Growth Disorders

Question 1

What are disorders of too little growth?

Answer 1

agenesis (aplasia)
atresia
hypoplasia

Question 2

What is agenesis?

Answer 2

failure of development of a organ or a structure within an organ

Question 3

What is atresia?

Answer 3

failure of development of a lumen in a tubular epithelial structure

Question 4

What is hypoplasia?

Answer 4

less tissue formed, normal structure

Question 5

What are disorders of too much growth? (hamartoma disorders)

Answer 5

pigmented naevi (moles)
haemangioma
lymphangioma
odantoma (dental hard tissues)

Question 6

When do hamartoma disorders occur in a person’s life?

Answer 6

only during growth period but excessively

Question 7

What is haemangioma?

Answer 7

excessive growth of blood vessels - usually present at birth mostly in the head and neck area

Question 8

What syndrome is haemangioma a part of?

Answer 8

Sturge-Weber Syndrome

Question 9

What can haemangioma present as?

Answer 9

Capillary – made up of tiny capillaries

Cavernous – large blood filled spaces

Question 10

What is lymphangioma?

Answer 10

excessive growth of lymph vessels

Question 11

What does lymphangioma mostly present as?

Answer 11

Cavernous - large lymph fluid filled spaces

Question 12

What is the commonest area for lymphangioma to occur?

Answer 12

tongue

Question 13

What is lymphangioma from birth called?

Answer 13

cystic hygroma

Question 14

What is naevus?

Answer 14

a mole
large amount of melanocytes present in the dermis

Question 15

What is ectopia?

Answer 15

normal tissue in abnormal location

Question 16

What are examples of ectopia and what tissue are they?

Answer 16

Mickel’s diverticulum, an outpouching of the small intestine.
Gastric type tissue in SI

Fertilised egg in Fallopian tube instead of uterus

Teeth in palate

Question 17

What are acquired growth disorders?

Answer 17

adaptation of cells to environmental stress - not always reversible

Question 18

What are examples of acquired growth disorders?

Answer 18

atrophy
hypertrophy
hyperplasia
metaplasia
dysplasia

Question 19

What is atrophy?

Answer 19

reduction in size and number of cells

Question 20

What is an example of physiological atrophy?

Answer 20

ageing under hormonal influence (menopause)

Question 21

What is cellular atrophy?

Answer 21

reduction of organelles of a cell

Question 22

What is organ atrophy?

Answer 22

cell loss is larger than cell production - may be caused by apoptosis

Question 23

What are reasons localised atrophy may happen?

Answer 23

• ischaemic
• pressure (tumours)
• disuse/ denervation (immobile for long period)
• autoimmune
• idiopathic

Question 24

What are reasons generalised atrophy may happen?

Answer 24

• Inadequate nutrition
• senile (ageing - cell loss ^)
• endocrine

Question 25

What happens in mandible atrophy?

Answer 25

mental foramen and mental nerve get closer to alveolar ridge as mandible recedes

Question 26

Why can osteoporosis occur?

Answer 26

menopause, ageing, physical activity, corticosteroids

Question 27

What effect does oestrogen have on osteoclasts?

Answer 27

inhibits effect

Question 28

What happens to oestrogen after menopause?

Answer 28

decreases therefore increased oestoclast activity

Question 29

What is hyperplasia?

Answer 29

increase in cell numbers resulting in increased tissue size and function

Question 30

What cell types can become hyper-plastic?

Answer 30

labile and stable

Question 31

What can cause gingival hyperplasia?

Answer 31

medications (anti-epileptic) in combination with poor oral hygiene

Question 32

What cell is proliferated in gingival hyperplasia?

Answer 32

fibroblasts

Question 33

What are causes of pathologic hyperplasia and what are examples of each?

Answer 33

- endocrine (hormonal) stimulation by hormone producing organs hyperplasia of target organs - benign prostatic hyperplasia - chronic injury and inflammation stimulated by inflammatory cytokine - growth factors hyperplasia of bone marrow and lymphoid tissue - HPV can induce hyperplasia of epithelium

Question 34

What is controlled hyperplasia?

Answer 34

regresses when stimulus is removed

Question 35

By which mechanisms can hyperplasia occur?

Answer 35

* Growth factor-driven proliferation of cells * Increased output of cells from stem cells.

Question 36

What is an example of beneficial hyperplasia?

Answer 36

liver regeneration

Question 37

What is hypertrophy?

Answer 37

increased cell size due to intracellular components

Question 38

What does hypertrophy often occur with?

Answer 38

hyperplasia

Question 39

Where is pure hypertrophy seen?

Answer 39

in cells with poor division (mitotic) ability muscle

Question 40

When is muscle hypertrophy pathologic and when is it physiological?

Answer 40

* skeletal–exercise (physiologic-increased function) * smooth–pregnancy (physiologic-hormones) * cardiac – LVH in hypertension (pathologic)

Question 41

In ventricular hypertrophy, what does the increased workload of BP cause?

Answer 41

increased number myofilaments in a myocyte

Question 42

When cell death occurs in cardiac muscle what does this cause?

Answer 42

infarction

Question 43

What causes goitre? (hypertrophy of the thyroid gland)

Answer 43

iodine deficiency

Question 44

What does iodine deficiency cause and why does this cause hypertrophy?

Answer 44

decreased synthesis of thyroid hormone compensatory increase in thyroid stimulating hormone thyroid follicular cell hypertrophy and hyperplasia together

Question 45

What is metaplasia?

Answer 45

change from one type of tissue to another (e.g. squamous > columnar)

Question 46

Why does metaplasia occur?

Answer 46

adaptive to changes in environmental demands (e.g. trauma)

Question 47

What are the common epithelium changes that occur?

Answer 47

changes to squamous as withholds more trauma and mucous

Question 48

What are the mesenchymal changes that can occur?

Answer 48

osseous (calcification)

Question 49

What are examples of metaplasia?

Answer 49

* in smokers : ciliated columnar epithelium to squamous (squamous metaplasia) * Barrett’s oesophagus : squamous to columnar (columnar metaplasia)

Question 50

What is dysplasia?

Answer 50

disordered growth that has potential for malignant change

Question 51

Where is dysplasia mostly seen?

Answer 51

epithelia

Question 52

What is neoplasia?

Answer 52

an abnormal mass of tissue with excessive growth uncoordinated with that of normal tissues persists after the provoking stimulus is removed

Question 53

What does neoplasia include?

Answer 53

benign and malignant tumours