High-Yield Exam Mnemonics
- Sella = Saddle for the pituitary to sit.
Recall: The pituitary gland sits in the sella turcica, a saddle-shaped depression in the sphenoid bone.
- Neuro-hypophysis = Neuro-ectoderm origin.
Recall: The posterior pituitary (neurohypophysis) develops from neuroectoderm as a downgrowth from the diencephalon (infundibulum).
- Stalk through the Sellae roof.
Recall: The pituitary stalk (infundibulum) passes through the central aperture of the diaphragma sellae connecting hypothalamus to pituitary.
- Acidophils = GH and Prolactin (both ‘A’ for acidophilic).
Recall: Lactotrophs (mammotrophs) are acidophilic cells that secrete prolactin.
- Cortico-trophs = Cortex stimulators = ACTH.
Recall: Corticotrophs are basophilic cells that secrete ACTH (adrenocorticotropic hormone), which stimulates the adrenal cortex.
- Medulla = Migrated neural crest = Modified sympathetic ganglion.
Recall: The adrenal medulla develops from neural crest cells (chromaffin cells) that migrate into the developing gland.
- Cortex = Coelomic mesoderm; Medulla = Migrating neural crest.
Recall: The adrenal cortex develops from intermediate mesoderm (specifically, coelomic epithelium near the urogenital ridge).
- Foramen Cecum = First site of thyroid development.
Recall: The thyroid develops from an endodermal diverticulum at the foramen cecum (junction of anterior 2/3 and posterior 1/3 of tongue) and descends via the thyroglossal duct.
- Recurrent = Runs with inferior thyroid = Risk during surgery.
Recall: The recurrent laryngeal nerve crosses the inferior thyroid artery (anterior or posterior) near the thyroid gland.
- Rathke’s forms the Roof cells (anterior pituitary).
Recall: Rathke’s pouch is an ectodermal outpouching from the roof of the stomodeum that forms the adenohypophysis.
- Chiasma Compression = Classic tunnel vision.
Recall: The optic chiasma lies directly above the pituitary gland.
- The Infundibulum is the Information highway from Hypothalamus.
Recall: The infundibulum (pituitary stalk) connects the pituitary gland to the hypothalamus.
- Adrenals have 3 A’s: Aorta, phrenic Artery, renal Artery.
Recall: The adrenal gland receives blood from three sources: superior suprarenal artery (from inferior phrenic), middle suprarenal artery (from aorta), and inferior suprarenal artery (from renal artery).
- Adrenals at Twelve–Top of the kidneys.
Recall: The adrenal glands sit on the superior poles of the kidneys at approximately the T12 vertebral level.
- Fetal zone = Fades after birth.
Recall: The fetal adrenal cortex has a large inner fetal zone (80%) that produces DHEA for placental estrogen synthesis.
- C cells = Calcitonin, Calcium-lowering.
Recall: Parafollicular cells (C cells) are derived from neural crest and secrete calcitonin, which lowers blood calcium.
- Isthmus = In the middle, rings 2-4.
Recall: The thyroid isthmus typically overlies tracheal rings 2-4, just below the cricoid cartilage.
- 3rd pouch = inferior (descends with thymus), 4th = superior (stays put).
Recall: Superior parathyroids develop from the 4th pharyngeal pouch (with ultimobranchial body).
- Chief cells are Chief PTH producers.
Recall: Chief cells (principal cells) are the main PTH-secreting cells.
- Parathyroids are captive in the thyroid capsule.
Recall: Parathyroid glands lie within the thyroid capsule (true capsule of the thyroid) but outside the thyroid parenchyma.
- Pancreas = Compound Acinar, purely serous.
Recall: The exocrine pancreas is a compound acinar (serous) gland producing digestive enzymes.
- Main duct = Major papilla.
Recall: The main pancreatic duct joins the common bile duct to form the hepatopancreatic ampulla, opening at the major duodenal papilla (of Vater).
- Zymogen = Zero activity until activated (proenzymes).
Recall: Zymogen granules contain inactive enzyme precursors (trypsinogen, chymotrypsinogen, procarboxypeptidase, etc.) that are activated in the duodenum.
- Renal arteries come directly from the Aorta at L1-L2.
Recall: Renal arteries arise from the abdominal aorta at L1-L2 level, just below the SMA.
- Macula densa is in the DCT, detecting NaCl.
