Cell adaptation

Question 1

What are the 3 ways cells react to injury?

Answer 1

Adaptation - new physiological state
Injury - sublethal state
Cell death - not capable of recovering

Question 2

What causes cells to adapt into a new physiological state?

Answer 2

Prolonged stimulus, e.g.
Excessive physiological stress
Pathological stimuli

Question 3

Cellular adaptation affects growth/differentiation of cells. What can it cause?

Answer 3

Atrophy
Hypertrophy
Hypoplasia
Hyperplasia
Aplasia 
Metaplasia

Question 4

What is atrophy?

Answer 4

Decrease in size and number of cells and organ

Question 5

Atrophy can be pathological. Give an example of when pathological atrophy might occur

Answer 5

Disuse of muscle e.g. due to fraction
Reduce organ perforation
Inadequate nutrition
Compression

Question 6

Why does atrophy occur after disuse/reduced perforation/other pathological causes?

Answer 6

Decreased metabolism
Reduced organelles
Reduced cell volume

Question 7

What disassembles non-required/damaged organelles?

Answer 7

Autophagic vacuoles

Contains lysozymes

Question 8

Give examples of when involution or physiological atrophy may occur

Answer 8

To uterus after parturition

Thymus after puberty

Question 9

What is hypoplasia?

Answer 9

Decreased organ volume due to incomplete cell proliferation (less cells)

Question 10

What is aplasia?

Answer 10

Organ absence due to defective cell proliferation

Question 11

What is hypertrophy?

Answer 11

Increased organ size due to increased size of cells

Question 12

What causes hypertrophy?

Give examples of when this might occur

Answer 12

Increased functional demand
Can be physiological e.g. muscle in body builders
Can be pathological e.g. cardiomyocytes with overload

Question 13

What is hyperplasia?

Answer 13

Increased organ size due to increased number of cells

Question 14

What causes cell number to increase in hyperplasia?

Answer 14

Cells undergo mitosis in response to hormones and growth factors

Question 15

Hyperplasia can be physiological. Give examples of the 2 types of physiological hyperplasia

Answer 15

Physiological hyperplasia - hormonal e.g. mammary glands during pregnancy
Compensatory hyperplasia - loss of parenchyma

Question 16

Give examples of what can cause pathological hyperplasia

Answer 16

Excessive hormonal stimulation/growth factors on target cells
E.g. attempt of regeneration, viral infections like papilloma

Question 17

What is metaplasia?

Answer 17

Stem cells reprogram themselves to another mature cell type

Or differentiated cells transform to another differentiated cell

Question 18

Is metaplasia permanent or reversible?

Answer 18

Reversible

Question 19

Give an example of metaplasia

Answer 19

Replacement of respiratory epithelium to squamous epithelium due to irritation

Question 20

What are intracellular accumulations? What is it due to?

Answer 20

Accumulations of various substances in abnormal amounts

Metabolic abnormalities in cell

Question 21

What processes cause cause intracellular accumulation?

Answer 21

Normal production but increased removal of endogenous substances
Transport of normal endogenous substances
Abnormal exogenous substances

Question 22

What are the 3 categories of intracellular accumulation?

Answer 22

Normal cell constituents (water, lipid, protein, carbs)

Abnormal exogenous and endogenous substances

Question 23

What is lipidosis?

Answer 23

Abnormal accumulation of triglycerides in parenchymal cells (liver)

Question 24

What does lipidosis cause?

Answer 24

Toxin production
Protein malnutrition
Diabetes
Obesity

Question 25

What morphological changes happen to the liver during lipidosis? What causes the swelling?

Answer 25

Liver turns yellow Becomes fatty, oily and swollen Swelling due to large vacuoles in adipocytes

Question 26

What happens to free fatty acids from intestines and adipose tissue?

Answer 26

Chylomicrons transport them in the blood | Stored as lipoproteins for use in other cells

Question 27

What causes protein accumulation? (2 main ways)

Answer 27

1. Excess synthesis, excess protein presented to cell, reabsorption in renal tubules, excessive amounts of secretory protein 2. Defects in protein folding

Question 28

What may cause defects in protein folding?

