Reproductive Anatomy, Physiology & the Menstrual Cycle - Memory Anchors
Memory anchors transform dry anatomical facts into vivid, unforgettable mental images. For the NLE, where a single misremembered number (like confusing 24 hours with 72 hours for sperm survival) can cost you a point, these anchors give you an almost automatic retrieval path. Think of each anchor as a mental 'hook' — the moment you see a question about ovulation, your brain instantly pulls up the correct chain of facts. Use these anchors during your review sessions, say them out loud, draw them, and share them with a batchmate. The more senses you engage, the stronger the memory trace becomes.
Memory anchors
Fertilisation occurs in the AMPULLA (outer third) of the fallopian tube — NOT the uterus
Memory aid
Think of the fallopian tube as the EDSA highway at rush hour. The sperm are commuters rushing from Pasay heading to Quezon City (the uterus). But the big meeting — fertilisation — does NOT happen at the final destination. It happens at the AMPANG interchange (AMPULLA) — the OUTER THIRD of the tube — before the journey even finishes. The fertilised egg (zygote) then rides the rest of the way to the uterus for implantation.
Why it works
The familiar Manila traffic analogy anchors a spatial concept (outer third of tube) to a vivid, emotionally recognisable Filipino experience. The word 'AMPANG' phonetically echoes 'AMPULLA', strengthening the sound link.
Example usage
Q: Where does fertilisation normally occur? Recall EDSA — the meeting happens at AMPANG (AMPULLA), the outer third of the fallopian tube. Answer: Ampulla of the fallopian tube.
Recall trigger
Think: 'EDSA rush hour meeting' → AMPULLA → outer third → fertilisation
LH SURGE triggers OVULATION (~Day 14 of a 28-day cycle)
Memory aid
Imagine the ovarian follicle as a ripe SANTOL fruit hanging on a tree. For days it just grows bigger and bigger (follicular phase). Then suddenly a burst of wind — the LH SURGE — hits the tree on Day 14, and BOOM — the santol drops (ovulation). The LH surge is the wind that knocks the ripe egg loose. No LH surge = no ovulation, just like no wind = santol stays on the tree.
Why it works
The santol (a familiar Filipino fruit) makes the concept tangible. The action of fruit falling mirrors the rupture of the follicle. The 'wind = LH surge' is a cause-effect image that is hard to forget once visualised.
Example usage
Q: What hormone triggers ovulation? Picture the santol dropping in the wind. The wind = LH surge. Answer: LH (luteinizing hormone) surge triggers ovulation.
Recall trigger
Santol falling from tree = LH surge triggering ovulation on Day 14
Progesterone RAISES Basal Body Temperature by 0.3–0.5°C AFTER ovulation
Memory aid
Progesterone is like a BLANKET being thrown over the body after ovulation. Once the egg is released, progesterone says 'time to keep this warm!' — it wraps you in a blanket and your body temperature rises by 0.3–0.5°C. Progesterone = PROGRESSING toward pregnancy = needs WARMTH. If you never feel the blanket (no temperature rise), ovulation probably did not happen.
Why it works
The blanket analogy directly links progesterone's thermal effect to a sensory experience (warmth). The word play 'PROGESTERone = PROGRESSing toward pregnancy = needs protection/warmth' creates a semantic triple link.
Example usage
Q: What hormone causes the rise in basal body temperature after ovulation? Think of the blanket. Blanket = Progesterone = warmth = 0.3–0.5°C rise. Answer: Progesterone.
Recall trigger
'Blanket thrown after ovulation' → Progesterone → BBT rises 0.3–0.5°C
OESTROGEN makes cervical mucus thin, clear, and stretchy (SPINNBARKEIT) around ovulation
Memory aid
Visualise cracking a fresh raw ITLOG (egg) — the egg white stretches between your fingers in a long, slippery, clear thread. That stringiness is SPINNBARKEIT. Now remember: OESTROGEN = EGG WHITE mucus. And the word SPINNBARKEIT sounds like 'SPIN' + 'BARKEIT' — like spinning a long thread. Fertile mucus SPINS into a long thread just like egg white. Under oestrogen's influence, the cervix rolls out the 'welcome mat' for sperm.
