Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MSK/Derm > SM 233: Metabolic Disease > Flashcards

SM 233: Metabolic Disease Flashcards

1
Q

What is the Axial skeleton?

A

Vertebra and ribs derived from para-axial plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the embryonic origin of the Axial skeleton?

A

Para-axial plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the Appendicular skeleton?

A

Arms and Legs and hip derived from lateral plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the embryogenic origin of the Appendicular skeleton?

A

Lateral plate mesoderm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the cranofacial bones of the skeleton derived from?

A

Neural crest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the composition of the normal skeletal system?

A

70% inorganic matrix (Calcium Hydroxyapatite) 30% organic (Type I collagen and Osteocalcin)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Osteocalcin?

A

A serum marker of bone formation and density

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Which region of bone contains hematopoeitic cells?

A

The Medullary cavity, with medullary bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which region of bone is normally made of compact bone?

A

The cortex

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is intramembranous bone formation?

A

Minor contributor, bone develops from Collagen undifferentiated osteoprogenitor cells and produces flat bones of skull and clavicles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is endochondral bone formation?

A

Major contributor, bone develops from epiphyseal cartilage of the growth plate, forming the appendicular and axial skeleton

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the 5 zones of Endochondral Bone formation?

A

Resting Zone

Zone of Proliferation

Zone of Hypertrophy

Zone of Calcification

Primary Trabeculae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What factors stimulate endochondral bone formation and cartilage growth, and where do they act?

A

PTHrP and BMP at the Zone of Proliferation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What factors inhibit endochondral bone formation and cartilage growth, and where do they act?

A

FGF, at the Zone of Proliferation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which diseases can be traced back to the Zone of Proliferation?

A

Achondroplasia

Mucopolysaccharidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which diseases can be traced back to the Zone of Provisional Calcification?

A

Rickets/Osteomalacia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which diseases can be traced back to the Primary Trabeculae in endochondrail bone formation?

A

Osteogenesis Imperfecta
Scurvy
Osteoperosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the two types of bone?

A

Immature (Osteoid and Woven)
Mature (Lamellar)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is Osteoid?

A

Unmineralized poorly organized bone matrix composed of Type I collaged formed rapidly

Mineralization needed to become adult bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is Woven bone?

A

Mineralized immature bone formed rapidly, and the main componenet of prepubertal bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is lamellar bone?

A

Mature bone with parallel Type I collagen fibers that form Lamellae and evenly distributed osteocytes

Two types: Cortical and Cancellous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is cortical bone?

A

Cortical = compact bone that is initially part of a lamellae which laters becomes part of a Haverisian canal when Collagen deposits to handle stress

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is cancellous bone?

A

Cancellous = spongy bone formed by endochondral ossification, found in the center of long bones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are Osteoblasts?

