2 - Cell Growth And Differentiation Flashcards
1
Q
This is the process of increase in size resulting from the synthesis of specific tissue components
A
Growth
2
Q
True or False.
Growth may be applied to populations, individuals, organs, cells or even subcellular organelles such as mitochondria.
A
True
3
Q
Four types of growth in a tissue
A
- Multiplicative
- Auxetic
- Accretionary
- Combined patterns of multiplicative, auxetic and accretionary growth
4
Q
This is a type of growth where there is increase in number of somatic cells (mitosis) and gametocytes) (meiosis)
A
Multiplicative
5
Q
This type of growth is present in all tissues
A
Multiplicative
6
Q
This is a type of growth where there is increase in size of the cell
A
Auxetic
7
Q
An example of this type of growth is muscle growth.
A
Auxetic
8
Q
This is the type of growth where increase in intercellular components/ground substance
A
Accretionary
9
Q
An example of this growth include cartilage and bone (collagen, ECM, GS and elastin amount).
A
Accretionary
10
Q
An example of this growth is embyological development.
A
Combined patterns of multiplicative, auxeti camd accretionary growth
11
Q
This is the process where by a cell develops an overt specialized function or mophology that distinguishes it from its parent cell
(example: overt function of the cilia)
A
Differentiation
12
Q
This is the process by which genes are expressed selectively and gene products act to produce a cell with a specialized function
A
Differentitation
13
Q
Cells undergo this process in their passage to fully differentiation cells, such as the ciliated epithelial cells lining the respiratory passages of the nose and trachea
A
Differentiation
14
Q
Three cell fates
A
- Proliferation
- Differentiation
- Apoptosis
15
Q
This is determined by the net balance between proliferation, differentiation and apoptosis
A
Growth rate
16
Q
Parameter for studying cell growth
A
- Cell cycle
- Group of cells according to proliferative potential
- Growth factors
- Cellular adaptation
17
Q
Different phase of cell cycle
A
G0 phase G1 (Gap 1) phase S phase G2 phase M (mitotitic) phase
18
Q
This is a tightly regulated process of cell growth that is continuous unless the cell dies
A
Cell cycle
19
Q
True or False.
The activation of a phase depends on the completion of the previous stage
A
True
20
Q
Main purpose of cell cycle
A
DNA replication
Cell division
21
Q
A problematic cell may _____________.
A
Go back, undergo apoptosis or continue to cause a disease
22
Q
This phase in the cell cycle is known as the resting phase in which cells are in the quiescent state
A
G0 phase
23
Q
This phase of the cell cycle that is viewed as either an extended G1 phase, where the cell in neither dividing no preparing to divide or a distinct quiescent stage that occurs outside of the cell cycle
A
G0 phase
24
Q
This is the phase where cell cycle is dismantled and cyclings and cyclin-dependent kinases disappear
A
G0 phase
25
This phase of the cell cycle is also known as the growth phase or pre-synthetic phase, where cells resume their biosynthesis activity at a high rate
G1 phase
26
This phase of the cell cycle is where cells grow and size and synthesizes mRNA and proteins in preparation for subsequent steps leading to mitosis
G1 phase
27
This is different from a checkpoint because it does not determine whether cell conditions are ideal to move on to the next phase
Restriction (R) point
28
This assures a high amount of growth factor and a steady rate of protein synthesis, otherwise the cell will move into G0 phase
Restriction (R) point
29
This is the rate limiting rate or the point of no return in the cell cycle. If the cells pass this, they will be allowed to proceed to the next phases.
Restriction (R) point
30
This is the part of the cell cycle where cells are cleared for progression in to the S phase
G1/S checkpoint
31
Reasons why the cell would not move into the S phase
1. Insufficient cell growth
2. Damaged DNA
3. Other preparation have not been completed
32
This checks if the DNA has the correct number and structure and cell is cleared out for progression into the S phase
G1/S checkpoint
33
True or False.
