B12 Path Bone Flashcards

8156369633	What are osteoclasts derived from?	Monocytes	0
8156369634	What cells send signals to the osteoclasts?	Osteoblasts	1
8156369635	What are the important interleukins/ cytokines that act on osteoblasts?	IL-1, IL-6, TNF	2
8156369636	What stimulatory signals are produced by the osteoblasts and sent to the osteoclasts?	Rank-Ligand & M-CSF (Monocyte- Colony stimulating factor)	3
8156369637	What signals act to inhibit osteoclasts?	OPG (), calcitonin, biphosphonates	4
8156369638	True or False: Human calcitonin is what maintains bone in humans.	False: calcitonin is a vestigial hormone in humans! Doesn't do a thing to serum calcium levels. Whaaat	5
8156369639	True or False: Harvested calcitonin from salmon can be administered to maintain bone in humans.	Truth We can take it from other animals just fine, human calcitonin is the only one inactive	6
8156369640	What do we call congenital malformations, like an extra rib, a missing rib, fusion of bones, or myelominingocele due to failure of the skull/spinal column to fuse?	Bone dystoses	7
8156369641	What's a supernumerary bone?	Like an extra finger or rib	8
8156369642	What's syndactyly?	Fusion of adjacent digits	9
8156369643	What do we call it when there's failure of skull/spinal column to close?	Craniorachischisis	10
8156369644	What's it called if a person has a disorder that affects cartilage and bone tissues globally because of underlying mutations in matrix components or cell signaling mechanisms?	Bone dysplasia	11
8156369645	What's the most common disease of the growth plate?	Achondroplasia	12
8156369646	Importante: What's the gene defect in Achondroplasia?	Fibroblast Growth Factor Receptor 3 (FGFR3)	13
8156369647	What's the normal action of * Fibroblast Growth Factor Receptor 3 (FGFR3)*?	Inhibition of cartilage proliferation	14
8156369648	What's going on in a person with * Achondroplasia*?	Constant activation of the receptor, suppresses growth	15
8156369649	Tyrion Lannister is c/o of pain in his legs. He's diagnosed with Achondroplasia. What causes the pain?	narrowing of spinal canal/ neural foramina	16
8156369650	What's inhibited in Achondroplasia/ FGFR3 mutation?	Type I collagen	17
8156369651	What's the most common lethal form of dwarfism?	Thanatophoric dwarfism caused by frameshift or point mutation in FGFR3	18
8156369652	What makes * Thanatophoric dwarfism* or homozygous achondroplasia lethal?	Underdeveloped thoracic cavity that causes respiratory insufficiency	19
8156369653	What's the problem with Osteogenesis Imperfecta?	Type I collagen is structurally messed up	20
8156369654	What's the most common genetic disease of the skeleton (15-20k patients in U.S.)?	Osteogenesis Imperfecta	21
8156369655	What are the two ways that Osteogenesis Imperfecta can be caused?	1. Null Allele 2. Dominant negative	22
8156369656	What's the defect in Osteogenesis Imperfecta caused by the Null Allele Effect?	Reduced collagen	23
8156369657	What's the defect in Osteogenesis Imperfecta caused by Dominant Negative?	Abnormal chains of collagen	24
8156369658	What's the lethal form of Osteogenesis Imperfecta?	Type II	25
8156369659	A baby dies within days of birth. They have skeletal deformities and blue sclera. What did this baby have?	Type II Osteogenesis Imperfecta	26
8156369660	A child comes in with multiple fractures, but is normal in height. Child abuse is not a factor. They also have hearing impairment. What is going on in this kid?	Type I Osteogenesis Imperfecta	27
8156369661	An adult comes in with multiple fractures. They are abnormally short (4ft tall) and have bowed legs. When they were born, they note they had blue sclera, but now it's gone. What could be going on?	Type III Osteogenesis Imperfecta	28
8156369662	What type of Osteogenesis Imperfecta is not characterized by blue sclera?	Type IV	29
