Disorders of Growth and Differentiation Flashcards
what is an example of physiological hypertrophy?
athletes building muscle
what is an example of pathological hypertrophy?
right ventricular hypertrophy
what are examples of physiological hyperplasia?
- adaption to altitude
- from embryo through puberty to maturity
- pregnancy
- lactation
what are examples of pathological hyperplasia?
psoriasis
- auto-immune
- stimulates proliferation
what are examples of hyperplasia in tissue repair?
- angiogenesis
- wound healing
- liver regeneration
- heart
what are examples of physiological atrophy?
- thymus undergoing regressive alterations with age
- ageing
what are examples of pathological atrophy?
- muscle: fractures
- nerves: paraplegics
- blood supply: circulatory problems
- pressure: bedsores
- diet: anorexia
what is Turner’s Syndrome?
- A.K.A 45, XO
- female is completely/partially missing a chromosome
- short and underdeveloped ovaries
what is Beckwith-Weidemann Syndrome?
- inheriting two copies of a chromosome from one (paternal) parent and none from other
- increased expression IGF-II
- decreased expression of H19
- overgrowth in early childhood
what causes pituitary gigantism?
- increased IGF-1
- increased growth hormone
- often pituitary tumours
in children - gigantism
in adults - increased size hands, feet, jaw, forehead
what is the cause of achondroplasia?
mutation of FGFR3
what is metaplasia?
- change of differentiated cell type
- response altered cellular environment
- often epithelial or mesenchymal cells
- one mature cell type to another (not premalignant)
what are examples of metaplasia?
- epithelium of trachea and bronchi in smokers
what is dysplasia?
- increased cell proliferation
- atypical morphology
- decreased differentiation
- often premalignant
- expansion of immature cells
- disordered proliferation and differentiation
what is neoplasia?
- abnormal uncoordinated excessive cell proliferation
- persists after initiating stimulus withdrawn
what are the different anomalies of organogenesis?
- agenesis
- atresia
- hypoplasia
- ectopia/heterotopia
- maldifferentiation
what is agenesis?
failure to develop an organ or structure
e.g. renal agenesis
what is atresia?
failure to develop a lumen
- oesophageal atresia
- duodenal atresia
- imperforate anus
failure to close
- spina bifida
- cleft palate
what is hypoplasia?
failure of organ to develop to normal size
- may only apply to a segment of an organ
what is ectopia/heterotopia?
small areas of mature tissue from one organ present in another
e.g. endometriosis
what is maldifferentiation?
- failure of normal differentiation
- persistence of primitive embryological features
what is Wilms’ Tumour?
- a developmental malignancy
- can contain cartilage, bone and smooth muscle
what is hypertrophy?
the enlargement of an organ or tissue from the increase in size of its cells
what is hyperplasia?
the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells (often as an initial stage in the development of cancer)
what is accretionary growth?
growth resulting from an increase of intercellular material
what is the result of hyperplasia in tissue repair going too far and becoming harmful?
- hypertrophic scar
- cirrhosis: fibrosis, scar tissue and regenerative nodules
what is achondroplasia?
- bone growth disorder that causes disproportionate dwarfism
- short in stature with a normal sized torso and short limbs
malformation
a primary defect due to abnormal development affecting part of the body or an organ, such as a cleft lip
dysplasia
a primary defect of tissue formation, such as a vascular malformation
sequence
a primary defect that results in secondary structural changes, such as oligohydramnios (reduced amniotic fluid) that leads to growth deficiencies, facial and limb deformities and pulmonary hypoplasia
syndrome
multiple primary malformations with a single cause, such as Down’s syndrome
deformation
change in body shape due to external sources affecting the developing foetus, such as a mechanical force
disruption
a change due to breakdown of an originally normal development, such as a limb not developing properly because a vascular problem has limited the blood flow