| Failure of the G1/S checkpoint to filter proper DNA can lead to genetic defects
True
34
This is also known as the synthesis phase
S phase
35
This is the phase of the cell cycle where DNA is replicated, occurring between G1 phase and G2 phase
S phase
36
In this phase of cell cycle, precise and accurate DNA replication is necessary to prevent genetic abnormalities which often leads to cell death or disease
S phase
37
This is a complex process of embryological development because if involves cell growth, differentiation and relative movement of cell groups
Morphogenesis
38
This is responsible for formation of shape and oraganization of body organs
(example: heart)
Morphogenesis
39
This involves apoptosis which removes unwanted features
Morphogenesis
40
This phase of the cell is also known as the pre-mitotic phase
G2 phase
41
This phase of the cell cycle that follows the successful completion of the S phase
G2 phase
42
This phase of the cell cycle where a period of rapid cell growth and protein synthesis during which the cell readies itself for mitosis
G2 phase
43
This checkpoint assures that there is no damage in the DNA before cells go to cell division/mitosis
G2/M checkpoint
44
This phase of the cell cycle is where cell growth stops and all cellular activity is focuses on producing 2 daughter cells
M phase
45
This phase of the cell cycle is important for the maintenance of chromosomal set
M phase
46
In this phase of the cell cycle, each cell formed receives chromosomes that are alike in composition and equal in number to the chromosaome of the parent cell
M phase
47
These define the M phase of the cell
Mitosis and cytokinesis
48
Phases of mitosis
Interphase, prophase, metaphase, anaphase, telophase
49
This is the process of the division of the cytoplasm
Cytokinesis
50
Group of cells according to their proliferative potential
1. Labile cells
2. Stable cells
3. Permanent cells
51
These group cells continuously divide throughout postnatal life
Labile cells
52
These group cells has a short life span and rapid cell turnover
Labile cells
53
These group of cells is usually noted with hyperplasia
Labile cells
54
Example of labile cells
Squamous cells of the skin
Columnar epithelium of the GIT
Transition epithelium of the urinary tract
Hematopoietic cells
55
These group cells are quiescent cells
Stable cells
56
These group cells divide very infrequently under normal conditions but when are lost, their stem cells are easily
stimulated to differentiate or divide
Stable cells
57
Example of stable cells
Hepatocytes (partial hepatectomy)
Parenchymal cells of the kidneys and pancreas
Mesenchymal cells such as fibroblasts and smooth muscles
58
These group cells are non-dividing cells
Permanent cells
59
Examples of permanent cells
Neurons and myocardial cells
60
These growth factors are protein mediators of inflammation and immune response
Cytokines
61
These growth factors have growth-promoting activitied for a variety of cells
Cytokines
62
Examples of cytokines
IL
IFN
TNF
63
True or False.
| Cytokines also act as inhibitory siganals
True
64
This is also known as receptor-mediated signal transduction
Signalling mechanism
65
This occurs upon binding of ligands to specific receptors
Signalling mechanisms
66
True or False.
| In signalling mechanisms, receptor activation leads to expression of specific genes and illicit growth.
True
67
General modes of signalling according to the source of ligand and location of its receptors
1. Autocrine
2. Paracrine
3. Endocrine
68
In this mode of signalling, cells respond to the signallingmolecules they themselve secrete, hence creating a loop
Autocrine
69
In this mode of signalling, cells stimulate self-growth without distant or adjacent receptor
Autocrine
70
Examples of autocrine mode
Liver regeneration
Antigen-stimulated lymphocyte proliferation
Tumor growth
Keratinocytes during skin injury
71
In this mode of signalling, one cell produces the ligand which acts on the adjacent target cells that express the appropriate receptor
Paracrine
72
In this mode of signalling, the adjacent cell is of different type from the cell expressing the ligand
Paracrine
73
Example of paracrine mode
Wound repair and embryological development
74
In this mode of signalling, a gland produces hormones targeting distant cells, usually carried out by the blood
Endocrine
75
Examples of endocrine mode
Posterior pituitary gland secretes oxytocin which goes to the breast (lactation) and uterus (contraction during parturition)
76
Reversible changes in the size, number, phenotype, metabolic activity or functions of the cells in response to changes in their environment
Cellular adaptations
77
Different types of cellular adaptations
Hypertophy
Hyperplasia
Atrophy
Metaplasia
78
This is a type of cellular adaptation where there is increase in the size of the cells with resultant increase of the size of the organ
Hypertrophy
79
Most common stimulus for hypertrophy
Increase workload
80
This is a type of cellular adaptation where subcellular organelles develop hypertrophy
Selective hypertrophy
81
Example of selective hypertrophy
Hypertrophy of smooth endoplasmic reticulum in the hepatocytes in patients treated with barbituate (increase CYP450 to detoxify drugs)
82
Mechanism of hypertrophy
Synthesis of more structural components of the cells and cellular proteins
83
Analogy.
