Cellular adaptations to an altered environment in disease

Question 1

Define metaplasia

Answer 1

Change in tissue type present in an organ
Often associated with cancer
Usually involves changes in type of epithelium

Question 2

Define hypertrophy

Answer 2

enlargement of an organ or tissue from the increase in size of its cells.

Question 3

Define hyperplasia

Answer 3

the enlargement of an organ or tissue caused by an increase in number of cells

Question 4

Define neoplasia

Answer 4

New abnormal growth of tissue

Question 5

Define fibrosis

Answer 5

Thickening and scarring of connective tissue typically due to injury

Question 6

Define atrophy

Answer 6

Thinning or loss of muscle tissue via reduction in cell volume or number

Question 7

Define involution

Answer 7

shrinking or return of an organ to a former size as a result of withdrawal of endocrine stimulus

Question 8

Methods of molecular regulation

Answer 8

Activation of enzyme
Down-regulation of enzyme
Increases synthesis
Decreased secretion

Question 9

Function of growth factors

Answer 9

Control cellular adaptation by linking to TFs via secondary messenger systems

Question 10

Give an example of pathological hypertrophy

Answer 10

Hypetrophy of myocardium occurs in hypertensive heart disease

Question 11

Give 2 examples of physiological hyperplasia

Answer 11

Endometrium (uterus lining) during menstrual cycle

Uterus during pregnancy

Question 12

Non-uniform hyperplasia is called ….

Answer 12

Modular hyperplasia

Question 13

Where does nodular hyperplasia typically occur ?

Answer 13

Prostate gland and breasts

Question 14

Briefly describe what happens in the cell stress response

Answer 14

Housekeeping genes switched off

Cell stress genes switched on

Question 15

cell stress proteins

Answer 15

Small cell stress proteins act as molecular chaperones to coordinate destruction of misfolded proteins
Other types of cell stress proteins act within the nucleus

Question 16

Describe the function of ubiquitin

Answer 16

Flags damaged proteins for elimination Via proteosomes

Question 17

Events in cell atrophy

Answer 17

Cytosolic proteolysis via ubiquitin system
Autophagy
Residual brown lipid material - lipfuscin

Question 18

Events in autophagy

Answer 18

Organelles packaged in ER-derived membrane to form autophagic body
Autophagic body fused with lysosome
Organelle hydrolysed back into macromolecules for reuse
Indigestible molecules remain as residual body

Question 19

Cellular changes during apoptosis

Answer 19

Loss of cell junction and rounding of cell
Nuclear/cytoplasmic condensation
Apoptotic cell fragments to form apoptotic bodies
Apoptotic bodies recognised by phagocytes and local cell and internalised and degraded

Question 20

What type of enzymes are controlled by apoptosis

Answer 20

CASPASES

Question 21

During apoptosis, DNA between nucleosomes is cleaved into fragments by

Answer 21

Endonucleases

Question 22

During apoptosis , proteins in cells are cross linked by

Answer 22

Transglutaminases

Question 23

Apoptosis triggers

Answer 23

Surface receptor activation
Plasma membrane damage
Mito membrane damage
DNA damage

Question 24

Cell loss is commonly replaced by

Answer 24

Adipose(body fat) or fibrous tissue

Question 25

Causes of atrophy

Answer 25

Denervation (loss of nerve supply)
Immobilisation 
Reduced endocrine stimulation 
Ischaemia 
Ageing

Question 26

Define hypoplasia

Answer 26

Incomplete growth of organ

Question 27

Define agenesis

Answer 27

Failure of development of organ during embryogenesis

Question 28

Examples of metaplasia

Answer 28

Squamous epithelium to columnar in oesophagus due to acid reflux
Columnar epithelium to squamous in lungs in response to smoking
Transitional epithelium to squamous in bladder in response to stones
Collagenous tissue to osseus tissue(found in bones) in connective tissue in response to trauma

Question 29

Give 3 examples of involution

Answer 29

Breasts after cessation of lactation
Uterus after parturition
Thymus after puberty

Question 30

What are the 3 possible end results post lethal damage

Answer 30

Apoptosis
Liquefaction necrosis
Coagulative necrosis (when there is massive damage)

Question 31

Describe vacuolation in damaged cells

Answer 31

In damaged cells, ion pumps that maintain osmolarity may fail
Water is retained by cell leading to dilated membrane systems
Cell appears pail-stained in a histological slide

Question 32

What is hydropic degeneration

Answer 32

Severe vacuolation due to pathological stimuli

Question 33

Describe fatty change in response to sub-lethal damage

Answer 33

Sub-lethal damage to some cell types may alter the metabolism of the cell, causing it to accumulate triglycerides
This accumulated fat distends the cytoplasm of the cell

Question 34

Give an example of fatty change

Answer 34

In liver in response to excess alcohol intake

Can also occur due to malnutrition, diabetes, hypoxia

Question 35

Describe coagulative necrosis

Answer 35

Some tumuli cause cells to undergo sudden protein coagulation
Stimuli : extreme heat, extreme pH change, sudden anoxia

Question 36

Liquefactive necrosis

Answer 36

Cell death is followed by necrosis :

Pyknosis (shrinking and granulation of nucleus) > karyorrhexis (fragmentation of nucleus) > karyolysis (nucleus no longer present)

Most common form of necrosis

Accompanied by spillage of lysosomal hydrolases into surrounding environment ; proteins released detected in blood