Diseases of the Muscles and Bones

Vocabulary terms and definitions regarding the composition, pathologies, and classifications of bone and muscle diseases as described in the lecture transcript.

Organic matter of bone

$1/3$ of bone composition consisting of collagen and polysaccharide glycosaminoglycan.

Inorganic matter of bone

$2/3$ of bone composition consisting of inorganic salts of calcium and phosphorous, including calcium carbonate and magnesium phosphate.

Intramembranous ossification

Bone formation from its membranous precursors.

Endochondral ossification

Bone formation from its cartilaginous precursors.

Osteoblast

A bone-forming cell.

Osteocyte

A type of bone cell.

Osteoclast

A type of bone cell involved in bone tissue maintenance or resorption.

Osteopenia

Too little bone due to decreased calcium deposition.

Osteopetrosis

Too much bone resulting from increased calcium deposition or an increase in bone mass.

Osteosteoporosis

Decreased mineralization of bones in adult animals.

Rickets

Decreased mineralization of bones in young animals.

Osteonecrosis

Necrosis of bone tissue.

Osteitis

Inflammation of the bone.

Osteomyelitis

Inflammation of the bone marrow.

Kyphosis

Dorsal curvature of the spine.

Scoliosis

Lateral curvature of the spine.

Lordosis

Ventral curvature of the spine.

Kyphoscoliosis

A combination of dorsal and lateral curvature of the spine.

Syndactyly

Fusion of adjacent digits.

Synostosis

Osseous union of bones that are normally separated distinctly.

Phocomelia

Hypoplasia of limbs where hands and feet are attached directly to the body; limbs are abnormally missing or short.

Amelia

Absence of limbs.

Polymelia

An excess in the number of limbs.

Hemimelia

Absence of one or more segments of a limb.

Osteoporosis

A clinical disease of bone pain and fracture characterized by a reduction of bone mass ($osteopenia$) but with the remaining bone being normally mineralized.

Exostosis (osteophyte)

A nodular, benign bony growth projecting outward from a surface of bone.

Enostosis

A bony growth within the medullary cavity, also known as a bone island or osteopoikilosis.

Callus

An unorganized meshwork of woven bone that forms following a fracture.

Myasthenia gravis

An auto-immune disease characterized by muscle weakness, increased fatigue, and reduced tolerance to exercise.

Myotonia

A condition where muscle continues to contract actively even after the stimulus has ceased.

Myositis

Inflammation of muscle.

Steatosis (myosteatosis)

A fatty muscle disease where fat accumulates and the muscle is infiltrated with fat.

Myorrhexis

Tearing or rupture of muscle.

Eosinophilic myositis

In some contexts, refers to the contraction and stiffening of muscles after death; in cattle and sheep, it is an immune-mediated inflammation.

Creatine Kinase (CK)

The most specific marker of muscle injury in dogs; elevated levels in the blood indicate severity of muscle damage.

SGOT (AST)

Serum glutamic oxaloacetic transaminase or aspartate aminotransferase; a liver enzyme that is also present in muscle.

Myoglobin

A non-specific marker of damage present in both muscle and hepatocytes of the liver.

Clostridial myositis

Muscle inflammation caused by bacteria such as $C. novyi$ (gas gangrene), $C. septicum$ (malignant edema), and $C. chauvoei$ (blackleg).

White muscle disease

An endocrine myopathy due to a deficiency of Vitamin E, Selenium, or both.

Selenium

A component of glutathione peroxidase, an intracellular enzyme that neutralizes free radicals.

Exertional myopathy

Muscle damage due to intensive activity, known as equine rhabdomyolysis or Monday morning sickness.