Reproductive System Lecture Notes

Flashcards about the reproductive system.

Asexual Reproduction

Reproduction from one parent; offspring are genetically identical to the parent.

Hermaphroditic Organisms

Organisms with both testes and ovaries in one individual such as Tapeworms.

Sexual Reproduction

Reproduction requiring two parents which produces gametes in gonads. Testes produce sperm and ovaries produce eggs. Union of egg and sperm is a zygote.

External Fertilization

Egg and sperm unite outside the body.

Internal Fertilization

Sperm and egg unite inside the female body.

Copulation

A sexual union to facilitate the reception of the sperm by the female.

Oviparity

Eggs are fertilized internally, and deposited outside to complete development. Seen in aquatic animals, most reptiles, some amphibians, and all birds.

Ovoviviparity

Eggs are fertilized internally, and retained within the mother to complete their development. Embryo obtains nourishment from the egg yolk; seen in bony fish, cartilaginous fish, and some reptiles.

Viviparity

Young develop within the mother, and nourishment is taken directly from the mother’s blood via the placenta; found in almost all mammals.

Placenta

Structure through where blood and gas exchange occur between mother and fetus. Only evolved in mammals.

Gonads

Organs that produce gametes and sex hormones.

Accessory Organs

Organs that conduct gametes and in females house the embryo/fetus.

Testes

Male gonads that produce sperm; housed in scrotum for cooler temperature.

Epididymis

Site of sperm maturation.

Vas Deferens

Duct that carries sperm; severed or blocked during vasectomy.

Urethra

Part of urinary and reproductive system in males.

Erection

Produced when neurons in the parasympathetic division cause the release of nitric oxide, leading to engorgement of erectile tissue with blood.

Semen

Seminal fluid containing sperm and secretions from seminal vesicles, prostate gland, and bulbourethral gland.

Seminal Vesicles

Secrete a thick, viscous fluid containing nutrients for sperm; about 60% of semen volume.

Prostate Gland

Secretes milky alkaline fluid believed to activate sperm; contributes about 30% of semen volume.

Bulbourethral Gland

Mucous secretions with a lubricating effect; 10% semen volume.

Spermatogenesis

Meiosis reduces chromosome number from diploid (2n) to haploid (n) in the testes.

Sertoli Cells

Cells that support, nourish, and regulate the production of sperm.

Sperm

Male gamete with head (acrosome and nucleus), middle piece (mitochondria), and tail (flagellum).

Gonadotropin-Releasing Hormone (GnRH)

Secreted by the hypothalamus, stimulates the anterior pituitary to produce gonadotropic hormones.

Follicle-Stimulating Hormone (FSH)

Gonadotropic hormone that promotes spermatogenesis in men.

Luteinizing Hormone (LH)

Gonadotropic hormone that controls the production of testosterone in men.

Ovaries

Female gonads.

Oviducts

Uterine or fallopian tubes extending from ovaries to uterus.

Uterus

Pear-sized organ where embryo embeds in lining (endometrium).

Cervix

Narrow end of the uterus.

Vagina

Female reproductive canal at a 45° angle with the body's vertical axis.

Vulva

External genitalia of the female, including mons pubis, labia majora and minora, clitoris, and hymen.

Clitoris

Homologous to penis; comprised of erectile tissue at the junction of labia minora.

Ovarian Cycle

Events in the ovary controlled by FSH and LH, consisting of follicular and luteal phases.

Menstrual Cycle

Events in the uterus.

Follicular Phase

First phase of the ovarian cycle, lasting from the first day of menstruation until the 13th day.

Luteal Phase

Second phase of the ovarian cycle, from day 15 to day 28, where the egg is released into the fallopian tubes.

Menstrual Cycle Stages

Days 1–5: sex hormones low, endometrium sheds. Days 6–13: increased estrogen thickens endometrium. Day 14: ovulation. Days 15–28: increased progesterone thickens endometrium; if no embryo, hormones drop and process begins again.

Birth Control Methods

Include male condoms, female condoms, diaphragms, abstinence, birth control pills, contraceptive implants/injections, IUDs, morning after pill, sterilization/vasectomy.

Infertility

Failure of a couple to achieve pregnancy after one year of regular unprotected sex.

AID

Artificial Insemination by Donor - Harvested sperm are placed in the vagina by a physician.

ICSI

Intracytoplasmic Sperm Injection - Single sperm injected into an egg.

IVF

In Vitro Fertilization - Immature eggs taken to maturity in the lab dish, sperm added for fertilization, and embryos transferred to woman.

GIFT

Gamete Intrafallopian Transfer - Same method as IVF except eggs and sperm placed in the oviduct immediately after being brought together.

STDs

Sexually Transmitted Diseases - abstinence is the best protection, viral STDs can be treated but not cured, bacterial STDs can be cured.

Viral STDs

Include AIDS, genital warts, genital herpes, and hepatitis.

Bacterial STDs

Include Chlamydia, Gonorrhea, and Syphilis.

Trichomoniasis

STD caused by flagellated protozoan Trichomonas vaginalis. Symptoms only found in females, asymptomatic males usually reservoir.

Candida Albicans

Yeast infection; normal organism found in the vagina but overgrows in some circumstances.

Human Embryonic Development

All the events that occur from the time of fertilization until the animal is fully formed.

Amniotic Egg

Composed of the embryo, leathery shell, chorion, allantois, and yolk sac.

Fertilization

Egg and sperm fuse to form a zygote.

Morula

Following fertilization, the embryo undergoes cell division without growth resulting in a tight ball of cells.

Blastula

Morula continues to divide and then hollows out to form this.