Why it works
The egg-white image is universally familiar to Filipino students (cooking, baking). The tactile sensation of stretching egg white is a strong sensory anchor. The phonetic breakdown of 'Spinnbarkeit' makes the German word memorable.
Example usage
Q: What type of cervical mucus indicates peak fertility? Think of stretching egg white (itlog). Oestrogen → egg white-like mucus → Spinnbarkeit. Answer: Clear, thin, stretchy cervical mucus (Spinnbarkeit) caused by oestrogen.
Recall trigger
Raw egg white stretching between fingers = Spinnbarkeit = Oestrogen = fertile mucus
Ovum survives ~24 hours; Sperm survives ~48–72 hours (up to 5 days in fertile mucus)
Memory aid
Remember this rhyme: 'The EGG has ONE day — then it's gone away. The SPERM can stay LONGER — 48 to 72, even FIVE DAYS if the mucus is stretchy and true!' Shorter version: ONE for the egg, THREE (days) for the sperm — at minimum. The fertile WINDOW opens 5 days before ovulation and closes 1 day after = 6 days total.
Why it works
Rhyme exploits phonological loop memory, making numbers easier to retain. The contrast (1 day vs 3–5 days) is embedded in the rhythm, preventing number confusion — a common exam trap.
Example usage
Q: How long does an ovum survive after ovulation? Recall the rhyme — 'the EGG has ONE day.' Answer: Approximately 24 hours.
Recall trigger
'ONE day for the egg, FIVE days for the sperm' rhyme
The FATHER determines fetal sex (X or Y sperm)
Memory aid
Acronym: DAD DECIDES SEX. The mother always contributes an X chromosome. The father contributes either X (baby girl) or Y (baby boy). Think: 'DADDY chose — X = daXghter (daughter), Y = boY.' Dad holds the Y chromosome like a trophy. No Y from dad = no boy. Filipino bonus: 'Tatay ang nagpili ng kasarian ng anak!' (Father chose the child's sex!) — a fun myth-busting fact.
Why it works
The Filipino cultural hook (correcting a common misconception that the mother determines sex) creates surprise — and surprise boosts memory consolidation. The X = daXghter, Y = boY phonetic link ties the letter to the outcome.
Example usage
Q: Who determines the sex of the baby? Recall 'Tatay ang nagpili.' The father's sperm carries either X or Y. Answer: The father (through the X or Y chromosome in the sperm).
Recall trigger
'Tatay ang nagpili' → Father determines sex → X = daughter, Y = boy
hCG MAINTAINS the corpus luteum (and is detected by pregnancy tests)
Memory aid
Imagine the corpus luteum as a weary barangay tanod (security guard) who has been working night shifts (secreting progesterone) for 10–12 days straight. He is about to resign (corpus luteum degenerating). But then a new baby is born (implantation happens) and the baby's family (the trophoblast) sends him an urgent message: 'Please STAY on duty! We need you!' That message is hCG. hCG = 'Hindi Ka puwedeng Gumalis' (You cannot leave!) — the signal that keeps the corpus luteum working until the placenta takes over.
Why it works
The barangay tanod micro-story is deeply Filipino and culturally relatable. The acronym hCG = 'Hindi Ka puwedeng Gumalis' is a humorous Filipino sentence that perfectly captures the biological function and is impossible to forget.
Example usage
Q: What hormone maintains the corpus luteum during early pregnancy? Think 'Hindi Ka puwedeng Gumalis.' hCG keeps the corpus luteum active. Answer: hCG (human chorionic gonadotropin).
Recall trigger
'Hindi Ka puwedeng Gumalis' = hCG = maintains corpus luteum = detected by pregnancy test
Luteal phase is a FIXED ~14 days; cycle variation comes from the FOLLICULAR phase
Memory aid
Think of the menstrual cycle as a tricycle (trike) ride. The LUTEAL PHASE is the FIXED route from the last stop to the terminal — it is ALWAYS 14 minutes (days), no matter what. But the FOLLICULAR PHASE is the unpredictable portion — traffic (delayed follicle growth) can make this part 10 days or 20 days. Formula: Ovulation Day = Cycle Length − 14. So if cycle = 35 days, ovulation is on Day 21 (35 − 14). If cycle = 21 days, ovulation is Day 7 (21 − 14).
