Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Y1 - PP > Lecture 7 - Regeneration And Repair > Flashcards

Lecture 7 - Regeneration And Repair Flashcards

(93 cards)

Start Studying
1
Q

What is repair?

A

(Fibrosis)
When tissue has been substantially damaged leading to repair with connective tissue

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

What are the general stages of wound healing?

A

Injury occurs
Haemostasis (blood clot when blood vessels damaged)
Inflammation
Then either Regeneration and/or repair

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

What is regeneration?

A

Re growth of cells with minimal evidence of injury (cant tell injury has happened)

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

What type of injuries can be regenerated?

A

Minor injuries (skin incision/abrasion)

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

What area the 3 criteria for regeneration to happen?

A

1.) Injury must be minor (skin abrasion/incision)
2.) Connective tissue architecture must be intact
3.) Tissue must have ability of regeneration

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

What is an example of physiological regeneration (normal)?

A

Haematopoiesis
(Production of blood cells from bone marrow)

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

What type of cells do new cells come from?

A

Stem cells

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

What are the features of stem cells?

A

Differentiation
Self-renewal

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

What is meant by potency of a stem cell?

A

The ability of the stem cell to differentiate into different types of cell

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

What is a Totipotent stem cell?
Where can they be found?

A

Can differentiate into all cell types
Embryonic stem cells

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

What is a Multipotent stem cell?
Where can they be found?

A

Can differentiate into several cell types but NOT ALL
Haematopoietic stem cells (Bone marrow)

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

What is a Unipotent stem cell?
Where can they be found?

A

Can only differentiate into ONE cell type
Epithelial stem cells (only into epithelium)

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

What are the 3 categories of tissue when referring to their ability to regenerate?

A

Labile Tissue
Stable Tissue
Permanent Tissue

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

What is the regenerative ability of Labile tissue?

A

Continuously replicating and regenerating

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

What are some examples of Labile tissues?

A

Epithelium
Haematopoietic tissue

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

What is the regenerative ability of stable tissue?

A

Normally undergoing low level replication but can rapidly replicate and regenerate if required

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

What are some examples of Stable tissue?

A

Liver
Kidneys
Pancreas
Smooth muscle
Bone

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

What is the regenerative ability of Permanent tissue?

A

Cells do not replicate (regenerate)
If damaged must undergo repair (scarring)

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

How do Labile cells navigate the cell cycle?

A

Continuously cycling

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

How do Stable cells navigate the cell cycle?

A

Enter G0 (Left cell cycle)
But can re-enter the cycle

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

How do Permanent cells navigate the cell cycle?

A

Cell permanently in G0
Cannot re-enter the cell cycle

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

Can regeneration occur with on going chronic inflammation?

A

No only FIbrous scar REPAIR

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

What is meant by fibrous repair?

A

The replacement of functioning tissue with a scar

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

What are the 4 phases to scar formation?

