Brainscape's Knowledge GenomeTM

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


See full index

MOD > Lecture 3 > Flashcards

Lecture 3 Flashcards

1
Q

What 3 factors does the healing process depend on?

A

The type of tissue damaged
The extent of the injury
Underlying host factors

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

Parenchymal vs Stromal

A

Parenchymal tissue refers to the functioning cells of a body part, such as a hepatocyte or nephron.

Stromal tissue refers to the structural cells of a body part such as connective tissue or the ECM.

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

What are the 3 cell types?

A

Labile, Stable, and Permanent

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

Where do I find labile cells?

A

They are cells that continually reproduce/divide. They are often found in epithelial tissue, such as the skin, oropharynx, bone marrow and GI/GU tract.

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

Where do I find stable cells?

A

Stable cells normally stop dividing once growth ceases, but can regenerate.
Usually found as hepatocytes or smooth muscle cells.
They require a stromal framework for regeneration.

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

Where do I find permanent cells?

A

Fixed cells that rarely regenerate or divide.
Examples include neurons, heart, skeletal muscle cells, and RBCs.

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

What 4 categories make up the ECM?

A

Fibrous Structural Proteins, Water-hydrated gels, Adhesive glycoproteins, and ground substance.

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

What are the fibrous structural proteins of the ECM?

A

Collagen and elastin

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

What are the water-hydrated gels of the ECM?

A

Hyaluronan and proteoglycans

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

What are the adhesive glycoproteins of the ECM?

A

Fibronectin and laminin

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

What is ground substance?

A

It refers to the ECM except for fibrous proteins.

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

What is a basement membrane?

A

It is the underlying epithelial, endothelial, and smooth muscle cells; separating the lining from the connective tissue.

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

What is the interstitial matrix?

A

It is the gel-like substance found between cells.

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

What are integrins and what are they used for?

A

They are integral/transmembrane proteins that allow for attachment to the ECM and communication between the intracellular and extracellular environment.

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

What is granulation tissue?

A

It is the precursor to scar tissue. It develops when there is a wound that can’t be resolved with regeneration alone. It is a highly vascularized tissue that is typically reddish, moist, soft, bumpy, and granular in appearance. It is very fragile and bleeds easily.

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

What is angiogenesis and what triggers it?

A

It is the generation of new blood vessels from existing blood vessels, triggered by the release of VEGF from hypoxic cells.

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

What are the 4 steps of angiogenesis?

A
  1. Proteolytic degradation of parent vessel basement membrane by VEGF, leading to a sprout.
  2. Migration of endothelial cells from parent vessel towards an angiogenic stimulus.
  3. Proliferation of endothelial behind the leading edge of migrating cells.
  4. Maturation of endothelial cells and vessel walls.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are examples of conditions that cause angiogenesis?

A

Damaged or disrupted tissue
Cancerous lesions
Diabetic Retinopathy

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

What makes scar tissue?

A

Fibroblasts

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

What are the initial ECM components secreted by fibroblasts?

A

Fibronectin, collagen, hyaluronan, and proteoglycans

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

What happens to scar tissue over time as it is constructed?

A

Increased collagen synthesis, diminished fibroblast proliferation, and diminishing new blood vessels.

Involves loss of vascularization and becomes a dense collagen matrix.

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

What mediators regulate the healing process?

A

ILs, IFNs, prostaglandins, and leukotrienes, which promote chemotaxis and leukocytes and fibroblasts, along with mediating the inflammatory response.

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

What are the 4 growth factors?

A

Vascular Endothelial Growth Factor (VEGF)
Platelet-Derived Growth Factor (PDGF)
Fibroblast Growth Factor (FGF)
Epithelial Growth Factor (EGF)

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

What are the effects of growth factors?

A

Mediate proliferation, differentiation, cell metabolism, and inflammatory response.
Promote chemotaxis of leukocytes and fibroblasts
Stimulate angiogenesis
Contribute to the generation of ECM

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are the stages of Tissue Repair?

