Midwife Licensure Exam Reproductive Anatomy & Physiology — Reproductive Anatomy, Physiology & the Menstrual CycleRevision Notes

Exam Tips

• REMEMBER: 'Sertoli = FSH; Leydig = LH' — use the mnemonic 'FSH Finds Sertoli; LH Loves Leydig.'
• The vas deferens is the ONLY structure cut in vasectomy — boards may describe the procedure and ask you to name the structure.
• If a board item describes a male with normal libido but azoospermia (no sperm in ejaculate), consider vasectomy or bilateral epididymal obstruction.
• Sperm temperature regulation is a common item — the scrotum keeps testes 1–2°C below core temperature.
• Normal sperm count ≥15 million/mL — memorise this WHO reference value for NLE calculations and clinical scenario questions.

Key Points

• The testes are paired gonads housed in the scrotum; they serve TWO main functions: spermatogenesis (sperm production in the seminiferous tubules) and testosterone secretion (by Leydig/interstitial cells).
• The scrotum maintains testicular temperature 1–2°C BELOW core body temperature — this lower temperature is essential for normal sperm production. Cryptorchidism (undescended testes) causes infertility because the testes are too warm.
• Sperm MATURE and gain motility in the EPIDIDYMIS, where they are also stored.
• The VAS DEFERENS (ductus deferens) transports sperm from the epididymis to the ejaculatory duct — this is the structure severed in a VASECTOMY for male sterilisation.
• Accessory glands and their secretions: Seminal vesicles — fructose-rich alkaline fluid (nourishes sperm, largest volume contributor to semen); Prostate gland — thin alkaline fluid (neutralises vaginal acidity, enhances motility); Bulbourethral/Cowper's glands — pre-ejaculatory mucus (lubricates and neutralises the urethra).
• The urethra is a SHARED passage for urine and semen, but NEVER simultaneously — a reflex closes the bladder neck during ejaculation.
• Spermatogenesis takes approximately 64–74 days and is continuous from puberty onward.
• Normal semen analysis (WHO reference): volume 2–5 mL, sperm concentration ≥15 million/mL, normal morphology ≥4%, motility ≥32% progressive.
• The FATHER determines fetal sex — sperm carry either an X chromosome (produces female offspring) or a Y chromosome (produces male offspring). The mother's egg always carries an X chromosome.
• FSH acts on Sertoli cells to support developing sperm; LH acts on Leydig cells to stimulate testosterone production.

Definitions

Section Title

The Male Reproductive System

Common Mistakes

• Confusing FSH and LH roles in males — FSH acts on SERTOLI cells (supports sperm development); LH acts on LEYDIG cells (stimulates testosterone). Many students reverse these.
• Thinking the epididymis produces sperm — it does NOT. Sperm are PRODUCED in the seminiferous tubules and only MATURE in the epididymis.
• Assuming vasectomy eliminates ejaculation — it does not. Semen is still produced by the accessory glands; only sperm are absent from the ejaculate.
• Forgetting that the FATHER determines sex — students sometimes attribute sex determination to the mother.
• Underestimating the duration of spermatogenesis — 64–74 days is clinically significant (e.g., when counselling couples about how long it takes to recover sperm quality after illness or toxin exposure).

Formulas

Exam Tips

• HIGH-YIELD: 'Fertilisation = Ampulla; Implantation = Endometrium (uterus).' These two facts appear on almost every NLE exam.
• For pelvic measurements: DIAGONAL conjugate = 12.5 cm (measured); TRUE conjugate = 11 cm (estimated = DC − 1.5 cm). Android pelvis is worst for vaginal delivery.
• Remember vaginal pH is ACIDIC (3.5–4.5) — this is protective. Boards may ask what maintains this and the nursing implication (front-to-back wiping, avoiding douching).
• The MYOMETRIUM contracts during labour AND postpartum — its contraction after delivery compresses blood vessels and prevents hemorrhage. This is why uterine atony (failure to contract) is the #1 cause of postpartum hemorrhage.
• The FUNDUS is the part of the uterus palpated during pregnancy (fundal height measurement) and postpartum (to assess involution).