A

Bleeding + Haemostasis
Inflammation
Proliferation
Remodelling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is the Haemostasis stage of scar formation?
Formation of blood clots to prevent blood loss
26
What is the inflammation stage of scar formation?
Acute then chronic inflammation Digestion of blood clot occurs
27
What is the proliferation stage of scar formation?
Increase in the number of cells forming granulation tissue: Capillaries (Angiogenesis) Fibroblasts Myofibroblasts Extracellular matrix
28
Which proliferated cells produce the increased amount of Extracellular matrix in scar formation?
Fibroblasts Myofibroblasts
29
What is Granulation tissue?
The tissue that proliferates in scar formation consisting of: Fibroblasts Myofibroblasts Extracellular matrix Capillaries
30
What is the function of Granulation tissue?
Capillaries supply oxygen and nutrients Contracts (myofibroblasts) and closes the defect Essentially fills the gap
31
What is the remodelling phase of scar formation?
Reduced cell population Increased collagen in ECM Myofibroblasts contract
32
What type of cell proliferates which causes Angiogenesis?
Endothelial cell
33
What is the role of neutrophils and macrophages in Fibrous repair?
Phagocytosis Release of mediators that control the inflammatory and repair process APCs
34
What is the role of lymphocytes in fibrous repair?
Eliminate pathogens (killer cytotoxic) Co-ordinate other cells T and B cells involved in cytokine production
35
What are the characteristic features of a Fibroblast?
Elongated/spindle/ovoid shaped nuclei Cytoplasmic extensions
36
What is the function of the fibroblast tin Fibrous repair?
Secrete collagen and elastin for Extracellular Matrix
37
What is a myofibroblast?
A fibroblast containing intracellular actin A cross between fibroblast and smooth muscle cell
38
What is the function of a myofibroblast?
WOUND CONTRACTION
39
At a basic level what are the steps of collagen synthesis?
Pre-pro collagen Pro collagen Tropocollagen Collagen
40
How is pre-procollagen (alpha polypeptide chain) converted to pro collagen?
Hydroxylation + Crosslinking of 3 hydroxylated alpha chains
41
What vitamin is an essential cofactor for the enzyme that carries out hydroxylation of pre-pro collagen to pro collagen?
Vitamin C
42
What is the structure of Pro collagen?
3 alpha chains in a triple helix
43
What are the amino acids that get hydroxylated when converting from pre-pro collagen to pro collagen?
Proline Lysine
44
How is pro collagen converted into tropocollagen?
Procollagen pumped OUT of cytoplasm Terminal ends (C ends and N ends) cleaved
45
How does Tropocollagen go onto form collagen?
Cross links (polymerisation) form with other Tropocollagens leading to formation of microfibrils, fibrils and then collagen fibres
46
What is Tropocollagen with respect to collagen?
The structural unit of tropocollagen made up of a triple helix of alpha chains
47
What amino acid is found at every third position in collagen?
Glycine
48
What is an example of an acquired defect of collagen?
Scurvy
49
How is Scurvy acquired?
Vitamin C defect
50
Why does a vitamin C defect cause defective collagen in Scurvy?
Vit C needed in hydroxylation of pre-pro collagen Triple helix defective due to infective cross linking Weak tensile strength
51
What do people usually present with in scurvy?
Inefficient wound healing Tendency to bleed Tooth loss
52
What are 3 Inherited collagen disorders?
Ehlers-Danlos Syndrome Osteogenesis Imperfecta Alport Syndrome
53
What is Ehlers-Danlos syndrome?
Group of 6 disorder where collagen fibres lack adequate tensile strength
54
How do patients present with Ehlers-Danlos syndrome?
Poor wound healing Hyper mobile joints Predisposition to join dislocation Hyperextensible skin Prone to colon or artery rupture (collage in organs also affected) Corneal rupture Retinal detachment
55
What is Osteogensis imperfecta and what is it caused by?
Brittle bone disease (Prone to fractures) COL1A gene mutation Defective Type 1 Collagen
56
How do people with osteogenesis imperfecta present?
Fragile bones Blue sclera Dental impairments Hearing impatients (Due to bone instability some times bowing)
57
What is Alport syndrome?
Abnormal Type IV Collagen X-linked disease
58
How do patients with Alport syndrome usually present?
Usually male Haematuria ——— Chronic renal failure Neural deafness Eye disorders
59
Why do patients with Alport syndrome usually present with Haematuria then chronic renal failure, neural deafness and eye disorders?
Type IV collagen essential for basement membrane formation Basement membrane of glomerulus, cochlea of ear and lens of eye affected
60
What are the 3 ways that cells signal/communicate with each other to stimulate of inhibit proliferation in regeneration or repair?
