Animal Reproduction Terms Animal Science

Reproduction: when organisms multiply or produce offspring Sexual Reproduction: involves the union of a male and female gamete Asexual reproduction: does not involve gametes -Ex. Simple cell division

Copulation: The mating of a male and female The male gamete (sperm) is placed in the reproductive tract of the female Sperm moves toward egg cell Fertilization: occurs when sperm penetrates the egg cell

Embryo: the new animal Parturition: act of giving birth final step in reproduction

Male Reproduction Parts Scrotum: saclike part of the male reproduction system Outside the body cavity Contains the testicles and epididymis Sterile: cannot produce live sperm Ridgeling/ Ridgel: male with 1 or both testicles held in the body cavity

Cryptorchidism: when a male has 1 or both testicles held in the body cavity Testicles: produce sperm - produce hormone – testosterone chemical compounds that help regulate body functions

Epididymis – tube connected to each testicle Sperm cells stored here while they mature Vas deferens – connects epididymis with urethra Spermatic cord – sheath that protects vas deferens

Urethra – tube carries urine from bladder - Found in both males and females - Semen also moves through the urethra Accessory glands - create fluids for certain tasks - Seminal vesicles – open into urethra - Fluid protects and transports sperm - Prostate gland – near the urethra and bladder - Fluid mixed w/ seminal fluid - Cowper’s gland – Fluid moves ahead of seminal fluid - Fluid cleans and neutralizes urethra

Semen – mixture of seminal and prostate fluid and sperm Penis – deposits semen w/in female reprod. System Signoid flexure – extend penis from sheath Retractor muscle – extend penis from sheath Draws penis back into sheath after copulation Sheath – tubular fold of skin

Female Reproductive Parts Female parts are very different from male parts Produces female gametes / sex cells - eggs Must provide a place for fetus to grow

Fetus – embryo in later stages Ovaries – cow has 2 - Hundreds of tiny follicles - Produce eggs - 2 Female sex hormones are also produced here - Estrogen & Progesterone

Ovaries also form the Corpus Luteum Oviducts – 2 tubes Carry eggs from ovaries to uterus Fallopian tubes Infundibulum Funnel-shaped end of each oviduct that is close to the ovary

Uterus – place for fetus to grow - Womb - Has 2 horns or branches that are connected to oviducts Cervix – neck of the uterus - Separates uterus from vagina Vagina – passage between cervix and vulva - Fetus passes through at birth Vulva - external opening of the reproductive & urinary systems

Breeding Estrus Cycle Estrus – also known as heat Time during which the female will accept the male for copulation Begins when old enough to be bred Begins when a follicle on the ovary begins to develop Estrogen causes the animal to show signs of heat

Ovulation – release of the egg cell from the ovary # of young indicates # of egg cells Usually near end of cycle Follicle breaks open & releases egg into oviduct

After ovulation corpus luteum forms on ovary - Releases progesterone 1) Fertilized egg implanted in uterus 2) Other eggs are stopped from forming 3) Maintain pregnant condition 4) Begin development of mammary glands -produce milk

Atrophy -wastes away -if not fert. Fraternal twins – animal releases more than 1 egg at ovulation Identical twins – egg cell divides to form 2 animals

Fertilization – union of sperm and egg cells Occurs in infundibulum – 1 sperm cell Gestation – time during pregnancy Umbilical cord – carries nutrients through blood vessels and oxygen & carry off waste Placenta – attached to umbilical cord Diffusion – movement of food, oxygen, and wastes from areas of high concentration to low

Parturition – process of giving birth Progesterone decreases Estrogen increases – uterine muscles contract Umbilical cord broken @ birth - Colostrum – 1st milk - Rich in antibodies, vitamins, & minerals needed - Antibodies – substances that protect animal from infections and poisons - Afterbirth – placenta and other membranes not expelled