Why it works
The trike analogy uses a quintessentially Filipino transportation experience. The fixed final leg = luteal phase. Variable first leg = follicular phase. The formula naturally falls out of the analogy.
Example usage
Q: A woman has a 32-day cycle. On which day does she most likely ovulate? Recall the trike — fixed last 14 days. 32 − 14 = Day 18. Answer: Approximately Day 18.
Recall trigger
Trike's fixed last 14 minutes = fixed luteal phase → Ovulation = Cycle length − 14
TESTOSTERONE produced by LEYDIG (interstitial) cells; FSH + SERTOLI cells support spermatogenesis
Memory aid
Use the acronym: 'LET'S TALK': L = Leydig makes Testosterone; S = Sertoli supports Spermatogenesis (driven by FSH). Imagine LEydig cells as LEaders (LET) — they produce testosterone, the dominant male hormone. Sertoli cells are like SERBIDORES (servers/supporters) — they support and nurture the developing sperm. FSH tells the Sertoli serbidores to get to work.
Why it works
The 'LET'S TALK' acronym creates a memorable two-part split between Leydig and Sertoli functions. 'Serbidor' is a Filipino term for a devoted helper, perfectly capturing Sertoli cell function.
Example usage
Q: Which cells in the testes secrete testosterone? Recall 'LET'S TALK' — L = Leydig produces Testosterone. Answer: Leydig (interstitial) cells.
Recall trigger
'LET'S TALK' — L=Leydig/Testosterone, S=Sertoli/Spermatogenesis via FSH
Spermatogenesis requires temperature ~1–2°C BELOW core body temperature (scrotum keeps testes cool)
Memory aid
Think of sperm production like storing a leftover adobo in the ref (refrigerator). You CANNOT leave sperm production happening at oven temperature (37°C core). The scrotum is the body's built-in ref — it keeps the testes 1–2°C cooler than the rest of the body (around 35–36°C). Tight underwear, prolonged hot baths, and varicoceles all raise scrotal temperature, just like leaving adobo near the stove — it spoils (reduced sperm count and motility).
Why it works
Adobo-in-the-ref is a universally relatable Filipino domestic scene. The food-spoilage consequence drives home the clinical significance (heat = reduced fertility). It also explains varicocele, tight underwear, and fever as causes of male infertility.
Example usage
Q: Why is the scrotum located outside the body? Recall the adobo analogy — sperm production needs it cooler. Answer: To maintain a temperature 1–2°C below core body temperature, which is required for normal spermatogenesis.
Recall trigger
Adobo in the ref = scrotum as cooler = testes need 1–2°C below core for sperm
IMPLANTATION occurs ~6–10 days after fertilisation in the ENDOMETRIUM
Memory aid
Remember the ZYGOTE JOURNEY in chunks: Day 0: Fertilisation in the AMPULLA (zygote formed). Days 1–3: Zygote divides → MORULA (looks like a mulberry = moras). Days 3–4: Morula becomes BLASTOCYST. Days 6–10: Blastocyst IMPLANTS in the endometrium. Chunking phrase: 'F-M-B-I' = Fertilised, Morula, Blastocyst, Implanted. Or say it like a text message: 'FeMBer Implanted' (F=Fertilise, M=Morula, B=Blastocyst, Implanted at 6–10 days).
Why it works
Chunking breaks the 10-day journey into 4 manageable stages. The F-M-B-I acronym creates a retrievable sequence. 'FeMBer Implanted' sounds like the month December — cold and nesting — reinforcing the implantation image.
Example usage
Q: How many days after fertilisation does implantation occur? Run F-M-B-I — Implantation is the 'I' = 6–10 days. Answer: Approximately 6–10 days after fertilisation.
Recall trigger
F-M-B-I → Fertilisation → Morula → Blastocyst → Implantation (Days 6–10)
Phases of the ENDOMETRIAL CYCLE: Menstrual (Days 1–5) → Proliferative (Days 6–14) → Secretory (Days 15–28)
Memory aid
Acronym: 'MaPS the Way' — M = Menstrual (Days 1–5, shedding), P = Proliferative (Days 6–14, oestrogen rebuilds), S = Secretory (Days 15–28, progesterone prepares for baby). Think of the endometrium as a school classroom: M = Mop and clean the room (shedding), P = Paint and fix the walls (proliferating/building), S = Set up the chairs and supplies (secretory/preparing for a student = the embryo).