A

Hemostasis: clotting and vascular response
Inflammation
Proliferation: Epithelial healing, contraction, and scar formation.
Remodeling: Scar remodeling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 3 types of wound intention?

A

Primary: small, incision-like wounds with well-approximated edges that can be sutured easily.

Secondary: large, crater-like wounds with greater loss of tissue.

Tertiary: large wounds that are intentionally left open to drain or are infected and are then sutured at a later date.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Describe the process of hemostasis

A
  1. Initial blood vessel constriction at the site (transient vasoconstriction)
  2. Increased platelet aggregation and attraction
  3. Thrombus forms to promote hemostasis and prevent entry of foreign agents.
  4. Following the blockage of the vessel injury, dilation and increased capillary membrane permeability can then occur.
    Leukocytes neutralize foreign bodies and pathogens introduced into the tissue at the site of injury.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What removes debris?

A

Neutrophils and Macrophages
They remove foreign matter, extracellular debris, damaged fibrin, and cell fragments.

29
Q

What additional things do macrophages do over neutrophils?

A

Macrophages also release growth factors to stimulate cell growth, attract fibroblasts, and help with angiogenesis.

30
Q

When does proliferation in wound healing begin occurring?

A

Within 2 days.

31
Q

What is the early form of the ECM called during proliferation?

A

Provisional matrix

32
Q

What is the purpose of provisional matrix?

A

Attracting and supporting fibroblasts, endothelial cells, and epidermal cells.
Provides the materials to start granulation tissue construction.

33
Q

How soon can granulation tissue begin forming?

A

Within 24 hours.

34
Q

What begins forming granulation tissue?

A

Fibrolasts begin secreting collagen and other components, as well as releasing growth factors to encourage the healing process.

35
Q

What are the 3 healing outcomes?

A

Resolution, Regeneration, and Replacement

36
Q

What cell types are seen in regeneration?

A

Labile or stable cell types. They can differentiate, proliferate, and do diapedesis.

37
Q

How soon can remodeling begin in uncomplicated wounds?

A

3 weeks - 6 months

38
Q

What occurs during remodeling?

A
  1. Collagenase enzymes remove collagen
  2. Fibroblasts lay down new collagen
  3. Reorientation of scar architecture to surrounding tissue to maximize tensile strength of wound.
39
Q

How much strength does a sutured wound have? After its removed?

A

70% once closed, 10% once removed.

40
Q

What is the most tensile strength wounds have after 3-6 months?

A

70-80%

41
Q

Why is secondary contraction common in large wounds?

A

Wounds often undergo contraction if they are in an area that constantly stretches, such as at the base of the neck.

42
Q

What are all the complications that can occur during wound healing?

A

Ulcerations, Dehiscence, Keloids, Hypertrophic Scars, Adhesions, and Proud Flesh

43
Q

What is an ulceration and what makes it hard to heal?

A

It is an open, crater-like lesion of skin or mucous membranes. Common to have necrotic epithelium with subepithelial inflammation.

It is difficult to heal because of poor perfusion to that area, the patient’s limited inflammatory or immune response, and frequent colonization by microbes.

44
Q

What is a dehiscence and what are the early/late causes of its formation?

A

It is a deficient scar formation, usually caused by a wound bursting at the site of injury before scarring finishes.

Early causes include mechanical stress
Later causes include deficient ECM or collagen formation, such as someone with Ehlers-Danlos Syndrome.

45
Q

What is a keloid and its risk factors?

A

Excessive collagen production at the site of injury which often exceeds margins of wound

Risk factors include darker pigmented skin, age 10-30, and family history of keloids.

46
Q

What is a hypertrophic scar?

A

Excessive collagen production at site of injury that stays within the margins of the wound.

47
Q

What are adhesions and where are they normally found?

A

Inappropriate fibrous connections between injury and nearby tissues. Commonly inhibits the movement of surrounding tissues.

Most commonly occurs in intra-abdominal surgeries.

48
Q

Why are adhesions difficult to treat?

A

Excision of an adhesion typically causes more scarring.

