Disorders of growth

Question 1

Examples of disorders of growth

Answer 1

Moles

Too many BVs?

Question 2

Hyperplasia

Answer 2

> in cell numbers
Response to stimulus
Regression once stimulus removed
size and function

Question 3

Endocrine growth control stimulus to hyperplasia

Answer 3

Physiological
-normal growth and development
-puberty and pregnancy
Pathological 
-parathyroids and thyroid

Question 4

Other growth control stimulus to hyperplasia

Answer 4

Chronic irritation/ inflammation

Bone marrow, lymphoid tissue

Question 5

Thyroid hyperplasia

Answer 5

Places in low % of iodine

Pituitary produces more and more thyroid hormone but little iodine so can’t do it

Question 6

Nifedipine

Answer 6

> effect of inflammation on gingival tissue
in fibrous CT underlying epithelium of gingiva
Gingival hyperplasia (teeth sometimes almost not able to be seen)

Question 7

Hyperplasia of tonsil

Answer 7

Lymphocytes divide and expand

Question 8

Hypertophy

Answer 8

> in cell size

Often occurs with hyperplasia

Question 9

Pure hypertophy

Answer 9

Muscle: mechanical stimulus

• skeletal: exercise
• smooth: pregnancy
• cardiac: LVH in hypertension

Question 10

Hypertrophy in relation to heart

Answer 10

Hypertension –> resistance to pumping blood around body
> size of cardiac muscle fibres in left ventricle
Can lead to heart failure

Question 11

Neoplasia

Answer 11

Growth which is uncontrolled & does not

stop and which persists after stimulus is removed

Question 12

Too little tissue

Answer 12

Developmental

• Agenesis (does not develop at all) e.g. wisdom teeth
• Aplasia (fails to develop normal structure so some deficit in function)
• Hypoplasia (less tissue formed)

Question 13

Achondroplasia

Answer 13

Cartilagenous structures in body do not develop properly
Inherited disorder
Hypoplasia

Question 14

Enamel hypoplasia

Answer 14

Can be inherited (every tooth affected)
An effect on single tooth e.g. after knocking front teeth
Hypoplastic mandible and malocclusion

Question 15

Atrophy

Answer 15

< in size after growth

• size and number of cells
• can be physiological - in embryology

Question 16

Mechanisms of atrophy

Answer 16

Imbalance of cell loss and production

• apoptosis
• not necrosis (mostly)
• < in structural components of cell, esp. proteins

Question 17

Generalised atrophy

Answer 17

Nutritional e..g in starvation
Senile e.g. as we grow older we get shorter
Endocrine e.g. maintenance of bone mass by oestrogen
Bone - osteoporosis (reduction in structural density of bone)

Question 18

Nutritional deficiency

Answer 18

Tongue e.g. without papillae - iron deficient. Lacking full development of epithelium

Question 19

Localised atrophy

Answer 19

• Ischaemic
• Pressure e.g. bed-ridden pxs
• DIsuse e.g. if you stop gyming
• Neuropathic/ denervation e.g. damage to nerve supplying muscle
• Immune mediated (autoimmune)
• Idiopathic

Question 20

Ischaemic atrophy in kidney

Answer 20

Partially occluded renal artery –> smaller kidney to cope with reduced amount of oxygen & nutrients

Question 21

Atrophic mandible

Answer 21

In edentulous pxs

Affects retention of denture

Question 22

Alzheimer’s brain

Answer 22

Atrophic

< of white matter

Question 23

Romberg’s disease

Answer 23

Hemifacial atrophy
Not developmental
Affects soft tissue and muscular structures
Not well understoof

Question 24

Metaplasia

Answer 24

Abnormal differentiation

• change from one differentiated tissue to another (within same germinal layer)
• result from changes in environmental demands
• epithelium (mucous or squamous)
• mesenchymal

Question 25

Examples of metaplasia

Answer 25

Bronchi of smokers - columnar pseudostratified squamous cells with goblet cells --> stratifiied epithelium because better barrier, worse at expelling 'rubbish' - Can be first step on route to cancer

Question 26

Gastric metaplasia

Answer 26

In pxs with acid reflex Barrett's esophagus Squamous --> columnar with goblet cells

Question 27

Dysplasia

Answer 27

Abnormal growth & differentiation in a tissue, with abnormal cells & tissue architecture -may be premalignant

Question 28

Ectopia

Answer 28

Developmental abnormality Normal tissue Abnormal site e.g. offset kidney or in orthodontics!

Question 29

Cell stress --> cell death

Answer 29

Cell stress + (dose intensity and cell vulnerability) --> adaptation or injury Structural or metabolic adaptation Structural adaptation --> injury Injury --> reversible --> irreversible (past point of no return) --> cell death

Question 30

Normal cell adaptations

Answer 30

Atrophy Hypertrophy Hyperplasia

Question 31

Hamartoma

Answer 31

Tumour-like overgrowth - grows in px's growth period - stops growing - tissues are normal for site, but excessive - e.g. pigemented naevi (moles), haemangioma