17. Abnormalities of growth, differentiation and morphogenesis Flashcards Preview

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Flashcards in 17. Abnormalities of growth, differentiation and morphogenesis Deck (85)
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1

What is a cellular adaptation?

Reversible changes in cellular size/number/phenotype/metabolic activity/function due to changes in environment or demand

2

During cellular adaptation, the cell may make changes in what?

- size
- number
- phenotype
- metabolic activity
- function

3

How is cellular adaptation different to cell injury and neoplasia?

Cell injury and neoplasia are irreversible whereas cellular adaptation is most often reversible

4

What is the role of cellular adaptation?

- acquire new, steady state of metabolism and structure
- better equips cell to survive in new environment

5

What may failure of adaptation lead to?

Sub-lethal or lethal cell injury

- marked susceptibility to injury
- stimulus is too severe

6

Tissues differ in their susceptibility to stress. Give examples

Cerebral neurons = very sensitive to hypoxia, rapidly die when subject to hypoxic stress

Fibroblasts = very resistant to damage, can survive for long periods in challenging environments

7

Depending on the cell population type, tissues either
- don't need to adapt
- adapt easily
- cannot adapt
Give an example of a tissue type that does not need to adapt

Fibroblasts

Survive severe metabolic stress without harm eg. absence of O2

8

Depending on the cell population type, tissues either
- don't need to adapt
- adapt easily
- cannot adapt
Give an example of a tissue type that can adapt easily

Epithelial cells

Labile cell population, active stem cell population, highly adaptive in number and function

9

Depending on the cell population type, tissues either
- don't need to adapt
- adapt easily
- cannot adapt
Give an example of a tissue type that cannot adapt

Cerebral neurons

Terminally differentiated, permanent cell population, highly specialised function, easily damaged by environmental change

10

What is PHYSIOLOGICAL cellular adaptation?

Responding to normal changes in physiology or demand

11

What is PATHOLOGICAL cellular adaptation?

Responding to disease related changes

12

What are 3 types of adaptive responses

- increased cellular activity
- decreased cellular activity
- changes in cell function and/or morphology

13

In what ways can a cell adapt to increase cellular activity?

Increase size and/or number of cells

14

In what ways can a cell adapt to decrease cellular activity?

Decreased size and/or number of cells

15

Increase in SIZE of cells is called what?

Hypertrophy

16

Increase in NUMER of cells is called what?

Hyperplasia

17

Hypertrophy and hyperplasia may co-exist. What do they both lead to?

Hypertrophy/hyperplasia = increased cell mass = increased capacity

18

Hypertrophy is an increase in size of existing cells and therefore an increase in functional capacity. What does this lead to?

- increased synthesis of structural components

- increased metabolism

19

In which tissues is hypertrophy particularly seen in?

Permanent cell populations, especially cardiac and skeletal muscle

20

Under what circumstances might a uterus be pathologically hypertrophied?

Adhered placenta causing post-partum haemorrhage

Causes uterus to be significantly larger after delivery

21

The prostate becomes enlarged as part of the ageing process, by a process of ....? hyperplasia

Adenomyomatous hyperplasia

22

When the prostate undergoes hyperplasia, what effect does this have on the bladder?

Detrusor muscle has to work harder during micturition - undergoes hyperplasia

23

Hyperplasia of the prostate can lead to further hyperplasia of the detrusor muscle of the bladder. What appearance does this give?

Trabeculated appearance

Can also get bladder diverticuli

24

Permanent cell populations can only respond to increased demand by doing what?

Increasing cell size

(hypertrophy)

25

How many cusps does the aortic valve have?

Give an abnormality

Normally has 3

Can get congenitally bicuspid aortic valve - often suffers from abnormal fibrosis and pathological calcification leading to inflexibility and narrowing of the orifice

26

What causes left ventricular failure?

Long standing systemic hypertension

Increased peripheral vascular resistance, increasing demand on left ventricle - hypertrophy will compensate for some time but if hypertension is left untreated, compensation may eventually fail

27

How might you diagnose left ventricular hypertrophy?

- clinical examination
- ECG
- imaging

28

Which valve abnormality would lead to left ventricular hypertrophy (LVH)?

Aortic stenosis

29

What can LVH predispose to?

- sudden degeneration of rhythm
- ventricular tachycardia
- ventricular fibrillation and sudden cardiac death

30

What is subcellular hypertrophy and hyperplasia?

Increase in size and number of subcellular organelles