Recall: The macula densa is a specialized region of the distal convoluted tubule adjacent to the afferent arteriole.
- Intermediate mesoderm = In-between, forms kidney and gonads.
Recall: The permanent kidney (metanephros) develops from intermediate mesoderm (metanephric blastema and ureteric bud).
- Pelvic kidney = Paused in the Pelvis, failed ascent.
Recall: Pelvic kidney occurs when the developing kidney fails to ascend from its origin in the pelvis to its normal lumbar position.
- Trigone = Triangle at the base with 3 openings.
Recall: The trigone is a smooth triangular area on the posterior wall (base) of the bladder, bounded by the two ureteric orifices and the internal urethral orifice.
- Internal = Involuntary, smooth muscle.
Recall: The internal urethral sphincter is composed of smooth muscle fibers from the detrusor at the bladder neck, under autonomic control.
- Transitional zone Troubles with BPH, Peripheral with cancer.
Recall: BPH occurs primarily in the transitional zone surrounding the urethra, causing urinary obstruction.
- Central zone is where ejaculatory ducts cross.
Recall: The ejaculatory ducts (formed by union of vas deferens and seminal vesicle duct) traverse the central zone to open into the prostatic urethra at the seminal colliculus.
- Transverse line at tuberosities = Two triangles.
Recall: An imaginary transverse line between the ischial tuberosities divides the perineum into the anterior urogenital triangle (containing external genitalia) and posterior anal triangle (containing anal canal).
- “Auto = Self, acts on itself.” Second Messengers
Recall: In autocrine signaling, a cell secretes a hormone that binds to receptors on its own surface.
- Guanylyl = GTP → cGMP.
Recall: Guanylyl cyclase converts GTP to cyclic GMP (cGMP). cAMP is made by adenylyl cyclase.
- Pheo triad = Head pounds, Sweat pours, Heart races.
Recall: The classic triad is episodic headache, sweating, and palpitations (tachycardia).
- 1+2=3 (MIT+DIT=T3), 2+2=4 (DIT+DIT=T4).
Recall: MIT (monoiodotyrosine) + DIT (diiodotyrosine) = T3 (triiodothyronine, 3 iodines).
- High Glucose = High Insulin.
Recall: Elevated blood glucose is the primary stimulus for insulin release from beta cells.
- Insulin = Into storage (builds up).
Recall: Insulin is anabolic–it promotes glycogenesis (glycogen synthesis), lipogenesis, and protein synthesis.
- 126 = Diabetes Door.
Recall: Fasting plasma glucose ≥126 mg/dL on two separate occasions diagnoses diabetes mellitus.
- Glycolysis = Glucose lysis in cytosol.
Recall: Glycolysis is a cytoplasmic pathway converting glucose to pyruvate.
- 3 NADH = 3 dehydrogenases in TCA.
Recall: One TCA cycle turn produces 3 NADH (at isocitrate dehydrogenase, α-ketoglutarate dehydrogenase, and malate dehydrogenase).
- Fumarate = Fusion point of urea and TCA.
Recall: Fumarate is produced in the urea cycle (from argininosuccinate) and enters TCA cycle.
- Prolactin = Pro-milk Production.
Recall: Prolactin from anterior pituitary stimulates milk production (lactogenesis) in mammary glands.
- Posterior Pituitary = Pale because of Pituicytes and nerve Processes.
Recall: The neurohypophysis (posterior pituitary) appears paler because it consists of unmyelinated axons from hypothalamic neurons (supraoptic and paraventricular nuclei) and supporting pituicytes (modified glial cells).
- CHROMaffin cells contain Catecholamines that turn CHROMium brown.
Recall: Chromaffin cells (pheochromocytes) of the adrenal medulla contain catecholamines (epinephrine, norepinephrine) in membrane-bound granules.
- 3rd pouch = inferior parathyroid + thymus (3 letters = INF, descends more, more variable).
Recall: The superior parathyroids develop from the 4th pharyngeal pouch and have a short descent, so their position is relatively constant (posterior to middle thyroid).
- Beta cells are BLUE with aldehyde fuchsin–B for Beta, B for Blue.
Recall: Special stains like aldehyde fuchsin or modified Gomori stain differentiate islet cells: beta cells contain zinc-insulin complexes that stain blue/purple with these stains, while alpha cells (glucagon granules) stain red/pink.
