Skeletal System: Axial and Appendicular Skeleton

What are the basic components and functions of the Axial Skeleton?

Composed of the bones along the body’s central axis; Including the bones of the skull (and associated bones), vertebral column, sternum, and ribs.

The main function is to form a framework of support and protect the organs. Most of the bones spongy tissue contains hematopoietic tissue.

Axial Skeleton subdivisions (80)

Skull (22)

Associated bones of Skull (7)

Vertebral Column (26)

Thoracic Cage (25)

What are the two subdivision of the Skull bones?

Cranial (8) and Facial (14) bones

What are the Cranial bones?

Frontal bone (1)

Parietal bones (2)

Temporal bones (2)

Occipital bone (1)

Sphenoid bone (1)

Ethmoid bone (1)

What are the Facial bones?

Zygomatic bones (2)

Lacrimal bones (2)

Nasal bones (2)

Vomer (1)

Inferior Nasal Conchae (2)

Palatine bones (2)

Maxillae (2)

Mandible (1)

What are the bones associated with the Skull?

Auditory Ossicles (6)

• Malleus (2)

• Incus (2)

• Stapes (2)

Hyoid bone (1)

What are the bones of the Vertebral Column?

Cervical Vertebrae (7)

Thoracic Vertebrae (12)

Lumbar Vertebrae (5)

Sacrum (1)

Coccyx (1)

What are the bones of the Thoracic Cage?

Sternum (1)

Ribs (24)

What are the basic components and functions of the Appendicular Skeleton?

Composed of the bones of the upper and lower limbs and their attaching girdles (pectoral and pelvic). The main function is to facilitate movement and support the body's locomotion.

Appendicular Skeleton Subdivisions

Pectoral Girdle (4)

Upper Limbs (30/30)

Pelvic Girdle (4)

Lower limbs (30/30)

What are the bones of the Pectoral Girdle?

Clavicle (1/1)

Scapula (1/1)

What are the bones of the Upper Limbs?

Humerus (1/1)

Radius (1/1)

Ulna (1/1)

Carpals (8/8)

Metacarpals (5/5)

Phalanges (14/14)

What are the bones of the Pelvic Girdle?

Hip bone (1/1)

What are the bones of the Lower Limbs?

Femur (1/1)

Patella (1/1)

Tibia (1/1)

Fibula (1/1)

Tarsals (7/7)

Metatarsals (5/5)

Phalanges (14/14)

What are Bone Markings?

Surface features that characterize each bone in the body.

What are Articulator Surfaces?

The typically smooth points where two bones meet.

Condyle

Large, smooth, rounded, oval structure.

Facet

Small, flat, shallow surface.

Head

Prominent, rounded epiphysis.

Trochlea

Smooth, grooved, pulleylike process.

What are Depressions?

Deeper indented surface on a bone. Provides space for a bony articulation, muscular structure, or other body component.

Alveolus (pl. alveoli)

Deep pit or socket in the Maxillae or Mandible.

Fossa (pl. fossae)

Flattened or shallow depression.

Sulcus

Narrow groove.

What are Projections?

The bone surface that marks the points where muscles, tendons, and ligaments attach.

Crest

Narrow, prominent, ridgelike projection.

Epicondyle

Projection adjacent to a condyle.

Line

Low ridge.

Process

Any marked bony prominence.

Ramus (pl. rami)

Angular extension of a bone relative to the rest of the structure.

Spine

Pointed, slender process.

Trochanter

Massive, rough projection found only on the femur.

Tubercle

Small, round projection.

Tuberosity

Large, rough projection.

What purpose do Openings and Spaces through bones serve?

A passageway for blood vessels and nerves.

Canal

Passageway through a bone.

Fissure

Narrow, slit-like opening through a bone.

Foramen (pl. foramina)

Opening or hole in a bone.

Meatus

Passageway through a bone.

Sinus

Cavity or hollow space in a bone.