Why it works
MaPS connects the sequence to the idea of navigation — you are mapping the cycle. The classroom preparation metaphor stages are sequential and logical (clean → fix → prepare), which mirrors the endometrial phases perfectly.
Example usage
Q: What happens to the endometrium during the secretory phase? Recall 'MaPS' — S = Set up the classroom = progesterone makes endometrium glandular and nutrient-rich for implantation. Answer: Progesterone makes the endometrium secretory and receptive to implantation.
Recall trigger
'MaPS the Way' — M=Menstrual, P=Proliferative, S=Secretory
NORMAL menstrual values: Cycle 21–35 days; Flow 2–7 days; Blood loss 30–80 mL
Memory aid
Remember '2-2-2 with doubles': Cycle = 21–35 days (2 and 1 to 3 and 5 = start with 2), Flow = 2–7 days (starts with 2), Blood loss = 30–80 mL (30 and 80 — both end in zero). Or use the phrase 'TWENTY-one to THIRTY-five days in a cycle, TWO to SEVEN days of flow, THIRTY to EIGHTY mL blood.' Clue: 'Think of a 3-week minimum (21 days) to 5-week maximum (35 days) — anything outside that range is abnormal.'
Why it works
Pattern recognition (both cycle and flow start with '2') reduces cognitive load. The verbal phrase locks in three numbers simultaneously through rhythm and repetition. Framing cycle length in 'weeks' (3 to 5 weeks) uses familiar time units.
Example usage
Q: A patient reports a menstrual cycle of 38 days. Is this normal? Recall 21–35 days is normal. 38 days > 35 days = OLIGOMENORRHOEA (infrequent periods). Answer: This is outside the normal range — it may indicate oligomenorrhoea.
Recall trigger
21–35 / 2–7 / 30–80 → CYCLE / FLOW / BLOOD LOSS
VASECTOMY = cutting/tying the VAS DEFERENS; the vas deferens carries sperm from epididymis to ejaculatory duct
Memory aid
Visualise the word VASECTOMY: VAS = VASE. A vase is a tube that holds flowers. Imagine a garden hose (vas deferens) that carries water (sperm) from a bucket (epididymis). A vasectomy CUTS the hose — no more water reaches the sprinkler (ejaculatory duct). The vase gets a SNIP. Once cut, sperm can no longer pass, resulting in sterility without affecting testosterone (Leydig cells still work = libido intact).
Why it works
The vase-as-tube visual association makes the anatomy concrete. The garden hose cut is a kinesthetic image that emphasises what is physically happening. The important clinical nuance (testosterone not affected) is embedded in the explanation.
Example usage
Q: What structure is cut during a vasectomy? Recall the VASE = VAS deferens. Answer: The vas deferens (ductus deferens) is cut and ligated during a vasectomy.
Recall trigger
Vase = Vas deferens = tube carrying sperm → Vasectomy cuts the vase
MENSTRUAL DISORDER TERMINOLOGY: Amenorrhoea, Menorrhagia, Metrorrhagia, Dysmenorrhoea, Oligomenorrhoea
Memory aid
Use the phrase 'All Menses Make Doctors Observe': A = Amenorrhoea (absent menses), M = Menorrhagia (massive/heavy flow), M = Metrorrhagia (mid-cycle/irregular bleeding — Metro = in between stops, like LRT stations), D = Dysmenorrhoea (difficult/painful menses), O = Oligomenorrhoea (occasionally comes — infrequent light periods). BONUS for Metrorrhagia: Think of LRT stops — metrorrhagia bleeds at irregular 'stations' between periods, just like an unscheduled train stop.
Why it works
The phrase creates an easy acronym (AMMDO) with a vivid sentence. The LRT Metro analogy for metrorrhagia is brilliantly Filipino-relevant and distinguishes metrorrhagia (irregular/between) from menorrhagia (heavy but on schedule).
Example usage
Q: A patient reports heavy, prolonged menstrual flow. What is this called? Recall 'All Menses Make Doctors Observe' — M = Menorrhagia = massive/heavy flow. Answer: Menorrhagia.
Recall trigger
'All Menses Make Doctors Observe' = A-M-M-D-O menstrual disorders
GYNECOID pelvis is most favourable for vaginal delivery; Diagonal conjugate ~12.5 cm, True conjugate ~11 cm
Memory aid
Imagine a GYNO-COID (Gynecoid) pelvis as a PERFECT ROUND BILAO (a large round winnowing tray used in Filipino kitchens). Its wide, rounded inlet allows the baby's head to pass through easily — just like how a bilao lets rice grains fall through without being stuck. The diagonal conjugate is the nurse's 'measuring tape' reach — fingers touching the sacral promontory while the thumb marks the pubic arch — approximately 12.5 cm. Subtract 1.5 cm to get the TRUE (obstetric) conjugate (~11 cm). 'DIAGONAL minus 1.5 = TRUE.'
Why it works
The bilao is a Filipino kitchen staple every nursing student knows. The round shape perfectly mirrors the gynecoid inlet. The subtraction formula (12.5 − 1.5 = 11) is embedded in the story, making it easy to apply in calculations.
Example usage
Q: What pelvic type is most favourable for vaginal delivery? Think of the round bilao. Answer: Gynecoid pelvis.
Recall trigger
Bilao (round) = Gynecoid pelvis = best for birth; Diagonal 12.5 cm − 1.5 = True conjugate 11 cm
Vaginal pH is normally ACIDIC (~3.5–4.5) due to Döderlein's lactobacilli — protects against infection
Memory aid
Think of the vagina as a bottle of SUKANG PAOMBONG (Philippine white coconut vinegar) — naturally acidic and hostile to bacteria. Döderlein's lactobacilli are the microscopic SUKANG MAKERS who produce lactic acid, keeping the pH between 3.5 and 4.5. This acidity kills off harmful bacteria. When you douche or disrupt this balance (like diluting the suka with water), you remove this protection — exactly why excessive douching is discouraged in patient teaching.
Why it works
Sukang Paombong is a familiar Filipino condiment known for its strong acidity. The analogy makes the concept of vaginal pH instantly concrete and also embeds the nursing teaching point (no excessive douching) in a culturally resonant frame.
Example usage
Q: What maintains the normal acidic pH of the vagina? Recall the suka. Answer: Döderlein's lactobacilli produce lactic acid, maintaining a vaginal pH of approximately 3.5–4.5.
Recall trigger
Suka (vinegar) = acidic vaginal pH 3.5–4.5 = Döderlein's lactobacilli = infection protection
Spermatogenesis takes ~64–74 days; Normal semen: 2–5 mL volume, ≥15 million sperm/mL
Memory aid
Remember the SPERM SCHOOL SEMESTER: Sperm production is like a full academic SEMESTER — about 64–74 days (roughly 2 months) of training from start to finish. Normal semen output: '2-5 mL volume' = size of a small shot glass (think San Miguel soda cap); '15 million per mL' = WHO minimum. Chunking: '64 days to graduate, 2–5 mL at convocation, 15 million graduates per mL.'
Why it works
The semester analogy frames the long production time in a familiar academic context. The San Miguel soda cap is a culturally familiar volume reference. Chunking the three numbers into one 'graduation sentence' links them cognitively.
Example usage
Q: What is the WHO reference value for normal sperm concentration? Recall the graduation — 15 million graduates per mL. Answer: ≥15 million sperm per mL.
Recall trigger
Sperm semester = 64–74 days; Shot glass = 2–5 mL; 15 million/mL minimum
GnRH → FSH + LH (hypothalamus → anterior pituitary → gonads) — the hormonal AXIS
Memory aid
Walk through a BAHAY (Filipino house) from top to bottom: Start at the BUBONG (roof/attic) = HYPOTHALAMUS releases GnRH. Descend to the SALA (living room) = ANTERIOR PITUITARY releases FSH and LH. Go down to the SILONG (basement/ground floor) = GONADS (ovaries/testes) respond to FSH and LH. The pathway is always TOP to BOTTOM: Bubong → Sala → Silong. GnRH tells the sala, the sala tells the silong. This is the HYPOTHALAMIC-PITUITARY-GONADAL (HPG) axis.
Why it works
Method of loci (memory palace) using a Filipino bahay leverages spatial memory — one of the strongest memory systems. The architectural layout creates a permanent 3D mental map of the hormonal hierarchy.
