Anatomy: Bone Shapes, Skull, and Vertebral Column

Vocabulary flashcards covering bone classifications, cranial and facial skull structures, dental anatomy, and regions/features of the vertebral column, ribs, and sternum.

Four Basic Bone Shapes

The four main structural classifications of bones: long, short, flat, and irregular (along with sesamoid bones as an additional specialized category).

Sesamoid Bone (Patella)

A specialized bone embedded within a tendon; features a base, articular surface, and apex.

Axial Skeleton

The central division of the skeleton that comprises the skull, hyoid bone, spinal column, ribs, and sternum.

Suture

An immovable fibrous joint connecting most individual bones of the skull.

Mandible Articulation

The lower jaw bone's connection to the skull, formed by a movable synovial joint at the mandibular fossa.

External Bones of the Cranium

The outer cranial bones, consisting of frontal bones (2), interparietal bones (2), occipital bone (1), parietal bones (2), and temporal bones (2).

Internal Bones of the Cranium

The cranial bones located inside the skull cavity, consisting of the ethmoid bone (1) and sphenoid bone (1).

Premaxilla (Incisive Bone)

The paired anterior skull bones located at the tip of the upper jaw that house the upper incisor teeth.

Zygomatic Bone (Malar / Jugular)

The facial bone forming the cheek prominence and contributing to the ventral border of the orbit and zygomatic arch.

Vomer

A single midline bone located on the floor of the nasal cavity that forms the inferior portion of the nasal septum.

Turbinates (Nasal Conchae)

Scroll-like bony structures (superior and inferior) located inside the nasal cavity that increase surface area for warming and moistening air.

Carnassial Tooth

The specialized shearing tooth adapted for cutting meat in carnivores, corresponding to lower molar #1.

Diastema

A naturally occurring toothless gap separating different functional groups of teeth, such as between the canine and premolars.

Sagittal Crest

A prominent dorsal midline ridge of bone running longitudinally on the top of the skull that serves as an attachment site for temporal jaw muscles.

Tympanic Bulla

A smooth, bulbous bony capsule located on the ventral posterior aspect of the skull housing the structures of the middle ear.

Foramen Magnum

The large opening in the occipital bone at the posterior base of the skull through which the brainstem connects to the spinal cord.

Intervertebral Disks

Cartilaginous pads situated between adjacent vertebral bodies that cushion impacts and provide flexibility along the spinal column.

Vertebral Arch

The dorsal portion of a vertebra composed of pedicles and laminae that surrounds the vertebral foramen and protects the spinal cord.

Five Vertebral Regions

The functional divisions of the spinal column: cervical, thoracic, lumbar, sacral (sacrum), and caudal regions.

Atlas (C1)

The first cervical vertebra, lacking a typical body and spinous process, distinguished by large lateral expansions known as wings.

Axis (C2)

The second cervical vertebra, characterized by an elongate neural process and an anterior peg-like projection called the dens.

Dens

An anterior tooth-like process projecting from the centrum of the axis (C2) that acts as a pivot axis for rotation of the atlas.

Thoracic Vertebrae Features

Vertebrae characterized by tall, slender spinous processes pointing caudally, along with costal facets and demifacet articulators for ribs.

Lumbar Vertebrae Features

Large spinal vertebrae possessing prominent forward-projecting pleurapophyses (transverse processes), mamillary processes, and accessory processes.

Sacrum

A composite triangular bone formed by the fusion of sacral vertebrae that articulates laterally with the ilium of the pelvis.

Caudal Vertebra

A tail vertebra that gradually becomes simpler caudally, often featuring anterior hemal processes forming a ventral hemal arch.

Cat Rib Structure

A curved thoracic bone consisting of a capitulum (head), neck, tuberculum (tubercle), articular facet for transverse process, angle, shaft, and costal cartilage.

Vertebrosternal Ribs

True ribs whose costal cartilages attach directly to the sternum.

Vertebrochondral Ribs

False ribs whose costal cartilages merge together to attach indirectly to the sternum via the cartilage of the preceding rib.

Vertebral Ribs

Floating ribs whose distal ends lack cartilage attachment to the sternum and end freely in the body wall musculature.

Sternum of the Cat

The segmented ventral bone of the thorax consisting of an anterior manubrium, central sternebrae, posterior xiphisternum, and terminal xiphoid cartilage.

Sella Turcica

A saddle-shaped depression on the interior surface of the sphenoid bone within the cranial floor that houses the pituitary gland.

Cribriform Plate

A sieve-like horizontal plate of the ethmoid bone located at the anterior base of the cranial cavity that permits olfactory nerves to pass into the nasal cavity.