Skeletal System: Axial and Appendicular Anatomy

Comprehensive vocabulary flashcards covering the axial and appendicular skeleton, bone classifications, anatomical regions, and bone articulations based on lecture presentations and practical bone lists.

Articulation

The connection or joint where two or more bones connect to one another.

Axial Skeleton

The central longitudinal division of the skeletal system comprising the skull, auditory ossicles of the middle ear, hyoid bone, vertebral column, and thoracic cage (rib cage).

Appendicular Skeleton

The division of the skeletal system comprising the bones of the upper and lower limbs and the supporting girdles (pectoral/shoulder girdle and pelvic girdle).

Pectoral Girdle

The appendicular shoulder girdle composed of the clavicle and scapula that attaches the upper limbs to the axial skeleton.

Pelvic Girdle

The appendicular girdle composed of the paired coxal (hip) bones that articulates with the sacrum to connect the lower limbs to the trunk.

Cranial Bones

The group of $8$ axial bones of the skull that enclose and protect the brain: frontal ($1$), parietal ($2$), temporal ($2$), occipital ($1$), sphenoid, and ethmoid.

Facial Bones

The group of $14$ axial bones that form the anterior facial framework, including the paired maxillae ($2$) and the mandible ($1$).

Frontal Bone

An axial cranial bone ($1$) forming the forehead and superior part of each orbit that articulates with the parietal bones.

Parietal Bone

A paired axial cranial bone ($2$) forming the superior and lateral walls of the cranium that articulates with the frontal, temporal, and occipital bones.

Temporal Bone

A paired axial cranial bone ($2$) situated at the lateral base of the skull that articulates with the parietal and occipital bones.

Occipital Bone

An axial cranial bone ($1$) forming the posterior base of the skull that articulates with the parietal bones and contains the foramen magnum.

Maxilla

A paired axial facial bone ($2$) forming the upper jaw that articulates with the mandible.

Mandible

An axial facial bone ($1$) forming the lower jaw; articulates with the maxilla.

Foramen Magnum

The large aperture located in the occipital region of the skull through which the spinal cord passes.

Hyoid Bone

A U-shaped axial bone in the neck ($1$ bone) that serves as a moveable base for the tongue and is the only bone in the body that does not articulate with another bone.

Auditory Ossicles

A set of $6$ tiny axial bones located in the middle ear ($3$ per ear) listed in order of articulation from the tympanic membrane: malleus (hammer), incus (anvil), and stapes (stirrup).

Malleus

The hammer-shaped auditory ossicle of the middle ear that articulates directly with the tympanic membrane and with the incus.

Incus

The anvil-shaped auditory ossicle of the middle ear that articulates intermediate between the malleus and the stapes.

Stapes

The stirrup-shaped auditory ossicle of the middle ear that articulates with the incus.

Vertebral Column

The axial skeletal spine composed of $26$ bones: $7$ cervical vertebrae, $12$ thoracic vertebrae, $5$ lumbar vertebrae, $1$ sacrum, and $1$ coccyx.

Cervical Vertebrae

The $7$ axial vertebrae situated immediately below the head that articulate superiorly with the skull and inferiorly with the thoracic vertebrae, containing special vertebrae C1 (atlas) and C2 (axis).

Atlas (C1)

The first cervical vertebra ($C1$) located immediately below the head that articulates with the skull and the axis ($C2$).

Axis (C2)

The second cervical vertebra ($C2$) featuring an upright tooth-like process called the dens that articulates with the atlas ($C1$).

Dens

The prominent vertical peg-like projection of the axis ($C2$) vertebra that articulates with the anterior arch of the atlas ($C1$) to serve as a pivot for head rotation.

Thoracic Vertebrae

The $12$ axial vertebrae of the vertebral column that articulate with cervical vertebrae, lumbar vertebrae, and ribs, each carrying a pair of ribs.

Lumbar Vertebrae

The $5$ axial vertebrae of the lower back that do not carry ribs, articulating superiorly with the thoracic vertebrae and inferiorly with the sacrum.

Types of Vertebrae

The three regional types of movable vertebrae in the human spine: cervical (smallest), thoracic (intermediate, carrying ribs), and lumbar (largest body, carrying no ribs).