Homeostasis: ___________
Adaptation: __________
Homeostasis: steady state
Adaptation: altered steady state
84
Example of hypertrophy
Left Ventricular Hypertrophy - increase in organ size and histologically seen as box-card shaped nuclei and thicker cardiac muscle fiber
85
Two types of hypertrophy
Physiologic hypertrophy
| Pathologic hypertrophy
86
This type of hypertrophy is inflence by hormones and growth factors
Physiologic hypertrophy
87
Example of physiologic hypertrophy
Skeletal muscles of body builders
| Smooth muscle cells of the uterus during pregnancy
88
This type of hypertrophy is influenced by existing medical condition/disease or a chronic hemodynamic overload
Pathologic hypertrophy
89
Example of pathologic hypertrophy
Myocardial hypertrophy secondary to hypertension and defective heart valves (mitral stenosis)
90
This is a type of cellular adaptation where there is increase in the number of cells in an organ or tissue
Hyperplasia
91
This is a type of cellular adaptation results in increased mass of the organ or tissue
Hyperplasia
92
This is a type of cellular adaptation occurs in cells capable of dividine
Hyperplasia
93
This is a type of cellular adaptation may occur with hypertrophy
Hyperplasia
94
This is a type of cellular adaptation is characterized by a shaggy endometrium and increase in number of cork-screw shaped glands during pregnancy
Hyperplasia
95
True or False.
| Hyperplasia is not cancer.
True
96
Mechanism of hyperplasia
Result of the growth factor-driven proliferation of mature cells, and in some cases, by increase output of new cells from the tissue stem cells
97
Two types of hyperplasia
Physiologic hyperplasia
| Pathologic hyperplasia
98
Two types of physiologic hyperplasia
Hormonal hyperplasia
| Compensatory hyperplasia
99
An example of this type of physiologic hyperplasia is increase in number of glands during puberty and pregnancy.
Hormonal hyperplasia
100
An example of this type of physiologic hyperplasia is compensatory hyperplasia is partial hepatectomy.
Compensatory hyperplasia
101
This type of hyperplasia is caused by excess of hormones or growth factors acting on target cells
Pathologic hyperplasia
102
Mechanism of pathologic hyperplasia in endometrial hyperplasia
Secondary to ovarian tumors
| Increase in glandural stroma
103
Mechanism of pathologic hyperplasia in benign prostatic arrangement
Coalesced arrangement
| Increase in glandular stroma
104
Mechanism of pathologic hyperplasia in viral infection of the skin
Verruca
| Thickened stratum corneum
105
This type of cellular adaptation is characterized by reduction in cell size of an organ or tissue resulting from a decrease in cell size, mass and number
Atrophy
106
Two types of atrophy
Physiologic atrophy
| Pathologic atrophy
107
In atrophy, degradation of cellular proteins occurs mainly through _____________.
Ubiquitin-Proteasome Pathway
108
Mechanism of Ubiquitin-Proteasome pathway
Conjugation with a 26s proteasome which is male up of a catalytic 20s core and 19s regulatory protein)
109
True or False.
| Atrophy is accompanied by autophagy where autophagic vacuoles are formed.
True
110
Analogy: Autophagic vacuoles.
