Cell Growth,injury, Death

Question 1

What is pathology?

Answer 1

The study of structural and functional changes in cells,tissues and organs that underlie disease

Question 2

State different ways cells can grow

Answer 2

Multiplicative growth
Auxetic growth - grow in size
Accretionary growth - shrink in size
Combined pattern of growth

Question 3

List types of cells

Answer 3

Liable cells - always regenerating e.g hemopoietic or epithelial cells
Stable cells- stops at G0 and renters cell cycle after injury e.g hepatocytes renal tubules
Permanent cells- once dead cannot be replaced skeletal/cardiac muscle ,neurons

Question 4

List 5 types of cellular adaptation

Answer 4

Hyperplasia
Hypertrophy
Atrophy
Hypoplasia 
Metaplasia

Question 5

Define hyperplasia and state two causes for adaptation

Answer 5

Increase in number if cells (normal)
Increase growth factor

Physiological - eg hormonal (puberty growth of breast) compensatory ( multiplication of liver if cut)
Pathologic - abnormal hormones (benign prostate hyperplasia), viral (warts) ,

Question 6

What is hypertrophy and state causes

And mechanism

Answer 6

Increase in size of the cell
Causes - high demand , hormones, growth factors

Physiologic - increase in skeletal/cardiac muscle size (does not multiply)
Pathologic - hypertension( cardiac muscle increase)
Mechanism - GF stimulated,vasoactive agents

Question 7

What is atrophy
Causes
Mechanism

Answer 7

(Reversible) Shrinkage of size of the cell due to loss of cell substance without cell actually dying
Causes- physiological- thymus and uterus(with age)
Disuse - loss of type 11 muscles
Loss of innervation- loss of blood supple, nutrition

Question 8

What is the mechanism of atrophy

Answer 8

Mechanism- decreased protein synthesis and increase protein degeneration- ubiquitin protease pathway
Autophagy
Reduced metabolic activity

Question 9

What is Metaplasia?
State types
Give examples

Answer 9

A reversible change in which one adult cell type replaced by another cell type

Types: epithelial & mesenchymal
Epithelial - squamous and columnar

Eg. Respiratory epithelial(smoke causes columnar with squamous which cannot have cilia), Barrett’s esophagus( acid reflux replaces squamous with columnar which is less strong)

Question 10

List some causes of cell injury

Answer 10

Hypoxia - oxygen deprivation is very common cause of cell injury and death
Physical agents (temperature)
Chemical agents and drugs
Infectious agents
Immunologic reactions
Genetic derangement 
Nutritional imbalance

Question 11

Cellular injury

Answer 11

Loss of oxygen causes these cellular injury

ATP depletion
Oxygen derive free radicals
Loss of calcium homeostatasis
Defects in membrane permeability( electrolyte imbalance)
Irreversible mitochondrial damage(less ATP)

Question 12

State how cell injury can lead to ER swelling, cellular swelling, loss of microbiology and blend

Answer 12

Blockage causes decreased oxygen
Decrease oxygen leads do decrease oxidative phosphorylation
Dec. OP causes dec. in Na pumps
Dec. Na causes higher influx of Na, Ca and H2O

Question 13

Describe how cell injury can lead to clumping of nuclear chromatins

Answer 13

Dec. OP
Dec. ATP
Inc. anaerobic glycolysis
Dec. glycogen , inc. lactic acid.. dec. ph

Question 14

How does cell injury affect lipid deposition

Answer 14

Dec OF
Dec ATP
Detachment of ribosomes
Dec protein syntheses

Question 15

State the types of cell injury

Answer 15

Normal homeostasis - normal physiological demands
Reversible cell damage- pathologic changes may be reversed once stimulus is removed
Irreversible cell damage- irreversible changes to structure and function
Virus induced cell injury

Question 16

What is necessary for reversible injury to take place

State morphology of reversible cell injury

Answer 16

Oxygen must be present
Cellular swelling - hydronic or vacuoles change if there is a formation of vacuoles

Intracellular accumulation-
Of normal cellular constituents eg. TAG in fatty liver
Of abnormal substance - product of abnormal metabolism
Of a pigment

Depending on intensity and time can become irreversible

Question 17

What morphological changes occur in irreversible cell injury?

Answer 17

Mitochondrial dysfunction - influx of Ca
Membrane damage - degradation of phospholipid membrane, cytoskeletal damage, toxic free radicals
Hydrolytic enzymes and release

Question 18

State the differences between reversible and irreversible cell injury adaptive response, cell membrane function, global cellular response, mitochondria and nucleus response

Answer 18

Reversible cell injury- adaptive response of cell intact and balance injury, sodium potassium pumps malfunctions(electrolyte imbalance), swelling increase fat storage, swelling, rare fraction and lipid accumulation in mitochondria, aggregation of fibulae nuclear elements

Irreversible cell injury- adaptive response exceeded cannot restore, cell membrane starts to degrade, loss of cellular permeability(toxin formation, swelling leakage of cytochrome c into cytoplasm, dissolution of chromatin

Question 19

Fb

Answer 19

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Question 20

List the two important cell death

Answer 20

Apoptsis - expends energy to commit suicide eg embryogenesis
Necrosis- morphological changes that causes cell death (dead cells in living tissue and has INFLAMMATORY response)

Question 21

List types of necrosis

Answer 21

Coagulation necrosis- changes in nuclear shape
Liquefaction necrosis- inflammation from infection
Caseous necrosis- related to tb (cheese appearance)
Fat necrosis - acute inflammation affecting adipoctyes such as enzymatic (pancreas) or non enzymatic (breast)
Dry gangrene necrosis- diabetic with cut on foot
Wet gangrene necrosis- bacteria block blood vessels to prevent immune system meeting tissue

Question 22

State the two types of calcification and describe

Answer 22

Metastatic calcification- calcium deposits in previously normal tissue
Dystrophic calcification occurs in previously damaged tissue