Master Index: Endocrinology Study Guide
I. Command & Control: The Hypothalamus & Pituitary
● Anatomy & Physiology: The Hypophyseal Portal System, Pulsatility vs.
Continuous Signaling (GnRH).
● The Anterior Pituitary: Prolactin, GH, TSH, ACTH, and LH/FSH.
● The Posterior Pituitary: ADH (Vasopressin) and Oxytocin (The Let-Down
Reflex).
● Pathology:
○ Sheehan Syndrome: Postpartum Necrosis & The "Empty Sella."
○ Pituitary Adenomas: Prolactinoma, Acromegaly, and Bitemporal
Hemianopsia.
○ Diabetes Insipidus: Central vs. Nephrogenic (Water Deprivation Test).
○ Pituitary Apoplexy: The "Thunderclap" Emergency.
II. Metabolism & Energy: The Pancreas & Appetite
● Glucose Regulation: Insulin vs. Glucagon, The "Honeymoon Phase" in T1DM.
● Diabetes Mellitus:
○ Pathophysiology: DKA (Kussmaul breathing, Anion Gap) vs. HHS.
○ Phenomena: Somogyi Effect vs. Dawn Phenomenon.
○ Pharmacology: Metformin, Sulfonylureas, and the Incretin Effect.
● Appetite Mastery: Ghrelin (The Gas) vs. Leptin (The Brake), Leptin
Resistance.
● Tumors: Insulinoma (Whipple Triad), VIPoma (WDHA Syndrome),
Glucagonoma (NME Rash).
III. The Stress & Salt Axis: The Adrenal Glands
● Anatomy: The GFR Layers (Salt, Sugar, Sex).
● Hypercortisolism: Cushing Disease vs. Cushing Syndrome, Ectopic ACTH.
● Adrenal Insufficiency: Addison’s Disease (Hyperpigmentation) vs. Secondary
Failure.
● Mineralocorticoids: Conn’s Syndrome (Primary Hyperaldosteronism) &
RAAS.
, ● The Medulla: Pheochromocytoma (The 5 P's & The "Alpha-Before-Beta"
Rule).
IV. Growth & Minerals: Thyroid & Parathyroid
● Thyroid Disorders:
○ Hyper: Graves’ Disease (TSI antibodies, Exophthalmos), Thyroid
Storm.
○ Hypo: Hashimoto’s Thyroiditis, Myxedema Coma.
○ Cancer: Papillary (Orphan Annie Eye) vs. Medullary (Amyloid/RET).
● Calcium Homeostasis:
○ PTH & Vitamin D: The Calcium/Phosphate see-saw.
○ Imbalances: Hypercalcemia (Stones, Groans, Bones) vs. Hypocalcemia
(Chvostek/Trousseau).
V. Reproductive & Gestational Endocrinology
● Pregnancy Physiology: Human Placental Lactogen (hPL) and hCG.
● Gestational Diabetes (GDM): Fetal Macrosomia and Neonatal Hypoglycemia.
● Polycystic Ovary Syndrome (PCOS): Insulin resistance and SHBG levels.
VI. Multi-System Syndromes (MEN)
● MEN Type 1: The 3 P's (Pituitary, Parathyroid, Pancreas).
● MEN Type 2A/2B: RET mutations, Medullary Thyroid Cancer, and Marfanoid
Habitus.
,Endocrinology is essentially the body's wireless communication system. It’s high-
yield because once you master the "wiring" (the pathways), the "short circuits" (the
pathologies) become much easier to predict.
1. Adrenal Steroidogenesis: The High-Stakes Factory
, The adrenal cortex is organized into three layers—Glomerulosa, Fasciculata, and
Reticularis (mnemonic: GFR). Each layer produces a specific type of hormone: Salt,
Sugar, Sex.
The Pathway
Everything starts with cholesterol. The key to understanding the deficiencies is
knowing which direction the pathway flows. If an enzyme is blocked, the precursors
"leak" into the next available open pipe.
Congenital Adrenal Hyperplasias (CAH)
These are enzymatic "dam removals." If a path is blocked, the body overproduces
what it can still make.
Enzyme Mineralocorticoid Cortisol Androgens Clinical Clues
Deficiency s (Aldosterone) (Testosterone
)
21- ↓ (Low BP, High ↓ ↑↑ Virilization in
Hydroxylase K+) females; "Salt-
(Most wasting" crisis
Common) in infants.
11$\beta$- ↓ (but 11- ↓ ↑ HTN (due to
Hydroxylase deoxycorticoster precursor
one ↑) buildup) +
Virilization.
17$\alpha$- ↑ ↓ ↓ HTN + Lack of
Hydroxylase secondary sex
characteristics
(delayed
puberty).