Key Points

• EXTERNAL GENITALIA (vulva): mons pubis, labia majora and minora, clitoris (erectile and sensory, homologous to the penis), vestibule, urethral and vaginal openings, Bartholin's glands (secrete lubrication during sexual arousal), and the perineum.
• The PERINEUM is the area between the vaginal opening and the anus — the site of episiotomy and lacerations during childbirth. Nurses assess and care for this area in the postpartum period.
• VAGINA: Muscular canal serving as the birth canal, passage for menstrual flow, and organ of coitus. Normal vaginal pH is ACIDIC at 3.5–4.5, maintained by Döderlein's lactobacilli. This acidity is a first-line defense against infection.
• UTERUS: Pear-shaped muscular organ with three parts — FUNDUS (top, assessed postpartum for involution), BODY/CORPUS, and CERVIX (lower neck opening into vagina). Normal position: ANTEVERTED and ANTEFLEXED.
• The three UTERINE LAYERS: PERIMETRIUM (outer serous layer), MYOMETRIUM (thick muscle — contracts in labour and clamps blood vessels postpartum to prevent hemorrhage), and ENDOMETRIUM (inner lining — shed in menstruation, site of implantation).
• FALLOPIAN (UTERINE) TUBES: Approximately 10 cm long. The FIMBRIAE sweep the ovum from the ovary into the tube. FERTILISATION NORMALLY OCCURS IN THE AMPULLA (outer/distal third) of the fallopian tube — NOT in the uterus.
• OVARIES: Paired gonads that store oocytes, release one mature ovum per cycle (ovulation), and secrete oestrogen and progesterone. A female is BORN WITH ALL HER OOCYTES (approximately 1–2 million at birth, declining to ~400,000 at puberty, with approximately 400 ovulated in a lifetime).
• THE BONY PELVIS: The TRUE (LESSER) PELVIS is the actual birth canal. The GYNECOID pelvis (rounded inlet) is the most favourable shape for vaginal delivery. The DIAGONAL CONJUGATE (~12.5 cm) and TRUE/OBSTETRIC CONJUGATE (~11 cm or more) estimate pelvic adequacy. A contracted pelvis leads to CEPHALOPELVIC DISPROPORTION (CPD).
• Four pelvic types (GOAP mnemonic): Gynecoid (most favourable, rounded), Android (heart-shaped, male-type, unfavourable), Anthropoid (oval, narrow), Platypelloid (flat, wide transverse diameter, unfavourable for engagement).

Definitions

Section Title

The Female Reproductive System

Common Mistakes

• Stating fertilisation occurs in the UTERUS — it occurs in the AMPULLA of the fallopian tube. The uterus is the site of IMPLANTATION.
• Confusing the diagonal conjugate (12.5 cm, clinically measurable) with the true/obstetric conjugate (11 cm, estimated by subtracting 1.5 cm) — boards test both values and their difference.
• Forgetting that women are BORN with all their oocytes — female oocytes are not produced after birth, unlike male sperm which are continuously produced.
• Confusing the three uterine layers — students often mix up PERIMETRIUM (outer serous), MYOMETRIUM (muscle), and ENDOMETRIUM (inner lining). Use the mnemonic 'PEMs: Perimetrium, myomEtrium, Endometrium — Peeling from outside in.'
• Thinking the clitoris has no significant reproductive function — while not directly involved in conception, it is part of the vulva and its assessment is relevant in perineal care and trauma assessment.

Exam Tips

• HORMONE SEQUENCE BEFORE OVULATION: GnRH → FSH → Follicle grows → Oestrogen rises → LH SURGE → OVULATION. Memorise this chain.
• AFTER OVULATION: Ruptured follicle → CORPUS LUTEUM → PROGESTERONE rises → BBT rises 0.3–0.5°C → Endometrium becomes SECRETORY.
• Pregnancy test = hCG detection. If pregnant → trophoblast releases hCG → maintains corpus luteum → progesterone continues → no menstruation.
• Combined OCP mimics LUTEAL PHASE hormones (high oestrogen + progesterone) → negative feedback → no FSH/LH → no follicle → no ovulation.
• BBT + cervical mucus assessment are the physiological basis of NATURAL FAMILY PLANNING — highly relevant for Philippine clinical practice and board exams.

