Human Reproduction, Development, and Reproductive Health

Vocabulary flashcards covering the male and female reproductive systems, puberty, gametogenesis, menstrual and ovarian cycles, fertilisation, embryonic development, birth, contraception, STIs, infertility treatments, surrogacy, and foetal alcohol syndrome.

Scrotum

Protects the testes + regulates temp to be $2-3\,^\circ\text{C}$ lower than body temperature for fertile sperm production.

Testes

The male reproductive organs that produce sperm and secrete the hormone testosterone.

Seminiferous Tubules

Coiled tubules inside the testes lined with germinal epithelium and cells of Leydig, where sperm cells develop and mature.

Epididymis

A duct that stores immature sperm until they mature, become motile, and become fertile.

Vas Deferens (Sperm Duct)

The duct that pushes mature sperm forward from the epididymis to the urethra via peristalsis during ejaculation.

Urethra (Male)

The common duct responsible for transporting semen and urine out of the body, though not at the same time.

Prostate Gland

An accessory gland that secretes fluid assisting the transport of sperm and contains enzymes that make sperm motile.

Cowper's Gland

A gland that produces an alkaline fluid when sexually aroused to neutralize acidic urine and lubricate the urethra, protecting sperm from mechanical injury during ejaculation.

Penis

The male copulatory organ that deposits semen containing sperm into the female vagina during copulation.

Erection

The process in which dilation of dorsal and central arteries fills $3$ erectile tissue chambers with blood, causing the penis to lengthen and stiffen.

Ejaculation

The expulsion of semen from the male reproductive tract.

Semen (Seminal Fluid)

The fluid mixture composed of sperm and secretions from the sperm ducts and accessory glands.

Fallopian Tubes (Oviducts)

Muscular pathways lined with cilia connecting the ovaries to the uterus; the site of fertilisation and initial cell division that enables the egg or developing zygote to travel toward the uterus.

Uterus

Where blastocyst implants, develops, and grows throughout pregnancy.

Myometrium

The muscular middle layer of the uterine wall whose contractions push the baby out during childbirth.

Endometrium

The vascular inner lining of the uterus to which the blastocyst attaches, which is shed every $28\text{ days}$ during menstruation if fertilisation does not occur.

Cervix

The narrow lower opening of the uterus that protects the uterine cavity and dilates during childbirth.

Vagina

The muscular canal that receives semen during copulation and birth canal during delivery.

Clitoris

A sensitive structure composed of erectile tissue located at the anterior end of the female external genitalia.

Puberty

Physical and physiological changes during adolescence = development of secondary sexual characteristics = an immature individual capable of reproduction.

Interstitial-Cell-Stimulating Hormone (ICSH)

A gonadotropic hormone released by the pituitary gland that stimulates the testes to secrete testosterone in males.

Follicle-Stimulating Hormone (FSH)

A pituitary gonadotropin that stimulates the development of primary follicles in the ovaries to produce oestrogen.

Menarche

First menstrual bleeding

Gametogenesis

The formation of mature haploid gametes by the gonads via meiosis.

Spermatogenesis

The process occurring in the seminiferous tubules where diploid germinal epithelial cells undergo meiosis to form $4$ mature haploid sperm cells, each containing $23\text{ chromosomes}$.

Sperm cell structure

Oogenesis

Production of mature, haploid eggs

1. Under FSH diploid cells in ovary undergo mitosis = many follicles

2. 1 cell in a follicle enlarges & undergoes meiosis

3. of 4 cells produced 1 survives = form mature, haploid ovum

Zona Pellucida

A protective jelly-like outer layer surrounding the ovum.

Follicular Phase

The phase of the ovarian cycle during which primary follicles mature into a Graafian follicle under the influence of FSH while secreting oestrogen.

Graafian Follicle

A mature fluid-filled ovarian follicle containing a haploid egg cell that moves to the surface of the ovary prior to ovulation.

Ovulation

A sudden surge in LH causes the mature Graafian follicle to rupture, resulting in the release of the ovum (ovulation)

High levels of oestrogen stimulate the pituitary gland to release LH, contributing to the LH surge that triggers ovulation.

Corpus Luteum

A glandular yellow body formed from the ruptured Graafian follicle remnants under LH and FSH influence that secretes oestrogen and progesterone.

Uterine Cycle

The series of cyclic changes in the endometrium, including repair stimulated by oestrogen and vascularization and thickening stimulated by progesterone.

Menstruation

The breakdown and shedding of the endometrium between days $1$ and $5$ following the degeneration of the corpus luteum and the drop in progesterone.

Menopause

The permanent biological stopping of the menstrual cycle and ovulation caused by the ovaries halting the production of oestrogen and progesterone.

Hormone Replacement Therapy (HRT)

Medical administration of low doses of oestrogen and progesterone to relieve symptoms associated with menopause.

Fertilisation

The fusion of the haploid nucleus of a sperm with the haploid nucleus of an egg to form a single diploid zygote.

