Human Reproductive Human Reproductive SystemSystem

Living EnvironmentLiving Environment

Puberty – when a person becomes Puberty – when a person becomes sexually mature and is capable of sexually mature and is capable of reproduction.reproduction.

Male Reproductive System:Male Reproductive System:Gonads = Testes Gonads = Testes Gametes = Sperm CellsGametes = Sperm Cells

Sperm Cells made in the testesSperm Cells made in the testesTestes - also act as an endocrine Testes - also act as an endocrine

gland secreting testosterone, which gland secreting testosterone, which is responsible for secondary sex is responsible for secondary sex characteristics. Body Hair, muscle characteristics. Body Hair, muscle development, deeper voice…development, deeper voice…

Male Reproductive SystemMale Reproductive SystemEach testical consists of small Each testical consists of small

coiled tubes called the coiled tubes called the Seminiferous TubulesSeminiferous Tubules..

Immature sperm are produced in Immature sperm are produced in the seminiferous tubules.the seminiferous tubules.

After being produced sperm After being produced sperm move to the move to the epididymisepididymis where where they are stored. they are stored.

Sperm leave the epididymis Sperm leave the epididymis through the through the vas deferensvas deferens..

Male Reproductive System Male Reproductive System (continued)(continued)

The two vas deferens meet at the The two vas deferens meet at the urethra.urethra.

Glands secrete fluids into the Glands secrete fluids into the sperm.sperm.

The mixture or fluids and sperm = The mixture or fluids and sperm = semensemen..

The semen passes through the The semen passes through the urethra by the process of urethra by the process of ejaculation.ejaculation.

Urine is blocked shortly before and Urine is blocked shortly before and after ejaculation.after ejaculation.

Female Reproductive System:Female Reproductive System:- Gonads = OvariesGonads = Ovaries- Gametes = EggsGametes = Eggs

Ovaries make EggsOvaries make Eggs

Ovaries – also secrete female hormones Ovaries – also secrete female hormones including estrogen, which is responsible including estrogen, which is responsible for secondary sex characteristics. Breast for secondary sex characteristics. Breast Development, Broadened Pelvis…Development, Broadened Pelvis…

2 ovaries that contain about 200,000 tiny 2 ovaries that contain about 200,000 tiny egg sacs called follicles. Each Follicle egg sacs called follicles. Each Follicle contains 1 immature egg. These contains 1 immature egg. These immature eggs are present at the time of immature eggs are present at the time of birth.birth.

When one of the follicles ruptures When one of the follicles ruptures the egg is released at the surface of the egg is released at the surface of the ovary = ovulation. First occurs the ovary = ovulation. First occurs at puberty.at puberty.

Oviduct or Fallopian Tube = tube Oviduct or Fallopian Tube = tube with funnel like opening. Ciliated with funnel like opening. Ciliated cells draw the egg into the oviduct. cells draw the egg into the oviduct. Passes through the oviduct into the Passes through the oviduct into the uterus. Uterus = thick walled uterus. Uterus = thick walled muscular pear shaped organ.muscular pear shaped organ.

Once the egg is in the uterus it Once the egg is in the uterus it can be fertilized by a sperm cell.can be fertilized by a sperm cell.

Cervix connects uterus to the Cervix connects uterus to the Vagina. During Pregnancy the Vagina. During Pregnancy the child will pass through the cervix child will pass through the cervix and leave the mother through and leave the mother through the Vagina.the Vagina.

Menstrual CycleMenstrual Cycle

Mature egg is developed and Mature egg is developed and released from one of the ovaries released from one of the ovaries approximately every 28 days. approximately every 28 days.

The walls of the uterus have been The walls of the uterus have been building up preparing to accept the building up preparing to accept the egg. egg.

If the egg is not fertilized the wall of If the egg is not fertilized the wall of the uterus breaks down. Material the uterus breaks down. Material from the wall and the unfertilized from the wall and the unfertilized egg are eliminated from the body. egg are eliminated from the body.

Menstrual CycleMenstrual CycleThe cycle begins again with the The cycle begins again with the

maturing of another egg. maturing of another egg.

This process is called the This process is called the menstrual cycle. menstrual cycle.

Begins during puberty age 12-Begins during puberty age 12-15. Controlled by hormones.15. Controlled by hormones.

