Brainscape's Knowledge GenomeTM

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


See full index

Medical Perspectives 411 > Osteoporosis > Flashcards

Osteoporosis Flashcards

You may prefer our related Brainscape-certified flashcards:
USMLE® Step 1 flashcards
1
Q

osteoporosis literal meaning

A

porous bone

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

osteoporosis defination

A

A combination of decreased bone mass and micro-damage to the bone structure that results in an increased susceptibility to fracture

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

Primary Osteoporosis etiology

A

Most common, occurs in both genders, yet follows menopause in females and occurs later in life in males

Post-menopausal/estrogen deficient
Age related/senile
Mild/prolonged negative calcium balance

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

Secondary Osteoporosis etiology

A

associated with medication, other conditions, or diseases

Cortico-steroids/heparin/anti-convulsants/alcohol/mal-nutrition/endocrine disorder

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

Most common metabolic bone disease

A

osteoporosis

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

When affected, men have a higher

A

morbidity and mortality rate compared to women (30% compared to 9%)
Men are affected at a later age, therefore, prognosis is worse

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

Bone: 2 purposes

A

1) rigid framework for the body

2) readily available and interchangeable calcium pool

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

Appropriate balance must exist between

A

formation and resorption

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

Mineral resorption occurs at

A

the expense of bone formation

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

Bone: Composed of a

A

complex meshwork of collagen fibers inlaid with calcium and phosphate, mixed with water resulting in a hard, cement-like substance called hydroxyapatite/osteoid.

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

Minerals in bone

A

Sodium, magnesium, and potassium are also present in smaller concentrations

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

Bone composition:

A

Trabecular bone: (spongy or cancellous bone) is the central meshwork of bone

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

@ 20% of the adult skeleton/

A

large surface area

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

Bone Very sensitive to

A

metabolic and/or hormonal influences

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

Cortical bone: (compact bone)

A

found primarily in the shafts of long bones and comprising 80% of skeletal mass

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

80%-90% of cortical bone is calcified, whereas

A

only 15% to 25% of trabecular bone mass is calcified

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

The remaining volume of bo e

A

is composed of bone marrow, fat, and blood vessels

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

Bone resorption is a

A

surface area event

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

Bone renews itself through a constant process called

A

remodeling

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

Remolding

A

Repeated cycle of osteoclastic, which is breaking down the existing bone (resorption) and osteoblastic activity which is laying down new bone cells for mineralization(formation)

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

BMD: Increases during

A

growth and development

22
Q

Peak bone mass achieved in

A

the third decade of life

This is the reserve for the rest of the person’s life

23
Q

Osteoporosis: begins when bone formation

A

falls behind resorption

24
Q

Menopause: reduction in circulating concentrations of

A

estradiol and progesterone

25
Q

Bone strength is a function of

A

skeletal load

26
Q

May be the only natural process in order to induce formation modeling in

A

mature bone

27
Q

Young bone responds tremendously well

A

to loading

28
Q

New theories regarding remodeling:

Voltage potential generated from

A

muscle contraction

29
Q

Remodeling: Maintains the

A

strength and integrity of the skeleton by replacing fatigued/older/weakened bone with new bone

30
Q

Remolding makes a

A

Storage site for vital minerals

31
Q

Calcium:

A

Heart rate regulation, muscle contraction, blood pressure

32
Q

When low plasma Ca++, then calcium is

A

resorbed from the bone via PTH mechanism

33
Q

Bone Remodeling:

A

Modified by immune triggers

T and B cells and neural pathways

34
Q

Modified by immune triggers derived from

A

T-cell and neural pathways

35
Q

Estrogen deficiency triggers reproductive aging through:

A

Amplification of TNF producing T-cells
Lack of trabecular estrogen receptor stimulation results in reduced anabolic stimulus
Increased bone resorption by inducing inflammation responses to heightened levels of:
Interleukin-1 and TNF
Occurs most prevalently in trabecular bone
Femoral neck/vertebral body/calcaneous/carpals

36
Q

Interleukin-1 and TNF are the most

A

potent osteoclastic stimulators

37
Q

Estrogen deprivation results in:

A

Increased T-cell concentrations in the bone marrow
TNF is produced from those T-cells, in conjunction with IL-1, enhance bone resorption through lysosome stimulation
SERMs block this cascade

38
Q 
Loss of height (real or pseudo?)
Postural Changes: 
Unstable abdominal/lumber stabilization muscles
Forward head, kyphosis (dowager’s hump)
Loss of lumbar lordosis
Posterior pelvic tilt
Scapular protraction
All resulting in significant loss of height
Contributing to loss of height are vertebral compression fractures
Muscular pain:
Lumbar paraspinal extensor spasm/burning
Thoracic musculature burning
Fractures:
Vertebral bodies
Hip
Radius
Ribs
Femur
A

Clinical manifestions for osteop

39
Q

Diagnosis:

A

History/Observation: posture/loss of height
Bone mineral density testing: osteoporosis is labeled at > -2.5 standard deviations from the norm, with osteopenia labeled at -1.0 to -2.5 standard deviation from normal bone mass
Dual Energy X-ray absorptiometry (previously DEXA, now called DXA) most sensitive
CT scan
X-ray: can detect osteopenia and fractures
Laboratory testing: biochemical markers of bone turnover