Blastocyst formation

1. diploid zygote divides by mitosis = 2 cells

2. each cell divides into a ball of cells (morula)

3. morula = blastocyst

Implantation

When the blastocyst sinks & embeds itself into the thickened endometrium of the uterus.

Trophoblast

The outer cellular layer of the blastocyst that develops villi extending into the endometrium to form the placenta.

Embryo

The developing organism from the blastocyst's inner cell mass, which develops into ectoderm, mesoderm, and endoderm

Foetus

The developing unborn baby following the embryonic stage, characterized by rapid growth, tissue and organ differentiation, and turning head-down toward the cervix.

Ultrasound Imaging

High-pitched sound waves bounced off solid structures to create images determining foetal age, size, and complications.

Placenta

A temporary organ that facilitates nutrient and $O_2$ exchange, waste excretion, antibody transfer, and secretes oestrogen + progesterone (maintain pregnancy) and relaxin

Relaxin

A placental hormone that relaxes pelvic joints and ligaments to assist in the delivery of the baby.

Amnion

The membrane surrounding the embryo and foetus that produces and contains amniotic fluid.

Amniotic Fluid

A protective liquid medium that cushions the foetus, prevents gravity-induced malformations, allows practice swallowing and breathing, and buffers against temperature changes and dehydration.

Amniocentesis

A clinical procedure in which a sample of amniotic fluid containing foetal cells is extracted to detect chromosomal abnormalities.

Umbilical Cord

A vascular structure containing $2$ umbilical arteries that carry metabolic wastes away from the foetus and $1$ umbilical vein that transports oxygenated blood and nutrients to the foetus.

Oxytocin

A hormone secreted by pituitary gland that stimulates uterine myometrial contractions during labour and triggers milk ejection during lactation.

Cervical Dilation

The widening of the cervix to a diameter of $10\,\text{cm}$ caused by uterine contractions forcing the amnion and foetus toward the opening.

Afterbirth

The placenta and attached foetal membranes that are separated from the uterine wall and expelled by contractions following the delivery of the infant.

Cesarean Section

Cutting open abdomen & uterus = remove baby

Mammary Glands

Milk-producing accessory glands of the female reproductive system that develop during pregnancy to nourish offspring after birth.

Prolactin

A hormone that stimulates the mammary glands to produce milk after childbirth.

The Pill (Oral Contraceptive)

A daily hormonal contraceptive containing oestrogen and progesterone that inhibits ovulation but does not protect against STIs.

Male Condom

A rubber sheath barrier worn over the erect penis that collects semen before entering the vagina and protects against STIs.

Female Condom

A loose, elongated balloon-like barrier inserted into the vagina prior to sexual intercourse that prevents sperm entry and protects against STIs.

Diaphragm (Contraceptive)

A bendable, cup-shaped barrier placed over the cervix and left in place for $6\text{ hours}$ after intercourse to block sperm from reaching the egg.

Intrauterine Device (IUD)

A small T-shaped device made of copper, steel, or plastic inserted into the uterus to prevent blastocyst implantation.

Injectable Contraceptives

Progestin injections, such as Depo-Provera or Nur-Isterate, that prevent ovulation and thicken cervical mucus to block sperm passage.

Rhythm Method

A natural family planning strategy that tracks menstrual history to predict fertile days and ovulation; noted as the least effective method.

Human Immunodeficiency Virus (HIV)

A virus transmitted through bodily fluids (semen, vaginal secretions, blood transfusions) that attacks the immune system.

Acquired Immune Deficiency Syndrome (AIDS)

The advanced disease condition resulting from HIV infection characterized by a severely depleted immune system incapable of fighting other diseases.

Syphilis

A bacterial sexually transmitted infection entering through micro-tears in genital mucous membranes, causing ulcers/sores, skin rashes, and potentially severe organ damage if not treated with antibiotics.

Gonorrhoea

A bacterial STI causing painful urination, intercourse discomfort, and cloudy yellow discharge, which can lead to pelvic inflammatory disease and female infertility.

Artificial Insemination

An assisted reproduction technique where donor or partner sperm is mechanically deposited into the female reproductive tract without intercourse.

In Vitro Fertilisation (IVF)

An assisted reproductive procedure in which mature eggs are removed from the ovary, fertilized by sperm in a laboratory, and the resulting embryo is placed into the uterus.

Gamete Intra-Fallopian Transfer (GIFT)

An assisted conception method in which collected eggs and sperm are placed directly into the fallopian tube to enable fertilisation within the body.

Intra-Cytoplasmic Sperm Injection (ICSI)

A specialized in vitro micro-fertilisation technique where a single sperm is injected directly into the cytoplasm of a harvested egg cell.

Surrogacy

A legally binding arrangement requiring High Court approval in which a surrogate woman carries a pregnancy for commissioning parents unable to carry, with no commercial gain permitted.

Foetal Alcohol Syndrome (FAS)

A developmental disorder caused by maternal alcohol intake during pregnancy, leading to short stature, low birth weight, poor attention span, slow language development, and learning disabilities.