Stages of the Menstrual Cycle:Stages of the Menstrual Cycle:

Follicle Stage = FSH (Follicle) Stimulating Follicle Stage = FSH (Follicle) Stimulating Hormone is secreted by the pituitary Hormone is secreted by the pituitary gland. FSH causes several follicles to gland. FSH causes several follicles to begin to develop. Usually only one begin to develop. Usually only one matures. As the follicle develops it matures. As the follicle develops it secretes estrogen. Estrogen causes the secretes estrogen. Estrogen causes the uterine lining to become thicker.Usually uterine lining to become thicker.Usually lasts about 10 dayslasts about 10 days

Ovulation = High level of estrogen in the blood Ovulation = High level of estrogen in the blood causes the pituitary gland to decrease the causes the pituitary gland to decrease the secretion of FSH and begin the secretion of LH secretion of FSH and begin the secretion of LH (Luteinizing Hormone).When LH levels reach a (Luteinizing Hormone).When LH levels reach a certain point ovulation occurs. Follicle ruptures. certain point ovulation occurs. Follicle ruptures. Usually Takes place in the middle of the Usually Takes place in the middle of the menstrual cycle.menstrual cycle.

Corpus Luteum Stage = After Corpus Luteum Stage = After ovulation LH causes the ruptured ovulation LH causes the ruptured follicle to fill with cells forming a follicle to fill with cells forming a yellow body called the corpus luteum. yellow body called the corpus luteum. Corpus Luteum begins to excrete the Corpus Luteum begins to excrete the hormone progesterone, which hormone progesterone, which continues the growth of the uterine continues the growth of the uterine lining. Lasts about 14 days.lining. Lasts about 14 days.

Menstruation = No fertilization occursMenstruation = No fertilization occurs

Menstruation = No fertilization occursMenstruation = No fertilization occurs LH levels drop off LH levels drop off Corpus Luteum breaks down Corpus Luteum breaks down Progesterone levels drop offProgesterone levels drop off Thick lining of uterus can not be Thick lining of uterus can not be

maintained so it breaks downmaintained so it breaks down The extra lining, unfertilized egg, and a The extra lining, unfertilized egg, and a

small amount of blood pass out the body small amount of blood pass out the body through the vagina.through the vagina.

Lasts about 4 daysLasts about 4 days Pituitary gland begins to produce FSH Pituitary gland begins to produce FSH

againagain New egg begins to develop and cycle New egg begins to develop and cycle

starts all over againstarts all over againMenstrual Cycle will stop temporarily during Menstrual Cycle will stop temporarily during

pregnancy. Around middle age (45-50) pregnancy. Around middle age (45-50) will stop permanently = menopause.will stop permanently = menopause.

Fertilization and Fertilization and Development:Development:

Sex - Hundreds of millions Sex - Hundreds of millions of sperm are ejaculated of sperm are ejaculated into the vagina. Travel into the vagina. Travel through the cervix, across through the cervix, across the uterus, and into the the uterus, and into the oviducts. If an egg is oviducts. If an egg is passing through the passing through the oviducts fertilization may oviducts fertilization may occur. Zygote is formed.occur. Zygote is formed.

ImplantationImplantation – Zygote undergoes – Zygote undergoes cleavage developing into a cleavage developing into a blastulablastula. . At the same time it is moving down At the same time it is moving down the oviduct toward the uterus. 5-10 the oviduct toward the uterus. 5-10 days after fertilization zygote enters days after fertilization zygote enters the uterus. Outer cells of the zygote the uterus. Outer cells of the zygote secretes enzymes that eat away the secretes enzymes that eat away the lining of the uterus. Zygote attaches lining of the uterus. Zygote attaches to that spot.to that spot.

Three Three germ layersgerm layers develop. From this develop. From this point on the developing human is point on the developing human is called an called an EmbryoEmbryo. After 8 weeks the . After 8 weeks the developing human is called a developing human is called a fetusfetus..

Week 3 Week 4 Week 5

Week 6 Week 7 Week 8

During pregnancy the menstrual During pregnancy the menstrual cycle is stopped. A hormone is cycle is stopped. A hormone is secreted that prevents the break secreted that prevents the break down of the corpus luteum, which down of the corpus luteum, which continues to secrete progesterone, continues to secrete progesterone, which maintains the thick lining of which maintains the thick lining of the uterus.the uterus.

In Vitro fertilization – fertilization In Vitro fertilization – fertilization occurs outside the body in a lab then occurs outside the body in a lab then zygote is placed back in the female’s zygote is placed back in the female’s uterus to develop. uterus to develop.

Between Between fertilization and fertilization and implantation implantation embryo survives embryo survives off of food stored off of food stored in the egg. After in the egg. After implantation implantation embryo receives embryo receives food and oxygen food and oxygen from the mother from the mother through the through the placenta. placenta.

Outer layer of Outer layer of blastula forms blastula forms chronin. Chronin = chronin. Chronin = membrane that membrane that surrounds the surrounds the embryo. Chronin embryo. Chronin villi project into the villi project into the uterine lining and uterine lining and form the placenta.form the placenta.

