Lecture 2 - response to cellular strength

Question 1

What state are labile cells

Answer 1

Cells constantly multiplying

Question 2

What state are stable cells

Answer 2

Only multiply when needed

Question 3

What state are quiescent cells

Answer 3

Cells retain the ability to proliferate (reversible state)

Question 4

What are the 3 main causes of cellular stress

Answer 4

Oxygen deprivation (hypoxia)
Physical trauma
Chemical trauma

Question 5

What are the types of oxygen deprivation (hypoxia)

Answer 5

Ischemia - most devastating cause (restriction of blood)
Hypoxic hypoxia - insufficient O2 to the lungs -> insufficient blood to the body
Anaemic hypoxia - decreased haemoglobin conc. (decreased or delayed RBC production)
Ischaemic hypoxia - inadequate blood to tissue (generalised heart failure, local vessel obstruction, arteriosclerosis, infarctions)

Question 6

What types of physical trauma cause cellular stress

Answer 6

Mechanical
thermal (hypo, hyper)
Electrical
radiation (damages DNA)
Changes in atmospheric pressure (blast injury and decompression sickness)

Question 7

What are the types of chemical chemical trauma

Answer 7

Hypertonicity (glucose), poisons, strong acids/alkalis, environmental pollutants and recreational drugs
(increased temp, increased water consumption, cell swells bursts and dies)

Question 8

Describe helicobacter pylori

Answer 8

in upper GI tract of 50-75% of people - linked to gastric ulcers (neutralises acid of stomach and damages epithelial cells)

Question 9

What are the immunological agents of Helicobacter pylori

Answer 9

Hypersensitivity reactions - allergies and autoimmunity
Anaphylactic reaction - allergic response to allergen

Question 10

what are examples of point mutations

Answer 10

Sickle cell anaemia
INDELS
trinucleotide repeat mutations

Question 11

Give an example of an autosomal dominant disorder

Answer 11

Huntington’s disease - repeat of CAG in HD gene (35 copies) - gain of function, increased num. of repeats (earlier age of onset), loss of medium spiny striatal neurons that normally dampen motor activity

Question 12

What is an example of autosomal recessive disorder

Answer 12

Cystic fibrosis

Question 13

What is an example of an X-linked disorder

Answer 13

Duchenne’s muscular dystrophy

Question 14

Describe thalassemia

Answer 14

Inherited mutations that decrease alpha or beta-globin synthesis rate -> haemoglobin deficiency

Question 15

Describe effects of nutritional imbalances

Answer 15

Deficiency of nutrients (protein, minerals, vitamins)
Excess of nutrients (carbohydrates, fat, vitamins, minerals)

Question 16

What is hypertrophy

Answer 16

Increase in size of individual cells - accumulation of protein (not cellular fluid), increased work load (heart and kidney susceptible)

Question 17

What is hyperplasia

Answer 17

Increased number of cells (increased rate of cellular division - can lead to cell death)
Compensatory - enables certain organs to regenerate
Hormonal - oestrogen dependent organs (excessive hormone response)

Question 18

What is metaplasia

Answer 18

Reversible replacement from one mature cell type to another
(less differentiated) - Barrett’s oesophagus

Question 19

What is atrophy

Answer 19

Reduction in cell size (decreased protein synth. and increased protein degradation) -> organ shrinkage, cell changes
(decreased workload, blood supply, nutrition, hormonal stimulation and aging)

Question 20

Describe poliomyelitis

Answer 20

damage to anterior hon of motor neurons causes atrophy of limbs - loss of nerve innervation

Question 21

Describe reversible injury

Answer 21

Able to be repaired - cellular swelling (failure of ATP dependent ion pumps in plasma membrane)
- fatty change (lipid vacuoles in cytoplasm)