Patho Exam 1

A set of flashcards to assist in reviewing key concepts from pathology exam notes, focusing on bone and cartilage structure, disorders, and soft tissue tumors.

What is the main function of cartilage?

To bear mechanical stresses without permanent distortion.

What type of tissue is cartilage?

Avascular tissue.

How do nutrients reach chondrocytes in cartilage?

Through simple diffusion from surrounding connective tissue.

What are the main cells found in cartilage?

Chondroblasts and chondrocytes.

What do chondroblasts do?

Make cartilage.

Where are chondrocytes located in cartilage?

In lacunae.

What is the composition of the extracellular matrix (ECM) of cartilage largely made up of?

Glycosaminoglycans (GAGs) and proteoglycans.

What type of collagen is primarily present in hyaline cartilage?

Type II collagen.

What distinguishes elastic cartilage from hyaline cartilage?

Presence of elastic fibers.

What is the typical arrangement of chondrocytes in hyaline cartilage?

Isolated or in small isogenous groups.

Does fibrocartilage have a perichondrium?

No.

Where is hyaline cartilage typically found?

Upper respiratory tract, articular ends of bones, and epiphyseal plates.

What is the main function of fibrocartilage?

Provides cushioning and tensile strength.

What is the perichondrium?

Dense connective tissue that covers nearly all hyaline cartilage except articular joints.

What are the two layers of the perichondrium?

Outer layer with type I collagen fibers and fibroblasts, inner layer with mesenchymal cells.

What are the two main types of ossification in bone formation?

Intramembranous ossification and endochondral ossification.

What characterizes intramembranous ossification?

Osteoblasts differentiate directly from mesenchyme and secrete osteoid.

In endochondral ossification, what is replaced by bone?

Hyaline cartilage.

What is the role of osteoblasts in bone?

Synthesize organic components of the matrix.

What determines the rigidity of bone?

Calcium hydroxyapatite.

What is compact bone primarily consisted of?

Cortical bone.

What is spongy bone also known as?

Cancellous or trabecular bone.

What is an osteon?

Concentric lamellae surrounding a central canal containing blood vessels and nerves.

What are osteocytes and where are they located?

Mature bone cells located in lacunae.

What is osteopetrosis?

A condition characterized by excessive density of bones due to failure of osteoclast function.

How does parathyroid hormone affect blood calcium levels?

It raises blood calcium by stimulating osteoclasts.

What is the genetic basis of achondroplasia?

Mutation in the FGFR3 gene, which is autosomal dominant.

What are primary symptoms of thanatophoric dysplasia?

Severe limb shortening and thoracic hypoplasia.

What does osteogenesis imperfecta lead to in terms of bone health?

Hypomineralization and high risk of fractures.

What are the hallmarks of Marfan syndrome?

Aortic root dilation, mitral valve prolapse, and tall stature.

What is the main feature of classical Ehlers-Danlos syndrome?

Joint hypermobility and skin hyperextensibility.

In osteoporosis, what is the standard diagnostic procedure?

DEXA scan.

Which bone density score indicates osteoporosis?

A T-score of -2.5 or lower.

What types of fractures are common in osteoporosis?

Vertebral compression fractures and fragility fractures.

What is osteonecrosis?

Death of bone tissue due to inadequate blood flow.

Which bones are most commonly affected by osteomyelitis?

Metaphysis near growth plate in long bones in children.

What distinguishes acute osteomyelitis in children?

Commonly presents with systemic symptoms like fever and pain.

What is a major complication of chronic osteomyelitis?

Pathologic fractures due to structural bone integrity loss.

What imaging study is preferred for diagnosing osteomyelitis?

MRI.

What are common bacterial causes of osteomyelitis?

S. aureus, E. coli, and Pseudomonas.

How is vitamin D related to rickets and osteomalacia?

Deficiency of vitamin D leads to defective mineralization.

What is Myasthenia Gravis?

An autoimmune disorder that blocks acetylcholine receptors leading to muscle weakness.

What is the histological characteristic of osteosarcoma?

Production of osteoid or immature bone.

Which soft tissue tumor is characterized by spindle cells and poor circumscription?

Leiomyosarcoma.

What is the clinical significance of the FOS gene in osteoid osteoma?

Transcriptional regulator of osteoid production.

Where do giant cell tumors typically arise?

In the epiphysis of long bones.

What does Ewing sarcoma histological appearance resemble?

Primitive round cells without differentiation.

What is a key feature of chondrosarcoma?

Malignant cartilage forming tumors.

What are the characteristics of liposarcoma?

Most common soft tissue sarcoma with deep soft tissue origin.

