Pathophysiology Of Conditions

Question 1

Rickets, osteomalacia

Answer 1

Vit D deficiency causes improper ossification and the formation of a pliable matrix called osteoid. Long bones are unable to bear weight normally and bend, more prone to fractures.

Question 2

Psoriasis

Answer 2

• genetic component w an environmental trigger (eg infection)
• increased rate of turnover of epidermis 3-7 days rather than the normal 28 days
• extreme proliferation of basal layer, thickened spinous layer, lost granular layer that disrupts cornfield layer, parakeratosis

Question 3

Ehlers-Danos syndrome (some types are autosomal D, autosomal r)

Answer 3

Heterogeneous group of heritable CT disorders characterised by articular Hypermobility, skin extensibility and tissue fragility. Affects skin, joints, ligaments and blood vessels.

Due to mutation that causes defects in collagen - collagen types 1, 3, 5 or lysyl oxidase deficiency (makes cov bonds btw lysine residues on tropocollagen subunits)

Question 4

Dystrophic epidermolysis bullosa

Answer 4

Mutation in collagen VII

Reduced dermal-epidermal integrity leads to blistering.

Question 5

OI

Answer 5

Autosomal dominant mutation in gene that produces type 1 collagen.
8 types of OI

Question 6

Ectopic pregnancy

Answer 6

Implantation of blastocyst in improper location - peritoneal cavity, ovary - rather than posterior uterine wall

Question 7

Hereditary haemochromatosis (bronze diabetes).

Answer 7

• haemosiderin (Fe storage molecule) forms due to Fe overload
• eg. Haemolytic anaemia, liver disease
• builds up in skin, liver, hear, pancreas and endocrine organs
• causes liver scarring (cirrhosis) and pancreatic damage
• damage to pancreas —> impaired insulin sec and diabetes
• accumulation in skin —> bronze