Brainscape's Knowledge GenomeTM

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


See full index

BIOL 2030 > Ch. 21 Tissues and Cancer > Flashcards

Ch. 21 Tissues and Cancer Flashcards

1
Q

define tissues

A

organized mixtures of specialized cell types that are reflective of that particular tissues needs

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

what do tissues require

A
  • mechanical strength and support
  • innervation
  • defense (immune response)
  • metabolic support: nutrient uptake, oxygen, waste disposal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how do tissues receive mechanical strength and support

A

most often through fibroblasts interacting with extracellular matrix (connective tissue)

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

why do tissues require innervation

A

in order to respond to signals sent to them

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

what are the layers of the skin

A
  • epidermis w keratinocytes
  • dermis: loose connective tissue then dense connective tissue
    hypodermis: fatty connective tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is the density of dermis connective tissue referring to

A

collagen fibres, fibroblasts, capillaries

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

what is the purpose of the hypodermis

A

supply of nutrients and removal of waste products

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

what are the key factors of structural stability in tissues

A
  • cell communication
  • selective cell-cell adhesion
  • cell memory
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe the main molecule present in selective cell-cell adhesion

A
  • cadherins
  • make adherin junctions
  • allow for specific attachment between cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what is the importance of attachments to ECM in selective cell-cell adhesion

A

controls organization of tissues and set patterns of cell adherence

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

what do we mean by cell memory

A

patterns of gene expression turned on during embryonic development remain maintained thruout life of cell (Ex when fibroblast cells divide, more fibroblast cells are made)

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

what is the importance of tissue rate renewal variability amongst cells

A

reflects the sensitivity and roles of those cells

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

what are the cells involved in replacing the matrix and cells in bone

A

osteoclasts and osteoblasts

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

what is the role of osteoclasts

A

destroy and eat old bone matrix

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

what is the role of osteoblasts

A

deposit new matrix

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

how does red blood cell turnover occur

A
  • aged red blood cells have markers on surface
  • markers recognized by macrophages and phagocytose the cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

if terminally differentiated cells cannot divide in tissues, where do the replacement cells come from

A
  • stem cells
  • proliferating precursor cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

when stem cells divide, what pathway(s) could it take

A
  • remaining as stem cells (continuing self-renewing cycle)
  • differentiation into proliferating precursor cells which divide set number of times to make the terminally differentiated cells we see in tissues
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the role of stem cells in tissues

A

to provide continuous cell supply for each tissue type

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

how is it ensured that stem cell progeny will be of a certain cell type

A

expression of specific gene regulatory proteins

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

why are stem cells difficult to study

A
  • present in tissues in very low numbers
  • don’t have unique markers because they are not terminally differentiated - hard to identify
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

draw out a cross section of a crypt

A

main points: differentiated nondividing terminally differentiated cells at top; rapidly dividing precursor cells in middle; slowly dividing stem cells lower; nondividing terminally differentiated cells at most bottom

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

what are paneth cells

A

secretory cells in the crypts of gut

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

draw a diagram of the gut lumen

A

includes: villus, crypt, loose connective tissue, epithelial cells, epithelial cell migration from bottom of crypt to top of villus

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

what is a very good example of a tissue that goes through cell renewal

A

gut epithelium

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

explain cell replacement in the dermis

A
  • multiple layers to skin
  • starts at basal lamina layer with dividing basal cells (stem)
  • move upward to epidermis whilst differentiating
  • surface layer has dead flattened cells packed w keratin where cells are continually shed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

how are dead cells on the surface of skin connected

A

thru keratin IFs and desmosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

draw a flowchart of how hemopoietic stem cells produce the different cell types in circulation and immune system

A
  • hemopoietic stem cells make T and B lymphocytes, eosinophils, basophils, rbcs, megakaryocytes
  • neutrophils and monocytes stem from same branch
  • monocytes lead to osteoclast and macrophages
  • megakaryocytes make platelets
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

in intestinal epithelium, what are some cells are made thru stem cells

A

absorptive, goblet

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

describe embryonic stem cells

A
  • isolated from embryos at about five to seven days in age
  • source is inner cell mass (inside trophoblast cell layer)
  • pluripotent
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is the source of maturation for the placenta

A

trophoblast

32
Q

what are the non-embryonic stem cells

A
  • umbilical cord blood
  • placental
  • adult (present at birth)
33
Q

what is unique about the embryonic stem cells

A
  • can keep dividing in culture
  • can also differentiate in culture if given appropriate hormones and growth factors, making them mature into distinct cell types
  • when returned to embryonic environment it will still give rise to all tissues and cell types in body (pluripotent)
34
Q

what are the challenges to using embryonic stem cells for research

A
  • hard to grow and establish culture
  • hard to maintain culture
  • controlling direction of differentiation (inconsistency)
  • unstable gene expression (unpredictable differentiation patterns) → tumour potential
  • transplant rejection
35
Q

why is transplant rejection a problem; how could it be prevented

A
  • immune system is very good at rejecting foreign tissue unless it is coming from same person or from extremely good match;
  • requires immunosuppressive drugs
36
Q

why is there a shift towards research using adult stem cells

A
  • adult stem cells are available in all tissues
  • some adult stem cells (ex bone marrow, brain) are able to produce very different cell types
  • rapid and long term division can occur
37
Q

cancer cells and their progeny often violate the basic rules of

A

social cell behaviour (do opposite of what they should)

