Animal reproduction

Asexual reproduction

Method of reproduction, which required only one parent that contributes all of their DNA to their offspring without fusion of gametes

Sexual reproduction

Reproduction arising from fusion of two gametes

Budding

Offspring arises as outgrowth of parent

Fission

Organism splits itself into two individuals of approximately equal size

Fragmentation

The breaking of the body into several pieces, followed by regeneration. If more than one piece grows into animal, result is asexual reproduction

Parthenogenesis

The development of an egg that is not fertilized

Fertilization

Union of sperm and egg to form zygote

Hermaphroditism

A condition in which an individual has both female and male gonads and functions as both a male and a female in sexual reproduction by producing both sperm and eggs

External fertilization

Males and females release gametes into environment

Internal fertilization

Sperm is deposited in or near female reproductive tract to fertilize eggs

Penis

The copulatory structure of male mammals

Testes

Male gonads that produce sperm and reproductive hormones

Seminiferous tubules

Highly coiled tube in the testies in which sperm are produced via meiosis

Epididymis

A coiled tubule located adjacent to the mammalian tests where sperm are stored

Vas deferens

Tube in the male reproductive system in which sperm travel from the epididymis to the urethra

Urethra

In males, exit tube for both excretory and reproductive system

Spermatogenesis

The continuous and prolific production of mature sperm in testes

Vagina

Muscular opening for copulation and childbirth in female reproductive system

Vulva

Female external genitalia made up of labia and clitoris

Labia

A series of skin folds that surround the vaginal and urethral openings

Clitoris

Erectile tissue in females

Ovaries

Female gonads that produce ova (eggs) and reproductive hormones

Oviduct

A tube passing from the ovary to the uterus (fallopian tube)

Uterus

A female organ where eggs are fertilized and development of the young occurs (womb)

Endometrium

The inner lining of the urerus, which is richly supplied with blood vessels

Cervix

The neck of the uterus, which opens into the vagina

Oogenesis

The process in the ovary that results in the production of female gametes

Ovarian cycle

Cycle that occurs in ovaries to develop and release eggs

Follicular phase

First stage of ovarian cycle (day 0-14 of menstrual cycle). In this phase estradiol concentration slowly rises. Causes thickening of endometrium. At peak level triggers ovulation

Ovulation

The release of an egg from an ovary. Egg travels from ovary up oviduct, where it has the chance to be fertilized

Luteal phase

Final stage of ovarian cycle (day 15-28 of menstrual cycle). Concentration of progesterone slowly rises, preparing uterus for possible pregnancy

Menstrual cycle

The periodic growth and shedding of the uterine lining that occurs in the absence of pregnancy

Menstruation

The shedding of portions of the endometrium during a menstrual cycle

Pregnancy

The condition of carrying one or more embryos in the uterus; also called gestation

Fetus

A developing mammal that has all the major structures of an adult (heart beating by 4th week)

Placenta

Structure in the uterus of a pregnant eutherian mammal that nourishes the fetus with the maternal blood supply

Contraception

Deliberate prevention of pregnancy

Menopause

The cessation of ovulation and menstruation marking the end of a human females reproductive years

Infertility

Inability of a couple to achieve pregnancy after one year of regular, unprotected intercourse

In vitro fertilization (IVF)

Fertilization of oocytes in laboratory containers followed by artificial implantation of the early embryo in the uterus