Key Points

• The HYPOTHALAMIC-PITUITARY-GONADAL (HPG) AXIS is the master regulatory system: Hypothalamus releases GnRH → Anterior pituitary releases FSH and LH → Gonads (ovaries/testes) produce sex hormones and gametes.
• GnRH (Gonadotropin-Releasing Hormone): Released in PULSES from the hypothalamus. Stimulates the anterior pituitary to secrete FSH and LH. Basis for GnRH agonist therapy in reproductive medicine.
• FSH (Follicle-Stimulating Hormone): From anterior pituitary. In FEMALES — stimulates FOLLICLE GROWTH and oestrogen production. In MALES — stimulates SERTOLI CELLS to support spermatogenesis.
• LH (Luteinizing Hormone): From anterior pituitary. In FEMALES — the MID-CYCLE LH SURGE triggers OVULATION and forms the CORPUS LUTEUM. In MALES — stimulates LEYDIG CELLS to produce TESTOSTERONE.
• OESTROGEN: Primarily from the OVARIAN FOLLICLE. Actions: promotes endometrial PROLIFERATION, develops secondary female sex characteristics, produces thin/stretchy/clear cervical mucus (SPINNBARKEIT — a sign of fertility), and triggers the LH surge via POSITIVE FEEDBACK when oestrogen rises sharply.
• PROGESTERONE: The 'hormone of pregnancy.' Secreted by the CORPUS LUTEUM (and later the PLACENTA). Actions: makes endometrium SECRETORY (nutrient-rich for implantation), THICKENS cervical mucus (hostile to sperm — used by progesterone-only pills), RAISES BASAL BODY TEMPERATURE (BBT) by ~0.3–0.5°C after ovulation, and RELAXES SMOOTH MUSCLE to maintain pregnancy.
• hCG (Human Chorionic Gonadotropin): Secreted by the TROPHOBLAST after implantation. MAINTAINS THE CORPUS LUTEUM so progesterone production continues during early pregnancy. hCG is the hormone DETECTED BY PREGNANCY TESTS (urine and serum). hCG peaks around weeks 8–10 of pregnancy.
• INHIBIN: Secreted by ovarian granulosa cells (and Sertoli cells in males); provides NEGATIVE FEEDBACK to the anterior pituitary to suppress FSH — prevents multiple follicle recruitment.
• TESTOSTERONE: In FEMALES, small amounts are secreted by the adrenal cortex and ovaries, contributing to libido. In males, produced by Leydig cells, responsible for virilisation, spermatogenesis support, and libido.

Definitions

Section Title

Reproductive Hormones

Common Mistakes

• Confusing which hormone rises BEFORE ovulation vs AFTER — OESTROGEN peaks just before ovulation (triggering the LH surge); PROGESTERONE rises AFTER ovulation (from the corpus luteum).
• Forgetting that progesterone RAISES BBT — students often attribute BBT changes to oestrogen. Oestrogen makes cervical mucus thin; PROGESTERONE raises BBT.
• Thinking hCG is produced by the ovary — it is produced by the TROPHOBLAST (embryonic tissue/placenta), not the ovary. hCG then acts on the corpus luteum.
• Mixing up positive and negative feedback — RISING oestrogen causes POSITIVE feedback (LH surge); HIGH progesterone + oestrogen during the luteal phase causes NEGATIVE feedback (suppressing FSH and LH, which is the basis of combined oral contraceptive pills).
• Forgetting that combined OCP works via negative feedback — it mimics the luteal phase hormonal milieu to suppress the LH surge and prevent ovulation.

Formulas

Exam Tips

• MEMORISE THE PARALLEL PHASES: Follicular = Proliferative (Oestrogen); Luteal = Secretory (Progesterone). These parallel relationships appear in EVERY NLE set.
• The LUTEAL PHASE IS FIXED at ~14 days. ALL cycle length variation is due to the FOLLICULAR PHASE. This is the most commonly tested menstrual cycle fact.
• Use the formula CYCLE LENGTH − 14 to find ovulation day. A board item that gives a cycle length other than 28 and asks for the expected ovulation day is testing THIS concept.
• For dysmenorrhoea management: PRIMARY → NSAIDs (mefenamic acid is most commonly used in Philippine clinical practice) + heat. Advise to take with food to prevent GI upset. SECONDARY → refer for pelvic evaluation.
• AMENORRHOEA in a woman of reproductive age: ALWAYS consider PREGNANCY FIRST as the most common cause. This is both a clinical and board principle.
• BBT interpretation: A sustained rise of 0.3–0.5°C lasting at least 3 days AFTER ovulation confirms ovulation has occurred. Ovulation is in the PAST once BBT rises — it cannot predict ovulation IN ADVANCE (unlike cervical mucus changes).