38
Q

describe primary tumours

A

tumour located at its origin (the starting tumour)

39
Q

describe secondary tumours

A
  • aka metastases
  • colonies of cancer cells due to migration away from primary tumour (tumours that spread away from origin)
40
Q

secondary tumours can exist if primary tumours have

A

properties that allow them to travel out from tissues to lymph/blood, and set up a new site

41
Q

what are the heritable properties of cancer cells

A
  1. ability to proliferate in defiance of normal constraints
  2. invade and colonize locations meant for other cells
42
Q

define benign tumours

A

tumours that form from cancer cells that only proliferate in defiance of normal constraints

43
Q

why are benign tumours not as dangerous

A
  • unable to invade and colonize other areas
  • removal by surgery
44
Q

define malignant tumours

A

tumours that form from both heritable properties of cancer cells (i.e. can uncontrollably divide when not supposed to in one spot, and invade and migrate to other tissues)

45
Q

why are malignant tumours able to invade surrounding tissue

A
  • may produce enzymes that make it do so
  • may lack normal properties required for cell-cell communication and adhesion
46
Q

define metastasize

A

tumours spreading to other sites in body

47
Q

how do cancers develop

A

accumulation of mutations (usually somatic) by mutagens or spontaneous mutation (errors)

48
Q

what are somatic mutations

A

non-germ (egg or sperm) cell that mutates

49
Q

define mutagens

A
  • agents able to cause mutations in DNA
  • ionizing radiation
  • chemical carcinogens
50
Q

why are cancer cells genetically unstable

A
  • mutations that interfere with accurate replication
  • mutations that decrease DNA repair efficiency
  • mutations that increase occurrence of chromosomal breaks and rearrangements

these overall give enhanced mutation rates

51
Q

why type of advantage do cancer cells receive with mutations

A

competitive

52
Q

what types of cells does natural selection favour

A

cells with mutations that enhance cell proliferation and survival

53
Q

define angiogenesis

A

formation of new blood vessels

54
Q

why may cancer cells cause angiogenesis

A

blood supply is required to feed all the cells of the tumour that are internal

55
Q

what does invasion mean in the context of cancer

A

ability to digest and take over underlying tissue

56
Q

define metastasis

A

ability to enter and exit blood or lymph, and colonize new regions of the body

57
Q

what are some key attributes of cancer cells

A
  1. reduced independence on signals from other cells due to mutations
  2. less prone to apoptosis
  3. immortality
  4. genetically unstable
  5. abnormally invasive
  6. ability to survive and grow well in other tissues
58
Q

how do Ras gene mutations support cancer cells

A
  • unable to “turn off” due to mutation in GTPase activity
  • leads to uncontrolled proliferation
59
Q

how do p53 mutations support cancer cells

A
  • unable to trigger apoptosis for cells with damaged DNA in the checkpoint stage
  • leads to uncontrolled proliferation
60
Q

what does it mean when we say cancer cells are immortal

A

able to divide over and over again

61
Q

how does telomerase activity support cancer cells

A

telomerase expression occurs which maintains telomere length (not normally expressed in mature cells)

62
Q

why are cancer cells considered abnormally invasive

A
  • due to enzymes that make it this way
  • often lacking or have down-regulated cell-adhesion molecules (like cadherins)
63
Q

define oncogenes

A
  • genes involved in triggering cancerous characteristics in cells (permanently turned on)
  • generally mutants of normal genes involved in control of cell growth or division
64
Q

define proto-oncogenes

A

genes that normally help cells grow and divide to make new cells (ex Ras)

65
Q

describe dominant mutations

A

when only one mutant copy is required to have a significant impact on a cell

66
Q

what genes are critical for cancer cells

A

oncogenes, tumour suppressor genes

67
Q

describe tumour suppressor genes

A

genes that normally inhibit progress through cell cycle

68
Q

why are tumour suppressor gene mutations considered recessive

A

both copies of the gene must be lost before effect on cell is seen

69
Q

define overactivity mutations

A

gaining of function

70
Q

define underactivity mutations

A

loss of function (p53, Rb)

71
Q

draw out a flowchart of overactivity mutations

A

…

72
Q

draw out a flowchart of underactivity mutations

A

….

73
Q

how does chronic myeloid leukemia occur

A

mutation in Abl gene (which encodes tyrosine kinase) leads to a hyperactive kinase, causing repeated signaling for cell division

74
Q

describe oncogenic kinase activity; what does it result in

A
  • substrate protein and active oncogenic kinase are bound with ATP
  • ATP hydrolysis occurs and the phosphate keeps the substrate protein activated
  • leads to signal for cell proliferation and survival;
  • leukemia
75
Q

how can oncogenic kinase activity be prevented

A
  • Gleevec drug binds to ATP binding site of the kinase
  • prevents signals from being received
  • no leukemia (effective in leukemia treatment)

BIOL 2030 (16 decks)

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