Bones Flashcards
What is bone composed of?
Connective tissue composed of ground substance, cells, and fibers
Bone consists of an extracellular matrix and several cell types.
How many bones are in the human body?
206 bones
What are the main functions of bones?
- Mechanical support
- Force transmission
- Internal organ protection
- Mineral homeostasis
What is the extracellular component of bone called?
Matrix
What are the components of the bone matrix?
- Osteoid (35%)
- Minerals (65%)
What is the role of osteoblasts?
Build bone
What do osteoclasts do?
Consume/absorb bone
What is the function of osteocytes?
Help control calcium and phosphate levels
What is the process of bone formation called?
Osteogenesis or ossification
What is endochondral ossification?
Replacement of hyaline cartilage with bony tissue
What is intramembranous ossification?
Replacement of sheet-like connective tissue with bony tissue
What are the two classifications of bones based on microscopic structure?
- Compact bone
- Spongy bone
At what age do girls typically close their growth plates?
15-20 years
At what age do boys typically close their growth plates?
18-22 years
What is osteopetrosis?
Rare genetic disease characterized by reduced bone resorption
What is osteopenia?
Decreased bone mass
Define osteoporosis.
Severe osteopenia that significantly increases the risk of fracture
What are the two types of osteoporosis?
- Primary
- Secondary
What can lead to secondary osteoporosis?
- Chronic thyrotoxicosis
- Hyperparathyroidism
- Malabsorption
- Alcohol/smoking
- Medications
What is a common clinical feature of osteoporosis?
Vertebral fractures
What is osteomalacia?
Impaired mineralization of bone matrix in adults
What is rickets?
Impaired mineralization of bone matrix in children
What causes hyperparathyroidism?
Increases bone resorption
What is renal osteodystrophy?
Skeletal changes occurring in chronic renal disease
What is Paget’s Disease?
Increased, disordered, and structurally unsound bone mass
What are the three stages of Paget’s Disease?
- Initial osteolytic stage
- Mixed osteoclastic-osteoblastic stage
- Burned out quiescent osteosclerotic stage
What is a common feature of Paget’s Disease?
Lion face (leontiasis ossea)
What are the types of fractures?
- Simple
- Compound
- Displaced
- Stress
- Greenstick
- Pathological
What is required for optimal fracture recovery?
Immobilization
What is osteonecrosis?
Infarction of bone and marrow
What are common causes of osteomyelitis?
- Virus
- Bacteria
- Fungi
- Parasites
What are the most common primary bone tumors?
- Osteosarcoma
- Chondrosarcoma
- Ewing sarcoma
What is the most common primary malignant tumor of the bone?
Osteosarcoma
What is the typical age range for osteosarcoma occurrence?
75% occur before 20 years old
What is the hallmark of rheumatoid arthritis?
Joint effusions, juxta-articular osteopenia with erosions
What is the autoimmune response in rheumatoid arthritis initiated by?
CD4+ helper T-cells
What are common symptoms of rheumatoid arthritis?
- Malaise
- Fatigue
- Symmetrical joint lesions
What is juvenile idiopathic arthritis?
Unknown cause, present under 16 years, persists for at least 6 weeks
What is a common feature of ankylosing spondylitis?
Destruction of articular cartilage and bony ankyloses
What is polymyalgia rheumatica?
Muscle pain and stiffness in the upper body and hips
What is the treatment for infectious arthritis?
Antibiotics and supportive care
What blood tests may be included in the diagnosis of Rheumatica?
- Antinuclear antibody (ANA)
- Complete blood count (CBC)
- C-reactive protein (CRP)
- Erythrocyte sedimentation rate (ESR)
- Rheumatoid factor (RF)
These tests help assess inflammation and immune response.
What are common treatments for Rheumatica?
- Corticosteroids
- NSAIDS
- Exercise
- Rest
- Self-care
These treatments aim to reduce inflammation and manage symptoms.
What characterizes Suppurative Arthritis?
Haematogenous spread of bacterial infection leading to sudden development of acutely painful and restricted joint with a restricted ROM
Fever, leukocytosis, and elevated ESR are also common.
Which joints are most commonly involved in Infectious Arthritis?
- Knee
- Hip
- Shoulder
- Elbow
- Wrist
- Sternoclavicular joint
Typically involves a single joint.
What is the definition of Gout?
Transient attacks of acute arthritis initiated by monosodium urate crystals deposited within and around joints
Hyperuricaemia (plasma urate >6.8mg/dL) is a key factor.
What are the primary risk factors for Gout?
- Age >20 years
- Male > Female
- Genetic predisposition (HGPRT gene)
- Alcohol consumption
- Obesity/drugs
These factors contribute to the development of elevated uric acid levels.
What are the typical symptoms of a Gout attack?
- Sudden onset
- Excruciating pain
- Localised hyperaemia and warmth
- Monoarticular involvement
- Lasts hours to weeks
Subsequent attacks may become polyarticular.
What lifestyle modifications can help manage Gout?
- Weight loss
- Reduce purine intake
- Reduce alcohol and sugar
- Regular exercise
These changes can help control uric acid levels.
What pharmacological management options are available for Gout?
- Uricosuric drugs (allopurinol)
- NSAIDS
- Colchicine
These medications aim to lower uric acid levels and relieve pain.
What is Crystal Deposition Disease (CPPD) also known as?
Pseudogout
It typically affects individuals over 50 years.
What is a common radiographic finding in CPPD?
Chondrocalcinosis
This condition can present with acute, subacute, or chronic arthritis.
What are Ganglion Cysts?
Small cysts usually located near a joint capsule or tendon sheath
They develop due to connective tissue degeneration.
What is a Synovial Cyst?
Herniation of synovium through a joint capsule
An example is the Popliteal cyst (Baker Cyst) associated with RA.
What is a Lipoma?
Benign tumour of fat, the most common soft tissue tumour in adults
It is usually asymptomatic and harmless.
What is Liposarcoma?
Malignant tumour of adipose tissue
It develops in deep tissues of proximal extremities or the retroperitoneum, typically in individuals over 60 years.
What characterizes Nodular Fasciitis?
Self-limiting fibroblastic proliferation in young adults, often following trauma
It typically shows rapid growth over weeks to months.
What is Superficial Fibromatosis?
Benign growth that can cause local deformity
It presents as nodular proliferative lesions and is more common in males.
What is Dupuytren Contracture?
Thickening of the palmar fascia
It is a type of Superficial Fibromatosis.
What are the types of Bone Fractures?
Various classifications exist, including but not limited to:
* Simple
* Compound
* Comminuted
* Greenstick
Each type has distinct characteristics and implications for treatment.