Key Points

• The menstrual cycle has an AVERAGE of 28 days but a NORMAL RANGE of 21–35 days. Day 1 is the FIRST DAY OF BLEEDING (menstruation).
• Normal menstrual flow: DURATION 2–7 days; BLOOD LOSS approximately 30–80 mL per cycle. Blood loss >80 mL per cycle defines menorrhagia.
• The cycle is described in TWO PARALLEL SETS: the OVARIAN CYCLE (what happens in the ovary) and the ENDOMETRIAL/UTERINE CYCLE (what happens in the uterus).
• OVARIAN CYCLE has THREE PHASES: (1) Follicular Phase (days 1–13, VARIABLE length) — FSH stimulates follicles; dominant Graafian follicle secretes rising oestrogen. (2) Ovulation (approximately day 14 in a 28-day cycle) — LH surge ruptures the mature follicle, releasing the ovum. (3) Luteal Phase (days 15–28, FIXED ~14 days) — corpus luteum secretes progesterone.
• THE LUTEAL PHASE IS ALWAYS APPROXIMATELY 14 DAYS. Cycle length variation comes from the FOLLICULAR PHASE. This is why the formula to estimate ovulation is: OVULATION = CYCLE LENGTH MINUS 14 DAYS (NOT always day 14).
• ENDOMETRIAL (UTERINE) CYCLE has THREE PHASES: (1) Menstrual Phase (days 1–5) — functional endometrium sheds due to falling progesterone and oestrogen. (2) Proliferative Phase (days 6–14) — OESTROGEN rebuilds the endometrium. (3) Secretory Phase (days 15–28) — PROGESTERONE makes endometrium glandular and nutrient-rich for implantation.
• SIGNS OF OVULATION — used in fertility awareness: (1) BBT dips slightly then RISES ~0.3–0.5°C (due to progesterone) and stays elevated. (2) Cervical mucus becomes CLEAR, THIN, STRETCHY (spinnbarkeit) — oestrogen effect. (3) Cervix softens, opens slightly (os), and rises in the vaginal vault. (4) MITTELSCHMERZ — mid-cycle unilateral pelvic pain from follicle rupture or peritoneal irritation from follicular fluid.
• If FERTILISATION DOES NOT occur: corpus luteum regresses after 10–12 days → progesterone and oestrogen drop → endometrium breaks down → MENSTRUATION begins.
• If FERTILISATION OCCURS: trophoblast secretes hCG → maintains corpus luteum → progesterone continues → no menstruation = AMENORRHOEA (earliest sign of pregnancy).

Definitions

Section Title

The Menstrual Cycle

Common Mistakes

• Assuming ovulation is ALWAYS on day 14 — it is ONLY on day 14 in a PERFECT 28-day cycle. Use the formula: Cycle Length − 14 = estimated day of ovulation.
• Confusing the follicular and proliferative phases — FOLLICULAR is the ovarian phase; PROLIFERATIVE is the corresponding UTERINE (endometrial) phase. Both occur during days 1–14 and are driven by OESTROGEN.
• Similarly, confusing luteal and secretory phases — LUTEAL is ovarian; SECRETORY is uterine. Both occur during days 15–28 and are driven by PROGESTERONE.
• Forgetting which hormone drives which endometrial phase: OESTROGEN → PROLIFERATIVE; PROGESTERONE → SECRETORY. Think: 'Oestrogen Proliferates; Progesterone Prepares (for pregnancy).'
• Believing that a woman CANNOT get pregnant during menstruation — she CAN, especially if she has a short cycle (e.g., 21 days, ovulation on day 7) and sperm can survive 5 days from day 1–3. This is an important myth to address in health teaching.

