Brainscape's Knowledge GenomeTM

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


See full index

Semester 2 - Mechanism of Disease > MoD S4 - Healing and repair > Flashcards

MoD S4 - Healing and repair Flashcards

1
Q

Define regeneration in terms of wound healing

A

Growth of cells and tissues to replace lost structures

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

Define labile tissues and give an example of a labile tissue

A

Tissues that are continuously dividing throughout life replacing cells that are destroyed

Skin epithelial cells, cells of bone marrow, columnar epithelia of the GI tract and uterus

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

Define stable tissues and give an example of a stable tissue

A

Tissues that normally have a low level of replication but can undergo rapid division in response to tissue

Parenchymal cells of liver, pancreas and kidneys, fibroblasts, smooth muscle cells

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

Define permanent tissues and give an example of permanent tissue

A

Non‐dividing tissues which contain cells that have left the cell cycle and can’t undergo mitotic division in postnatal life

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

What are the three types of stem cell and how do they differ?

A

Unipotent‐ can form one type of differentiated cell

Multipotent‐ can form several types of differentiate cells

Totipotent‐ can form any type of cell

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

Outline the process of fibrous repair

A

● Blood clot forms

● Acute inflammation occurs

● Progresses to chronic inflammation as macrophages and lymphocytes migrate

● Phagocytes clear necrotic tissue debris which is replaced by granulation tissue

● Angiogenesis

● Myofibroblasts migrate and proliferate which produced extracellular matrix and cause wound
contraction

● Granulation tissue becomes less vascular and cell population falls

● Collagen increases and maturation occurs to form fibrous scar

● Contraction of fibrils in myofibroblasts cause mature scar to shrink

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

What is angiogenesis and why is this process so important?

A

Development of new blood vessels

Gives access to wound for inflammatory cells and fibroblasts and delivers oxygen and other nutrients

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

What stimulates angiogenesis to occur?

A

Pro‐angiogenic growth factors such as VEGF

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

Outline the process of angiogenesis

A
  • Endothelial cells proteolysis of basement membrane
  • Migration of endothelial cells via chemotaxis
  • Endothelial cells proliferate
  • Maturation and tubular remodelling occurs
  • Recruitment of periendothelial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

List the functions of the extracellular matrix

A
  • Supports and anchors cells
  • Separates tissue into compartments
  • Allows communication between cells
  • Facilitates cell migration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the functions of matrix glycoproteins in the extracellular matrix?

A

Organise and orientate cells

Support cell migration

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

What are the functions of proteoglycans in the extracellular matrix?

A

Cell support
Matrix organisation
Regulate availability of growth factor

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

What is Alport syndrome and what would be symptoms of this disorder?

A

X‐linked disease in which type 4 collagen is abnormal resulting in dysfunction of the glomerular basement membrane, cochlea of the ear and lens of the eye

Symptoms include haematuria leading to chronic renal failure, neural deafness and eye disorders

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

What are the two main influences over tissue regeneration?

A

Growth factors

Contact between basement membranes and adjacent cells

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

Outline how growth factors may produce proliferation in stem cell populations

A
  • Extracellular signal is transduced into cell
  • Tyrosine kinase dimerizes
  • Initiates phosphorylation cascade
  • Increases transcription of genes regulating the cell cycle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What processes does tumour necrosis factor stimulate?

A

Fibroblast migration, fibroblast proliferation and collagenase secretion

17
Q

What is stimulated by platelet derived growth factor?

A

Fibroblast, smooth muscle cell and monocyte migration and proliferation

18
Q

Give an example of a adhesion molecule

A

E‐cadherin, Integrin, ICAMs, Selectins

19
Q

How is fibrous repair controlled?

A
  • Inflammatory cells recruited by chemotaxis
  • Angiogenesis induced by pro‐angiogenic cytokines in response to hypoxia
  • Fibrosis is induced by pro‐fibrotic cytokines from macrophages
20
Q

Outline the differences between healing primary intention compared to secondary intention

A

Primary‐ minimal contraction of wound, minimal clot and granulation tissue, smaller scar

Secondary‐ maximal contraction of wound, large clot forms a scab and large amounts of
granulation tissue produced, larger scar

21
Q

Outline the process of healing of bone fractures from haematoma to soft callus stage

A
  • Blood clot forms from ruptured cells in marrow cavity and periosteum
  • Provides framework for ingress of macrophages (acute inflammation)
  • Endothelial cells, fibroblasts and osteoblasts also enter
  • Necrotic tissue removed
  • Capillaries develop
22
Q

How does a soft callus develop into a bony callus?

A

Bone laid down in an irregular, woven fashion in fibrous and cartilage tissue

External callus provides splint‐like support

23
Q

What replaces woven bone?

A

Organised lamellar bone

24
Q

What does bone remodelling occur in response to?

A

Mechanical stress

25
Q

List the local factors influencing healing

A
  • Radiation damage
  • Site, size and type of wound
  • Infection
  • Foreign material
  • Blood supply
  • Apposition and lack of movement
26
Q

List the systemic factors influencing healing

A
  • Age
  • General cardiovascular status
  • General dietary deficiencies
  • Specific dietary deficiencies
  • Drugs
  • General state of health
27
Q

What may cause insufficient fibrosis?

A

Obesity, malnutrition, steroids, elderly

28
Q

What can insufficient fibrosis result in?

A

Hernia, wound dehiscence, ulceration

29
Q

List some examples of excessive scarring

A
  • Keloids
  • Cirrhosis
  • Lung fibrosis
30
Q

Give three problems that can arise from excessive contraction

A

Strictures ‐ obstruction of tubes and channels

Contractures ‐ inhibition of joint movement

Impair blood circulation

31
Q

What complication often follows scar formation in cardiac muscle?

A

Loss of cardiac function

32
Q

Describe the repair of peripheral nerves

A

Proximal stumps of degenerated axons sprout and elongate

Schwann cells guide them back to the tissue that the nerve innervates

33
Q

What is the rate of axon growth?

A

1-3mm/day

34
Q

How is neural tissue in the CNS replaced?

A

Proliferation of glial cells

Semester 2 - Mechanism of Disease (10 decks)

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