Week 11 Flashcards
1
Q
2 Main Causes of Nephrogenic Diabetes Insipidus
A
Drugs (Lithium)
Rare Genetic Mutation (in AQP2 or ADH receptor)
2
Q
Define Natriuresis (and what hormone stimulates it)
A
ANP
- Natriuresis occurs when there is an increase in blood pressure inhibiting the reabsorption of sodium, hence more sodium is excreted.
3
Q
4 Types of Diabetes Insipidus
A
- Central/ Hypothalamic DI
- Nephrogenic DI
- Gestational DI
4.
4
Q
Discuss Central/ Hypothalamic Diabetes Insipidus
A
Central/ Hypothalamic DI
- Caused by tumour/ brain damage inhibiting the synthesis and release of ADH from the hypothalamus
- Low ADH
- Increase in urine concentration when administered Desmopressin (DDAVP)
5
Q
Discuss Nephrogenic Diabetes Insipidus
A
Nephrogenic Diabetes Insipidus
- Caused by drugs (lithium) or mutation in receptor/ unable to synthesis 2nd messenger/ no AQ2 in the luminal membrane
- High to normal levels of ADH
- No response when administered Desmopressin (DDAVP)
6
Q
3 Symptoms of Diabetes Insipidus
A
- Polyuria (increased diluted urine)
- Polydipsia (increased thirst due to high levels of urine lost)
- No change in glucose/ blood sugar levels and NO Polyphagia
7
Q
Causes of SIADH (3)
A
SIADH (syndrome of inappropriate ADH)
- Ectopic secretion of ADH (e.g. from adenoma or carcinoma in lungs or pancreas)
- Tumour in the CNS
- Drug induced (e.g. with nicotine + morphine + chlopropamide)
8
Q
Consequences of SIADH
A
- Excess water retention
- More water in ECF causing dilutional hyponatremia (CNS symptoms: vomiting, nausea, head ache, confusion, convulsions and sometimes a COMA)
