Sexual Reproduction Flashcards
How do sperm develop and and what happens when they have made tails
Sperm develop from cells in the tubules and once they have made tails they move down the center of the tubule and move into the epididymus
When is sperm produced and how
At puberty the Brain tells the testicles to produce testosterone and sperm
Explain the travel of sperm
Sperm travel to the epidydymas where they mature and travel. Through the vas deferens, past the prostrate gland and seminal vessels , through the urethra and spurted out at the tip of the penis.
What is the purpose of the male
To produce gametes or sperm and to transfer these to the female system
What do the testes look like
Oval structures, 5 cm long
Where are the 2 testes found and where is this found and why
In a sac called the scrotum found between the legs. Sperm are lower than body temp therofr they need to be kept outside of the body
What is a vasectomy
Sterilized man
What are the male secondary sex characteristics
Hair growth on the penis, arms and facial
Descending of testes
Voice depends
Growth
What is the epdidymus
A tube attached to the outside of the testis. Sperm stored here after being formed
What is the vas deferens / sperm duct
A continuation of the epidydimus. Carries sperm from the epidymis to urethra
What are the seminal vesicles
Glands that produce a fluid which contains nutrients and enzhymes so that the sperm will move more actively
What is the mixture of fluid and sperm
Semen
How is the ejaculatoryduct formed
When the ducts from the seminal vesicles and the vas deferens unite. When the muscle of the ejaculatory ducts contract its content is expelled through the urethra, to the outside.
What does the urethra do
Transports semen and urine. Transfer sperm through vagina
What is the prostrate gland
A conical shaped gland whitch lies against the bladder. It secretes a milky liquid and gives seman its Oder. This liquid is alkaline and keeps sperm alive in vagina,
In a women at puberty what does the brain do
Tells the ovaries to produce oestrogen whitch tells the eggs to mature. And then once a month an egg leaves an ovary and pops into a Fallopian tube. Where it waits before travelling to the uterus. In the uterus the egg and lining dissolve and leave.
Explain ovulation
In notes
What two hormones do the peturitory gland produce and what do they do
Follicle stimulating hormone - instructs ovary to make mature egg
Leuatnaising hormone - goes to ovary and oestrogen is realesed,
What happens after ovulation process
Each egg waits in the Fallopian tube to be fertilized by sperm
Sperm leaves the penis, swims up the vagina through the uterus into the Fallopian tube where an egg may be waiting to unite with a sperm. If one sperm enters the egg, (head of sperm penetrate the ovum )they become one cell and pregnancy can begin fertilized by one soerm only the others die
What happens as the baby develops
Grows bigger, the uterus stretches to accommodate.
Foetus develops within amniotic sac (surrounded by amniotic fluid that protects and nourishes baby)
Ambilical chord connects baby to mom
What is the definition of fertilization
The fusion of the nucleus of the sperm with the nucleus of the egg
What is the product of fusion so sex cells
A zygote
After the zygote is made ( fusion of cells) what happens
It moves along the Fallopian tube to the uterus. As it moves it divides by mitosis. ( cell division) until it’s a round mass of cells. It reaches the uterus after about 4 days , by then it’s a hollow ball of several thousand cells, the blastula
What is the blastula
Hollow ball of several thousand cells
Explain what the blastula does
When it touches the endometrium or uterus wall it is implanted. This is where the blastula develops into an embryo surrounded by a number of membranes
What is the outermost protective membrane
The chorion witch has a number of finger like projections called villi
What happens to ensure that the villi are bathed in blood
Large, blood , filled spaces develop between the villi
What blood never mixes
Blood of foetus and mother
What is pressed close to the chorion and what does this do
The amnion whitch is filled with amniotic fluid whitch surrounds the foetus.
