CH 6

Flashcards covering key vocabulary and concepts from a lecture on bone structure and function.

Axial Skeleton

Bones of the skull, thorax, and vertebral column, forming the longitudinal axis of the body.

Appendicular Skeleton

Bones of the limbs and girdles that attach them to the axial skeleton.

Flat Bones

Thin, roughly parallel surfaces; examples include cranial bones, sternum, ribs, scapulae. They protect underlying soft tissues and provide surface area for skeletal muscle attachment.

Sutural Bones (Wormian Bones)

Irregular bones formed between cranial bones; number, size, and shape vary.

Long Bones

Relatively long and slender; examples include various bones of the limbs.

Irregular Bones

Complex shapes with short, flat, notched, or ridged surfaces; examples include vertebrae, bones of the pelvis, facial bones.

Sesamoid Bones

Small, flat, and somewhat shaped like a sesame seed; develop inside tendons of knee, hands, and feet; individual variation in location and number.

Short Bones

Small and boxy; examples include bones of the wrist (carpals) and ankles (tarsals).

Head (Bone Marking)

Expanded proximal end of a bone that forms part of a joint.

Diaphysis (Shaft)

Elongated body of a long bone.

Neck (Bone Marking)

Narrow connection between the head and diaphysis of a bone.

Process (Bone Marking)

Any projection or bump on a bone

Tubercle (Bone Marking)

Small, rounded projection on a bone.

Tuberosity (Bone Marking)

Small, rough projection that takes up a broad area on a bone.

Trochlea (Bone Marking)

Smooth, grooved articular process shaped like a pulley.

Condyle (Bone Marking)

Smooth, rounded articular process on a bone.

Trochanter (Bone Marking)

Large, rough projection on a bone.

Facet (Bone Marking)

Small, flat articular surface on a bone.

Crest (Bone Marking)

Prominent ridge on a bone.

Line (Bone Marking)

Low ridge, more delicate than a crest, on a bone.

Spine (Bone Marking)

Pointed or narrow process on a bone.

Ramus (Bone Marking)

Extension of a bone that makes an angle with the rest of a structure.

Canal or Meatus (Bone Marking)

Large passageway through a bone.

Sinus (Bone Marking)

Chamber within a bone, normally filled with air.

Foramen (Bone Marking)

Small, rounded passageway for blood vessels or nerves to pass through bone.

Fissure (Bone Marking)

Elongated cleft or gap in a bone.

Sulcus (Bone Marking)

Deep, narrow groove in a bone.

Fossa (Bone Marking)

Shallow depression or recess in bone surface.

Epiphysis

The expanded area at each end of a long bone, largely consisting of spongy bone with an outer covering of compact bone.

Metaphysis

Connects the epiphysis to the shaft of a long bone.

Diaphysis (Long Bone)

The shaft of a long bone, containing the medullary cavity.

Nutrient Foramen

Tunnel providing access to the marrow cavity for blood vessels.

Osteogenic Cells (Osteoprogenitor Cells)

Mesenchymal (stem) cells that produce cells that differentiate into osteoblasts; important in fracture repair.

Osteoblasts

Produce new bony matrix (osteogenesis or ossification), producing unmineralized matrix (osteoid) and assisting in depositing calcium salts to convert osteoid to bone.

Osteocytes

Mature bone cells that cannot divide; maintain protein and mineral content of surrounding matrix; occupy lacunae and are interconnected by canaliculi.

Osteoclasts

Remove and remodel bone matrix; release acids and proteolytic enzymes to dissolve matrix and release stored minerals (osteolysis).

Osteon (Haversian System)

Functional unit of compact bone, consisting of organized concentric lamellae around a central canal.

Appositional Growth

Increases bone diameter of existing bones by adding bone matrix under the periosteum.

Endochondral Ossification

Initial skeleton of embryo formed of hyaline cartilage, which is gradually replaced by bone.

Intramembranous Ossification

Begins when mesenchymal (stem) cells differentiate into osteoblasts within embryonic or fibrous connective tissue, forming bone without a prior cartilage model.

Pituitary Growth Failure

Inadequate growth hormone production, leading to reduced epiphyseal cartilage activity and abnormally short bones.

Achondroplasia

Epiphyseal cartilage of long bones grows slowly, replaced by bone early in life, resulting in short, stocky limbs.

Marfan Syndrome

Inherited metabolic condition with excessive cartilage formation at epiphyseal cartilages, resulting in a very tall person with long, slender limbs.

Fibrodysplasia Ossificans Progressiva (FOP)

Gene mutation that causes bone deposition around skeletal muscles, with bones developing in unusual places.

Acromegaly

Overproduction of growth hormone after epiphyseal plates close, resulting in bones getting thicker, not longer, especially in the face, jaw, and hands.

Fracture

Crack or break in a bone due to extreme mechanical stress.

Closed or Simple Fracture

Completely internal fracture with no break in the skin.

Open or Compound Fracture

Fracture that projects through the skin.

Transverse Fracture

Fracture that breaks the shaft across the long axis.

Spiral Fracture

Fracture produced by twisting stresses, spreading along the length of the bone.

Displaced Fracture

Fracture that produces new and abnormal bone arrangements; if alignment is retained, it is considered a nondisplaced fracture.

Compression Fracture

Fracture that occurs in vertebrae subjected to extreme stresses, often associated with osteoporosis.

Greenstick Fracture

Fracture where one side of the shaft is broken and the other side is bent; generally occurs in children.

Comminuted Fracture

Fracture that shatters the affected area, producing fragments.

Epiphyseal Fracture

Fracture that occurs where bone matrix is calcifying; breaks between epiphyseal plate and cartilage can stop growth at the site.

Pott’s (Bimalleolar) Fracture

Fracture that occurs at the ankle and affects both the medial malleolus and lateral malleolus.

Colles Fracture

Fracture which is a break in the distal radius.

Parathyroid Hormone (PTH)

Hormone secreted from the parathyroid glands that increases blood calcium levels by stimulating osteoclasts, enhancing calcitriol effects, and stimulating calcium reabsorption in kidneys.

Calcitonin

Hormone secreted from C cells in the thyroid gland that decreases blood calcium levels by inhibiting osteoclast activity, decreasing calcium absorption in intestines, and inhibiting calcitriol release and calcium reabsorption in kidneys.