2.1 The structure & function of reproductive organs and gametes & their role in fertilisation. Hormonal Control of reproduction Flashcards
What are the testes?
site of sperm production and the male sex hormone testosterone.
What is the male sex hormone?
testosterone.
What are sperm and what and where are they formed from?
male gametes and they are formed germline cells by meiosis in tubules called seminiferous tubules
What do seminiferous tubules come together to form ?
coiled tubules that connect to the sperm duct.
How do sperm leave the testis?
via sperm duct
Where are interstitual cells located and what do they do?
in the tissue between the seminiferous tubules and produce testosterone
What is testosterone directly passed into?
the bloodstream
What does testosterone do?
stimulate sperm production and also brings about the development of male secondary sexual characteristics
When are sperm released into the vagina?
during sexual intercourse
What are sperm which allow them to travel to the egg?
they are motile
As sperm are motile what are they able to move through?
the uterus and along the oviducts where they may meet an egg and fertilise it
What do sperm require?
a fluid medium and a source of energy
Name 9 main parts of the male reproductive organs?
penis opening of urethra urethra testes scrotum sperm duct prostate gland seminal vesicle bladder
Name the 2 accessorary glands in the male reproductive system?
seminal vesicles and prostate gland.
What do seminal vesicles do?
secrete liquid rich in fructose and hormone-like compounds called PROSTAGLANDINS.
What ways does fructose contribute to fertilisation?
sugar provides sperm with energy needed for motility following their relax at ejaculation
What ways do prostaglandins contribute to fertilisation?
stimulate contractions of the female reproductive tract . These movements help sperm reach the oviduct at a faster rate than could be achieved by swimming alone
What does the prostate gland do?
sectretes a thin, lubricating liquid containing enzymes
What ways do enzymes contribute to fertilisation?
maintains the fluid medium at the optimum viscosity for sperm mobility
What makes up semen?
sperm
liquid rich in fructose and prostaglandins
thin lubricating liquid containing enzymes
Name the 6 main parts of the female reproductive organs?
vagina cervix uterus endometrium oviduct ovaries
What is the female gametes?
ova (eggs)
What is ova formed from and where?
by germline cells by meiosis in the ovaries
At birth, what do female’s ovaries contain?
immature ova in various stages of development
What is each ovum surrounded by?
a follicle
What does the follicle do?
protect the developing ovum and secretes oestrogen
What is ovulation?
release of an egg
What happens during ovulation?
mature ova are released into the oviduct, the old follicle develops into the corpus luteum which secretes progesterone and some oestrogen
What is the first phase of the development of ova and how long does it usually last?
follicular phase
DAY 1-14.
Ovulation is aroundday 14.
Immature ovum develops into mature ovum
What is the second phase of the development of ova?
Luteal Phase
After ovulation, old follicle develops into corpus luteumwhich secretes progesterone and some oestrogen and then degeneates
What happens after the sperm enters the cytoplasm of the egg?
a reaction takes place, preventing other sperm from fertilising the same egg
What happens during fertilisation?
the sperm’s nucleus then fuses with the nucleus of the ovum.
What is the first cell of the new individual called?
zygote (diploid)
Following successful fertilisation, what does the zygote do?
move along the oviduct towards the uterus.
What happens to the zygote as it travels?
it undergoes a series of mitotic divisions (i.e. cleavage) to increase cell number (but not size)
What is cleavage?
special division where cells divide without an increase in cytoplasm
By the time the zygote arrives at the uterus what has it become?
a ball of cells called a blastocyst
What does the blastocyst do?
implants into the endometrium where it will continue to develop.
