FAST REVISION — HP-07 Chemical Coordination & Integration
TOP 5 NEET TRAPS (memorise first):
- ADH and oxytocin → synthesised in HYPOTHALAMUS, stored in posterior pituitary
- Acromegaly (adult GH excess, no height increase) ≠ Gigantism (child GH excess, height increase)
- Calcitonin (thyroid C-cells) LOWERS Ca2+; PTH (parathyroid) RAISES Ca2+
- Type 1 DM = autoimmune β-cell destruction; Type 2 = insulin resistance (different mechanisms)
- Goitre = enlarged thyroid; can be hypo (iodine deficiency) OR hyper (Graves') — check hormone levels
MNEMONIC BANK:
- Anterior pituitary: FLAT PG = FSH, LH, ACTH, TSH, Prolactin, GH
- Adrenal cortex: GFR = Salt-Sugar-Sex = Glomerulosa (aldosterone), Fasciculata (cortisol), Reticularis (androgens)
- Diabetes: Type 1 = 1mmune, Young, Absent; Type 2 = 2 much resistance, Older
ANTAGONISTIC PAIRS (blood glucose, calcium, volume):
| Parameter | Lowers | Raises |
|---|---|---|
| Blood glucose | Insulin (β-cells) | Glucagon (α-cells) |
| Blood calcium | Calcitonin (thyroid) | PTH (parathyroid) |
| Blood volume | ANF/ANP | ADH + Aldosterone |
DISORDERS QUICK TABLE:
| Disorder | Hormone | Hypo/Hyper | Key Sign |
|---|---|---|---|
| Pituitary dwarfism | GH | Hypo | Proportionate short stature, child |
| Gigantism | GH | Hyper | Excessive height, child |
| Acromegaly | GH | Hyper | Enlarged extremities, adult |
| Cretinism | T3/T4 | Hypo | Stunted growth + mental retardation, child |
| Myxoedema | T3/T4 | Hypo | Puffy face, low BMR, adult |
| Graves' disease | T3/T4 | Hyper | Exophthalmos, weight loss |
| Simple goitre | T3/T4 | Hypo | Enlarged thyroid, iodine deficiency |
| Addison's | Cortisol/Aldosterone | Hypo | Dark skin, hypoglycaemia, low BP |
| Cushing's | Cortisol | Hyper | Moon face, buffalo hump, hyperglycaemia |
| DM Type 1 | Insulin | Absent | Hyperglycaemia, young, autoimmune |
| DM Type 2 | Insulin | Resistance | Hyperglycaemia, adult, obese |
| Diabetes insipidus | ADH | Hypo | Massive dilute urine, normal glucose |
| Tetany | PTH | Hypo | Hypocalcaemia, muscle spasms |
| Conn's syndrome | Aldosterone | Hyper | Hypertension, hypokalaemia |
HORMONE MECHANISM IN 5 WORDS:
- Peptide hormones: Surface receptor → cAMP → phosphorylation
- Steroid hormones: Cross membrane → nuclear receptor → transcription
NEGATIVE FEEDBACK RULE:
- End hormone HIGH → upstream signals LOW (suppressed)
- End hormone LOW → upstream signals HIGH (compensatory)
- If TSH HIGH + T4 LOW → Primary hypothyroidism (thyroid failing)
- If TSH LOW + T4 LOW → Secondary hypothyroidism (pituitary failing)