A

Bone forming cellls that produce Matrix proteins, Type I collagen, and initiate mineralization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What cell surface receptors are found on Osteoblasts?
PTH, Vit D, Estrogen
26
What are Osteocytes and what key molecule do they produce?
Ostoecytes are osteoblasts that are incorporated into mature bone Osteocytes produces Sclerostin, a protein that inhibits further bone formation until osteocytes are stimulated
27
What is Sclerostin?
A protein made by Osteocytes that inhibits further bone formation until the Osteocytes are stimulated
28
What are Osteoclasts?
Multinucleated cells formed from monocytes in response to RANK-Ligand secred by osteoblasts Mediate bone resorption
29
What are resorption pits?
Pits on the surface of bone where Osteoclasts are found
30
How do Osteoblasts give rise to Osteoclasts?
Ostoblasts express RANK-Ligand Osteoclast precursors express RANK Receptor Osteoblast RANK-Ligand binds Osteoclast precursor RANK Receptor to differentiate precursor into Osteoclast
31
What is the function of an Osteoclast "resorption pit"?
Creates a sealed environment where Osteoclast H/K ATPases can acidify to high concentration and break down bone
32
How do Osteoclasts break down bone?
Osteoclast use a H ATPase to break down bone and release minerals and growth factors from bone Osteoperosis can arise from mutations in H ATPase
33
How do Osteoblasts and Osteoclasts form a cycle that promotes bone remodeling continually?
Osteoblasts build bone and activate Osteoclasts via RANK-Ligand to Rank-Receptor signalling respectively Osteoclasts chew up bone and release growth factors from bone Growth factors from bone further stimulate Osteoblasts
34
Why is it important that bone remodeling is continuous?
Dissipates bone stress over life and allows for bone to act as a repository of minerals
35
How are Osteons formed in Cortical bone?
Osteons form in response to stress Osteoclasts first resorb bone = primary osteon Osteoblasts fill cavity made by Oclasts in concentric Lamellae Osteocytes in the newly formed Osteon regulate remodelling
36
How is Trabecular bone formation controlled?
Osteoclasts are activated Resporb bone in their pits = Howship's Lacuna Reversal of cell type to Osteoblasts Bone formatino occurs
37
What can cause Acute Osteomyelitis, broadly speaking?
Hematogenous spread (bacterimia) Contiguous spread from abscess or ulcer Direct inoculation into bone Ischema from vascular insufficiency
38
What is the most common cause of Acute Osteomyelitis and why is it hard to treat?
S. aureus New bone forms around dead/infected bone, so it's hard for antibiotics to reach Treat with surgical debridement/removal of bone and long course of antibiotics
39
What is Osteogensis Imperfecta and what causes it?
A group of diseases with AR inheritance most severe and lethal in the perinatal period Defect in synthesis of Type I collagen
40
What's worse, abnormal Type I collagen or insufficient Type I collagen?
Abnormal Type I collagen, because it disrupts the strcutre of bone in Osteogensis Imperfecta
41
How does Osteogensis Imperfecta present?
Presentation reflects deficient Type I Collagen: Bone fractures + excess callus formation Blue Sclera Hearing Defects Teeth Defects
42
Which zone of Endochondral ossification is affected by Osteogenesis Imperfecta?
The Zone of Primary Trabeculation, since the Type I collagen is defective and mature bone can't form normally, resulting in lots of weak, woven bone
43
What defines Osteoperosis?
1+ atraumatic bone fractures (bone insufficiency) OR Low bone mineral density on DXA scan
44
What are the two broad categories of Osteoperosis?
Localized due to immobility/regional inflammation Generalized due to Age/PMP status
45
What causes localized Osteoperosis?
Immobility leading to Atrophy Inflammation around a specific bone like RA
46
What general principles underlie Senile and PMP Osteoperosis?
Osteoblasts lose ability to form new bones Growth factors lose potency Osteoclasts become activated
47
What causes PMP Osteoperosis and what bones are effected most?
Estrogen deficiency results in a disinhibition of Osteoclasts, leading to rapid bone breakdown Affects bones with large surface area (vertebrae)
48
What is a high turnover osteoperosis, and give an example?
Osteoperosis driven primary by increased Osteoclast activity as opposed to deceased Osteoblast activity Ex = PMP Osteoperosis
49
What is Senile Osteoperosis and who gets it?
Men and Women older than 70 Due primarily to Osteoblasts having less activity with age and growth factors becoming less potent
50
What type of fractures are common in Senile Osteoperosis?
Hip and Vertebra
51
What is a low turnover osteoperosis, and what is an example?
An osteoperosis driven by loss of activity of osteoblasts with normal osteoclast activity Ex = Senile Osteoperosis
52
What are Mucopolysaccharidoses?
Diseases caused by mutations in lysosomal enzymes that degraded GAGs resulting their accumulation and cellular damage
53
What are the signs and symptoms of Mucopolysaccharidoses?
Presentation varies by the enzyme effected, causing a different resulting Mucopolysaccharidoses: Cardiac valvular disease Mental retardation Macroglossia
54
How can Mucopolysaccharidoses be diagnosed?
Diagnosed prenatally by measuring enzyme activity in cultured placenta-derived cells or by measuring urinary GAG
55
What is the mode of inheritance of most Mucopolysaccharidoses?
Mostly Autosomal Recessive Hunter Syndrome is X-linked Recessive
56
What diseases are associated with a Vit D deficiency?
Rickets and Osteomalacia
57
What are the effects of Vit D?
Increased Ca and PO4 reabsorption from the intestine
58
How does Vit D relate to endochondral bone formation?
In kids, Vit D is required for calcifiation of Cartilage in the growth plate at the Zone of Provisional Calcification; deficiency = Rickets In adults, Vit D is required for conversion of osteoid to new adult bone; deficiency = Osteomalacia
59
How does a Vit D defiency effect kids?
Vit D deficiency causes growth plate to widen with uncalcified cartilage and osteoid because Vit D is needed for calcification = Rickets
60
How does Rickets effect bones?
Rickets can cause bowing of the femoral bones and large costochondral spots on the rib cage Also makes all bones weaker
61
How does a Vit D defiiency effect adults?
Vit D deficiency results in the inability to calcify osteoid to form new adult bone during remodeling Usually due to chronic renal failure
62
How does Hyperparathyroidism manifest?
Moans (GI Tract) Bones (Aches) Renal Stones Psychiatric Overtones
63
What is the difference between primary hyperparathyroidism and secondary hyperparathyroidism?
Primary HPT is due to overactivity of the Parathyroid itself, due often to Parathyroid adenoma Secondary HPT is often driven by renal failure and decreased serum Ca triggering excess PTH release
64
How does elevated PTH effect bone cells?
PTH activates osteoclasts and causes osteoperosis
65
What is the brown tumor of the bone?
In Hyperparathyroidism, osteoclasts are activated and form "cutting cones" that break down bone Severe HPT results in fractures that cause intramedulllary hemorrhage and fibrosis within these "cutting cone" derived cracks in the bone
66
What is Paget's Disease of Bone?
"Collage of Matrix Madness" due to dyssyncrhony of osteoclastic/osteoblastic activity Effects multiple bones causing fractures, spinal nerve compression, and high output cardiac failure
67
Explain the pathophysiology of Paget's Disease of Bone?
Due to dyssynchrony betwen Osteoclasts and Osteoblasts, obseve sharp cycles of bone resportion followed by bone formation Upregulation of NFKB-Osteoclastogensis 3 phases: osteolytic, "mixed" osteolytic osteoblastic, and sclerotic
68
What disease is characterized by a mosaic of cement lines in thickened bones?
Paget's disease
69
What is Osteopetrosis?
A disease of absent or deficient osteoclast activity, due to defficient H+ ATPase activity resulting in abnormally thickened bone
70
What clinical features are associated with Osteopetrosis?
Thickened bone Fractures due to loss of Osteon formation Anemia due to loss of Medullary bone spaces from bone thickeing Cranial nerve defects and Radiculopathy due to thickening of bone leading to compression of nerves
71
Which zone of endochondral bone formation does Osteopetrosis effect?
Osteopetrosis effects the Zone of Primary Bone Trabeculae formation because this is where osteoclasts activity would occur

MSK/Derm (46 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions