Chapter 44 disorders of the skeletal system metabolic and rheumatic disorders
1 / 24

Chapter 44 Disorders of the Skeletal System: Metabolic and Rheumatic Disorders - PowerPoint PPT Presentation

  • Uploaded on
  • Presentation posted in: General

Chapter 44 Disorders of the Skeletal System: Metabolic and Rheumatic Disorders. Normal Bone Remodeling. Osteoblasts are “bone building” cells They control bone remodeling by: Laying down new bone Secreting a compound (RANK ligand) that controls the osteoclasts , the “bone breaking” cells

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

Download Presentation

Chapter 44 Disorders of the Skeletal System: Metabolic and Rheumatic Disorders

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

Chapter 44Disorders of the Skeletal System: Metabolic and Rheumatic Disorders

Normal Bone Remodeling

  • Osteoblasts are “bone building” cells

  • They control bone remodeling by:

    • Laying down new bone

    • Secreting a compound (RANK ligand) that controls the osteoclasts, the “bone breaking” cells

  • Normally, bone formation and breakdown are balanced to:

    • Replace damaged bone

    • Maintain the amount and density of bone

Bone Growth

  • Bone cells and bone marrow cells produce OPG

    • It blocks the action of RANK ligand

    • The osteoclasts are not told to function

    • Bone breakdown decreases

    • Bones grow


Tell whether the following statement is true or false.

When osteoblasts work harder than osteoclasts, bones grow.



Osteoblasts build bone tissue; when they are more active than osteoclasts, bone grows. When osteoclasts work harder than osteoblasts, more bone is broken down.


How is bone remodeling affected by the following?

  • Vitamin D?

  • Mechanical stress?

  • Calcitonin?

  • Vitamin C?

Osteopenia and Osteoporosis

  • Osteopenia

    • Decreased bone

  • Osteoporosis

    • Decreased bone mass

    • Decreased cancellous (spongy) bone strength


Why are each of these people prone to osteoporosis?

  • A postmenopausal woman

  • A 70-year-old man

  • A hyperthyroid alcoholic

  • An Olympic figure skater who takes steroids to reduce joint inflammation

  • A man with a lung tumor that secretes PTH

Discussion (cont.)

  • Who would be most helped by the following?

  • Exercise

  • Increased Ca2+ and vitamin D in the diet

  • Estrogen receptor stimulators

  • Inhibitors of bone resorption


  • Bone is not mineralized properly; it is not rigid

  • It is caused by:

    • Insufficient calcium absorption

    • Insufficient phosphate

  • It results in:

    • Bone pain and tenderness

    • Fractures

    • Deformities


  • Vitamin D deficiency

  • Inadequate calcium absorption from diet

Paget Disease

  • Regions of excessive bone turnover

  • New bone is disorganized

  • Deformation and fracture common


Which bone disorder is characterized by “soft” bones?

  • Osteopenia

  • Osteomyelitis

  • Rickets

  • Paget disease


  • Rickets

    Calcium need vitamin D in order to be absorbed. In the case of vitamin D deficiency (rickets), calcium cannot be absorbed, and bones become soft.

Rheumatoid Arthritis

  • Autoimmune disorder

  • Antibodies against IgG fragments

  • Cause inflammation in the joint

  • Abnormal healing responses lay down granulation tissue (pannus)

Treatment of Rheumatoid Arthritis

  • NSAIDs

  • Corticosteroids

  • Leflunomide

  • Influximab

Systemic Lupus Erythematosus (SLE)

  • Autoantibodies include:

    • Antinuclear antibodies (ANA)

    • Antibodies against RBCs

    • Antibodies against platelets

    • Antibodies against coagulation factors

SLE Can Damage Any Tissue

  • Arthralgia

  • Skin lesions (butterfly rash)

  • Glomerulonephritis

  • Pleuritis

  • Pericarditis

  • Atherosclerosis

  • CNS inflammations


SLE produces antibodies against all but which of the following?

  • RBCs

  • WBCs

  • Platelets

  • Coagulation factors


  • WBCs

    SLE is an autoimmune disease that results in the production of the following antibodies: antinuclear antibodies, and antibodies against RBCs, platelets, and coagulation factors. WBCs are not affected.

Systemic Sclerosis (Scleroderma)

  • Collagen deposits in skin and internal organs


  • Inflammation at the insertions of tendons and ligaments

Reactive Arthropathies

  • Sterile joint inflammations caused by previous infection

  • The joints are not infected at the time of inflammation

  • Can follow infection with many agents including:

    • Chlamydia

    • Pseudomonas

    • Streptococcus

    • HIV

Osteoarthritis Syndrome

  • Degenerative joint disease

  • Inflammation of the joints often secondary to physical damage

  • Damaged joint cartilage tries to heal itself

    • Creating osteophytes or spurs

  • Cartilage contains more water, less collagen

    • Cartilage becomes weak, rough, eroded

    • No longer protects the surface of the bone

Gout Syndrome

  • Increased serum uric acid

  • Crystals precipitate in the joint

  • Inflammation results

  • Tophi are deposits containing monosodium urate crystals

  • Login