embryonic & fetal development chart

Weeks 3–4 (Early organ formation) Flashcard 1 Front: What major structure forms at week 3? Back: Neural tube forms (becomes spinal cord); heart and GI tract begin development. Flashcard 2 Front: What key event happens at week 4? Back: Neural tube closes; 4-chamber heart forms; brain differentiates; limb buds appear; lungs, kidneys, liver, genitalia begin forming. ❤ Weeks 5–8 (Organogenesis) Flashcard 3 Front: When does the fetal heart begin beating regularly? Back: Week 5. Flashcard 4 Front: What is a key milestone of week 6? Back: Fetal circulation established; brain waves detectable; liver produces RBCs; primitive skeleton forms. Flashcard 5 Front: What develops in week 7? Back: Ear begins forming; toes/elbows visible; limb movement; diaphragm formed; tooth buds appear. Flashcard 6 Front: What defines week 8 of development? Back: Organogenesis complete; eyelids form (sealed); placenta functioning; genital differentiation begins; intestines rotate. 👶 Weeks 9–12 (Early fetal stage)Flashcard 7 Front: When is fetal sex identifiable? Back: Around week 12. Flashcard 8 Front: What happens to movement in weeks 9–12? Back: Fetus kicks, swallows, and moves; urine production begins. Flashcard 9 Front: What proportion of body size is the head at this stage? Back: Nearly half the fetal size. 🌱 Weeks 13–16 (Early second trimester) Flashcard 10 Front: What is quickening? Back: First fetal movement felt by pregnant person (weeks 16–20). Flashcard 11 Front: What develops in weeks 13–16? Back: Fingernails/toenails; bone hardening; sucking motions; external genitalia visible. 🌿 Weeks 17–20 (Mid-pregnancy milestones) Flashcard 12 Front: What appears on fetus at 17–20 weeks? Back: Lanugo, vernix caseosa, eyebrows, scalp hair. Flashcard 13 Front: When can fetal heart tones be heard with a stethoscope? Back: Around 17–20 weeks. Flashcard 14 Front: What is a key fetal fat development at this stage? Back: Brown fat forms for temperature regulation. Weeks 21–24 (Viability begins) Flashcard 15 Front: What lung development begins at 21–24 weeks? Back: Alveoli formation and surfactant production begins. Flashcard 16 Front: What reflexes are present at this stage?Back: Startle and hand grasp reflexes. Flashcard 17 Front: What is the viability milestone? Back: Around 24 weeks (fetus may survive with intensive support). 👁 Weeks 25–28 Flashcard 18 Front: When do eyelids open? Back: Weeks 25–28. Flashcard 19 Front: What sensory abilities develop at this stage? Back: Responds to light and sound; can open eyes and suck thumb. Flashcard 20 Front: What major circulatory change occurs? Back: Bone marrow takes over RBC production. 🧠 Weeks 29–32 Flashcard 21 Front: What major development occurs in weeks 29–32? Back: Rapid brain development and increased body fat. Flashcard 22 Front: What lung activity is seen? Back: Rhythmic breathing movements (lungs still immature). Flashcard 23 Front: What reflex is present? Back: Pupillary light reflex. 👶 Weeks 33–39 (Full term development) Flashcard 24 Front: When is the fetus considered full term? Back: 39 weeks. Flashcard 25 Front: What happens to lanugo? Back: It disappears.Flashcard 26 Front: What lung-related change occurs near term? Back: Lungs mature and surfactant increases. Flashcard 27 Front: What immune protection does the fetus receive? Back: Maternal antibodies cross placenta. Flashcard 28 Front: What position does the fetus usually assume near term? Back: Head-down (vertex) position.