Reproductive system Reproductive system Gametic meiosis All Animal

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Reproductive system

Reproductive system

Reproductive system • Gametic meiosis • All Animal Kingdom • Gametes made by diploid

Reproductive system • Gametic meiosis • All Animal Kingdom • Gametes made by diploid organism directly by meiosis • Syngamy makes zygote, which develops into adult

Fertilization • External: Eggs and sperm released outside of bodies of male/female – Most

Fertilization • External: Eggs and sperm released outside of bodies of male/female – Most marine bony fish, most amphibians.

Fertilization • Internal: Sperm deposited inside body of female – Reptiles, birds, mammals

Fertilization • Internal: Sperm deposited inside body of female – Reptiles, birds, mammals

Vertebrate Reproduction (Internal fertilization) • Oviparity: Eggs fertilized internally. Deposited outside mother’s body to

Vertebrate Reproduction (Internal fertilization) • Oviparity: Eggs fertilized internally. Deposited outside mother’s body to develop. – Some cartilagenous fish, some bony fish, some amphibians, most reptiles, all birds, few mammals (monotremes).

Vertebrate Reproduction Ovoviviparity: Eggs fertilized internally, remain in mother. But rely on yolk for

Vertebrate Reproduction Ovoviviparity: Eggs fertilized internally, remain in mother. But rely on yolk for nourishment. Young developed and hatched when released. – Some bony fish, some cartilagenous fish, some amphibians, many reptiles Salamandra female giving birth to larvae

Vertebrate Reproduction • Viviparity: Young develop in mother and obtain nourishment mainly from mother

Vertebrate Reproduction • Viviparity: Young develop in mother and obtain nourishment mainly from mother (rather than ______). – Most cartilagenous fishes, few bony fishes, some amphibians, few reptiles, almost all mammals.

Reproductive system • Here, we emphasize human system (rat seen in lab) • Start

Reproductive system • Here, we emphasize human system (rat seen in lab) • Start with male, move to female

Reproductive system • Male: • 1) Makes gametes (sperm) by meiosis • 2) Delivers

Reproductive system • Male: • 1) Makes gametes (sperm) by meiosis • 2) Delivers sperm to vagina in female system

 • • • Reproductive system Sperm cell: Flagellum to swim with Mitochondria for

• • • Reproductive system Sperm cell: Flagellum to swim with Mitochondria for energy Nucleus (haploid) in head Acrosome: special ______, contains enzymes that help penetrate layers around egg.

Reproductive system • Male reproductive system • 1) Testes (plural: males have 2). Make

Reproductive system • Male reproductive system • 1) Testes (plural: males have 2). Make sperm androgens (male hormones, such as testosterone) • In bag called scrotum.

Reproductive system • 1) Testes: Seminiferous tubules – – 1) germinal cells divide (mitosis)

Reproductive system • 1) Testes: Seminiferous tubules – – 1) germinal cells divide (mitosis) to produce primary spermatocyte 2) primary spermatocyte divides by meiosis to make 4 spermatids 3) Spermatids develop into sperm 4) Process aided by _______ cells, which help spermatids transform into sperm.

Reproductive system • Making sperm: a fulltime job • 100 -200 million formed per

Reproductive system • Making sperm: a fulltime job • 100 -200 million formed per day, takes 100 days to make them • Influenced by temperature • Normal testis temperature is 34 degrees, compared to 37 degrees internal body temperature.

Reproductive system • Male reproductive system • 2) Ducts to carry sperm. Epididymis: collecting

Reproductive system • Male reproductive system • 2) Ducts to carry sperm. Epididymis: collecting duct at testis. Vas deferens: duct from epididymis to seminal vesicle. Ejaculatory ducts: from seminal vesicle to prostate gland.

Reproductive system • Male reproductive system • 3) Accessory glands (package sperm). Seminal vesicles:

Reproductive system • Male reproductive system • 3) Accessory glands (package sperm). Seminal vesicles: store sperm. Bulbourethral gland prostate gland (produce ______).