I. Command & Control: The Hypothalamus & Pituitary
● Anatomy & Physiology: The Hypophyseal Portal System, Pulsatility vs.
Continuous Signaling (GnRH).
● The Anterior Pituitary: Prolactin, GH, TSH, ACTH, and LH/FSH.
● The Posterior Pituitary: ADH (Vasopressin) and Oxytocin (The Let-Down
Reflex).
● Pathology:
○ Sheehan Syndrome: Postpartum Necrosis & The "Empty Sella."
○ Pituitary Adenomas: Prolactinoma, Acromegaly, and Bitemporal
Hemianopsia.
○ Diabetes Insipidus: Central vs. Nephrogenic (Water Deprivation Test).
○ Pituitary Apoplexy: The "Thunderclap" Emergency.
II. Metabolism & Energy: The Pancreas & Appetite
● Glucose Regulation: Insulin vs. Glucagon, The "Honeymoon Phase" in T1DM.
● Diabetes Mellitus:
○ Pathophysiology: DKA (Kussmaul breathing, Anion Gap) vs. HHS.
○ Phenomena: Somogyi Effect vs. Dawn Phenomenon.
○ Pharmacology: Metformin, Sulfonylureas, and the Incretin Effect.
● Appetite Mastery: Ghrelin (The Gas) vs. Leptin (The Brake), Leptin
Resistance.
● Tumors: Insulinoma (Whipple Triad), VIPoma (WDHA Syndrome),
Glucagonoma (NME Rash).
III. The Stress & Salt Axis: The Adrenal Glands
● Anatomy: The GFR Layers (Salt, Sugar, Sex).
● Hypercortisolism: Cushing Disease vs. Cushing Syndrome, Ectopic ACTH.
● Adrenal Insufficiency: Addison’s Disease (Hyperpigmentation) vs. Secondary
Failure.
● Mineralocorticoids: Conn’s Syndrome (Primary Hyperaldosteronism) &
RAAS.
, ● The Medulla: Pheochromocytoma (The 5 P's & The "Alpha-Before-Beta"
Rule).
IV. Growth & Minerals: Thyroid & Parathyroid
● Thyroid Disorders:
○ Hyper: Graves’ Disease (TSI antibodies, Exophthalmos), Thyroid
Storm.
○ Hypo: Hashimoto’s Thyroiditis, Myxedema Coma.
○ Cancer: Papillary (Orphan Annie Eye) vs. Medullary (Amyloid/RET).
● Calcium Homeostasis:
○ PTH & Vitamin D: The Calcium/Phosphate see-saw.
○ Imbalances: Hypercalcemia (Stones, Groans, Bones) vs. Hypocalcemia
(Chvostek/Trousseau).
V. Reproductive & Gestational Endocrinology
● Pregnancy Physiology: Human Placental Lactogen (hPL) and hCG.
● Gestational Diabetes (GDM): Fetal Macrosomia and Neonatal Hypoglycemia.
● Polycystic Ovary Syndrome (PCOS): Insulin resistance and SHBG levels.
VI. Multi-System Syndromes (MEN)
● MEN Type 1: The 3 P's (Pituitary, Parathyroid, Pancreas).
● MEN Type 2A/2B: RET mutations, Medullary Thyroid Cancer, and Marfanoid
Habitus.
,Endocrinology is essentially the body's wireless communication system. It’s high-
yield because once you master the "wiring" (the pathways), the "short circuits" (the
pathologies) become much easier to predict.
1. Adrenal Steroidogenesis: The High-Stakes Factory
, The adrenal cortex is organized into three layers—Glomerulosa, Fasciculata, and
Reticularis (mnemonic: GFR). Each layer produces a specific type of hormone: Salt,
Sugar, Sex.
The Pathway
Everything starts with cholesterol. The key to understanding the deficiencies is
knowing which direction the pathway flows. If an enzyme is blocked, the precursors
"leak" into the next available open pipe.
Congenital Adrenal Hyperplasias (CAH)
These are enzymatic "dam removals." If a path is blocked, the body overproduces
what it can still make.
Enzyme Mineralocorticoid Cortisol Androgens Clinical Clues
Deficiency s (Aldosterone) (Testosterone
)
21- ↓ (Low BP, High ↓ ↑↑ Virilization in
Hydroxylase K+) females; "Salt-
(Most wasting" crisis
Common) in infants.
11$\beta$- ↓ (but 11- ↓ ↑ HTN (due to
Hydroxylase deoxycorticoster precursor
one ↑) buildup) +
Virilization.
17$\alpha$- ↑ ↓ ↓ HTN + Lack of
Hydroxylase secondary sex
characteristics
(delayed
puberty).
