Anatomy and Physiology: The Axial Skeleton System

Vocabulary flashcards for the axial skeleton.

Axial Skeleton

Protects many of the body’s organs, such as the brain (cranium), spinal cord (vertebrae), and heart and lungs (ribs).

Axial Skeleton bones

Consists of 80 bones including skull bones, auditory ossicles, hyoid bone, ribs, sternum, vertebrae, and sacrum.

Appendicular Skeleton

Consists of 126 bones including bones of the upper and lower extremities and the bones forming the girdles that connect the limbs to the axial skeleton

Long Bones

Bones with a greater length than width

Short Bones

Cube shaped bones.

Flat Bones

Thin layers of parallel plates of bone.

Irregular Bones

Bones with complex shapes.

Sesamoid Bones

Bones shaped like a sesame seed.

Sutural Bones

Small, extra bone plates located within the sutures of cranial bones

Sutures

The jointed areas where flat bones come together

Fissure

Narrow slit between adjacent parts of bones through which blood vessels or nerves pass.

Foramen

Opening through which blood vessels, nerves, or ligaments pass.

Fossa

Shallow depression

Sulcus

Furrow along bone surface that accommodates blood vessel, nerve, or tendon.

Meatus

Tubelike opening.

Condyle

Large, round protuberance with a smooth articular surface at end of bone.

Facet

Smooth, flat, slightly concave or convex articular surface.

Head

Usually rounded articular projection supported on neck (constricted portion) of bone.

Crest

Prominent ridge or elongated projection.

Epicondyle

Typically roughened projection above condyle.

Line

Long, narrow ridge or border (less prominent than crest).

Spinous process

Sharp, slender projection.

Trochanter

Very large projection.

Tubercle

Variably-sized rounded projection.

Tuberosity

Variably-sized projection that has a rough, bumpy surface.

Suture

Immoveable joint found in the skull holding bones together

Paranasal Sinuses

Mucous membrane-lined cavities in the frontal, maxillary, sphenoid and ethmoid bones used as resonating chambers to enhance the voice, increase the surface area of the nasal mucosa and help to moisten it

Fontanels

Areas of a fetus/baby where unossified mesenchyme develops into dense connective tissue

Vertebral Column

Also known as Spinal column, backbone, or spine; composed of 26 vertebrae divided into 5 regions; protects the spinal cord

Intervertebral Discs

Located between the bodies of the vertebrae from the second cervical to the sacrum; composed of an outer ring of fibrocartilage (annulus fibrosus) and an inner, soft nucleus (nucleus pulposus) with a layer of hyaline cartilage on the top and bottom of each disc; absorb shock and separate the vertebrae from one another

Thorax

Entire chest region

True (Vertebrosternal) Ribs

First 7 pairs of ribs; their cartilage is directly connected to the sternum

False (Vertebrochondral) Ribs

Next 5 pairs of ribs; cartilage is indirectly connected to the sternum

Floating (Vertebral) Ribs

Last 2 pairs of ribs; these are not connected to the sternum

Scoliosis

Increased lateral curvature of the spine

Kyphosis

Increased thoracic curve (bent forward)

Lordosis

Increased lumbar curve (bent backwards)