Human Reproduction & Development – Lecture Overview

Vocabulary flashcards covering key hormones, structures, physiological processes, and pathologies discussed in the reproductive and developmental lecture.

Estradiol

A major ovarian estrogen; rises during the luteal phase and promotes endometrial growth and glycogen secretion.

Progesterone

Ovarian hormone that, with estradiol, maintains the endometrium during the luteal phase and early pregnancy.

Luteal Phase

Post-ovulation phase of the ovarian cycle characterized by high estradiol and progesterone from the corpus luteum.

Ovarian Cycle

Monthly sequence in the ovary (follicular phase → ovulation → luteal phase) that produces a mature oocyte.

Uterine (Menstrual) Cycle

Recurring changes in the endometrium (menstrual, proliferative, secretory phases) driven by ovarian hormones.

Chemotaxis

Movement of cells toward a chemical signal; sperm use chemotaxis to follow allurin toward the oocyte.

Allurin

Chemotactic chemical released from the oocyte’s vicinity that guides sperm up the correct uterine tube.

Zona Pellucida

Glycoprotein layer surrounding the oocyte beneath the corona radiata; sperm must digest through it to fertilize.

Corona Radiata

Outer ring of follicular cells attached to the oocyte; first barrier sperm encounter at fertilization.

Acrosomal Enzymes

Digestive enzymes in the sperm’s acrosomal cap that dissolve the corona radiata and zona pellucida.

Depolarization Block (Polyspermy Block)

Rapid change in oocyte membrane potential after first sperm entry that prevents additional sperm fusion.

Mitochondrial DNA (Maternal Inheritance)

Mitochondria—and their DNA—are supplied by the egg, so mtDNA is inherited solely from the mother.

Blastocyst

Early embryonic stage (≈5–6 days post-fertilization) that implants into the endometrium.

Human Chorionic Gonadotropin (hCG)

Hormone secreted by the blastocyst/placenta; maintains the corpus luteum and is detected in pregnancy tests.

Placenta

Fetal–maternal organ of exchange formed from chorion frondosum (fetus) and decidua basalis (mother).

Chorion Frondosum

Finger-like fetal portion of the placenta that interlaces with maternal tissue for nutrient exchange.

Decidua Basalis

Maternal endometrial tissue that forms the uterine side of the placenta.

Immune-Privileged Site

Region (e.g., placenta, amniotic sac) where fetal tissue is protected from maternal immune attack.

Neural Tube

Embryonic structure formed by fusion of neural crest cells; precursor to brain and spinal cord.

Oxytocin

Posterior-pituitary hormone that triggers uterine contractions during labor and milk let-down during nursing.

Prolactin

Anterior-pituitary hormone that stimulates milk synthesis in mammary glands postpartum.

Milk Ejection Reflex

Oxytocin-mediated contraction of mammary ducts in response to suckling, releasing milk to the infant.

Supply-and-Demand Lactation

Feedback system where emptying of the breast stimulates more milk production; residual milk suppresses it.

Sexually Transmitted Disease (STD)

Infections (e.g., chlamydia, gonorrhea, syphilis) transmitted through sexual contact; may be asymptomatic or fatal.

Cryptorchidism

Undescended testis; intra-abdominal heat impairs sperm production unless surgically corrected.

Endometriosis

Growth of endometrial tissue outside the uterus, causing pain, abnormal bleeding, and possible infertility.

Prostatitis

Inflammation of the prostate, often bacterial; leads to pain and discharge; treated with antibiotics.

Pelvic Inflammatory Disease (PID)

Infection of uterine tubes, usually from STDs; causes pain, fever, high WBC count; treated with antibiotics.

Impotence (Erectile Dysfunction)

Inability to maintain an erection; may involve neural, vascular, or psychological causes; treated with drugs like Viagra.

Cyclic GMP

Second messenger that mediates smooth-muscle relaxation in penile erectile tissue; boosted by Viagra.

Breast Cancer

Common female cancer (ages 35–45); early detection via self-exam/mammography greatly improves survival.

PSA (Prostate-Specific Antigen)

Blood marker used to screen for and monitor prostate cancer in men.

Testicular Cancer

Most common cancer in males 15–35; low incidence but high (≈95 %) survival with orchiectomy and chemotherapy.

Ovarian Cancer

Highly lethal female cancer due to late diagnosis; vague symptoms like bloating and pelvic pain.

Infertility

Inability of a couple to conceive after 1 year; causes include low sperm count, abnormal sperm, oocyte issues, tubal blockage, or uterine environment.

Cell-Mediated Immunity

Immune response involving T-cells; down-regulated in pregnancy to prevent fetal rejection.

Humoral Immunity

Antibody-mediated immune response; relatively maintained during pregnancy while cell-mediated immunity is reduced.

DHEAS

Fetal adrenal steroid that contributes to the cascade initiating labor via effects on maternal hormones.

Labor (Parturition)

Process of childbirth initiated by fetal adrenal cortisol leading to maternal oxytocin release and uterine contractions.