Cell Degranulation

Question 1

Which two types of cell form tissues?

Answer 1

Epithelial

Mesenchymal

Question 2

What is atrophy?

Answer 2

Decrease in the size and number of cells, or a decrease in the size of an organ

Question 3

Give the 4 types of cellular adaptation

Answer 3

Hypertrophy
Hyperplasia
Atrophy
Metaplasia

Question 4

Define what is meant by a cellular adaptation

Answer 4

Achieving a new, altered state due to excessive physiological stresses or pathological stimuli

Question 5

Define the following:

1. Hypoplasia

2. Aplasia

Answer 5

1. Reduced organ volume because of incomplete cell proliferation
2. Organ absence because of defective cell proliferation

Question 6

When does physiological atrophy occur?

Answer 6

• During early foetal development
• Uterus after parturition
• Thymus after puberty
• Age deterioration

Question 7

Give some examples of pathological atrophy

Answer 7

• Disuse of skeletal muscle
• Reduced oxygen blood perfusion
• Inadequate nutrition on skeletal muscle
• Loss of endocrine stimulation in neutered animals
• Loss of innervation
• Ageing

Question 8

What happens to the cells when they are atrophied?

Answer 8

• They are not dead
• There is a reduction of the cellular metabolism
• Reduction of cellular volume

Question 9

What is hypertrophy?

Answer 9

Increase in the size of cells or the size of an organ

• no new cells just larger cells
• no cell division involved

Question 10

When does hypertrophy occur?

Answer 10

When there is an increased functional demand

Response to an increase in nourishment

Question 11

Give 2 examples of physiological hypertrophy

Answer 11

• Smooth muscle cells in a pregnant uterus

- Skeletal muscle cells with training

Question 12

Give an example of pathological hypertrophy

Answer 12

Heart wall muscle thickens due to cardiac myocyte overload

Question 13

Define hyperplasia

Answer 13

Increase in organ volume due to an increased number of cells

- only possible in cells which can divide

Question 14

Give some examples of physiological hyperplasia

Answer 14

Hormonal:
- Proliferation of mammary epithelium during pregnancy
- Proliferation of uterine epithelium during pregnancy
Compensatory:
- Partial hepatectomy

Question 15

Give some examples of pathological hyperplasia

Answer 15

• Excessive hormonal stimulation
• Attempt at regeneration
• Wound healing

Question 16

Define metaplasia

Answer 16

Reversible change

Replacement of one adult cell type with another cell type

Question 17

Give some examples of metaplasia

Answer 17

• Replacement of respiratory epithelium by squamous epithelium
• Reprogramming of stem cells

Question 18

What are the 3 categories of intracellular accumulations?

Answer 18

• Normal cell constituents
• Abnormal substances
• Pigment

Question 19

Give examples of the processes involved that lead to intracellular accumulations

Answer 19

• Normal or increased production but inadequate removal of normal endogenous substances
• Genetic/acquired defect in metabolism, packaging or transport of normal substances
• Deposition of abnormal exogenous substance

Question 20

What is the name for an aggregation of lipids?

Answer 20

Chylomicron

Question 21

Define steatosis

Answer 21

Abnormal accumulations of triglycerides within parenchymal cells

Question 22

What are the causes of lipid accumulation?

Answer 22

• Toxins
• Protein malnutrition
• Diabetes
• Obesity
• Anorexia
• Alcohol abuse

Question 23

How do protein accumulations in a cell usually appear?

Answer 23

Round, eosinophilic droplets, vacuoles or aggregates within the cytoplasm

Question 24

What are the main reasons for protein accumulation?

Answer 24

• Excess protein presented to the cell beyond its cellular metabolism
• Defects in protein folding

Question 25

What are the reasons that protein folding defects may occur?

Answer 25

- Defective intracellular transport and secretion of critical proteins - Toxicity of abnormally folded proteins - Genetic mutations - Ageing - Amyloidosis

Question 26

What are the most common exogenous pigments that can accumulate in the body?

Answer 26

- Carbon - Coal dust - Tattooing

Question 27

Name the 3 most common endogenous pigment accumulations

Answer 27

- Lipofuscin - Melanin - Hemosiderin (storage form of iron) - Bilirubin

Question 28

What condition is caused by an excessive of bilirubin?

Answer 28

Jaundice

Question 29

What is bilirubin converted to at the end of an erythrocyte lifespan?

Answer 29

Bile

Question 30

Where are the different %s of iron found in the body and in what forms?

Answer 30

80% - in haemoglobin, myoglobin and enzymes | 20% - in a storage pool (haemosiderin, ferritin)

Question 31

The level of what can be a used as a good indicator of body iron stores?

Answer 31

Plasma ferritin level

Question 32

What are the 4 components of bile?

Answer 32

- Water - Cholesterol - Bile salts - Bile pigments (bilirubin)

Question 33

What are the 3 causes of jaundice?

Answer 33

- Excessive haemolysis - Severe hepatic injury - Obstructed bile flow

Question 34

What is meant by pathological calcification?

Answer 34

Abnormal deposition of calcium salts

Question 35

What are the 2 pathogenic phases of dystrophic calcification?

Answer 35

Initiation - Intracellular: Ca accumulates in mitochondria of dying cells - Extracellular: Initiated by the phospholipids in membrane bound vesicles Propagation: - Membrane facilitated calcification - Ca binds to phospholipids in membrane which form groups

Question 36

What is metastatic calcification?

Answer 36

Accumulation in normal tissues with hypercalcaemia

Question 37

What is dystrophic calcification?

Answer 37

Local accumulation in dying tissues, areas of necrosis

Question 38

Name 4 causes of hypercalcamia

Answer 38

- Increased parathyroid hormone - Destruction of bone tissue - Vitamin D intoxication - Renal failure

Question 39

What is an amyloid?

Answer 39

A pathological proteinaceous substance deposited between cells

Question 40

Give examples of the most common amyloid proteins seen in veterinary medicine

Answer 40

- AA: synthesised in the liver, no immunoglobulin - AL (amyloid light chain): derived from plasma cells - Beta amyloid protein - Islet amyloid protein - Transthyretin

Question 41

Compare primary and secondary amyloidosis

Answer 41

Primary - associated with immunocytic disorder | Secondary - complication of an underlying chronic inflammation