Diseases of the Muscles and Bones

1/3 organic matter

2/3 inorganic matter

Composition of Bones

1/3 organic matter

Composition of Bones
- Composed of collagen polysaccharide “glycosaminoglycan”

2/3 inorganic matter

Composition of Bones

• Composed of inorganic salts of calcium and phosporous: calcium carbonate and magnesium phospate.

Intramembranous Ossification

Endochondral Ossification

Types of Bone Formation/Ossification (IE)

Intramembranous ossification

Types of Bone Formation/Ossification

• Bone formation from its membranous precursors

Endochondral ossification

Types of Bone Formation/Ossification

• Bone formation from its cartilaginous precursors

• Osteoblast

• Osteocyte

• Osteoclast

Cellular Elements of Bone Tissue (O³ )

Osteoblast

Cellular Elements of Bone Tissue

• Bone-forming cell

Osteocyte

Cellular Elements of Bone Tissue

• Bone cell responsible for mineralization and demineralization.

Osteoclast

Cellular Elements of Bone Tissue

• Bone-destroying cell

• simple,

• greenstick,

• comminuted

Types of Bone Fractures (SGC)

Osteopenia

Types of Bone Fractures

• Too little bone (due to decreased calcium deposition)

Osteopetrosis

Types of Bone Fractures

• Too much bone (increased calcium deposition)

Osteoporosis

Types of Bone Fractures

• Decreased mineralization of bones (adult animals)

Rickets

Types of Bone Fractures

• Decreased mineralization of bones (young animals)

Osteonecrosis

Types of Bone Fractures

• Necrosis of bone tissue

• Infection

• Excessive mobility

• Malnutrition

• Poor vascularization

• Excessive distance

• Loss of periosteum

Factors that complicate fracture repair (IEMPEL)

• Osteitis

• Osteomyelitis

• Osteitis, periostitis, endosteitis

Inflammatory Bone Diseases (O³)

Osteitis

Inflammatory Bone Diseases

• Inflammation of bone

Osteomyelitis

Inflammatory Bone Diseases

• Inflammation of bone marrow

• Staphylococcus,

• Streptococcus,

• Corynebacteria

• Salmonella

• Actinomyces bovis

• Fusobacterium

• E.coli

Causes of suppurative and Non-suppurative Bone Diseases

• Suppurative (SSC) (SAFE)

• Brucella suis,

• Tubercle bacilli

• Fungi – Cryptococcus, Coccidioides, Blastomyces

Causes of suppurative and Non-suppurative Bone Diseases

• Non-suppurative (BTF)

• Kyphosis

• Scoliosis

• Lordosis

• Kyphoscoliosis

• Syndactyly

• Synostosis

• Phocomelia

• Amelia

• Polymelia

• Hemimelia

• Osteoporosis

• Osteopetrosis

• Exostosis

• Enostosis

• Pannus

• Callus

Pathological Disorders of the Bones

(Ky-Sco-Lor, Ky-Sco; Syn-Dac, Syn-Os; Pho-Am-Poly-Hemi; Poro-Petro, Exo-Eno; Pan-Call.)

Kyphosis

Pathological Disorders of the Bones

• Dorsal curvature of spine

Scoliosis

Pathological Disorder of the Bones

• Lateral curvature of spine

Lordosis

Pathological Disorder of the Bones

• Ventral curvature of spine

Kyphoscoliosis

Pathological Disorder of the Bones

• dorsal and lateral curvature of spine

Syndactyly

Pathological Disorder of the Bones

• Fusion of adjacent limbs (digits)

Synostosis

Pathological Disorder of the Bones

• osseous union of bones that are normally distinct

Phocomelia

Pathologic Disorders of the Bones

• Hypoplasia of limbs, hand and feet, attached directly to the body

Amelia

Pathologic Disorders of the Bones

• Absence of limbs

Polymelia

Pathologic Disorders of the Bones

• Excess in the number of limbs

Hemimelia

Pathologic Disorders of the Bones

• Absence of longitudinal segment of a limb

Osteoporosis

Pathologic Disorders of the Bones

• Clinical disease of bone pain and fracture characterized microscopically by a reduction of bone mass (osteopenia) but with the remaining bone normally mineralized.

Ostepetrosis

Pathologic Disorders of the Bones

• Increase bone mass

Exostosis

Pathologic Disorders of the Bones

• Nodular, benign bony growth projecting outward from a surface of bone.

Enostosis

Pathologic Disorders of the Bones

• a body growth within medullary cavity.

Pannus

Pathologic Disorders of the Bones

• Fibrovascular and histiocytic tissue that arises from the insertion of synovial membrane and spreads over adjacent cartilage as a velvety membrane,

Callus

Pathologic Disorders of the Bones

• Unorganized meshwork of woven bone that forms following a fracture.

• Osteoma,

• Osteosarcoma,

• Chondroma,

• Chondrosarcoma,

• Fibroma,

• Fibrosarcoma,

• Osteochondrosarcoma

Bone Neoplasms (O³CF²)

• myasthenia gravis

• myotonia

• myositis

• steatosis

• myorrhexia

• eosinophilic myositis

Pathologic Disorders of Muscles (M⁴SE)

Myasthenia gravis

Pathologic Disorders of Muscles

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

Myotonia

Pathologic Disorders of Muscles

• Muscle continues to contract actively even after the stimulus has ceased.

Myositis

Pathologic Disorders of Muscles

• Inflammation of muscle

Steatosis

Pathologic Disorders of Muscles

• Muscle infiltrated with fat

Myorrhexia

Pathologic Disorders of Muscles

• Pale hemorrhages in muscles.

Eosinophilic myositis

Pathologic Disorders of Muscles

• Contraction & stiffening of mm after death.

• Myolysis

• Extensive necrosis: toxic, metabolic, myopathy (causes: massive trauma, large burn)

• Degeneration: : pigmentation (melanin, lipofuscin, myoglobin); calcification, ossification, degeneration – cloudy swelling; vacuolar formation

• Segmental necrosis

Response of Muscle to Injury (MEDS)

Degeneration

Response of muscle to injury

• Pigmentation (melanin, lipofuscin, myoglobin); calcification, ossification, degeneration – cloudy swelling; vacuolar formation.

Extensive necrosis

Response of Muscle to Injury

• Toxic, metabolic, myopathy (causes: massive trauma large burn)

• CK/creatine kinase

• SGOT/ Serum Glutamic Oxaloacetic Transaminase/ Aspartate transaminase

• Myoglobin (non-specific: also present in hepatocytes of the liver.

Index of Extent of Muscle Fiber Damage (CSM)

Myoglobin

Index of Extent of Muscle Fiber Damage

• non-specific: also present in hepatocytes of the liver

Muscle Atrophy and Hypertrophy

Marked by decrease or increase in muscle mass (size of muscle fibers/myofibers)

Neurogenic,

Disuse;

Cachexia,

Malnutrition,

Senility,

Dystrophic;

Corticosteroids (make use of muscle protein for hepatic gluconeogenesis)

Causes of Muscle Atrophy (NDCM) (SDC)

• physiologic (increased workload)

• compensatory (secondary to degeneration atrophy of adjacent muscle fiber)

Causes of Muscle Hypertrophy

• Bacterial

• Viral

• Parasitic

• Immune-mediated

• Nutritional

Causes of Myositides (BadVibesPIN)

• Clostridial myositis

• Granulomatous myositis

• Bovine and ovine eosinophilic myositis

• Parasitic myositides

• Toxic myopathy

• Endocrine myopathy

• Exertional myopathy

Types of Myositides (CGBP) (TEE)

Clostridial myositis

Types of Myositides

• C. Noyvi (gas gangrene)

• C. Senticum (malignant edema)

• C. Chauvoei (blackleg)

Granulomatous myositis

Types of Myositides

• Tuberculosis and actinobacillosis

Bovine and ovine eosinophilic myositis

Types of Myositides

• An immune-mediated inflammation

Parasitic myositides

Types of Myositides

• Trichinella spiralis

• Cysticerus bovis

• Sarcocystis

Toxic myopathy

Types of Myositides

• Gossypol (from cottonseed)

• Monensin (a sodium ionophore from Streptomyces cinnamomensis)

Endocrine myopathy

Types of Myositides

• White muscle disease: due to vitamin E/ selenium deficiency of both.

Vitamin E

Scavenges free radicals in tissues

Selenium

A component of glutathione peroxidase

Glutathione peroxidase

An intracellular enzyme that scavenges free radicals

Free radical

By product of normal cell functions but can initiate cell injury by causing peroxidation of membrane lipids

Exertional myopathy

Types of Myositides

• due to intensive activity of major muscles

(equine rhabdomyolysis/ Monday morning sickness)