Exam Tips

• SEQUENCE TO MEMORISE: Ovulation (Day 14) → Ovum released → Fertilisation in AMPULLA (within 24 h of ovulation) → Zygote → Morula → Blastocyst → Implantation (Day 20–24, i.e., 6–10 days after fertilisation) → hCG secreted → Pregnancy confirmed.
• Ovum lifespan = 24 hours; Sperm lifespan = up to 5 days in fertile mucus. Fertile window = 5 days before + day of + 1 day after ovulation = approximately 6 days.
• Infertility evaluation: <35 years → after 12 months; ≥35 years → after 6 months. This distinction appears in NLE case scenarios.
• Post-ovulation signs (BBT rise, thick mucus) signal the INFERTILE phase in NFP — important for teaching the symptothermal method.
• Postmenopausal bleeding (any vaginal bleeding 12 months after the last period) is ALWAYS ABNORMAL and must be evaluated — key NLE red flag and patient education point.

Key Points

• The OVUM survives approximately 24 HOURS after ovulation. SPERM survive approximately 48–72 HOURS in regular vaginal secretions, but UP TO 5 DAYS in fertile (oestrogen-rich, spinnbarkeit) cervical mucus.
• The FERTILE WINDOW is approximately 5 DAYS BEFORE through 1 DAY AFTER ovulation — a total of about 6 days. This is the basis of all natural family planning (NFP) methods.
• FERTILISATION occurs in the AMPULLA (outer third) of the fallopian tube when ONE sperm penetrates the zona pellucida of the secondary oocyte. The zona reaction immediately prevents polyspermy.
• The ZYGOTE (46 chromosomes, diploid) is formed after fertilisation. It undergoes CLEAVAGE (mitotic divisions) to form a MORULA (solid ball of cells), then a BLASTOCYST (hollow, fluid-filled structure with an inner cell mass).
• The blastocyst travels through the fallopian tube to the uterus in approximately 3–4 DAYS. IMPLANTATION in the endometrium occurs approximately 6–10 DAYS AFTER FERTILISATION (approximately days 20–24 of a 28-day cycle).
• After implantation, the trophoblast secretes hCG, which maintains the corpus luteum, sustaining progesterone production until the placenta takes over at approximately 10–12 weeks of gestation.
• MENOPAUSE: Permanent cessation of menstruation, defined as 12 CONSECUTIVE MONTHS WITHOUT A PERIOD. Average age in the Philippines is approximately 49–52 years (global average ~51 years). The transitional period is the PERIMENOPAUSE/CLIMACTERIC, marked by irregular cycles, vasomotor symptoms (hot flushes, night sweats), and falling oestrogen.
• FECUNDITY (natural fertility) declines significantly after age 35 due to declining oocyte QUANTITY and QUALITY. This is a counselling point for women delaying childbearing.
• INFERTILITY is defined as FAILURE TO CONCEIVE after 12 MONTHS of regular (2–3 times per week) unprotected sexual intercourse. If the woman is OVER 35, evaluation begins after 6 MONTHS. Causes: approximately one-third female (ovulatory disorders, tubal blockage), one-third male (low count, poor motility, abnormal morphology), one-third combined or unexplained.

Definitions

Section Title

Fertility, Conception, and Common Infertility Concepts

Common Mistakes

• Confusing zygote → morula → blastocyst sequence — students sometimes skip or rearrange these stages. Memorise: Zygote → Cleavage → Morula → Blastocyst → Implantation.
• Stating that implantation occurs immediately after fertilisation — there is a 6–10 day journey from fertilisation (ampulla) to implantation (uterus). During this time, the embryo is NOT yet attached to the mother.
• Forgetting that fecundity declines after age 35 — this is relevant for patient education and is increasingly tested as more women delay childbearing.
• Misdefining infertility as 6 months for ALL women — it is 12 months for women under 35, and 6 months for women OVER 35.
• Thinking menopause is a sudden event — it is a PROCESS (perimenopause → menopause). Menopause is only CONFIRMED after 12 consecutive months without a period.