Example usage
Q: What hormone from the hypothalamus stimulates the release of FSH and LH? Walk through the bahay — Bubong releases GnRH. Answer: GnRH (gonadotropin-releasing hormone).
Recall trigger
Bahay: Bubong (hypothalamus/GnRH) → Sala (pituitary/FSH+LH) → Silong (gonads)
INFERTILITY defined as failure to conceive after 12 months (or 6 months if woman is >35 years old)
Memory aid
Rhyme: 'If ONE YEAR passes and no baby nears, check fertility — or after SIX MONTHS if she's THIRTY-FIVE YEARS.' Think of age 35 as the 'express lane' — older couples get a faster referral (6 months instead of 12) because ovarian reserve declines after 35. Also remember: causes are roughly 1/3 female factor, 1/3 male factor, 1/3 combined — so ALWAYS assess BOTH partners.
Why it works
The rhyme encodes both the standard (12 months) and the exception (6 months at >35) in a single memorable phrase. The 'express lane' analogy clarifies WHY the exception exists (declining ovarian reserve), making it conceptually coherent rather than an arbitrary fact.
Example usage
Q: A 37-year-old woman has been trying to conceive for 7 months without success. Should she be evaluated for infertility? Recall the rhyme — >35 years = 6-month rule. 7 months > 6 months. Answer: Yes, she meets the criteria for infertility evaluation (>35 years, unprotected intercourse >6 months without conception).
Recall trigger
Rhyme: 'One year or six months at thirty-five' = infertility definition
Revision game
I am the place where two become one — sperm meets egg inside me, in the outer third of a 10-cm tube. What am I?
Answer
The Ampulla of the Fallopian Tube
Memory link
A1 — EDSA highway meeting at AMPANG interchange
I am a hormone with a Filipino name that means 'You Cannot Leave!' I keep the corpus luteum alive after the baby has implanted. What am I?
Answer
hCG (human chorionic gonadotropin)
Memory link
A7 — 'Hindi Ka puwedeng Gumalis' micro-story
I am the egg's survival time after ovulation. I last only one day — if sperm do not meet me within 24 hours, the window closes. How long do I live?
Answer
Approximately 24 hours (1 day)
Memory link
A5 — 'ONE for the egg' rhyme
I am a phase of the menstrual cycle with a FIXED duration that never changes — 14 days, always. Whether your cycle is 21 or 35 days, I am always the last 14. What phase am I?
Answer
The Luteal Phase
Memory link
A8 — Trike's fixed last 14 minutes
I look like the white of a raw itlog — clear, slippery, and I can stretch between your fingers. I signal peak fertility. What am I called, and which hormone produces me?
Answer
Spinnbarkeit (fertile cervical mucus) — produced by Oestrogen
Memory link
A4 — Raw egg white (itlog) visual association
A woman has a 35-day menstrual cycle. Using the ovulation formula, on which day does she most likely ovulate?
Answer
Day 21 (35 − 14 = 21)
Memory link
A8 — Cycle length minus 14 = Ovulation day
I am a pelvic shape named after a woman. I look like a round bilao — wide and circular at the inlet. I am the most favourable pelvis for vaginal delivery. What am I?
Answer
Gynecoid Pelvis
Memory link
A16 — Round bilao = Gynecoid pelvis micro-story
I am the hormone that throws a blanket over your body after ovulation, raising your basal body temperature by 0.3 to 0.5 degrees Celsius. Who am I?
Answer
Progesterone
Memory link
A3 — Blanket analogy for progesterone and BBT
Formula mnemonics
Estimated Ovulation Day = Cycle Length − 14
Mnemonic
CYCLE minus FOURTEEN = Ovulation. Remember: 'FOURTEEN is the FINAL fixed leg of the trike ride (luteal phase). Subtract it from the total ride length to find WHERE the egg drops.'
When to use
Use when a patient has a non-standard cycle length (not 28 days) and you need to estimate ovulation day. Also used to calculate the fertile window (ovulation day ± 5 days before, 1 day after).
What each part means
Cycle Length = total number of days from Day 1 of one period to Day 1 of the next; 14 = the fixed duration of the luteal phase; Result = the approximate day of ovulation in that particular cycle.