49
Q

What is proud flesh and how is it treated?

A

It is the excess production of granulation tissue and extends beyond the anatomical edges of the wound. Prevents normal healing such as re-epithelialization.

Treated with surgical removal and/or chemical cauterization.

50
Q

What factors affect wound healing?

A

Malnutrition, blood flow/oxygenation, immune/inflammatory response, infection, foreign bodies, and age.

51
Q

What does a deficiency in Vitamin C cause?

A

Collagen synthesis impairment.

52
Q

What does a deficiency in Vitamin A cause?

A

Epithelialization, capillary formation, and collagen synthesis impairment.

Can reduce the anti-inflammatory effects of corticosteroids.

53
Q

What does a deficiency in zinc cause?

A

It is required for the enzyme used in cell proliferation.

54
Q

What does a protein deficiency cause for inflammation?

A

Needed for the mediation of the inflammatory phase, fibroblast proliferation, collagen synthesis, angiogenesis, and remodeling.

55
Q

Why is oxygen important in healing?

A

It is required for collagen synthesis and intracellular destruction of organisms by phagocytes (oxidation)

56
Q

What is the purpose of hyperbaric oxygen?

A

Hyperbaric oxygen is high pressure oxygen that is thought to improve the partial pressure of oxygen in the blood and improve the healing process.

57
Q

What conditions can impair inflammation/immune response?

A

Impaired perfusion to injury site
Impaired phagocytic function
Diabetes Mellitus
Corticosteroid Administration

58
Q

What is the effect of DM on inflammation?

A

Diminishes chemotaxis and phagocytosis
Impairs perfusion due to microvascular disease

59
Q

What is the effect of Corticosteroids on inflammation and the immune response?

A

Decreased immune mediator production
Decreased capillary permeability
Impaired phagocytosis
Inhibited fibroblast proliferation and function

60
Q

How do foreign bodies inhibit the healing process?

A

They prolong the inflammatory phase
They impair granulation tissue formation
They inhibit the proliferation of fibroblasts and deposition of collagen fibers
Contribute to pathogen invasion via becoming a reservoir and mechanical barrier to wound closure.

61
Q

Why are children bad at healing?

A

They have a greater capacity for healing but greater metabolic demands. They also have an immature immune system and therefore a prolonged immune response.

62
Q

Why are old people bad at healing?

A

The elderly have decreased dermal thickness, collagen content in their skin, and elasticity of skin.

They produce less fibroblasts and less collagen.
They take longer to re-epithelialize their wounds and are more vulnerable to slower wound healing and chronic wounds.

63
Q

What are the two most common causes for chronic inflammation?

A

Persistent injury/infection (Ulcerations, pathogens, and foreign bodies)
Autoimmune conditions (RA, MS, SLE)

64
Q

What are the systemic manifestations of chronic inflammation?

A

Fever, malaise, fatigue/weakness, anemia, anorexia and weight loss

65
Q

What causes anemia in chronic inflammation?

A

IL-6 production, which goes to the liver and makes more hepcidin, which is an inhibitor for ferroportin.
Ferroportin is an iron exporter, so reduced iron leads to reduced RBC formation.

66
Q

What inhibits the release of erythropoietin?

A

Il-1, TNF-alpha, and IFN-gamma

67
Q

Why do cancer cells proliferate?

A

They are classified as abnormal/damaged by the body and cause go into cellular distress. They then release cytokines and cause angiogenesis and nutrients to come to them.

The release of more growth factors allow them to expand and proliferate.

68
Q

What is granulamatous inflammation?

A

They are nodular inflammatory lesions that encase substances not easily destroyed by usual inflammatory and immune responses.

Giant cells are formed by macrophages and surround the insult. Epithelioid cells then surround the offending agent and the giant cells. Fibrous tissue is formed to encapsulate the area, which then becomes a bubble of necrotic remains.

69
Q

What commonly causes granulamatous inflammation?

A

Retained foreign bodies and certain bacterias, such as M. tub, syphilis, and fungal infections.

MOD (16 decks)

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