REPRODUCTION TERMS

Oviparous Reproductive strategy where animals lay eggs that hatch outside
the body.
Viviparous Reproductive strategy where the animal’s offspring develop inside
the mother’s body and are fed via a placenta
Ovoviviparous Reproductive strategy in animals that perform mostly internal
fertilization forming eggs that hatch inside the body
Precocial The type of growth and development in animals where offspring are
development born with open eyes and fur, leaving the nest at an early age
Altricial The type of growth and development in animals where offspring are
development born with their eyes closed, no fur and are cared for by their
parents until they are strong enough to fend for themselves
Gametogenesis The collective term referring to the processes through which
gametes (sperm cells and ova) are produced
Oogenesis The formation of ova / egg cells in females
Spermatogenesis The formation of sperm cells in males
Germinal The lining made of epithelial cells on the inside of the testes and
epithelium ovaries that give rise to gametes
Gametes Sex cells namely sperm cells and egg cells / ova
Sperm cell The male gamete
Ovum / egg cell The female gamete
Gonades The sex organs i.e. the testes in males and the ovaries in females
Testes The male sex organ in which male gametes are made
Ovaries The female sex organ in which female gametes are made
Penis The external male sex organ that transfers semen into the female
reproductive system
Vas deferens The sperm duct that transports sperm cells from to testes to the
penis
Scrotum The sack-like structure that houses the testes outside the body
Seminiferous Tubules in the testes where spermatogenesis occurs
tubules
Epididymis Folded tubes branching from the testes in which sperm cells mature
Urethra Common duct for the transport of both semen and urine in males /
only urine in females
Glans Tip of the penis
Sertoli cells Cells in the seminiferous tubules that nurture / feed the developing
sperm cells
Leydig cells Cells in between the seminiferous tubules that secrete testosterone
Acrosome Vesicle at the tip of the sperm cell in which enzymes are located
that are used to chew through the egg cell’s wall
Semen Sperm cells plus gland secretions
Ejaculation The release of semen from the penis
Fallopian tube The tube that transports the egg cell to the uterus. Fertilization
 usually occurs here.
Vagina Structure in the female reproductive tract that receives the semen
during ejaculation. Also forms the birth canal during birth.
Cervix The opening to the uterus
Uterus The muscular organ in which the foetus develops until birth
Endometrium The innermost, blood-rich layer of the uterus that is built up and
broken down to be released as blood during menstruation in a
woman’s monthly cycle
Fimbria Finger-like protrusions of the fallopian tube that pulls the ovum into
the fallopian tube during ovulation
Corona radiata The layer of follicular cells around the ovum in the Graafian follicle
Graafian follicle The structure that carries the ovum just before ovulation
Follicle Hormone released by the pituitary gland. Stimulates gametogenesis
stimulating in males and females
hormone (FSH)
Luteinizing Hormone released by the pituitary gland. Stimulates ovulation in
hormone (LH) females and the release of testosterone in males
Oestrogen The female reproductive hormone. Gives rise to secondary sexual
characteristics in women.
Progesterone Hormone that is released by the corpus luteum and builds up the
endometrium in preparation for pregnancy.
Gonadotropin Hormone released by the hypothalamus that activates the release
releasing of FSH and LH.
hormone (GnRH)
Prolactin Hormone in woman that stimulates milk production in the breasts.
Testosterone The male sexual hormone. Gives rise to the secondary sexual
characteristics in males.
Oxytocin Hormone that causes contraction of the uterus during birth as well
as the release of milk from the breasts.
Hypophysis / Gland in the brain that secretes FSH and LH.
Pituitary gland
Corpus Luteum Structure that forms out of the remains of the Graafian follicle,
under the control of LH.
Ovulation The release of an ovum out of the ovary on Day 14 of the menstrual
cycle. Caused by a peak in LH.
Puberty The stage in development when boys and girls become sexually
mature. In girls this is characterized by the first period and in boys
by the first release of sperm in the semen during ejaculation.
Zygote A fertilized egg cell with both the sperm and egg cell nucleus,
therefore 46 chromosomes.
Embryo A dividing zygote that goes through various stages of cellular
division (mitosis) such as 4-cells, 8-cells etc. The morula and
blastocyst are also stages of embryonic development. The
embryonic stage continues up to 8 weeks after fertilization.
Blastocyst The stage in embryonic development characterized by a layer of
trophoblastic cells surrounding a fluid-filled cavity with an inner cell
mass
Trophoblast The outer layer of cells of the blastocyst that creates the chorion,
amnion and placenta
Foetus The developmental stage from 8 weeks after fertilization up to
birth. The developing foetus has human characteristics and all its
organs are already formed.
Human chorionic The hormone secreted by the embryo as it moves down the
gonadotropin fallopian tube towards the uterus. This hormone maintains the
(HCG) corpus luteum until the placenta is fully formed.
Fertilization The process through which a haploid sperm cell and a haploid ovum
fuse
Implanting The process through which the blastocyst sinks into the endometrial
wall
Chorion The protective membrane on the outside of the amniotic sack that
produces the chorionic villi in the placenta on the endometrial side
of the blastocyst
Amnion The inner membrane of the amniotic sack that surrounds the
amniotic fluid
Amniotic fluid The fluid inside the amnion that protects the developing foetus
against mechanical injuries, dehydration and large scale
temperature changes
Placenta The structure in the endometrium where there exists very close
contact between the maternal and foetal blood systems, but no
physical contact occurs. Nutrients, wastes, gasses etc. are
exchanged between maternal and foetal blood
Menstruation The release of blood through the vagina
Gestation / The period from fertilization until birth (about 40 weeks)
Pregnancy
Parturition / Birth The process of pushing the foetus out of the uterus through the
birth canal at 40 weeks of pregnancy.
Umbilical cord The structure, consisting of two oxygen-rich arteries and one
oxygen-poor vein which transports nutrients between the foetus
and the placenta.
Lactation The production of milk in the breasts.
Colostrum The first breast milk that is produced. Rich in antibodies.