reproductive system

sexual reproduction

method of reproduction in which a sperm cell uses with an egg cell (Fertilization) to produce a diploid zygote

sperm

-much smaller than eggs in most organisms

-Made up of a nucleus, flagellum, and mitochondria for energy

ova (eggs)

-contain a lot of nutrients to support the developing embryo, but only remain fertile for about one day

Testes

-located in the scrotum

-extensive network of seminiferous tubules within testicles are site of sperm production

-hormones at puberty stimulate development of sperm

epidiymis

-where sperm travel to located on top of each testicle where they finish maturing and are stored until ejaculation or they are reabsorbed into the body

-from here, sperm travel through vas deferens and the urethra to exit the penis during ejaculation

prostate gland & seminal vesicle

-produce seminal fluid

-seminal fluid +!sperm = semen

-sperm formed continuously from puberty until death

ovaries

-2, store eggs and typically release one at a time

-the egg travels through 1 of 2 fallopian tubes to the uterus

uterus

-where are the embryo will implant and develop

-during birth, the muscular ___ contracts to push the baby out of the it

cervix

-A muscle that separates the uterus from the vagina and supports the weight of the developing fetus

vagina

-passageway out of the uterus for the baby

-where sperm is deposited

-passageway for menstrual fluid

characteristics that set in at puberty

-deepening of the voice

-Increased body and pubic hair

-Breast development and fat deposits

puberty

-Beginning of sexual maturity

-occurs when the hypothalamus releases hormones

-sperm production, and maturation begin

menstrual cycle

-an egg matures with the help of follicles and is released from an ovary

-The endometrium builds up to prepare to receive a fertilized egg, and if it is not received, the lining will disintegrate and flow out of the vagina

-4 phases: follicular,Ovulation, Luteal, & menstruation

estradiol & progesterone

-produced by ovaries

-hypothalamus monitors, hormone levels via internal feedback systems

follicular phase

estradiol & progesterone levels low—> Hypothalamus releases, GnRH hormone

-changing hormone levels cause the endometrium to thicken and follicles to grow on the surface of the ovaries. Usually only one follicle will mature into an egg.

ovulation

Rush of LH (luteinizing hormone) from pituitary causes the follicle to burst and release the egg

Luteal phase

-The ruptured follicle becomes the corpus luteum which continues to release estradiol and progesterone

-hypothalamus detect this in slows the release of FSH & LH by the pituitary gland

menstruation

-if the egg isn’t fertilized, corpus luteum breaks down, lowering levels of estradiol & progesterone

-this signals the lining of the uterus to breakdown

-menstruation begin starting another cycle

STD

-sexually transmitted diseases are spread from one person to another via sexual contact

-May be bacterial or viral

-so maybe carried others you can have for life and some can kill

contraception

-Physical barriers: Condoms, diaphragm

-Chemical barriers: birth control, spermicides

-more permanent: vasectomy (cutting of vas deferens) & tubal ligation (severing and tying the fallopian tubes)

infertility

-The inability to have children

-Irregular menstrual cycles are blocked oviduct

-Low sperm count or mobility

-Overactive thyroid gland

fertilization

-occurs in fallopian tubes

-sperm nucleus (N) Fuses with egg nucleus (N) To form diploid (2N) zygote

-only one sperm cell can enter the ovum

pregnancy

-The embryo implants in the endometrium informs a placenta

-The placenta releases, HCG: Human chorionic gonadotropin

-HCG signals the corpus team to keep releasing high levels of estradiol & progesterone which support the uterine lining and prevents another cycle from starting

placenta

-Structure that exchanges waste, oxygen, & nutrients between the fetus and the parent

gestation

-Development of the embryo within the uterus

-For the first three months, Corpus luteum, releases, estradiol, & progesterone to prevent release of another egg

-The placenta takes over release of estradiol and progesterone and stops, releasing HCG

birth

-follows nine months of gestation

-Stimulated by the hormone oxytocin

-Causes the uterus to distract expelling the baby and then the placenta

-stimulates milk production

-helps the uterus return to its normal size