Metabolic & Vascular Bone Diseases

Question 1

(Mild/Severe) decreases in serum Ca++ is compensated by increased bone resorption activity at the Lining Cell/Osteocyte Complexes (LCOC’s)

Answer 1

Mild

Question 2

(Mild/Severe) decreases in serum Ca++ is compensated by additional Bone Multicellular Units (BMU’s) (clusters of osteoclasts and osteoblasts); however this can impair the structural integrity of the bone

Answer 2

Severe

Question 3

What are the 2 hormones in control of Calcium Homeostasis

Answer 3

PTH

Vitamin D3

Question 4

A hormone released from chief cells within the PT gland in response to decreases in serum Ca+2; inhibited by Vitamin D

Answer 4

Parathyroid Hormone

Question 5

Describe how PTH increase serum Ca+2 levels

Answer 5

1. PTH binds to receptors on osteoblasts
2. Osteoblasts secret RANKL (osteoclast activating factor)
3. RANKL binds to RANK receptors on osteoclasts for activation
4. Bone resorption at LCOC and BMU releases Ca+2

Question 6

A steroid hormone synthesized in inactive from in skin under sun exposure; increased availability of Ca+2 and PO43- for mineralization; enhances monocyte immune response

Answer 6

Vitamin D3

Question 7

Vitamin D3 is activated by

Answer 7

liver and kidney (PRT)

Question 8

Primary hyperparathyroidism is caused by

Answer 8

adenoma

Question 9

Lab findings of Primary hyperparathyroidism

Answer 9

High Ca+2
High PTH
High Alk Phos

Question 10

(Primary/Secondary) Hyperparathyroidism presents with symptoms of HYPERcalcemia –> kidney sones, GI symptoms, high bone turnover, fatigue

Answer 10

Primary

Question 11

Secondary hyperparathyroidism is caused by

Answer 11

renal disease, vitamin D deficiency, corticosteroids

Question 12

Lab findings of secondary hyperparathyroidism

Answer 12

Low Ca+2
High PTH
High Alk Phos

Question 13

T/F

Unlike primary hyperparathyroidism, hypercalcemia symptoms are NOT present in secondary hyperparathyroidism

Answer 13

True

Question 14

The most common cause of Secondary Hyperparathyroidism

Answer 14

Renal Osteodystrophy

• Can’t activate Vit D
• Can’t excrete phosphate

Question 15

Describe how renal osteodystrophy cause secondary hyperparathyroidism

Answer 15

1. Decreased phosphate excretion –> serum phosphate binds to serum Ca+2 –> low serum Ca+2
2. Vitamin D cannot be activated –> further decreased serum Ca+
3. In response to low Ca+2, PTH is increased

Question 16

A bone disorder in which bones are soft and flexible; caused by defective mineralization due to vitamin D deficiency; has calcium-phosphorous cross product of <30

Answer 16

Osteomalacia (rickets)

Question 17

Bowed legs, rachitic rosary (enlarged anterior ribs), physeal widening, and metaphyseal flare are findings of

Answer 17

rickets

Question 18

T/F

Osteoporosis, osteogenesis imperfecta, osteopetrosis, and paget disease will present with serum calcium abnormalities

Answer 18

False; they have normal serum Ca+2

Question 19

A bone disorder that has normal mineralization but decreased bone quantity; normal Ca+2 and PO43-; increased radiolucency on x-ray

Answer 19

Osteoporosis

Question 20

Primary Osteoporosis is divided into what two categories?

Answer 20

Postmenopausal (Type 1)

Age-related (Type 2)

Question 21

Type of PRIMARY Osteoporosis; more TRABECULAR than cortical involvement; presents with distal radius fractures (colle’s fractures) and vertebral fractures

Answer 21

Postmenopausal Osteoporosis

Question 22

Type of PRIMARY Osteoporosis; equal Trabecular and Cortical involvement; presents with proximal femur and vertebral fractures

Answer 22

Age-related osteoporosis

Question 23

(Primary/Secondary) Osteoporosis is due to steroids, parathyroid disease, or hyperthyroidism (activates osteoclast stimulation)

Answer 23

Secondary

Question 24

A disorder of bone formation that is also known as “brittle bone”

Answer 24

Osteogenesis Imperfecta

Question 25

Osteogenesis Imperfecta is caused by a defect in

Answer 25

Type I collagen

Question 26

Signs of Osteogenesis Imperfecta

Answer 26

1. Blue sclera 2. Hearing loss (ear bones) 3. tooth abnormalities 4. Multiple fractures

Question 27

A disorder of bone resorption that is also known as stone/marble bone; hardened bones due to osteoclast failure

Answer 27

Osteopetrosis

Question 28

"Erlenmeyer flask" appearance on X-ray and marrow cavity loss on histology is indicative of which intrinsic bone disease

Answer 28

Osteopetrosis

Question 29

A disorder of bone remodeling; elevated alk phos due to increased osteoclast fxn; lead to fragile or deformed bones

Answer 29

Paget Disease

Question 30

Mixed mature and immature bone (Cement or "Mosaic" lines) can be indicative of which Bone Disease

Answer 30

Paget Disease

Question 31

Moth-eaten radiographic appearance is indicative of which Bone Disease

Answer 31

Paget Disease

Question 32

What Bone Disease can degenerate into Osteosarcoma?

Answer 32

Paget Disease

Question 33

Avascular necrosis of hip is known as

Answer 33

Hip osteonecrosis

Question 34

Avascular necrosis of the Femoral head is usually due to disruption of blood flow via what vessel?

Answer 34

Medial Femoral Circumflex artery

Question 35

Rare CHILDHOOD condition that affects the hip; blood supply to the head of the femur is temporarily disrupted and bone cells die

Answer 35

Perthes disease

Question 36

Hip avascular necrosis has a relationship to prior ___________use

Answer 36

corticosteroid

Question 37

What bone disorder causes cystic changes on x-ray due to high bone turnover seen in hyperparathyroidism?

Answer 37

Osteitis fibrosa cystica