Sacrum

A single axial triangular bone formed by the fusion of $5$ sacral vertebrae after adolescence; articulates superiorly with the lumbar vertebrae and laterally with the coxal bones.

Coccyx

A single axial bone formed by the fusion of $4$ coccygeal vertebrae; also called the tailbone.

Typical Vertebra

A vertebra structured with two main functional parts: the rounded body (anterior part) and the vertebral arch (posterior part), surrounding the vertebral foramen.

Vertebral Arch

The posterior portion of a typical vertebra comprising pedicles, laminae, spinous process, transverse processes, superior articular processes, and inferior articular processes.

Vertebral Foramen

The central canal formed between the anterior body and posterior vertebral arch through which the spinal cord passes.

Thoracic Cage

The protective axial skeletal framework of the chest consisting of the sternum, $24$ ribs ($12$ pairs), and costal cartilages.

Sternum

A single axial breastbone in the thoracic cage that articulates with the clavicles and ribs, divided into three regions: manubrium, body, and xiphoid process.

Manubrium

The superior region of the sternum that articulates with the clavicles and ribs.

Body of the Sternum

The elongated central region of the sternum located between the manubrium and xiphoid process that articulates with rib costal cartilages.

Xiphoid Process

The small, inferior cartilaginous and bony region of the sternum.

Costal Cartilage

Bars of hyaline cartilage that articulate the true and false ribs with the sternum.

Ribs

The $24$ axial bones ($12$ pairs) of the thoracic cage categorized into true ribs ($7$ pairs), false ribs ($3$ pairs), and floating ribs ($2$ pairs).

True Ribs

The first $7$ pairs of ribs (ribs $1\text{--}7$) that attach directly to the sternum through their own costal cartilages.

False Ribs

The $3$ pairs of ribs (ribs $8\text{--}10$) that do not attach directly to the sternum, sharing a common cartilaginous connection attached to the $7\text{th}$ costal cartilage.

Floating Ribs

The last $2$ pairs of ribs (ribs $11\text{--}12$) that attach only to the thoracic vertebrae posteriorly and have no anterior attachment.

Clavicle

An appendicular bone of the pectoral girdle (collarbone) that articulates with the scapula and the sternum.

Scapula

An appendicular bone of the pectoral girdle (shoulder blade) that articulates with the humerus and the clavicle.

Humerus

An appendicular long bone of the upper limb (arm) that articulates proximally with the scapula and distally with the ulna.

Radius

An appendicular bone of the upper limb (lateral forearm) that articulates with the ulna and carpals.

Ulna

An appendicular bone of the upper limb (medial forearm) that articulates with the humerus and radius.

Carpals

The wrist bones of the appendicular upper limb that articulate with the radius, ulna, and metacarpals.

Metacarpals

The bones of the hand/palm in the appendicular upper limb that articulate proximally with the carpals and distally with the phalanges.

Phalanges (Hand)

The finger bones of the appendicular upper limb that articulate with the metacarpals.

Coxal Bone

An appendicular pelvic girdle bone formed by the fusion of three parts (ilium, ischium, pubis) that articulates with the femur and sacrum.

Ilium

The superior, broad, flared division of the coxal bone that includes the ala.

Ischium

The posteroinferior division of the coxal bone.

Pubis

The anteroinferior division of the coxal bone that articulates anteriorly at the pubic region.

Femur

An appendicular bone of the lower limb (thigh) that articulates with the coxal bone, patella, and tibia.

Patella

An appendicular sesamoid bone of the lower limb (kneecap) that articulates with the femur and tibia.

Tibia

An appendicular bone of the lower leg that articulates with the femur, patella, and fibula.

Fibula

An appendicular bone of the lateral lower leg that articulates with the tibia and tarsals.

Tarsals

The ankle bones of the appendicular lower limb that articulate with the tibia and metatarsals.

Calcaneus

The heel bone of the foot in the lower limb; a tarsal bone that articulates with other tarsals.

Metatarsals

The bones of the foot in the appendicular lower limb that articulate proximally with the tarsals and distally with the phalanges.

Phalanges (Foot)

The toe bones of the appendicular lower limb that articulate proximally with the metatarsals.

Note Card Setup (Practical)

The standardized study card format for bone identification consisting of: Picture of Bone, Name of Bone, Skeleton (Appendicular or Axial), Region (underlined body region), and Articulates with (connecting bones).