2. Cell response to injury: Morphological Changes 2

Question 1

how can labile and stable cells alter their pattern of growth?

Answer 1

1. size
2. differentiation
3. number

Question 2

2 mechanims in which cells respond to an increase in functional demand?

Answer 2

hyperplasia and hypertrophy

Question 3

which 3 cells is hyperplasia not seen in? why?

Answer 3

cardiac, skeletal and neuronal cells - they are permanent cells

Question 4

3 examples of physiological hyperplasia

Answer 4

1. bone marrow
2. glandular epithelium/endometrium
3. puberty + pregnancy

Question 5

in what circumstances does bone marrow hyperplasia occur?

Answer 5

in high altitude with low oxygen - stimulates erythropoiesis

Question 6

in what circumstances does glandular epithelium/endometrium hyperplasia occur?

Answer 6

menstrual cycle

Question 7

in pregnancy and puberty - which cells undergo hyperplasia?

Answer 7

breast and myometrial smooth cells

Question 8

in what 2 organ donations does compensatory hyperplasia occur?

Answer 8

liver and kidney

Question 9

which 3 GF allow the liver to regenerate?

Answer 9

TGF-alpha
Hepatocyte GF
IL-6

Question 10

which 2 growth inhibitors prevent liver regeneration?

Answer 10

TGF-beta

IL-1

Question 11

2 causes of pathological hyperplasia?

Answer 11

1. excess GF/hormones/GH receptors

2. up-regulation of cell-signalling systems

Question 12

2 examples of pathological hyperplasia?

Answer 12

1. graves disease - thyroid

2. benign prostatic hyperplasia

Question 13

what is graves disease?

Answer 13

increased secretion of TSH causing increased thyroid hormones

Question 14

what is benign prostatic hyperplasia?

Answer 14

increase androgens

Question 15

2 ways in which hypertrophy occurs?

Answer 15

1. increased synthesis of structural components

2. increased RNA synthesis and organelles required for protein synthesis

Question 16

which cell type is hypertrophy only seen in?

Answer 16

permanent/non-dividing cells

Question 17

2 causes of hypertrophy

Answer 17

1. increased functional demand

2. stimulation of hormones/GF

Question 18

2 examples of physiological hypertrophy?

Answer 18

1. skeletal muscle in athletes

2. smooth muscle - pregnancy

Question 19

what occurs in skeletal muscle hypertrophy in athletes?

Answer 19

increase in length and width of muscle fibres

Question 20

what causes skeletal muscle hypertrophy in athletes?

Answer 20

increased work load

Question 21

in skeletal muscle hypertrophy - what occurs if the stimulus (weight) is ceased?

Answer 21

the muscle size returns to normal

Question 22

what causes smooth muscle hypertrophy in pregnancy?

Answer 22

oestrogenic hormones bind to oestrogn receptors

Question 23

1 example of pathological hypertrophy?

Answer 23

cardiac muscle hypertrophy

Question 24

3 cause of cardiac muscle hypertrophy?

Answer 24

chronic haemodynamic overload, hypertension, faulty valves

Question 25

what is atrophy?

Answer 25

decrease in cell size

Question 26

what is involution?

Answer 26

decrease in cell size and number

Question 27

what 2 changes does involution/atrophy lead to

Answer 27

1. decreased cell metabolism | 2. decrease protein synthesis

Question 28

which cells undergo atrophy?

Answer 28

permanent

Question 29

which cells undergo involution?

Answer 29

stable and labile

Question 30

3 examples of physiological atrophy/involution?

Answer 30

1. loss of endocrine stimulation 2. embryological structures 3. thymus gland

Question 31

give an example of atrophy/involution due to loss of endocrine stimulation?

Answer 31

menopause - loss of oestrogen stimulation causes atrophy of endometrium of vagina and breast tissue

Question 32

give an example of atrophy/involution of embryonic structures?

Answer 32

notochord

Question 33

when does the thymus gland involute?

Answer 33

adolescence

Question 34

3 examples of pathological atrophy/involution

Answer 34

1. decreased workload 2. denervation 3. lipofusion

Question 35

give an example of atrophy/involution in terms of decreased workload?

Answer 35

immbolisation after fractured bone

Question 36

what is lipofusion in cellular atrpohy?

Answer 36

the build up of lipofuscin - which is the breakdown product of myocardial fibres as a result of atrophy

Question 37

what is agenesis?

Answer 37

absence of tissue/organ due to them not developing

Question 38

what is hypoplasia/aplasia

Answer 38

failure in development of normal sized organ

Question 39

describe hypoplasia/aplasia in aplastic anaemia

Answer 39

1. hypofunction of BM 2. Stem cells not produced 3. pantocytopenia 4. BM replaced by fat