- Horseshoe hooks on IMA at L3–can’t gallop past the artery.
Recall: Horseshoe kidney forms when the lower poles of metanephric kidneys fuse during the 5th-9th week as they ascend from the pelvis.
- VAU or VAP = Vein-Artery-Ureter (Pelvis) from Anterior to Posterior.
Recall: At the renal hilum, structures are arranged anterior to posterior as: Vein (most anterior), Artery (middle), and ureter/pelvis (most posterior and inferior).
- Trigone is Tight and smooth–from absorbed Mesonephric duct, not urogenital sinus.
Recall: The trigone is formed by absorption of the caudal mesonephric ducts into the developing bladder, giving it a mesodermal origin.
- Prostate has Pseudostratified epithelium producing PSA and Prostatic fluid–P’s go together.
Recall: Prostatic glands have pseudostratified columnar epithelium with a layer of basal cells (stem cells for regeneration).
- Pre-Pro-Mem-Spongy: narrowest at Membranous (like passing through a tight Membrane).
Recall: The male urethra has four parts: (1) preprostatic/intramural (within bladder wall), (2) prostatic (widest, through prostate), (3) membranous (shortest, narrowest, passes through urogenital diaphragm/external sphincter), (4) spongy/penile (longest, through corpus spongiosum).
- Diamond-shaped perineum: Pubic symphysis to Coccyx, with Ischial tuberosities on the sides, divided by IT-IT line.
Recall: The perineum is a diamond-shaped region bounded by the pubic symphysis anteriorly, tip of coccyx posteriorly, ischiopubic rami anterolaterally, sacrotuberous ligaments posterolaterally, and ischial tuberosities laterally.
- Ischioanal fossa: I-shaped spaces that communicate posteriorly, letting Infection spread like a horseshoe.
Recall: The ischioanal fossa (ischiorectal fossa) is a fat-filled wedge-shaped space lateral to the anal canal and rectum.
- Levator ani = 3 P’s: Pubococcygeus, Puborectalis, iliococcygeus (I is shy, doesn’t start with P)–they Lift the pelvic floor.
Recall: The levator ani has three parts: pubococcygeus (pubovesicalis, puboprostaticus/pubovaginalis, puboanalis), puborectalis (forms U-shaped sling around anorectal junction maintaining continence), and iliococcygeus.
- Water (ureter) Under the Bridge (uterine artery)–2cm lateral to cervix is the danger zone.
Recall: The ureter crosses inferior (under) to the uterine artery approximately 1.5-2 cm lateral to the supravaginal cervix at the level of the internal os, within the cardinal ligament.
- Left testicular vein → Left renal vein (both have L); Right goes Right to IVC.
Recall: The testicular artery arises directly from the abdominal aorta (below renal arteries) and descends through the inguinal canal.
- Seminal vesicles = Sixty percent of semen; their ducts join vas to form ejaculatory ducts.
Recall: The seminal vesicles are paired glands posterior to the bladder that produce 60-70% of semen volume.
- Para-Mesonephric = female Para-ts (uterus, tubes, upper vagina); Mesonephric = Male structures.
Recall: The uterus, cervix, and upper two-thirds of the vagina develop from the paramesonephric (Müllerian) ducts.
- Suspensory ligament Suspends the ovary with its blood Supply; Gubernaculum gives rise to ovarian and round ligaments.
Recall: The suspensory ligament (infundibulopelvic ligament) connects the ovary to the lateral pelvic wall and contains the ovarian vessels (artery from aorta, vein to IVC/renal vein), lymphatics, and autonomic nerves–must be ligated during oophorectomy.
- Clitoris and penis share the same origin–both have corpora cavernosa; Bartholin’s = Bulbourethral glands.
Recall: A patient with vulvar lesion requires understanding of vulvar anatomy. What are the major components of the external female genitalia (vulva), and which structure is homologous to the male penis?
- Cervix drains to External iliac and Obturator–along the Pelvic sidewall; Ovary drains to aOrtic (follows its artery).
Recall: The cervix and lower uterus drain primarily to external iliac and obturator lymph nodes (sentinel nodes for cervical cancer), then to common iliac and para-aortic nodes.
- Fetal zone is Fat during Fetal life, Fades after birth; adult zones develop from Definitive cortex.
Recall: During fetal life, the adrenal cortex has a large inner fetal zone (80% of gland) that produces DHEA for placental estrogen synthesis.