40
Q

Two modes: of treatment

A 
Antiresorptive Drugs
Bisphosphonates
Selective Estrogen Receptor Modulators (SERMs)
Anabolic Drugs
Parathyroid Hormone
41
Q

Bisphosphonates:
Indications:

A

Treatment and prevention of osteoporosis in men, post menopausal women, post glucocorticoid use, and treatment of Paget’s disease
Generic/trade names: Alendronate/Fosamax etidronate/didronel ibandronate/Boniva
Excreted in the kidneys, rapidly absorbed from the blood stream into the bones
Adverse reactions: Abdominal pain, nausea, dyspepsia, constipation, diarrhea, Gerd, bone and muscle pain, osteonecrosis of the jaw and femur

42
Q

Bisphosphonates: Mechanism of action

A

Demonstrates preferable localization to sites of bone resorption on hydroxyapatite
Sites of bone resorption are in conjunction with osteoclasts
Inhibit the activity of osteoclasts
10x more attracted to osteoclasts than osteoblasts
Studies show that normal bone forms on top of the bisphosphonate
Must be continuously added as it is not pharmacologically active, or else the new bone formation will be resorpted

43
Q

Ultimately, bisphosphonates slow the rate of

A

bone turnover, so bone formation exceeds bone resorption
Not to be taken for more than 10 years as it weakens bones, which resulted in:
Musculoskeletal pain
Osteonecrosis of the jaw
Femoral fractures
Renal impairment

44
Q

Selective Estrogen Receptor Modulators:

A

Activate estrogen receptors on some tissues and blocks the receptors on other tissues
Activate receptors on bone and vascular tissue
Act as estrogen antagonists (blockers) on uterine and breast tissue
Produce favorable effects on bone mineralization and cardiovascular tissue
Reduce the carcinogenic effects of estrogen on breast and uterine tissue

45
Q

Parathyroid Hormone:

A

Synthesized in the cells of the parathyroid gland
Regulated by the concentration of plasma calcium
Calcium receptor located on the surface of the parathyroid gland
Decrease in plasma calcium activates the receptor
Increase in plasma calcium results in receptor inhibition
Alters calcium metabolism in bone, kidney, and gastrointestinal tract
PTH directly affects skeletal tissue by increasing bone turnover, resulting in calcium liberation from skeletal storage.

46
Q

High levels of PTH result in increased osteoclastic activity, releasing calcium into the blood .
PTH increases reabsorption of calcium from the kidneys
Results in decreased phosphate levels through increased phosphate excretion
Increases calcium digestion from the gastrointestinal tract
PTH increases the conversion of Vit D to calcitriol which directly stimulates calcium absorption from the intestine
Normal, or intermittent PTH release has been shown to enhance bone formation (stimulates osteoblastic activity and promotes bone formation: Very anabolic)
Can utilize calcitonin to decrease plasma calcium concentrations and add mineralization to the bones, but less effective than bisphosphonates
Vitamin D toxicity can cause death
Calcium supplements: help to prevent bone loss, mildly effective
Supplements alone cannot prevent osteoporosis: Encourage bone formation in conjunction with Wolfe’s Law

A

tba

47
Q

Performing weight bearing and resistive exercise, most beneficially early in life while skeletal tissue is more anabolic opposed to catabolic, appeared to be the most significant mode to prevent osteoporosis.
Bone: Physical activity increased blood supply to muscle which also resulted in circulatory enhancement to bone tissue with increased nutritional supply, hormones, oxygen, etc.
Bone growth: Reacted to rhythmic physical activities
Tended to be insensitive to static loading
Required intermittent GH and PTH
Exercise during premenopausal/young adulthood rarely increased bone mass as that individual’s bone mass had already been maximized

A

s

48
Q

Exercise into adulthood serves to preserve BMD (Turner, et al.,2006).
Study:
Post-menopausal former athletes compared with non-athletes
All participants demonstrated similar levels of activity for the 15 years prior to the study
The sedentary control group demonstrated significantly lower BMD when compared to the groups of former athletes

A

s

49
Q

Wallace, Boxall, & Riddick (2004) reported that women were more willing to alter their diet than increase physical activity
Sinaki (2008) reported that most osteoporotic related non-vertebral fractures were a direct result of fall
Study:
Femoral neck T-score based on DXA
Exercise group (resistance/aerobic/balance/joint mobility)/control group
11 month protocol
Femoral neck T-score significantly improved in the exercise group
BMD decreased in the control group
Exercise group also demonstrated improved QOL scores and improved scores on physical function tests

A

tba

50
Q

A major contributor to osteoporosis that is rarely mentioned in the literature is the calcium carbonate buffer system that is essential to the maintenance of a neutral physiologic environment.
Under conditions of physiological high acid loads, which tend to be derived from:
Standard American diet (SAD)
Lifestyle
Medications
Bone becomes demineralized in an attempt to neutralize the physiologic state of reduced pH
Over a prolonged time period, this environment results in osteopenia, and osteoporosis
�

A

s

Medical Perspectives 411 (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions