Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

SEM1 BIOSCIENCE > Case 8 > Flashcards

Case 8 Flashcards

1
Q

During resorption, what attracts osteoclasts to the site?

A

Chemotactic factors

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

What cell type produces the RANK ligand?

A

Osteoblasts

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

What are the consequences of RANKL signalling?

A

Osteoclast differentiation

Increase in osteoclast activity

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

How do osteoclasts function?

A

Ruffled border formation
Actin ring
H+ Cl- pumps
Cathespin K (degrades collagen)

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

The reversal phase is the name given to the process of….

A

osteoclast apoptosis following bone resorption

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

What factors recruit osteoblasts to the area of osteoclastic activity?

A

TGFB and IGF1

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

Explain how IGF1 has its paracrine effects in bone…

A

IGF1 laid into bone matrix by osteoblasts and released following OC resorption

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

What structure is crystallised during bone mineralisation?

A

Hydroxyapatite

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

Osteoblasts entombed in lacuna are referred to as…

A

Osteocytes

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

How do inflammatory cytokines such as IL1 and prostaglandins regulate the bone remodelling process?

A

Bind RANK receptor on OB

Increase in RANKL and hence OC activity

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

How does estrogen regulate bone remodelling? (5 ways)

A

Increase in osteoprotegrin- inhibition of RANK receptor
Inhibits osteoblast synthesis of IL1, IL6 and TNFa
Increases alkaline phosphatase expression
Increases TI collagen synthesis
Regulates osteoclast apoptosis

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

What is the function of alkaline phosphatase?

A

Mineralisation and calcification of bone matrix

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

Collagen I is mainly involved in….

A

Bone production

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

Collagen II is the basis for….

A

Articular and hyaline cartilage

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

Collagen III is a….

A

Precollagen found in the proliferative phase of wound healing

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

What are the four stages of fracture healing?

A

Hematoma formation
Fibrocartilaginous callus
Callus ossification
Bone remodelling

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

What cells form the hematoma?

A

Blood cells
Bone marrow
Leukocytes

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

What factors are secreted by macrophages to attract other WBCs to the hematoma?

A

IL1 and TNFa

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

What function does the bone marrow have to play in the formation of a hematoma?

A

Secretes mesenchymal stem cells

later they differentiate into chondrocytes and OBs

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

What is the callus template?

A

Another name for hematoma coagulations

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

Outline the main steps in the formation of a fibrocartilaginous callus…

A

Death of hematoma cells
Mesenchymal cell differentiation
OBs and chondrocytes secrete collagen I and II respectively
revascularisation

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

Callus ossification refers to the process of…

A

OBs replacing cartilage with woven bone

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

What is woven bone?

A

Produced by OBs when they are secreting osteoid rapidly
Haphazard structural organisation
Relatively weak

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

During calcification, what factor initiates OC resorption of cartilage?

A

RANKL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What happens during the last stage of fracture repair?
OB-OC remodelling of woven bone to form a hard callus | Lamellar bone created
26
Name 5 age associated bone changes...
``` decrease in OB precursors Decrease in collagen crosslink Apoptosis deregulation of osteocytes and OCs Increased microfracture incidence Increase in OC activity relative to OB ```
27
What cell lineage gives rise to osteoblasts?
Mesenchymal stem cells
28
What cell lineage gives rise to osteoclasts?
Monocytes (hematopoietic stem cells)
29
What is the difference between intramembranous and endochondrial ossification?
IM-O doesn't use a cartilaginous intermediate- bone is directly laid down
30
What types of bone undergo intramembranous ossification?
Flat bones | Skull, clavicle
31
What is kyphosis?
over curvature of thoracic and sacral regions
32
What is lordosis?
Abnormal curvature in the Lumbar and cervical regions
33
What is scoliosis?
Abnormal lateral curvature of the spine
34
Early menopause is recognised by....
normal estrogen | normal FSH
35
Late menopause is recognised by....
low estrogen | increased FSH
36
What is the clinical definition of menopause?
No periods for 12 consecutive months
37
What is premature ovarian failure?
Loss of ovary function before the age of 40 Form of primary hypogonadism Indicated by high FSH/LH and low estrogen and progesterone
38
What is the climateric phase of menopause?
A sharp decrease in BMD following period cessation
39
Why is progesterone administered as well as estrogen in regards to HRT?
Progesterone has uterine anti-proliferative effects
40
Outline how menstruation ceases....
``` Follicle quality/quantity decreases Estrogen levels decrease Increase in FSH Ovaries become less sensitive to FSH No ovulation occurs ```
41
What is bone mineral density?
The amount of mineral (Ca2+ PO4-) in bone tissue
42
What is the average measure bone density for the spine and forearm?
Forearm - 700/800gcm-2 | Spine - 1000-1200gcm-2
43
What is a DEXA Z score?
standard deviations from mean for patients demographics (age/sex/weight etc)
44
What is a DEXA T score?
standard deviations from a healthy 30 year old of similar demographics
45
Define osteopenia
T score of within -1 to -2 standard deviations
46
Define osteoporosis
Entire loss of bone substance. T score of more than -2 standard deviations
47
Define osteomalacia
Decreased mineral content in the bone mainly due to vitamin deficiency (Ricketts)
48
Define osteomyelitis
Bacterial infection in the bone
49
How does alcohol increase risk of osteoporosis?
Decreases Ca2+ levels | Increases PTH
50
How does smoking increase risk of osteoporosis?
Increases metabolism of estrogen
51
How do steriods increase risk of osteoporosis?
Block Ca2+ absorbtion from the gut
52
How does gender increase risk of osteoporosis?
Women at increased risk due to lower peak bone mass, estrogen loss at menopause and increased longevity
53
How does weight baring exercise effect risk of osteoporosis?
Osteocytes regulate bone remodelling in response to stress
54
Describe the concept of Wolfs law
Osteocytes sense weight loading via detection of fluid movement away from areas of high compressive load
55
Describe the mechanism of action of bisphosphonates
absorbed into bone mineral crystals, cause osteoclast apoptosis, slows rate of bone resorption
56
What are the functions of the sclerostin protein? What drug targets sclerostin?
Secreted by osteocytes Inhibits osteoblast activity Increases RANKL expression from osteoclasts Romosozumab is a MC antibody that targets sclerostin
57
Denosumab is a monoclonal antibody drug treatment. What does it bind to?
RANKL
58
What are the characteristics of the inflammatory phase of wound healing?
Blood clot formation WBC invasion Phagocytes clear infection/necrosis
59
What are the characteristics of the Proliferative phase of wound healing?
Chondrocytes release ground substance and precollagen (III) | Angiogenesis
60
What are the characteristics of the remodelling phase of wound healing?
Collagen III remodelled to collagen I | Wound closure
61
Why is doseage reduction important when prescribing to the elderly?
Decrease in muscle mass, total body water and lipid content Decrease in hepatic output (Less FPM effect) Reduced renal function Increased sensitivity at receptor level
62
What is polypharmacy
More than 4 mediciations per day
63
What is an iatrogenic illness?
Illness as a consequence of medical treatment
64
What tool can be used as an indicator as to whether a drug needs to be prescribed?
numbers needed to treat - numbers needed to harm | NNT:NNH
65
What type of drug is prednisolone?
Glucocorticosteriod | Stimulates production of annexin and hence inhibition of PLA2- no prostaglandin production
66
What type of drug is Bendroflumethiazide?
Antihypertensive/diuretic | Induces renal water loss via inhibition of Na+ and K= pumps
67
What type of drug is diazepam?
Benzodiazapene Increases GABA neurone activity Used to treat anxiety and insomnia
68
Define frailty...
a state of increased vulnerability whereby a minor stressor event could have a major negative outcome
69
What is the phenotype model of frailty?
Acquisition of ageing characteristics in a random manner | If a pt possesses more than 3 then they are deemed to be frail
70
What is the cumulative deficit model of frailty?
The sequential acquisition of frailty characteristics that occur gradually and increase the frailty index
71
What does DAME stand for? What is it used for?
Drugs Ageing effects Medical conditions Environment Used as part of a complex geriatric assessment to combat risk of falls
72
What is biomedical ageing?
Life expectancy optimisation in the absence of chronic disease
73
What is physcosocial ageing?
Life satisfaction with both past and present life
74
What are the two biological theories of ageing?
Programmed- switiching off of genes | Damage- wear and tear theory
75
What are the two evolutional theories of ageing?
antagonistic pleiotrophy- genes become more dangerous with age Disposable soma- ageing is balance between repair and reproduction
76
What are the three theories relating to societies perceptions of age?
Functionalist Structured dependency Third age- retirement as a process of self enrichment
77
The unaffordance of health impacting possessions that most of society take for granted is called...
material deprivation
78
In which organ is vitamin D synthesised to 25OHVD?
Liver
79
Where does the synthesis of 1,25OHVD take place?
Kidneys
80
What is another name for 1,25OHVD?
Calcitriol
81
What is the function of PTH?
Stimulates the conversion of 25OHVD to 1,25OHVD in the kidneys
82
What are examples of non-hormonal menopausal treatment regimens?
Clonidine | SSRI's (antidepressants)
83
When should androgen therapy be used in post-menopausal women?
Presents with loss of libido and lethargy Due to post menopausal lack of LH Testosterone prescribed

SEM1 BIOSCIENCE (9 decks)

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