for respiration.

Sternum

The breastbone that attaches to the ribs and provides protection and stability to the thoracic cavity.

Keel/Carina

A flattened structure found in the ventral side of the sternum that allows for more muscle attachment and is a modification for flight in avian species.

Appendicular Skeleton

The components of the skeleton that include the pectoral and pelvic girdles and the limbs.

Pectoral Girdle

The structure that supports the pectoral limbs or fins, including the clavicle, collarbone, and shoulder bones in humans.

Glenoid Fossa

The socket in the pectoral girdle that serves as an attachment point for the forelimbs.

Pelvic Girdle

The structure that supports the pelvic limbs or fins, including the acetabulum, which is the socket in the pelvic girdle.

Fins

Appendages in fish that can be attached to the pectoral or pelvic girdles and are a source of limbs in tetrapods.

Limbs

Jointed structures that bear digits and consist of the stylopodium (humerus or femur), zeugopodium (radius and ulna or tibia and fibula), and autopodium (carpals, metacarpals, and phalanges or tarsals, metatarsals, and phalanges).

Autopodium

The distal part of the limb that includes the manus (hands) and pes (feet) and is further divided into the basipodium, metapodium, and acropodium.

AXIAL SKELETON

provides protection for vital internal organs

APPENDICULAR SKELETON

enables movement