Skeletal System (HLTAAP002 Session 4)

Vocabulary flashcards covering the structure, functions, and disorders of the human skeletal system, including the axial and appendicular skeletons, bone anatomy, and aging effects.

Axial skeleton

Composed of the bones of the skull, the thorax, and the vertebral column.

Appendicular skeleton

Consists of the pectoral girdle, upper limbs, pelvic girdle, and lower limbs.

Cranial bones

Bones of the skull that encase and protect the brain; there are $8$ in total.

Facial bones

Bones that form the front of the skull and provide shape to the face; there are $14$ in total.

Sutures

Joints that connect the bones of the skull, providing flexibility during childbirth and infancy growth.

Foramen magnum

A large opening in the occipital bone at the base of the skull that allows the spinal cord to connect to the brainstem.

Sinuses

Air-filled cavities (frontal, ethmoidal, sphenoidal, and maxillary) that lighten the skull and modulate voice sound.

Anencephaly

A fatal congenital birth defect where the upper part of the brain and skull are absent.

Microcephaly

A condition resulting in an abnormally small head and brain size, associated with neurological deficits.

Vertebral column sections

Divided into $7$ cervical bones, $12$ thoracic bones, and $5$ lumbar bones, with the sacral and coccyx being fused.

Atlas (C1)

The first cervical vertebra that enables the nodding "yes" movement.

Axis (C2)

The second cervical vertebra that allows for the rotating "no" motion.

Scoliosis

A disorder of the vertebral column characterized by a lateral curve of the spine.

Kyphosis

A spinal curvature disorder commonly known as hunchback.

Lordosis

A spinal curvature disorder commonly known as swayback.

Spina Bifida

A birth defect where the neural tube fails to close properly, leading to incomplete development of the spinal cord and its protective bones.

Sternum

The breastbone, made of three parts: the manubrium, the body, and the xiphoid process.

Ribs

Composed of $12$ pairs; includes seven pairs of true ribs and five pairs of false ribs (which includes two pairs of floating ribs).

Pectoral girdle

Connects the upper limbs to the axial body and consists of the clavicle and scapula.

Pelvis

Consists of the sacrum, coccyx, ilium, ischium, pubis, symphysis pubis, and acetabulum.

Bunion

A misalignment of the big toe joint causing a painful bony protrusion on the side of the foot.

Compact bone

The hard, outer section of the skeletal bone.

Spongy bone

The soft bone found mostly inside that resembles a honeycomb.

Epiphyseal plate

Also called a growth plate; a layer of cartilage at the ends of long bones that allows them to lengthen during growth.

Medullary cavity

The inside cavity of a bone.

Endosteum

A layer of bone cells lining the inside of the bone adjacent to the medullary cavity that helps with growth, repair, and remodeling.

Periosteum

An outer double-layered structure on bones containing blood and lymphatic vessels that nourish compact bone.

Osteocytes

Mature bone cells.

Osteoblasts

Bone-forming cells essential for growth and fracture repair.

Osteoclasts

Bone-resorbing cells responsible for breaking down bone tissue to maintain calcium balance.

Haematopoiesis

The production of red and white blood cells and platelets within the red bone marrow.

Osteogenesis Imperfecta

Known as "brittle bone disease," a genetic disorder characterized by fragile bones due to mutations in collagen-producing genes.

Cartilage

A strong, flexible connective tissue that cushions joints, absorbs shock, and reduces friction.

Hyaline cartilage

The most common and slippery type of cartilage, found at the ends of bones, between ribs, and in nasal passages.

Osteoarthritis

The most common type of arthritis, where joint cartilage breaks down due to aging, affecting approximately $80\%$ of adults over $55$.

Joint (Articulation)

The area of junction or union between two or more bones.

Rheumatoid Arthritis

A chronic inflammatory autoimmune condition where the immune system attacks joint linings.

Osteoporosis

A condition where new bone creation does not keep up with old bone loss, leading to fragile and less dense bones.