8156369663	A person has very thick, sclerotic looking bones, but they also have had multiple fractures. Their vertebrae have a rugger-jersey appearance. On X-Ray, their bones look like there's a "bone within a bone." What could this person have?	Osteopetrosis	30
8156369664	What's 2 scary things that can happen with osteopetrosis?	1. Cranial nerve compression 2. Anemia due to BMS	31
8156369665	Patients with osteopetrosis can have "erlenmeyer flask" long bones. Who else can have that, again?	Patients with Gaucher	32
8156369666	What causes osteopetrosis?	A bunch of mutations	33
8156369667	How can the chloride channel mutation that may be seen in osteopetrosis inhibit osteoclast activity?	Osteoclasts need that to secrete acid to resorb bone	34
8156369668	What does a deficiency in M-CSF cause?	Inability for osteoclasts to differentiate—> Osteopetrosis	35
8156369669	What's the take-home issue that all those mutations cause in Osteopetrosis?	Osteoclasts cant resorb bone	36
8156369670	A baby is born with a large head, flat facies, bell-shaped thorax, and curved femoral bones. There are no fractures. She died the day after birth. What does she likely have?	Thanatophoric dwarfism	37
8170504627	What are the risk factors for osteoporosis?	1. Genetic Factors (Vit D handling + estrogen) 2. Decreased Physical activity 3. Nutrition (Ca, Vit D)	38
8170504628	What genetic factors/ mutations can be risk factors for osteoporosis?	1. Vit D Receptor Allele COL1A1 2. Estrogen receptor IGF-1	39
8170504629	What's going on in menopause that makes women more prone to osteoporosis?	1. Estrogen is down 2. Inflammatory cytokines are up 3. RANK & RANK-L expression increased	40
8170504630	What's the effect of increased RANK/ RANK-L expression during menopause?	Increased osteoclast activity	41
8170504631	What's the big thing going on in aging that increases the risk of osteoporosis?	Decreased osteoblasts activity (no replacement)	42
8170504632	What are the common places for osteoporosis to show up?	1. Lower thoracic/ lumbar vertebrae 2. acetabular area 3. wrist	43
8170504633	What's going on in a vertebra with osteoporosis that causes the hunchback appearance?	Tiny little compression fractures that make the vertebra smaller and smaller, deforming them	44
8170504634	What's the difference in a T score & a Z score?	T: how someone's result compares to the average normal mean (young adult) Z: how someone's result compares to the average normal mean for someone their age	45
8170504635	A patient has a T score of -0.5. This patient has ____________ bone mass.	Normal (> -1)	46
8170504636	A patient has a T score of -2.5. This patient has ____________ bone mass.	Low/ Osteopenic (-1 to -2.5)	47
8170504637	A patient has a T score of -2.6 and no fractures. This patient has ____________ bone mass.	Osteoporotic (< -2.5 with no fractures)	48
8170504638	A patient has a T score of -2.6 and an osteoporotic fracture. This patient has ____________ bone mass.	Severe/ established osteoporotic ( < -2.5 & with at least 1 fracture)	49
8170504639	What score do we like to use to look at bone mass density— T or Z?	T	50
8170504640	Why does postmenopausal osteoporosis occur?	Missing estrogen (which usually inhibits the inflammatory cytokines that activate osteoblasts) Bone resorption is favored over formation	51
8170504641	Histology of the lungs of a 40 yo Danish patient shows noncaseating epitheliod granulomas that contain multinucleated giant cells. What's likely going on?	Sarcoidosis	52
8170504642	Histology of patient with sarcoidosis shows giant cells containing laminated concentrations of calcium and proteins. What are these things?	Schaumann bodies	53
8170504643	Histology of patient with sarcoidosis shows giant cells containing stellate inclusions. What are these things?	Asteroid bodies	54
8170504644	Asteroid bodies, giant cells, & Schaumann bodies.	Sarcoidosis.	55
8170504645	Why is there bone resorption in the hands and feet in sarcoidosis?	Granulomas produce factors that enhance Vit. D activation (So, now you've got all this Vit D activated saying "we need more calcium", but there isn't any more. So the hands and feet get resorbed to provide that Ca++)	56
8170504646	What differentiates osteomalacia from rickets?	Demarcation of the growth plates	57
8170504647	We always think of Vit D when we think about Calcium deficiency. Who's the forgotten player in that game?	Phosphorus!	58
8170504648	A child has bowed legs, an indentation of the rib cage, and bead-like bumps along the growth plates of the ribs. What's likely going on in this kid?	Rickets	59
8170504649	What's Harrisons groove?	An indentation of the rib cage in kids with rickets due to the diaphragm pulling on those poorly mineralized ribs	60
8170504650	What's it mean if a kid as a rachitic rosary?	Bead-like bumps along the growth plates of the ribs caused by rickets	61
8170504651	What's the big difference between rickets & OI?	Multiple fractures + blue sclera don't happen in rickets like they do in OI	62
8170504652	Importante: What's the best/ most sensitive serum test for any disease that favors osteoblasts activity?	Alkaline phosphatase level (these patients are trying really hard to mineralize the bone*	63
8170504653	What's the job of alkaline phosphatase?	Used by osteoblasts to mineralize bone	64
8170504654	What's the normal result of a Decalcified bone biopsy with tetracycline administration 7 days apart?	Two layers of deposits with a gap	65
8170504655	What's the result of a Decalcified bone biopsy with tetracycline administration 7 days apart that indicates osteomalacia?	No gap between depositions	66
8170504656	A patient's bone biopsy shows generalized osteitis fibrosa cystica. What's this the hallmark of?	Hyperparathyroidism	67
8170504657	Bone biopsy of a patient shows dissecting osteitis, peritrabecular fibrosis, & cystic brown tumors. X-Ray of their hands shows marked thinning of the cortices of the middle phalanges of the index & middle fingers. What could be going on in this patient?	Hyperparathyroidism	68
8170504658	What will you ALWAYS see with chronic renal disease?	Widespread bone disease	69
8170504659	What bone changes are seen in a kid with renal failure?	Rachitic & osteomalacic changes	70
8170504660	What bone changes are seen in an adult with renal failure?	Secondary Hyperparathyroidism & Osteomalacic changes	71
8170504661	What are the 3 stages of Paget's Disease?	1. Osteolytic 2. Mixed clast/blast 3. Osteosclerotic	72
8170504662	What's the current hypothesis as to the cause of Paget's Disease?	Paramyxovirus infection	73
8170504663	Importante: What are the most common places Paget's Disease shows up?	Vertebra or femur	74
8170504664	What can cause death in a patient with Paget's Disease?	Cardiac hypertrophy	75
8198481824	What does bone biopsy of a patient with Paget's disease show?	Mixed osteoblastic-osteoclastic stage with cement lines in the bone	76
8198481825	A bone has wedge-shaped necrosis, with live overlying articular cartilage. Inside the dead bone, there are ruptured adipocytes and calcium soap formation & "creeping substitution. What infarct is going on here?	Subchrondral infarct	77
8198481826	On X-ray, a bone has sclerotic lesions its center. What infarct could be happening?	Medullary infarct	78
8198481827	What's the #1 route for osteomyelitis to get to bone?	Hematogenous spread	79
8198481828	What are the most common organisms that cause osteomyelitis in adults?	1. Staph aureus 2. UTI: E. Coli, pseudomonas, klebsiella	80
8198481829	What are the most common organisms that cause osteomyelitis in neonates?	Haemophilus influenza & GBS	81
8198481830	What are the most common organisms that cause osteomyelitis in sickle cell pts?	Salmonella	82
8198481831	What serious complication can osteomyelitis lead to?	Sequestrum of dead bone with involumcrum sleeve reactive bone around it	83
8198481832	Where does TB usually go when it spreads to bone? What is this called?	Vertebral column; Pott's disease	84