PlacentaPlacenta has fetal side (fetus’s blood) and has fetal side (fetus’s blood) and

maternal side (mothers blood)maternal side (mothers blood) Mother’s blood and Fetus’s blood Mother’s blood and Fetus’s blood

never mix.never mix. Fetus is connected to the placenta by Fetus is connected to the placenta by

the umbilical cord.the umbilical cord.Carries nutrients and oxygen to the fetus, Carries nutrients and oxygen to the fetus,

waste out of and away from the fetus.waste out of and away from the fetus.

Placenta protects the fetus from Placenta protects the fetus from harmful agents in the mother’s blood.harmful agents in the mother’s blood.

Some things can still pass through the placenta Some things can still pass through the placenta = some viruses, alcohol, nicotine, most drugs.= some viruses, alcohol, nicotine, most drugs.

Extraembryonic Membranes – same Extraembryonic Membranes – same as birds and reptiles, different as birds and reptiles, different purposes.purposes.

Chronin = implantation.Chronin = implantation.

Amnion (Amniotic Sac) = filled with Amnion (Amniotic Sac) = filled with

amniotic fluid, which surrounds and amniotic fluid, which surrounds and protects the fetus.protects the fetus.

Allantois and yolk sac = develops Allantois and yolk sac = develops into the umbilical cord.into the umbilical cord.

BirthBirth Gestation period = length of Gestation period = length of

pregnancy. In humans it is pregnancy. In humans it is about nine months. (40 Weeks)about nine months. (40 Weeks)

1.1. When the fetus is ready to be When the fetus is ready to be born the uterus begin slow born the uterus begin slow rhythmic contractions = labor.rhythmic contractions = labor.

2.2. Same time cervix begins to Same time cervix begins to enlarge. It must expand from 1 enlarge. It must expand from 1 to 2cm to 11 or 12cm for birth to to 2cm to 11 or 12cm for birth to occur. occur.

Birth (Continued)Birth (Continued)3.3. When the cervix is completely expanded When the cervix is completely expanded

the amniotic membrane bursts lubricating the amniotic membrane bursts lubricating the birth canal.the birth canal.

4.4. Contractions force the fetus, head first, Contractions force the fetus, head first,

from the uterus into the vagina and out of from the uterus into the vagina and out of the mother’s body.the mother’s body.

5.5. Once outside the mother’s body the Once outside the mother’s body the umbilical cord is still attached. It is tied umbilical cord is still attached. It is tied and cut leaving a scar = naval or belly and cut leaving a scar = naval or belly button.button.

6.6. Contractions continue after birth which Contractions continue after birth which expel the placenta and amnion = expel the placenta and amnion = afterbirth.afterbirth.

Fraternal Twins – two Fraternal Twins – two eggs become eggs become fertilized, imbed fertilized, imbed separately and separately and develop separately.develop separately.

Identical twins – a fertilized egg Identical twins – a fertilized egg divides into two embryos at an divides into two embryos at an early stage of development. early stage of development. Each embryo then forms Each embryo then forms separately. Pregnancy drugs. separately. Pregnancy drugs.

Postnatal Development:Postnatal Development:

BirthBirth

GrowthGrowth

PubertyPuberty

AdultAdult

AgingAging

DeathDeath

WebsitesWebsites

Size of genetic materials:Size of genetic materials: http://www.accessexcellence.org/AB/GG/comparat

ive.html Karytope of Human genome:Karytope of Human genome: http://www.accessexcellence.org/AB/GG/http://www.accessexcellence.org/AB/GG/

human.htmlhuman.html Human Gene:Human Gene: http://www.accessexcellence.org/AB/GG/http://www.accessexcellence.org/AB/GG/

genes.htmlgenes.html Mutaions:Mutaions: http://www.accessexcellence.org/AB/GG/http://www.accessexcellence.org/AB/GG/

mutation.htmlmutation.html

Comparing mitosis to meiosisComparing mitosis to meiosis http://www.accessexcellence.org/AB/GG/http://www.accessexcellence.org/AB/GG/

comparison.htmlcomparison.html Mutations:Mutations: http://www.accessexcellence.org/AB/GG/http://www.accessexcellence.org/AB/GG/

mutation2.htmlmutation2.html Retroviruses (HIV):Retroviruses (HIV):http://www.accessexcellence.org/AB/http://www.accessexcellence.org/AB/

GG/diagram.htmlGG/diagram.html Stages of reproduction in a goat:Stages of reproduction in a goat: http://www.imagecyte.com/animations/http://www.imagecyte.com/animations/

reproduction.htmlreproduction.html