What does the amniotic fluid serve as
A shock resistor and provides constant medium for the delevopmwnt of the embryo
What do the ovaries produce
The female gametes or ova
Where are the 2 ovaries placed
In the abdomen by a ligament
What is each ovary surrounded by
A funnel that leads to a tube known as the oviduct (fallopian tube) that carries the egg to the uterus
Where does fertilization occur
In the Fallopian tube
What does the uterus have and why
A thick muscular wall, so that the developing embryo can attach. Embryo grows in uterus
What is at the end of the uterus
A glandular region called the cervix whitch leads to the vagina
What does the vagina do
Receives sperm and serves as birth canal
What is menstruation
Shredding of tissue and blood from the lining of the womb through a women’s vagina
When does ovulation occur (day)
Day 1
Why is menstruation continuous
It’s a cycle, and it’s getting ready for pregnancy
When is the best time to have sex in order to fall pregnant and why
5 days before egg is released or on day . As sex takes place in this time , egg and sperm can reach tube at the same time. Egg then fertilized
What is the period between fertilization and birth
Pregnancy
What happens in the time period of pregnancy
The embryo is protected within and develops inside uterus of mother
What does the human ovum contain and why
Little yolk because it is fed by juices secreted by the uterine wall
What are all the requirements for the embryo carried by
The blood of the mother to the blood spaces of the placenta and are transferred to foetus by division
Where does waste difuse to and from
Waste diffuses out of the foetus to the blood of the mother
What does the placenta do
Protect embryo. Serves as a micro filter preventing solids and bacteria from entering the blood of the foetus. In doing so provides immunity to foetus
What does the aminionic fluid protect baby from
Shock, temp changes, dehydration
How long after fertilization is baby ready to be born
40 weeks
What is labour
Walls of uterus contract, effect of contractions is to push the foetus in the direction of the cervix.
Pressure is exerted on the amnion and chorion whitch is then raptures and the amniotic fluid is released (water breaking)
Contractions increase in strength and the baby is pushed, head first, through the vagina to the exterior
What happens when the baby leaves the vagina
The shock of coming into the colder air makes the baby gasp, clearing the lungs of amniotic fluid and the baby takes first breath. Baby cries filling lungs with air and breathing process begins
What is the afterbirth
The placenta that is released through vagina after birth
What happens when more than one baby develops and grows in the womb at the same time
A multiple birth occurs
How do multiple births occur
A women produces more than one ovum during her cycle, there will be more than one ovum in the Fallopian tubes to be fertilized and seperate embryos will develop.
How are twins made fraternal
When 2 seperate ova are fertilized.
How are identical twins made
One ovum is fertilized , but splits into 2 Seperate embryos
What are Siamese twins
When the ball of cells or embryo split
Joined somewhere on the Body
Can be surgically seperated depending on what organs are shared
What diseases are in category 1
STDS that produce inflammation of the urethra, epidydyms, cervix or oviducts
Gonorrhea, chlamydia
Treated with antibiotics
Viral. Discharge
What diseases are in catagory 2
STDS that produce sores on the external genitals
Genital herpes most common. 25 million South Africans
Symptoms Treated by antiviral drugs, infection never cured
Syphillis is a bacterially caused infection and can if left untreated cause death . Cured with antibiotics
Disease in category 3
Includes viral diseases that affect organ systems other than those that affect reproductive system
AIDS , HEPAPTIIS B
Sexual contact or blood
Infected may appear symptom free for years after infection
Explain Aids ( acquired immunedefiency syndrome)
Develops after immune system has been serverly weakened and can no longer defend body from infections
As AIDS progresss the body is overhwelmed with life threatening illnesses and diseases
What virus causes AIDS
HIV ( AIDS virus )
What does HIV (human immunodeficiency virus) do
Destroys immune cells called T cells whitch are vital to the body for protection against infection and diiseases
AIDS will result when HIV has severely reduced number of T cells
Anyone can become infected with HIV .(anyone infected with HIV can develop AIDS ) unborn can be infected
How does AIDS infect bodies
Through exchange of infected blood, semen or vaginal secretions
Where does HIV live
In white blood cells called T cells
Where are T cells found
Blood, semen, breast milk, vaginal secretions , mesntrual blood
Common ways of being infected with HIV
Sexual activity
Eluting contaminated hypodermic needles
Transmission from mother to baby during pregnancy , birth , breast feeding
Where are the sperm made
In the seminiferous tubules in the testes
