Cell fate and Injury

Question 1

Cell injury lethal vs sublethal

Answer 1

Lethal: produces cell death

Sublethal: produces injury not amounting to cell death may be reversible or progress to cell death

Question 2

Causes of cell injury

Answer 2

Oxygen deprivaiton

Chemical agents - drug

Infectious - microbiology

Immunological reactions -

Genetic defects

Nutritional imbalances

Physical agents - trauma, radiation

Aging - increasing number of changes in cells

Question 3

What is infarction

Answer 3

Cell death due to ischemia

Question 4

How do cells respond to injurious stimuli

Answer 4

Type of injury

Duration

Severity

Question 5

What do the consequences of injurious stimulus depend on

Answer 5

Type of cell - more resilient

Status - low metabolic rate, more proliferation

Question 6

What are four intracellular systems that are particularly vulnerable during cell injury

Answer 6

Cell membrane integrity

ATP generation

Protein synthesis

Integrity of the genetic apparatus

Question 7

Why is it important to know that cellular function is lost before cell death

Answer 7

Morphological changes may not be seen

Question 8

What is atrophy

Answer 8

Shrinkage in the size of cell or organ by the loss of substance

Question 9

Atrophic brain

Answer 9

Advanced dementia

Question 10

What is hypertrophy

Answer 10

Increase in size of cells and increase in size of organ

Physiological - normal healthy people process

Pathological - disease process

Increase in functional demand or specific hormonal stimulation

Question 11

What are examples of physiological Hypertrophy

Answer 11

Increase in size of uterus during pregnancy

Question 12

Hyperplasia

Answer 12

Increase in the number of cells in an organ

Physiological hyperplasia - hormonal or compensatory

Pathological hyperplasia - Excessive hormonal or growth factor stimulation

Question 13

What is an example of physiological hyperlasia

Answer 13

Proliferative endometrium

Question 14

What is an example of pathological hyperplasia

Answer 14

Carcinoma

Question 15

Metaplasia

Answer 15

A reversible change where one adult cell type is replaced by another

May be physiological/pathological

Question 16

Physiological metaplasia

Answer 16

Cervix

Squamous outside columnar inside

Columnar turns into squamous during pregnancy

Question 17

What is a pathological metaplasia

Answer 17

Barrett’s Oesphagus

Columnar lined oesophagus - normally lined by non-keratinizing squamous

Due to acid reflux

Question 18

What is dysplasia

Answer 18

Precancerous cells which show the genetic and cytological features or malignancy but do not invade underlying tissue

Question 19

Dysplasia associated with Barrett’s oesphagus

Answer 19

Nucleus is darker and more pronounced

Nucleic cytoplasmic ratio has increased

Question 20

Light Microscopic Changes associated with reversible injury

Answer 20

Fatty change, cellular swelling

Degenerative chagnes e.g. changes associated with cell and tissue damage

Question 21

Alcoholic fatty changes

Answer 21

Reversible once you stop drinking alcohol

Question 22

What is ballooning degeneration

Answer 22

Strand of cytoplasm

Damage to cytoskeleton of hepatocyte

Proteins accumulate causing cells to swell

Question 23

What is necrosis

Answer 23

Confluent cell death associated with inflammation

Question 24

What is coagulated necrosis

Answer 24

Structure become fixed

E.g. myocardic infarction

Question 25

What is liquefactive

Answer 25

Tissue become liquified Old cerebral infarct - liquified brain

Question 26

What is caseous necrosis

Answer 26

Pulmonary TB Cheesy-oozy area

Question 27

What is fat necrosis

Answer 27

Acute pancreatitis Digestive enzymes activated in pancrease - digest tissue Lipase will digest fat - free fatty acid bind to calcium and make them into comparments

Question 28

What is the difference between apoptosis and necrosis

Answer 28

Dead cell due to apoptosis - dense becomes it becomes concentrated, shrunked, bits of nuclei shed Inflammatory reaction in necrosis Apoptosis - compartmentalised

Question 29

How is the inflammatory reaction apoptosis vs necrosis

Answer 29

Apoptosis - controlled Necrosis - not controlled

Question 30

What are teh causes of apoptosis

Answer 30

Embryogenesis - solid intestine into lumen Deletion of auto-reactive T cells in thymus Homrone dependent physiological involution - mensturation Cell deletion in proliferating - how cells die Mild injurious stimula that cause ireeparable DNA, suicide pathways

Question 31

What are the difference between apoptosis and necrosis

Answer 31

Apoptosis may be phsyiological Apoptosis is an active energy dependent process - maintain cell integrity and package cell Not associated with inflammation

Question 32

What is necroptosis

Answer 32

Energy dependent But you get inflammation and necrosis Causes include viral infections