Fuse with lysosomes: ________________
Not degraded: _________________
Fuse with lysosomes: Lysosomal degradation
| Not degraded: Residual bodies
111
Mechanism of atrophy
Due to decrease protein synthesis and increase protein degradation in cells
112
Two types of atrophy
1. Physiologic atrophy
| 2. Pathologic atrophy
113
This is the type of atrophy where tissues/structures present in embryo or childhood may undergo atrophy as growth and development progess (thymus)
Physiologic hypertrophy
114
This is the type of atrophy that occur as a result of disease of loss of trophic support
Pathologic atrophy
115
Causes of pathologic hypertrophy
```
Decreased workload (atrophy of disuse)
Denervation atrophy
Diminished blood supple
Inadequate nutrition
Loss of endocrine stimulation
Pressure
```
116
This is the type of cellular adaptation is characterized by a differentiated cell type that is replaced by another cell type as a response to altered environment state (chronic cellular injury and repair)
Metaplasia
117
This is the type of cellular adaptation is often associated with the increased rick of malignancy
Metaplasia
118
Most common type epithelial metaplasia
Squamous metaplasia (columnar to squamous cells)
119
Most common organ affected by squamoous metaplasia
Cervix
120
Mechanisms of metaplasia
1. Reprogramming of stem cells existing in normal tissues or of undifferentiated mesenchymal cells present in connective tissues
2. Differentiation is brought about by the signals generated by cytokine, GF and ECM components in the cells’ environment
121
This is an abnormal organization of cells characterized by increase cell proliferation with atypical morphology
Dysplasia
122
True or False.
| Dysplasia may be reversible in early stages.
True
123
True or False.
| Dysplastic lesions are often pre-neoplastic/pre-malignant
True
124
During this abnormal cellular adaptation, there is less polarity, loss of original layers, and higher nuclei to cytoplasm ratio.
Dysplasia
125
Cigarette smoking
Original tissue: ____________
Metaplastic tissue: _____________
Original tissue: Ciliated columnar epithelium of bronchial tree
Metaplastic tissue: Squamous epithelium
126
Trauma of the bladder calculus
Original tissue: ____________
Metaplastic tissue: _____________
Original tissue: Transitional epithelium of bladder
| Metaplastic tissue: Squamous epithelium
127
Trauma of calculus
Original tissue: ____________
Metaplastic tissue: _____________
Original tissue: Columnar epithelium in gland ducts
| Metaplastic tissue: Squamous epithelium
128
Chronic trauma
Original tissue: ____________
Metaplastic tissue: _____________
Original tissue: Fibrocollagenous tissue
| Metaplastic tissue: Bone (osseous) tissue
129
Gastric acid
Original tissue: ____________
Metaplastic tissue: _____________
Original tissue: Esophageal squamous epithelium
| Metaplastic tissue: Columnar epithelium
130
Vitamin A deficiency
Original tissue: ____________
Metaplastic tissue: _____________
Original tissue: Columnar glandular epithelium
| Metaplastic tissue: Squamous epithelium
131
Example results of defects in cell cycle
```
Turner syndrome (Barr Boddies is absent, otherwise know as 45, X0)
Edward’s syndrome (Trisomy 18)
Patau Syndrome (Trisomy 13)
```
132
True or False.
| DNA synthesis is already initiated at the R point.
True
133
True or False.
| G2 phase ends with the onset of prophase of the M phase.
True
134
True or False.
| Stable cells start to differentiate and divide in the G1 phase.
True
135
There are polypeptides which are components necessary for cell proliferation.
Growth factors
136
True or False.
| Growth factors may have a single or multiple cell targets.
True
137
True or False.
Growth factors may promote numerous effects such as cell survival, locomotion, contractility, differentiation and
angiogenesis.
True
138
True or False.
Growth factors are named after their respective
targets.
True
139
True or False.
Should growth factors be expressed in higher than
normal amounts, it may induce the development of tumors as growth will no longer adhere to the physiologic standard.
True
140
Physiologic example of autocrine mode
Liver regeneration and antigen-stimulated lymphocyte proliferation
141
Pathologic example of autocrine mode
Tumor growth (poorly regulated autocrine regulation induces too much cellular growth and proliferation which may cause malignancies especially if restriction points and checkpoints have been bypassed by the cell)
142
Range of autocrine mode
Self
143
True or False.
| Paracrine mode does not rely on blood flow since distance traversed in not too far.
True
144
Range of paracrine mode
Adjacent cells with appropriate receptors
145
True or False.
| The endocrine gland relies on the blood flow to deliver the hormone to distant organs/ targets
True
146
True or False.
Adaptation occurs if a normal cell in under constant, mild to transient stress. However, when stimulus becomes severe or progressive, irreversible injury occurs.
True