Exam Tips

• MENSTRUAL VOCABULARY DRILL: Know ALL the prefixes — 'oligo' = scanty/infrequent; 'poly' = many/frequent; 'metrorrhagia' = between periods; 'menorrhagia' = heavy during periods; 'dys' = painful; 'a' = absence.
• For dysmenorrhoea NLE items: the FIRST nursing action is HEAT APPLICATION (non-pharmacological) before or alongside NSAIDs. Always include the instruction to take NSAIDs WITH FOOD.
• SECONDARY AMENORRHOEA + REPRODUCTIVE AGE WOMAN = RULE OUT PREGNANCY FIRST. This answer choice is almost always correct in NLE scenario questions.
• The Billings Ovulation Method (cervical mucus observation) and the Symptothermal Method are the NFP methods taught in Philippine PHC — know their mechanism, which phase is fertile (peak mucus = fertile), and nursing teaching points.
• RA 9173 and its implementing rules support the nurse's role in reproductive health education — this may appear as a legal/ethical NLE item asking about the nurse's scope of practice in family planning counselling.

Key Points

• NURSES UNDER RA 9173 (Philippine Nursing Act of 2002) are mandated to provide health education, which includes reproductive health counselling. This is especially relevant in community health nursing (PHC level), RHUs, and lying-in clinics.
• PATIENT TEACHING — PERINEAL HYGIENE: Always wipe FRONT TO BACK (urethra to anus) to prevent contamination of the vagina and urethra with fecal organisms (E. coli). Avoid douching — it disrupts normal vaginal flora and the protective acidic pH.
• PATIENT TEACHING — FERTILITY AWARENESS: Teach clients to track their menstrual cycle, observe cervical mucus, and chart BBT to identify their fertile window. This is the basis of NFP methods (Billings, symptothermal) — important in Philippine Catholic health institutions and primary care.
• PATIENT TEACHING — DYSMENORRHOEA: For PRIMARY dysmenorrhoea — apply HEAT to the lower abdomen (promotes muscle relaxation), administer NSAIDs (mefenamic acid 500 mg or ibuprofen 400 mg TID with meals to avoid GI irritation), encourage light exercise. For SECONDARY dysmenorrhoea — refer to physician for pelvic evaluation (rule out endometriosis, fibroids).
• HEALTH EDUCATION — DISPELLING MYTHS: Correct the common myth that pregnancy CANNOT occur during menstruation — it CAN, especially in women with short cycles and/or long sperm survival. Correct the myth that withdrawal (coitus interruptus) is 100% effective — pre-ejaculate may contain sperm.
• NURSING ASSESSMENT OF MENSTRUAL HISTORY: Ask about cycle regularity, duration, volume (number of pads/tampons per day), pain (severity, timing, character), intermenstrual bleeding, and any recent changes. This is part of the complete obstetric-gynaecologic history.
• REPORT AND REFER: Any of the following warrant physician referral — amenorrhoea (rule out pregnancy, hormonal disorders, eating disorders), severe or worsening dysmenorrhoea (secondary cause), heavy bleeding with anaemia symptoms, intermenstrual bleeding, and postmenopausal bleeding.
• MENSTRUAL VARIATIONS VOCABULARY — Board items frequently test these terms: Amenorrhoea (no menses), Oligomenorrhoea (infrequent/scanty), Polymenorrhoea (frequent periods, <21-day cycle), Menorrhagia (heavy/prolonged flow), Metrorrhagia (inter-period bleeding), Menometrorrhagia (heavy AND irregular), Dysmenorrhoea (painful menses).

Definitions

Section Title

Nursing Considerations, Patient Teaching & Menstrual Variations

Common Mistakes

• Failing to rule out pregnancy in secondary amenorrhoea before other workup — this is the most common clinical and board mistake.
• Confusing polymenorrhoea (frequent periods — SHORT CYCLES <21 days) with menorrhagia (HEAVY flow but regular frequency). Two different dimensions: FREQUENCY vs VOLUME.
• Advising ibuprofen or mefenamic acid WITHOUT the instruction to take with food — GI irritation and ulcer risk must always be addressed in patient education.
• Forgetting to teach FRONT-TO-BACK perineal hygiene — a basic but frequently tested nursing health teaching point.
• Overlooking the emotional and psychological impact of menstrual disorders — pain, irregular bleeding, and fertility concerns cause significant anxiety and affect quality of life. Nursing diagnosis: Anxiety, Deficient Knowledge, Acute Pain.