Reproductive system • Male reproductive system • 3) Accessory glands (package sperm). • Semen:

Reproductive system • Male reproductive system • 3) Accessory glands (package sperm). • Semen: fluid that enhances longevity of sperm

Reproductive system • Semen: fluid that enhances longevity of sperm • Contains: – water

Reproductive system • Semen: fluid that enhances longevity of sperm • Contains: – water – sugars (fructose and glucose): used by sperm for energy – _________: neutralizes acidity from urine in male urethra and acidic conditions in vagina – prostaglandins: hormones that stimulate contractions of smooth muscle in female system – vitamins, minerals, amino acids, etc.

Reproductive system Male reproductive system • • 4) Penis: copulatory organ, delivers sperm to

Reproductive system Male reproductive system • • 4) Penis: copulatory organ, delivers sperm to _____ of female • When male excited, blood flow out decreased. Blood fills 2 corpora cavernosa (spongy tissue bodies on each side of penis) during erection.

Reproductive system • Female reproductive system • 1) Produces gametes (eggs) – actually oocytes:

Reproductive system • Female reproductive system • 1) Produces gametes (eggs) – actually oocytes: cells _______ to being eggs! • 2) Also nourishes embryo during gestation period (time from fertilization to birth: 9 months for human).

 • • Reproductive system Female reproductive system 1) Ovary (2 of them): Where

• • Reproductive system Female reproductive system 1) Ovary (2 of them): Where oocytes formed 2) Fallopian tube (2 of them): connect ovary to uterus 3) Uterus: where fertilized egg implants and embryo develops

Reproductive system • Female reproductive system • 4) Cervix: entrance to uterus • 5)

Reproductive system • Female reproductive system • 4) Cervix: entrance to uterus • 5) Vagina: connects uterus to outside body

Reproductive system • Making oocytes in ovary • Process starts before birth, when germinal

Reproductive system • Making oocytes in ovary • Process starts before birth, when germinal cells produce primary oocytes. These start meiosis I but stop at prophase I at time of birth as primary follicles.

Reproductive system • Follicles contain oocyte and cluster of other special cells • Each

Reproductive system • Follicles contain oocyte and cluster of other special cells • Each female has about 2 ______ follicles at birth.

Reproductive system • Once puberty begins, one primary follicle matures each month during menstrual

Reproductive system • Once puberty begins, one primary follicle matures each month during menstrual cycle. • Maturation, called _______, ruptures follicle and releases secondary oocyte.

Reproductive system • In secondary oocyte, meiosis I completed and meiosis II started. Stops

Reproductive system • In secondary oocyte, meiosis I completed and meiosis II started. Stops at metaphase II. • Will complete meiosis II to make egg only if fertilized by sperm!

Reproductive system • Note that follicle cells stay alive and secrete hormones for a

Reproductive system • Note that follicle cells stay alive and secrete hormones for a time after secondary oocyte released • Become corpus luteum.

Reproductive system • Hormones made by corpus luteum increase thickening of lining of uterus

Reproductive system • Hormones made by corpus luteum increase thickening of lining of uterus • This readies uterus in case fertilization occurs • Oocyte moves down Fallopian tube by _____ lining tube.

Reproductive system • Menstrual cycle (takes about 28 days)

Reproductive system • Menstrual cycle (takes about 28 days)

Reproductive system • 1) pituitary gland (in head under brain) secretes follicle stimulating hormone

Reproductive system • 1) pituitary gland (in head under brain) secretes follicle stimulating hormone (FSH) • 2) Follicles in ovaries begin to develop (only one continues to end)

Reproductive system • 3) Follicles release _______: uterus lining starts to thicken

Reproductive system • 3) Follicles release _______: uterus lining starts to thicken

Reproductive system • 4) Estradiol stimulates more FSH. Also luteinizing hormone (LH) made by

Reproductive system • 4) Estradiol stimulates more FSH. Also luteinizing hormone (LH) made by pituitary. • 5) Peak of FSH and LH at day 14 causes ovulation: release of secondary oocyte from 1 follicle.