- C cells from neural Crest, make Calcitonin; Clear cytoplasm, positioned Close to but not touching colloid.
Recall: Parafollicular (C cells) originate from neural crest cells that migrate via the ultimobranchial body (from 4th/5th pharyngeal pouch) into the developing thyroid.
- JG cells are the Janitors Guarding blood pressure–release renin when pressure, sodium, or sympathetic input changes.
Recall: Juxtaglomerular (JG) cells are modified smooth muscle cells in the afferent arteriolar wall containing renin granules.
- Upper pole ureter = Ectopic and Obstructed; Lower pole = Lateral and Refluxing.
Recall: The Weigert-Meyer rule describes duplex kidney ureteral insertion: the upper pole ureter (from a ureteric bud arising higher on mesonephric duct) inserts inferomedially and may be ectopic (into bladder neck, urethra, or genital structures).
- HYPOspadias = ventral HYPOgastric opening; urethral folds didn’t fuse from HYPOandrogenism.
Recall: Hypospadias results from incomplete fusion of the urethral folds over the urethral plate (ectodermal ingrowth that canalizes to form urethra).
- B-FLAT: Basophils secrete FSH, LH, ACTH, TSH.
Recall: PAS-positive cells in the anterior pituitary are basophils, which include corticotrophs (ACTH), thyrotrophs (TSH), and gonadotrophs (FSH/LH).
- Thyroid Takes its final position at C5-C7, matching the 5-7 week descent.
Recall: The thyroid gland descends from the foramen cecum at the base of the tongue, passing anterior to the hyoid bone and laryngeal cartilages to reach its final position at the C5-C7 vertebral level (overlying the 2nd-4th tracheal rings).
- Superior parathyroids are Stable in position at the Superior-Middle thyroid.
Recall: Superior parathyroid glands, developing from the fourth pharyngeal pouch, have a more predictable location posterior to the middle third of the thyroid lobe, approximately at the level of the cricoid cartilage.
- Ventral goes around the wrong way in Annular pancreas.
Recall: Annular pancreas results from abnormal rotation or bifid development of the ventral pancreatic bud.
- IMA Impedes the Inferior pole fusion from ascending.
Recall: In horseshoe kidney, the inferior poles of the kidneys fuse across the midline (connected by an isthmus).
- Atypical smooth muscle cells are the Automatic pacemakers of the ureter.
Recall: Ureteric peristalsis is initiated by atypical smooth muscle cells (pacemaker cells) located at the pelvi-ureteric junction.
- Internal pudendal artery goes through the Inside (lesser sciatic foramen) to supply Internal structures.
Recall: The internal pudendal artery, a branch of the internal iliac artery, enters the perineum through the lesser sciatic foramen along with the pudendal nerve and internal pudendal vein in Alcock’s canal.
- Testicular artery remembers its origin at L2 aorta from embryological position.
Recall: The testicular artery arises directly from the abdominal aorta at the L2 level (reflecting the original retroperitoneal position of the developing testis).
- Batson’s plexus is the Back door for prostate cancer spread to vertebrae.
Recall: The prostatic venous plexus communicates with the internal vertebral venous plexus (Batson’s plexus), a valveless system extending along the vertebral column.
- Parasympathetic causes Point (erection) via Pelvic splanchnics and cavernous nerves.
Recall: Erection is initiated by parasympathetic fibers from S2-S4 via pelvic splanchnic nerves, which synapse in the pelvic plexus and send cavernous nerves along the posterolateral aspect of the prostate to the corpora cavernosa.
- Endocervix has Columnar Cells, Ectocervix has Squamous – they meet at the transformation zone.
Recall: The endocervical canal is lined by simple columnar (mucus-secreting) epithelium, which meets the stratified squamous epithelium of the ectocervix at the squamocolumnar junction (transformation zone).
- Transverse septum is at the Transition point between two embryological origins.
Recall: A transverse vaginal septum occurs at the junction of the upper vagina (from the uterovaginal canal/paramesonephric ducts) and lower vagina (from sinovaginal bulbs/urogenital sinus).
- Chromaffin cells are Modified postganglionic neurons releasing hormones into blood.
Recall: Chromaffin cells of the adrenal medulla are homologous to postganglionic sympathetic neurons.
- Gerota’s fascia is open to the Ground (inferiorly) – infections and tumors can descend.