What describes the pathogenesis of rhabdomyosarcoma?

Soft tissue sarcoma with skeletal muscle differentiation.

Identify the most common primary soft tissue tumors.

Lipomas.

What is the most common soft tissue cancer in children?

Rhabdomyosarcoma.

What defines a fibromatosis tumor?

Well-differentiated fibroblasts with infiltrative growth.

Characteristics of acute hematogenous osteomyelitis?

Night pain, fever, and soft tissue swelling.

What is a brown tumor?

Bone lesion associated with osteitis fibrosa cystica.

What is a histological hallmark of Osteosarcoma?

Codman’s triangle on X-ray.

What is the role of osteoclasts in bone remodeling?

Resorb and remodel bone.

What is the characteristic X-ray appearance of Ewing sarcoma?

Onion-skin pattern of periosteal reaction.

In what age group does Osteoporosis most frequently occur?

Postmenopausal women.

What is the genetic mutation associated with Osteogenesis Imperfecta?

Mutations in type I collagen genes (COL1A1, COL1A2).

What factors contribute to osteomalacia?

Vitamin D deficiency, leading to poor mineralization.

What is the defining histological feature of chondromas?

Well-circumscribed hyaline cartilage.

How is Marfan syndrome inherited?

Autosomal dominant.

What are common locations for leiomyomas?

Uterus, skin, and deep soft tissues.

What does a Fibrocartilaginous callus signify?

Early stage of bone healing after fracture.

Which muscle type is known for voluntary control?

Skeletal muscle.

What enzyme is found in osteoclasts for bone resorption?

Carbonic anhydrase.

What is the primary cause of osteoporosis in aged individuals?

Decreased osteoblast function.

What defines the histology of skeletal muscle?

Cylindrical, multinucleated fibers with striations.

What is the role of the neuromuscular junction?

Site of signal transmission for muscle contraction.

What are the functions of smooth muscle?

Involuntary contraction of hollow organs.

What is a major characteristic of Duchenne muscular dystrophy?

Lack of dystrophin protein, leading to muscle degeneration.

What do pericytes do in smooth muscle regeneration?

Repair vascular smooth muscle.

What laboratory findings are associated with osteomalacia?

Increased alkaline phosphatase with normal calcium.

What is the most common bone tumor in adults?

Osteosarcoma.

What is the typical age range for the onset of Ewing sarcoma?

Children and young adults.

Which type of cartilage has the highest amount of elastin?

Elastic cartilage.

What is the relationship between fracture healing and osteoblast activity?

Increased osteoblast activity is critical for healing.

What type of tumors are rhabdomyosarcoma classified as?

Soft tissue sarcomas.

How do vitamin D levels affect calcium absorption?

Low levels lead to decreased calcium absorption.

What is the genetic basis of Osteopetrosis?

Mutations affecting osteoclast function.

What imaging technique is best for visualizing osteomyelitis?

MRI.

What is the first step in the treatment of osteomyelitis?

Antimicrobial therapy.

What is the histological feature of fibrosarcoma?

Spindle-shaped cells with minimal atypia.

How does the condition of osteogenesis imperfecta manifest?

Brittle bones with a tendency to fracture easily.

Which muscle cells can regenerate after injury?

Skeletal muscle cells via satellite cells.

What is the effect of bisphosphonates in treating osteoporosis?

Inhibit osteoclast activity.

Which type of cartilage is found at articular surfaces of joints?

Hyaline cartilage.

What condition is characterized by exacerbated bone fractures during activities?

Osteogenesis imperfecta.

What is the most common cause of Avascular necrosis?

Impaired blood flow resulting from trauma.

What conditions can lead to secondary osteoporosis?

Hyperthyroidism, glucocorticoids, and hypogonadism.

What morphological changes are seen in osteocytes during osteopetrosis?

Enlarged, dense, and abnormally structured.

What is the significance of alkaline phosphatase in bone diseases?

A marker for bone formation.

What are the most common clinical symptoms of osteoporosis?

Fractures and back pain.

What is the typical imaging finding for osteoarthritis?

Joint space narrowing and osteophyte formation.

Which type of bone density test is the gold standard for osteoporosis diagnosis?

DEXA scan.

How is Osteopetrosis visually diagnosed?

Through X-ray imaging showing increased bone density.

What nutrients are essential for bone health and prevention of osteoporosis?

Calcium and Vitamin D.

What is the primary mechanism of osteoarthritis-related pain?

Joint inflammation and cartilage degradation.

What laboratory test will help diagnose renal osteodystrophy?

Increased serum phosphate with low calcium.