Direct cell-cell contact Local mediators (Growth factors, autocrine or Paracrine signalling) Hormones (endocrine signalling)
61
What is autocrine signalling?
When cell produces and secretes a chemical signal that binds to and affects itself
62
What is Paracrine signalling?
When a cell releases chemical signals like growth factors affecting nearby cells
63
What is endocrine signalling/
Release of hormones/chemical signals acting on cells in different anatomical locations
64
How does cell to cell contact inhibit cell proliferation?
Cadherins of 2 cells come into contact signalling both cells to stop proliferating
65
In cancer how are Cadherins affected?
Defective Will continue proliferation even when in contact Instead of normal monolayer being formed multilayer forms
66
How do growth factors stimulate proliferation?
Polypeptides that bind to a cell triggering it to enter cell cycle
67
What is the function of Vascular Endothelial growth factor?
Stimulates Angiogenesis
68
What type of molecule is Tumour Necrosis Factor TNF?
Growth factor
69
What is meant by healing by Primary Intention?
Healing that occurs with Incisional injuries Closed Non infected Clean wounds with Opposed edges
70
What occurs during healing by primary intention?
Minimal clot and granulation tissue Epidermis regenerates Dermis undergoes Fibrous repair since some connective tissue architecture damaged
71
When does healing with Secondary intention happen?
Significant tissue loss Unopposed edges Infections/ulcers/abscesses
72
What happens in healing of skin via Secondary intention?
Abundant clot, inflammation and granulation tissue Lots of wound contraction needed (myofibroblasts) Dermis needs significant repair Epidermis regenerates from edges and bottom up
73
What are the 4 stages to Fracture healing?
Haematoma Soft callus Hard callus Remodelling
74
What happens in the Haematoma stage of fracture healing?
Blood collects in and around fracture and Granulation tissue accumulates
75
What happens in the Soft Callus (Week 1)?
Fibrous tissue and cartilage produced creating weak woven bone (Soft bone)
76
What happens in the Hard callus stage of fracture healing? (Several weeks)
Woven bone gradually organised into strong lamellar bone
77
What happens in the remodelling phase of fracture healing?
Lamellar bone remodelled to original outline of bone
78
What are the local factors affecting wound healing?
Size Location (what’s damaged) Blood supply (good = better healing) Local infection (slower with infection, has to deal with infection and healing) Foreign bodies
79
What are the systemic factors influencing wound healing?
Age (weaker collagen strength) Anaemia, hypoxia, hypovolaemia (blood supply issues = worse healing) Obesity Drugs Diabetes Vitamin deficiency Malnutrition
80
How does diabetes affect wound healing?
High blood sugar makes you prone to infections Blood vessels damage reducing O2 no nutrient supply to wound Nerve damage may lead to further damage to wound since you can’t feel it
81
What is Wound dehiscence and why does it occur?
When a wound opens up an contents start to push out Insufficient fibrosis
82
Where is wound dehiscence most common?
Obesity Elderly Malnutrition Steroid usage
83
What is a Keloid scar and how does it happen?
Excessive fibrosis where the fibrosis exceeds the boundary of the scar
84
What are Adhesions?
Inappropriate scar formation in tubes Fibrous bands can form after surgery obstruction the tube
85
How does fibrous repair lead to loss of function of tissue?
Any specialised cells that are replaced are lost E.g special conducting cardiac myocytes lost following ischaemic damage of the heart
86
How do myocardial infarctions usually lead to future cardiac arrhythmias?
Cardiac myocytes replaced with non conducting fibrous scar tissue Interferes with the conductance of the heart
87
How does fibrous repair of the liver disrupt its architecture?
Regeneration occurs which produces the Nodules + Repair occurs producing the fibrous cirrhotic parts
88
Why is excessive scar contraction dangerous?
Tubes constricted Scar over a joint may limit movement (Reduced Flexion)
89
What is the healing of Cardiac muscle like?
Very poor Scar formation allows follows myocardial infarction
90
What is the livers ability to regenerate?
Lobes with functioning hepatocytes that remain enlarge If severely damaged cirrhosis occurs
91
What is the ability of peripheral nerves to regenerate?
Axon regrows VERY VERY slowly but can regenerate
92
What is cartilages ability to regenerate?
Cant since it Lacks blood supply, innervation and lymphatic drainage
93
What is the CNS ability to regenerate?
Neural tissue is permanent Damaged CNS replaced by proliferation of CNS supportive cells like glial cells

Y1 - PP (20 decks)

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