ANIMAL Reproduction!!!

Asexual Reproduction Relies entirely on mitosis Invertebrates can reproduce asexually by: Fission- separation of parent into two or more individuals of equal size Budding- new individuals grow from outgrowths of “parent” Fragmentation and Regeneration- breaking of body into numerous pieces and the regrowth of detached body parts. Advantages: can live in isolation fast

Other Reproductive Patterns Parthenogenesis- egg develops without being fertilized. Switch seasonally. Ex: bees, wasps, etc. Hermaphroditism- individual has reproduction systems of both a male and female. Some fertilize themselves but most fertilize mutually where each donates and receives sperm. Sequential Hermaphroditism- an organism changes its gender throughout its lifetime.

Fertilization Fertilization: the union of sperm and egg, some species have external or internal External fertilization- female releases eggs into a wet environment where the male fertilizes them with sperm. In moist environments Internal fertilization- the male deposits sperm in/near the female reproductive tracts where fertilization occurs. Enables reproduction in dry climates Pheromones- chemical signals from one organism that influences the behavior of others- aid fertilization and act as mate attractants.

Female Reproductive System!!!! Ovaries- the female gonads (organs that produce gametes in animals) In abdominal cavity, enclosed in capsule for protection and contains follicles (one egg surrounded by cells that nourish and protect it) -When egg cell is released form follicle, it is now in ovulation Oviducts (fallopian tubes)- cilia on the lining of the oviduct help gather the egg cell by extracting fluid from the body cavity Uterus- thick, muscular organ that can get bigger during pregnancy

Female Reproductive System Vagina- thin-walled chamber that is the repository for sperm during copulation and that serves as the birth canal Vulva- the collective term for the external female genitalia Hymen- thin piece of tissue that partly covers the vaginal opening Labia Majora- fatty ridges that protect the labia minora and vestibule Vestibule: the space where the vagina opening empties Labia Minora- the skinny skin folds that enclose the vestibule

Female Reproductive System Clitoris- the organ that swells up with blood and erects itself during sexual arousal. Bartholin’s Glands- glands that secrete lubricating fluid for sexual activity. Mammary Glands- present in both genders but function in female mammals to secrete milk.

Male Reproductive System Testes- male gonads which produce sperm and hormones. Seminiferous tubule- coiled tube where sperm are made Leydig cell- produces testosterone Scrotum- a pouch of skin outside the abdomen that houses a testis- it cools the sperm. The sperm travels from the seminiferous tubules of a testis to the coiled tubules of the epididymis- (where the sperm become able to fertilize an egg. Also where the muscular vas deferens propel the sperm out of during ejaculation). Once sperm is ejaculated it becomes semen.

Male Reproductive System Glands add secretions to the semen The seminal vesicles contribute 60% of the semen fluid The prostate gland is the largest gland (causes problems in men when enlarged or cancer-infected). The Bulbourethral Glands are below the prostate and act to neutralize acid in the urine. Bulbourethral glands are responsible for the high failure rate of the withdrawal birth control method because it carries sperm out before ejaculation. Men usually ejaculate 2-5 mL which contains 50-130 million sperm. The female uterine muscles contract to move the semen up the uterus.

Male Reproductive System Penis The structure used to engage in sexual intercourse. Is stiffened by a baculum (bone) in rodents, walruses, whales, raccoons, and other mammals

Hormones Regulate Gametogenesis Oogenesis: the development of mature ova (egg cells). Ovulation occurs in both estrous cycle and menstrual cycle after the endometrium has started to thicken and developed a rich blood supply making pregnancy possible.

Ovarian cycle! The cycle begins with the release from the hypothalamus of GnRH stimulates the pituitary to secrete small amounts of FSH and LH The FSH (true to its name) stimulates follicle growth, aided by LH the cells of the growing follicles start to make estrogen the secretion of estrogen by the growing follicle begins to rise steeply steep increases in FSH and LH levels that occur soon after the increase in the concentration of estrogen The maturing follicle develops an internal fluid–filled cavity and grows very large, forming a bulge near the surface of the ovary Following ovulation, during the luteal phase of the ovarian cycle, LH stimulates the transformation of the follicular tissue left behind in the ovary to form the corpus luteum, a glandular structure

Menopause The cessation of ovulation and menstruation Occurs after about 450 cycles Results from decline in estrogen production

Pregnancy Conception: fertilization of egg by a sperm Cleavage: process where zygote divides Blastocyst: sphere of cells containing a cavity Human gestation (pregnancy) divided into three trimesters

First Trimester Time of most drastic change Main period of organogenesis Development of body organs Trophoblast: outer layer of blastocyst Grows out and mingles with endometrium to eventually form the placenta Placenta: disk-shaped organ containing embryonic and maternal blood vessels Where diffusion of nutrients and waste occurs

Second Trimester Fetus grows to about 30 cm and is very active Hormone levels stabilize Uterus grows enough for pregnancy to become apparent

Third Trimester Fetal activity usually decreases Regulators and hormones induce labor Process by which childbirth occurs Parturition: also known as birth

Contraception Contraception: the deliberate prevention of pregnancy Rhythm Method/Natural Family Planning: temporarily abstaining from intercourse Barrier Methods Condom, diaphragm, birth control pills

Sterilization Sterilization: permanent prevention of gamete release Tubal ligation: cauterizing/tying off a section of the oviducts to prevent eggs from traveling into uterus Vasectomy: cutting off of each vans deferens to prevent sperm from entering the urethra Abortion: termination of a pregnancy in progress

Reproductive Technology Assisted reproductive technology (ART): fertilization procedures In vitro fertilization (IFV): oocytes mixed with sperm in culture dishes, develop into embryos, and are implanted in woman’s uterus