Reproductive system • 6) Remnants of follicle are corpus luteum • 7) Secretes estradiol

Reproductive system • 6) Remnants of follicle are corpus luteum • 7) Secretes estradiol and progesterone. They influence pituitary to decrease FSH and LH production. Follicles stop developing.

Reproductive system • 8) After several days, corpus luteum starts to degenerate • 9)

Reproductive system • 8) After several days, corpus luteum starts to degenerate • 9) Estradiol and progesterone levels drop

Reproductive system • 10) Uterine lining(endometrium) sloughs off (period starts) • 11) Decrease in

Reproductive system • 10) Uterine lining(endometrium) sloughs off (period starts) • 11) Decrease in estradiol and progesterone cause pituitary to increase _______ production • 12) Cycle starts again.

Reproductive system • If fertilization happens: • Embryo implants in uterine wall • Eventually,

Reproductive system • If fertilization happens: • Embryo implants in uterine wall • Eventually, placenta takes over production of estradiol and progesterone. Lining stays thickened (no period). No more follicles develop.

Reproductive system • Lost along the way: fertilized oocyte can get outside system and

Reproductive system • Lost along the way: fertilized oocyte can get outside system and create ______ pregnancy (implants in wrong places) • Problem: won’t develop normally. Must be removed or can kill mother.

Manipulating the system • Birth control (or how not to make a baby) •

Manipulating the system • Birth control (or how not to make a baby) • See also: www. plannedparenth ood. org

Manipulating the system • 1) Abstinence. • Variation: rhythm method. Time between _____ release

Manipulating the system • 1) Abstinence. • Variation: rhythm method. Time between _____ release and arrival in uterus about 5 days (after ovulation). Sperm can remain alive in woman for several days.

Manipulating the system • 2) Sperm blockage (condom, cervical cap or diaphagm)

Manipulating the system • 2) Sperm blockage (condom, cervical cap or diaphagm)

Manipulating the system • 3) Sperm destruction • washing sperm out (douche) • spermicide

Manipulating the system • 3) Sperm destruction • washing sperm out (douche) • spermicide foams/jellies

Manipulating the system • 4) Preventing ovulation: the pill and implants of various types.

Manipulating the system • 4) Preventing ovulation: the pill and implants of various types. Contain chemicals that act like _______ (prevent follicle development).

Manipulating the system • 5) Preventing embryo implantation: IUD (intrauterine device). Irritates uterine lining.

Manipulating the system • 5) Preventing embryo implantation: IUD (intrauterine device). Irritates uterine lining.

Manipulating the system • 6) Sterilization – vasectomy for man (cutting/tying vas deferens) –

Manipulating the system • 6) Sterilization – vasectomy for man (cutting/tying vas deferens) – cutting/tying Fallopian tubes for woman.

Manipulating the system • Fertility clinics (how to make a baby) • _______% of

Manipulating the system • Fertility clinics (how to make a baby) • _______% of couples have difficulty conceiving a child • About half cases due to male infertility, other half female infertility

Manipulating the system • • • Male infertility: Large numbers sperm needed due to

Manipulating the system • • • Male infertility: Large numbers sperm needed due to barriers in journey 1) long distance (sperm swim 3 mm/hour) 2) acidic conditions in vagina 3) most are active for <48 hours Typically many hundreds of millions deposited, only few hundred reach fallopian tubes • So, numbers matter (Normal is____ million sperm/ml. Low is <20 million/ml). • Also vigor (activity level) and appearance (morphology) of sperm matter.

Manipulating the system • • Fertility clinics (how to make a baby) Female infertility:

Manipulating the system • • Fertility clinics (how to make a baby) Female infertility: _______ problems Anatomical problems

Manipulating the system • For both men and women: age ______ fertility

Manipulating the system • For both men and women: age ______ fertility