Recall: Gerota’s fascia (renal fascia) has anterior and posterior layers that fuse laterally and superiorly but remain open inferiorly and medially.
- Primordial germ cells take a Pilgrimage from Yolk sac to gonad during weeks 4-6.
Recall: Primordial germ cells originate from the wall of the yolk sac (near the allantois) and migrate during weeks 4-6 via the dorsal mesentery of the hindgut to reach the gonadal ridge.
- “Rathke’s pouch *Reaches up* from the mouth” – oral ectoderm migrating superiorly.
Recall: The anterior pituitary (adenohypophysis) develops from Rathke’s pouch, an upward evagination of oral ectoderm from the roof of the primitive mouth.
- “Glucagon = *Glucose-agon*ist” – first responder for glucose.
Recall: Glucagon is the primary and most rapid counterregulatory hormone, acting within seconds to minutes by activating hepatic glycogenolysis through cAMP-PKA pathway and stimulating gluconeogenesis.
- “Two cells, Two hormones” – LH→Theca→Androgens; FSH→Granulosa→Estrogens.
Recall: In the two-cell, two-gonadotropin model, LH stimulates theca cells to produce androgens (androstenedione, testosterone), while FSH stimulates granulosa cells to express aromatase, converting androgens to estrogens.
- “PTHrP *Pretends* to be PTH” – receptor mimicry.
Recall: PTHrP (PTH-related peptide) shares structural homology with PTH in the N-terminal region and binds the same PTH/PTHrP receptor (PTH1R).
- Prolactin *Pauses* the GnRH *Pulse*.
Recall: Elevated prolactin inhibits hypothalamic GnRH neurons, disrupting the pulsatile GnRH release essential for maintaining normal LH and FSH secretion.
- Fibroblasts Feel the hypoxia – make EPO.
Recall: Erythropoietin is primarily produced by peritubular interstitial fibroblasts in the renal cortex.
- Fewer nephrons = Fewer *Principal* secretors.
Recall: Potassium secretion occurs primarily in principal cells of the collecting duct through ROMK channels.
- Mg is the *Key* for PTH – no key, no secretion.
Recall: Severe hypomagnesemia impairs both PTH secretion from parathyroid chief cells and causes skeletal resistance to PTH action.
- Fanconi = Proximal *Failure of Everything*.
Recall: Fanconi syndrome involves global proximal tubule dysfunction with impaired reabsorption of glucose (glycosuria with normoglycemia), phosphate (hypophosphatemia), bicarbonate (proximal RTA, type 2), amino acids, and uric acid.
- “Vaptan = *Vapor* out water” – aquaresis.
Recall: Tolvaptan is a selective V2 receptor antagonist (“vaptan”).
- Slow to *Gain* osmolytes, slow to *Lose* them.
Recall: During chronic hypernatremia, brain cells accumulate organic osmolytes for protection.
- D2 Down-regulates prolactin Directly.
Recall: Cabergoline is a D2 receptor agonist.
- ACTH deficiency = *Acute* crisis threat.
Recall: ACTH deficiency leads to secondary adrenal insufficiency, which can cause life-threatening hypotension and hypoglycemia during physiological stress.
- Melatonin sets the *Master* clock in the SCN.
Recall: Melatonin produced by the pineal gland acts primarily on MT1 and MT2 receptors in the suprachiasmatic nucleus (SCN), the body’s master circadian clock.
- Serotonin Stimulates ADH Secretion from the *Stalk*.
Recall: SSRIs increase serotonergic neurotransmission, and serotonin stimulates ADH (vasopressin) release from the posterior pituitary.
- BPH = Blocked Prostate, High pressure needed.
Recall: In BPH, the enlarged prostate increases urethral resistance.
- Diabetes *Dampens* both feeling and function.
Recall: Diabetic cystopathy results from progressive autonomic neuropathy affecting both afferent (sensory) and efferent (motor) nerve fibers.
- PTH = Phosphate down, Vitamin D up, Calcium up.
Recall: Primary hyperparathyroidism causes: (1) hypercalcemia from increased bone resorption and renal calcium reabsorption; (2) hypophosphatemia from PTH-induced phosphaturia (inhibits NPT2a/c in proximal tubule); and (3) elevated 1,25(OH)₂D because PTH stimulates renal 1α-hydroxylase.