Cellular Adaptation Flashcards Preview

Year 2 EMS MoD > Cellular Adaptation > Flashcards

Flashcards in Cellular Adaptation Deck (59):
1

Are cellular adaptations normally reversible or irreversible?

Normally reversible.
-unlike cell injury and neoplasia

2

What are cellular adaptations?

Reversible (usually) changes in cellular size / number / phenotype / metabolic activity / function.

3

What causes cellular adaptations?

Changes in environment/demand.

4

What is the purpose of cell adaptations?

Cells acquire steady state of metabolism, and are better equipped to survive in new environment.

5

What type of cells don't normally need to adapt?

Fibroblasts.
-survive severe metabolic stress (e.g. absence of O2)

6

What type of cells adapt easily?

-Epithelial cells
-Labile cell populations
-Stem cells

7

What type of cells cannot adapt?

Cerebral neurons.
-terminally differentiated / highly specialised
-permanent cell population
-rapidly die when hypoxic

8

What are the main types of adaptive response? (3)

-Increased cellular activity
-Decreased cellular activity
-Change of function/morphology

9

How do cells respond to increased demand? (2)

-Hypertrophy
-Hyperplasia

>> increased cell mass

10

What is the difference between hypertrophy and hyperplasia?

HYPERTROPHY -increase in size of cells
HYPERPLASIA - increase in number of cells

11

What type of cell population is hypertrophy often seen in?

Permanent cell populations.
-especially cardiac and skeletal muscle

12

What type of cellular adaptation causes an enlarged uterus during pregnancy?

Hypertrophy.
-increase in cell size

13

What type of cellular adaptation occurs when the bladder has to work harder due to obstruction (e.g. prostate tumour)?

Hyperplasia.
-increase in cell number
-leads to diverticulum

14

How do permanent cell populations respond to increased demand?

Hypertrophy.
-can only increase cell size
-e.g. LVH

15

Give 2 examples of permanent cell populations undergoing hypertrophy to meet increased demands.

-Skeletal muscle cells of a marathon runner
-Cardiac cells due to aortic stenosis (LVH)

16

What causes left ventricular hypertrophy?

-Hypertension
-Aortic stenosis
-Cardiomyopathy
-Athletic training

17

How in left ventricular hypertrophy diagnosed?

-Electrocardiogram (ECG)
-Echocardiogram
-MRI

18

What are the main problems associated with left ventricular hypertrophy?

-Arrhythmias (^ ectopic beats)
-Increased stroke risk
-Increased heart attack risk
-Sudden unexpected death

19

What is subcellular hypertrophy and hyperplasia?

Increase in size and number of subcellular organisms.

20

Give an example of subcellular hypertrophy in the liver.

Barbiturates lead to smooth ER hypertrophy in hepatocytes.
>> increased metabolism of other drugs

21

What is hyperplasia?

An increase in number of cells.
-caused by cell division

22

What type of cell populations is hyperplasia possible in?

Labile and stable cell populations.

23

What is gynaecomastia?

Enlargement of male breast due to hyperplasia of glandular and stromal tissue.

24

Is gynaecomastia physiological or pathological?

Both;
PHYSIOLOGICAL - puberty, due to drugs
PATHOLOGICAL - due to liver cirrhosis

25

What is compensatory hyperplasia of the kidneys?

Hyperplasia of one kidney due to hypoplasia of the other kidney.

26

What is the process of cellular adaptation in Graves disease?

Auto-antibody switches on TSH receptor in thyroid
>> uncontrolled hyperplasia of thryroid (HYPERTHYROIDISM).

27

What does the abnormal healing process of liver cirrhosis lead to?

Hyperplasia nodules.

28

What is atrophy?

Reduction in the size of an organ/tissue.
-due to decreased cell size/number

29

Give 2 physiological types of atrophy.

-Embryogenesis
-Uterus after pregnancy / menopause

30

What are the main causes of pathological atrophy?

-Decreased workload
-Loss of innervation
-Diminished blood supply
-Inadequate nutrition
-Loss of endocrine stimulation
-Pressure

31

What is another name for atrophy due to decreased workload?

Disuse atrophy.
-e.g. muscles in cast when broken bone

32

Give an example of atrophy due to inadequate nutrition.

Cachexia.
-wasting of body in severe illness

33

How does a tumour in the pituitary cause atrophy due to pressure?

Benign pituitary tumour squashes the rest of the pituitary >> atrophy.

34

What happens to the brain with age?

It shrinks.
-bigger sulci, narrower gyri

35

What does renal artery stenosis cause?

Atrophy of the kidney.

36

What is the thymus an example of in adults?

Physiological atrophy.
-decreases in size with age

37

How do steroid therapies lead to adrenal cortex atrophy?

Reduces the ACTH drive to the adrenal >> decreased hormonal stimulation.

38

What are the 2 mechanisms of atrophy?

-Reduction in individual cell volume
-Death of individual cells

39

What is apoptosis?

Process of programmed cell death that occurs in multicellular organisms.

40

What is involution?

Physiological atrophy of an organ by apoptosis.
-e.g. womb after childbirth

41

What are the main developmental abnormalities that lead to a reduced cell mass? (4)

-Agenesis
-Aplasia
-Dysgenesis
-Hypoplasia

42

What is agenesis?

Failure of an organ to develop during embryonic growth.
-never grows
-due to absence of primordial tissue.

43

What is aplasia?

The failure of an organ to develop/function normally.
-e.g. may have been primordial tissue, but not organ-specific tissue

44

What is dysgenesis?

Defective development of an organ.
-especially gonads
-doesn't grow to full size

45

What is hypoplasia?

Underdevelopment of an organ/tissue.

46

What is metaplasia?

Transformation of one differentiated cell type into another.
-can >> better adaptation to environment

47

What is metaplasia caused by?

Transdifferentiation of stem cells.

48

What tissues can be affected by metaplasia? (2)

-Epithelium
-Mesechymal tissue

49

What type of epithelium does the cervix have before puberty?

Cervix has stratified squamous epithelium, endocervical canal has collumnar epithelium.

50

What happens to the cervix at puberty?

Oestrogen causes stratified squamous to descend and replace columnar epithelium.
-PHYSIOLOGIAL METAPLASIA

51

What can pathological hyperplasia and metaplasia lead to?

Carcinoma.

52

What pathological metaplastic change can cigarette smoke cause to bronchial epithelium?

Bronchial epithelium;
pseudostratified ciliated >> squamous.

53

What pathological metaplastic change can bladder calculus cause to bladder epithelium?

Bladder epithelium;
transitional >> squamous.

54

What pathological metaplastic change can chronic trauma cause to fibrocollagenous tissue?

Fibrocollagenous tissue >> bone.

55

What pathological metaplastic change can acid reflux cause to oesophageal epithelium?

Oesophageal epithelium;
squamous >> columnar (glandular).

56

What can endometrial hyperplasia due to increased oestrogens lead to?

Adenocarcinoma.

57

What is the earliest morphological manifestation of neoplasia?

Dysplasia.

58

What is dysplasia?

Enlargement of an organ / tissue by the proliferation of cells of an abnormal type.
-non-invasive (in-situ)

59

What test is dysplasia detected in?

Cervical screening test.
-detection before invasice