True (Obstetric) Conjugate ≈ Diagonal Conjugate − 1.5 cm
Mnemonic
DIAGONAL minus ONE-AND-A-HALF = TRUE. 'DIAL DOWN by 1.5 to get the TRUE measurement.' Diagonal = 12.5 cm (measured clinically); True conjugate = ~11 cm (the actual obstetric space). If True conjugate <10 cm = risk of cephalopelvic disproportion (CPD).
When to use
Use during obstetric pelvimetry assessment to determine whether the pelvic inlet is adequate for vaginal delivery. Key in NCM 103 maternal nursing and NLE questions on CPD.
What each part means
Diagonal conjugate = distance from the sacral promontory to the inferior edge of the pubic symphysis (measured via internal exam); 1.5 cm = standard correction factor; True/obstetric conjugate = the narrowest AP diameter of the pelvic inlet through which the fetal head must pass.
BBT rises by 0.3–0.5°C after ovulation (due to progesterone)
Mnemonic
The 'point-3 to point-5 BLANKET' — Progesterone throws a blanket of 0.3 to 0.5 degrees. If you see a temperature chart and the BBT climbs by this range and STAYS elevated for 3+ days, ovulation has occurred. LOWER before the rise = the dip before ovulation; SUSTAINED RISE = confirmed ovulation.
When to use
Apply when interpreting BBT charts in fertility awareness methods (FAM), teaching natural family planning (NFP), or answering NLE questions about signs of ovulation.
What each part means
BBT = Basal Body Temperature (temperature at rest, taken first thing in the morning before any activity); 0.3–0.5°C rise = thermogenic effect of progesterone secreted by the corpus luteum after the follicle ruptures.
Fertile Window = 5 days BEFORE ovulation + day of ovulation + 1 day AFTER = ~6 days total
Mnemonic
'FIVE BEFORE, ONE AFTER — that's your DANGER ZONE for pregnancy (or TARGET ZONE for conception).' Sperm can survive up to 5 days in fertile cervical mucus, so intercourse 5 days before ovulation can still result in fertilisation. The egg itself only lasts ~24 hours, so 1 day after ovulation closes the window.
When to use
Use in patient teaching for natural family planning (calendar/rhythm method), in contraception counselling, and when answering questions about timing of intercourse for conception or avoidance.
What each part means
5 days before = maximum sperm survival in fertile mucus; Day of ovulation = egg released, highest fertilisation probability; 1 day after = end of egg viability (~24 hours post-ovulation).
Quick recall chains
Pathway of Sperm from Production to Ejaculation
Recall test
Without looking, list the 7 structures sperm pass through from production to ejaculation in order.
Memory chain
Story: 'SEMINANDO (Seminiferous) lives in EPAD (Epididymis). He travels the VANDA road (Vas deferens) to reach an EJECTING door (Ejaculatory duct). At the PROSE store (Prostate), he gets supplies. He passes the BULOL bridge (Bulbourethral glands) and finally exits through the URETHRA tunnel.' Acronym: SE-VE-PB-U = 'Serbidores Every Victory Produces Beautiful Unions' (Seminiferous → Epididymis → Vas deferens → Ejaculatory duct → Prostate → Bulbourethral → Urethra).
Items to remember
- Seminiferous tubules (testes) — produced
- Epididymis — matured and stored
- Vas deferens — transported
- Ejaculatory duct — joins seminal vesicle secretions
- Prostate gland — alkaline fluid added
- Bulbourethral glands — pre-ejaculate added
- Urethra — exits the body
Phases of the Ovarian Cycle in Order
Recall test
Name the 3 phases of the ovarian cycle, state which hormone drives each phase, and identify which phase has a FIXED duration.
Memory chain
Chain phrase: 'FOLLOW the LIGHT to the LOOT.' F = Follicular phase (FSH = Follow-up hormone, grows follicle). L = Light = LH surge (a bright flash of light = sudden spike) triggering ovulation. L = Loot = Luteal phase (corpus luteum = treasure chest of progesterone). If you get pregnant, you KEEP the loot (corpus luteum maintained by hCG). If not, the loot disappears (corpus luteum degenerates) and menstruation begins.
Items to remember
- Follicular phase (Days 1–13) — FSH stimulates follicle growth
- Ovulation (Day 14) — LH surge ruptures follicle
- Luteal phase (Days 15–28) — corpus luteum secretes progesterone
Hormonal Sequence Leading to Ovulation
Recall test
Recite the 7-step hormonal sequence from GnRH release to corpus luteum progesterone secretion.
