Disorders of Growth and Differentiation

Question 1

What is the difference between hypertrophy and hyperplasia?

Answer 1

Hypertrophy = growth in cell SIZE
Hyperplasia = growth in cell NUMBER

Question 2

List the stages of the mammary cycle including the pre-cycle stages.

Answer 2

Embryonic
Pre-pubescent
Post-pubescent
Mature
Pregnancy
Lactation
Involution

Question 3

What type of growth is the mammary gland an example of?

Answer 3

Physiological hyperplasia

Question 4

Give an example of pathological hyperplasia.

Answer 4

Psoriasis

Question 5

How is hyperplasia involved in tissue repair?

Answer 5

Angiogenesis
Wound healing
Liver regeneration

Question 6

What is meant by atrophy?

Answer 6

Decreased cell growth, either in number, size or both

Question 7

Give two examples of physiological atrophy.

Answer 7

Age

Thymus - reduction in medulla & cortex

Question 8

Give three examples of pathological atrophy.

Answer 8

Muscle - fractures
Nerve - paraplegics
Blood supply - circulatory problems
Pressure - bedsores
Diet - annorexia

Question 9

What is Turner’s Syndrome?

Answer 9

Missing X chromosome
Only in females
Stunted growth, inability to have children, short and webbed neck & lack of breasts

Question 10

Name a gene that is important in growth and development.

Answer 10

SHOX

Question 11

Where is SHOX expressed in the body?

Answer 11

Chondrocytes

Question 12

What characterises Beckwith Wiedemann Syndrome?

Answer 12

Large tongue
2x copies of paternal chromosome
Decreased H19
IGF 2 increased
OVERGROWTH

Question 13

What is Achondroplasia?

Answer 13

Shortened limbs

Question 14

Does a loss of FGFR3 increase or decrease growth?

Answer 14

Increase

Question 15

What characterises pituitary gigantism?

Answer 15

IGF1 increased
Growth hormone increased
Often results from pituitary tumours

Question 16

Name a few factors that affect determination of differentiation.

Answer 16

Hormones
External factors
Paracrine growth factors
Autocrine factors

Question 17

What is metaplasia?

Answer 17

Change of differentiated cell type

Usually epithelial cells changing to mesenchymal cells or vice versa

Question 18

What is dysplasia?

Answer 18

Increased cell division
Degreased differentiation
Pre-malignant

Question 19

What is neoplasia?

Answer 19

Uncoordinated and excessive cell proliferation that persists even after the stimulus is withdrawn leading to cancer

Question 20

What is genesis?

Answer 20

Failure of an organ to develop during embryonic growth (due to absence of premordial tissue (the 3 germ layers)

Question 21

What is atresia?

Answer 21

The absence of a lumen in a passage of the body, mainly a vessel

Question 22

What is hypoplasia?

Answer 22

Underdevelopment of/incomplete development of an organ (or a tissue)

Question 23

What is an ectopic / a heterotopia?

Answer 23

A small area of mature tissue from one organ present in another

Question 24

What is maldifferentiation?

Answer 24

The failure of normal differentiation and therefore the persistence of primitive embryological features