Answer 28

``` Genetic mutation Aging Environmental factors Amyloidosis TSE ```

Question 29

Excess protein can be caused by excess amounts of secretory proteins. Give an example of a secretory protein

Answer 29

Russell bodies in plasma cells

Question 30

What causes an abnormal accumulation of glucose/glycogen?

Answer 30

Diabetes Glucocorticoid hepatopathy Glycogen storage diseases

Question 31

When might there be an accumulation of calcium salts? Does this affect calcium serum levels?

Answer 31

Non-viable, dying or necrotic tissues | Calcium serum remains normal

Question 32

What is dystrophic calcification?

Answer 32

Abnormal deposition of calcium due to tissue damage

Question 33

What process happens to normal tissues with hypercalcaemia?

Answer 33

Metastatic calcification

Question 34

What are the 2 phases of pathogenesis for dystrophic calcification?

Answer 34

1. Initiation - calcium accumulates in mitochondria of dying cells and phospholipids in vesicles of dying cells 2. calcium binds to phospholipids high causes calcium depolarisation. Microcrystals perforate membrane

Question 35

Abnormal substances can accumulate due to exogenous or endogenous causes. Give examples of each

Answer 35

Exogenous - mineralas, products of infectious agents | Endogenous - abnormal synthesis/metabolism

Question 36

What causes pigmentation in normal cells? What colour is this and what cells is it found in?

Answer 36

Melanin Brown/black Melanocytes

Question 37

Pigmentation can be normal or abnormal. Give examples of when pigmentation can be exogenous or endogenous

Answer 37

Exogenous -anthrax causes inhalation of carbon | Endogenous - melanin, haemosiderin, bilirubin

Question 38

What colour is lipofuscin? What is this?

Answer 38

Yellow/brain | Endogenous polymer of lipids and proteins

Question 39

What is haemosiderin? What colour is it?

Answer 39

Stores iron from the breakdown of haem | Gold colour

Question 40

What is heme broken down into to? Where is the iron stored?

Answer 40

Iron and biliverdin | Stored in haemosiderin

Question 41

What is bilirubin? What is jaundice?

Answer 41

Major pigment in bile | Excess bilirubin in blood

Question 42

Haem is broken down into biliverdin and iron. What happens to the iron?

Answer 42

Oxidised and stored in haemosiderin

Question 43

Haem is broken down into biliverdin and iron. What happens to the biliverdin?

Answer 43

Biliverdin broken down by macrophages/monocytes to bilirubin Bilirubin becomes bilirubin glucoronides in liver Becomes urobilinogens

Question 44

What colour is biliverdin? What about bilirubin?

Answer 44

Biliverdin - green | Bilirubin - blue/green

Question 45

What colour is bile? Jaundice is due to high bilirubin in blood (bilirubinaemia). What causes this?

Answer 45

Yellow/green | Obstructed bile flow, excessive haemolysis

Question 46

What does bile contain?

Answer 46

Water Choletserol Bile sals Bile pigments from haemoglobin (bilirubin)

Question 47

What is amyloidosis?

Answer 47

Abnormal build up of amyloid in organs and tissues

Question 48

What is amyloid? What does it look like histologically?

Answer 48

Pathological protein deposited between cells | Soft, pink, fluffy

Question 49

Where is amyloid associated protein synthesised? Does it contain Ig?

Answer 49

Hepatocytes | No Ig

Question 50

What is amyloid light chain derived from? Does it contain Ig?

Answer 50

Plasma cells | Contains Ig

Question 51

What disease cause deposition of beta amyloid protein?

Answer 51

Spongiform encephalopathies

Question 52

Where is islet amyloid polypeptide deposited?

Answer 52

Pancreatic islets

Question 53

Amyloidosis can be classed as systemic, localised, primary, secondary, hereditary or endocrine. What causes primary and secondary amyloidosis? What is endocrine amyloidosis?

Answer 53

Primary - immunocytic disorder Secondary - complication of amyloid associated chronic inflammation Endocrine - deposition of islet amyloid polypeptide

Question 54

What is the most common type of amyloidosis - localised or systemic? Primary or secondary?

Answer 54

Systemic | Secondary