Memory chain
Walk through the BAHAY again: Bubong (GnRH) tells the Sala (FSH → follicle grows → oestrogen rises). Oestrogen's 'good news' text (positive feedback) goes BACK UP to the sala, which then SURGES LH (the santol-dropping wind). Ovulation happens. Corpus luteum forms in the silong (ovary) and secretes progesterone (throws the blanket). Chain acronym: G-F-E-L-O-C-P = 'Great Filipino Eggs Like Ovulating Calmly, Please.'
Items to remember
- GnRH released by hypothalamus
- FSH released by anterior pituitary
- Dominant follicle grows, secretes rising oestrogen
- Rising oestrogen triggers positive feedback
- LH surge released by anterior pituitary
- Follicle ruptures — OVULATION
- Corpus luteum forms, secretes progesterone
Early Development After Fertilisation (Zygote to Implantation)
Recall test
On what day does implantation occur? What does the trophoblast immediately secrete and why?
Memory chain
FeMBer Implanted hCG (pronounced 'FeMBer'): F = Fertilisation (Day 0, ampulla), M = Morula (Days 1–3), B = Blastocyst (Days 3–4), Im = Implantation (Days 6–10), hCG = trophoblast secretes hCG. The month FeMBer (like September/December) is when everything 'nests' and settles in — just like the blastocyst nesting in the endometrium.
Items to remember
- Day 0: Fertilisation in the ampulla → ZYGOTE (46 chromosomes)
- Days 1–3: Cleavage divisions → MORULA (solid ball of cells)
- Days 3–4: Morula → BLASTOCYST (hollow ball, has trophoblast)
- Days 6–10: Blastocyst IMPLANTS in the endometrium
- Trophoblast secretes hCG to maintain corpus luteum
Menstrual Disorder Vocabulary (5 Key Terms)
Recall test
Define each of the 5 terms and state which type of dysmenorrhoea is associated with prostaglandin excess (primary) vs. endometriosis (secondary).
Memory chain
'All Menses Make Doctors Observe' (A-M-M-D-O). Each first letter matches the disorder: A=Amenorrhoea, M=Menorrhagia, M=Metrorrhagia, D=Dysmenorrhoea, O=Oligomenorrhoea. Visual: Picture a DOCTOR (D = Dysmenorrhoea) watching (Observe = O = Oligo) while a patient is ABSENT (A), MASSIVE bleeding (M), and bleeding BETWEEN check-ups (M = Metro/LRT between stations).
Items to remember
- Amenorrhoea — ABSENT menses
- Menorrhagia — MASSIVE/heavy prolonged flow
- Metrorrhagia — bleeding BETWEEN periods (irregular timing)
- Dysmenorrhoea — DIFFICULT/painful menses
- Oligomenorrhoea — OCCASIONAL/infrequent light periods
Diagrams
Hormonal Cascade: From Hypothalamus to Ovulation
This flowchart traces the complete hormonal pathway from GnRH release through ovulation to either menstruation or early pregnancy maintenance. Students can follow the arrows to see how each hormone triggers the next event in the cycle, reinforcing the HPG axis and the role of hCG.
Reproductive Anatomy and Physiology: Master Concept Map
This comprehensive mind map organises all major topics of the chapter into a single visual hierarchy. Students can use it as a visual roadmap to verify they have covered all key concepts, and as a quick review tool before the NLE. Each branch corresponds to a major section of the chapter.
The 28-Day Menstrual Cycle: Ovarian and Endometrial Phase Transitions
This state diagram shows the menstrual cycle as a series of transitions with clear triggers for each phase change. The dual exit from the Secretory Phase (to Menstruation OR Pregnancy) visually reinforces the critical decision point — fertilisation. Students can trace the pathway and immediately see the role of each hormone at each transition.
Zygote Journey: From Fertilisation to Implantation
This timeline visually maps the 10-day journey of the fertilised egg from ampulla to uterine implantation. Students can see the precise timing of each developmental stage (zygote → morula → blastocyst → implantation) and immediately understand why hCG appears only after Day 6–10 (when the trophoblast embeds and begins secreting).