Reproductive system human fertlization

Name: ______________________ Reproduction and Humans

I. Male Reproductive System a. It forms two main functions

i. Produces sperm ii. Deposits sperm into the female reproductive tract

b. How does it work?i. The testes (male gonad that produces sperm &

testosterone) produces the sperm ii. The testes are found in the scrotum

1. What is the Scrotum?a. Scrotum is a sac of skin, below male

genital organs and contains two testes. b. It is also 1-2 degrees Celsius cooler in

there than the rest of the body i. This provides the correct temp for

sperm production and storage. iii. From the testes the sperm moves through the sperm

duct and the urethra 1. Urethra is the tube inside the penis

a. The penis is a structural adaptation for internal fertilization

c. What is Semen? i. Glands secret (let out) a liquid into the tubes. ii. The liquid is used as a transport agent for the sperm iii. The liquid and sperm cells make up SEMEN.

d. What is Testosterone? i. Not only do the testes produce sperm, but it also

produces a hormone called Testosterone. 1. This regulates the maturity of the sperm 2. Also it causes a lower voice pitch 3. And beard development

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Name: ______________________ Reproduction and Humans

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Name: ______________________ Reproduction and Humans

II. The Female Reproduction Systema. What are the parts of the female reproductive system?

i. Ovaries 1. The ovaries are paired structures located in the

lower portion of the female body cavity. 2. Ovaries produce eggs (ova) in tiny cavities

called follicles ii. Oviduct

1. After ovulation ( release of the egg from the ovary) the egg is brought to the uterus (muscle organ in female where the fetus develops) through the oviduct (fallopian tube)

iii. Cervix1. At the lower end of the uterus, known as the

cervix, there is a muscular tube, called the vagina.

iv. Vagina1. The vagina receives the sperm from the male

and the birth canal. b. Where do the eggs come from?

i. When a female baby is born she has all her eggs that she will ovulate in an immature form.

ii. Usually only one egg is released in her body at a time

c. What else do the ovaries do?i. In addition to eggs the ovaries also produce the

female sex hormones1. estrogen 2. progesterone.

ii. These hormones are in charge of 1. secondary female sex characteristics

a. Mammary glands – breastsb. Wider pelvis c. Menstrual cycle

d. What is the Menstrual cycle ?i. The menstrual cycle begins when a girl hits puberty

and continues until she hits menopause. 1. Puberty – time in a person’s life where they

begin to produce gametes and sex hormones2. Menopause – a time in a woman's wife when

she stops menstruating ii. On average the cycle is 28 days long (every woman

is different)iii. There are 4 stages to the cycle

1. Stage #1 follicle stage

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Name: ______________________ Reproduction and Humans

a. Involves the maturing of an egg in a follicle

b. It also secrets the hormone estrogen c. Estrogen starts the thickening of the

blood tissue in the uterus2. Stage #2 Ovulation

a. When the follicle releases the egg3. Stage #3 Corpus Lustrum stage

a. After the release of the egg Corpus Lustrum comes out of the follicle

b. This is a yellow group of cells that lets out progesterone which enhances the uterine lining.

4. Stage #4 Menstruation a. So now the egg is in the Uterus ready to

be fertilizedb. If the egg is not fertilized it goes through

a periodic shedding of the thickened Uterine lining

i. Usually lasts a few days iv. Role of Hormones in Menstrual cycle

1. The reproductive cycle of human female involves interactions in hormones from hypothalamus, ovaries and pituitary glands

a. FSH – follicle stimulus hormone- i. Released during menstrual cycle

from the pituitary glandsii. Stimulates follicle growth and

ovaries to produce estrogen b. LH- Luteinizing Hormone

i. Also during cycle and from the pituitary gland

ii. Influences the functioning of the ovaries

iii. Stimulates growth of the Corpus lotem to secrete Progesterone which helps estrogen production

2. Homeostasis with the Hormones

a. The ovaries secrete estrogen and progesterone to start the changes in the uterus

b. Estrogen stops the release of FSH make sure not too much

III. Fertilization & Developmenta. We all know the basics of how humans fertilize

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Name: ______________________ Reproduction and Humans

b. Fertilization usually occurs in the upper 1/3 of the oviducti. Oviduct – same as fallopian tube – transports egg

from follicles to ovary ii. If eggs not fertilized within 24-48 hours after

ovulation the eggs starts to go bad. iii. If fertilization does occur the for 6-10 days cleavage

occurs in the oviduct and then the zygote goes and implants itself in the uterus lining

iv. At this stage the yolk has been depleted but the embryo gets it’s nourishment from the uterus.

IV. Twins a. If more than one egg is released and fertilized multiple

births can occur Identical Twins Fraternal TwinsWhen the zygote splits during the cleavage stageThe children will look alike

When the fallopian tubes release two eggs and they both get fertilized by sperm

V. Medical abilities to help parents have children a. In vertro fertilization (IVF) - is when doctors take out the

egg and the sperm and put them together in a test tube and then implants the zygote into the uterus of the woman

b. Done when woman have trouble conceiving

VI. Prenatal Development (STEP BY STEP AND DIFFERENT PARTS)1. Fertilization 2. Cleavage

When the sperm meets the egg a. the multiplying of cells

b. done in the oviduct

3. gastrulating 4. Differentiation and Growth

a. done after the embryo is implanted in uterus

• Results in the formation of specialized tissue and organs from the different layers of the gastrula

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Name: ______________________ Reproduction and Humans

a. Prenatal development is dependent on structures similar to those in external developing eggs

i. Placenta ii. Amnion iii. Umbilical cord

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Placenta Umbilical Corda. “connection” between mother

and babyb. Allows nutrients, respiratory

gases, and wastes to be exchanged between embryo and mom

c. There is no direct connection • Therefore the blood of the mother and embryo do not mix

a. AKA “life line” b. Holds the blood vessel

that carry material from mom to embryo

Amniona. Is the membrane that

surrounds the embryo b. It contains the ammonic

fluid that protects the embryo from shock and temperature changes

Name: ______________________ Reproduction and Humans

VII. Nutrition and Pregnancy a. It is important for prenatal development that there is a

balance of nutrients going to the embryo b. Good nutrition during pregnancy is good for mom and

embryo developmentVIII. Avoid Health Issues

a. In Humans Embryonic development of essential organs occur early on

b. The embryo may encounter risks from problems with genes and it’s mother exposure to hazards in the environment

i. Drugs ii. Toxiniii. Alcoholiv. Smoke v. Infections

IX. Birth a. Usually in humans occurs after 9 monthsb. During birth strong contractions of the uterine muscles

(labor) will force the baby through the cervix and the vagina ( birth canal)

c. The getting rid of the placenta occurs after birth d. If placenta stays in will probably cause infection

X. Postnatal development a. Continues with different parts of the body growing at

different rates b. This process goes all the way through until a person dies

does not stop at adults

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