Reproduction (Humans) Flashcards
What is the prostate gland and its function?
- It is the circular gland under the bladder, attached to the sperm ducts
- It produces a fluid called semen providing sperm cells with nutrients
They perform this function alongside the seminal vesicles
What are the seminal vesicles and their function?
- They are the two small circular glands attached to the sperm ducts
- They produce a fluid called semen providing sperm cells with nutrients
They perform this function alongside the prostate gland
What is the function of the sperm duct?
It is for sperm to pass through from the testes and mix with the fluids produced by the glands before passing into the urethra
In men, what is the urethra and its function?
- It runs down the centre of the penis, and is connected to the bladder and the sperm duct
- It carrys and releases either semen or urine
- A ring of muscle in the urethra prevents the two from mixing
What are the functions of the testes?
- Produces sperm (the male gametes)
- Produces testosterone
What is the function of the scrotum
The sac supports the testes, keeping them outside the body as sperm production prefers a temperature of roughly 34 not 37
What are the functions of the penis?
- To pass urine out of the body
- To allow semen to be released inside of a womens vagina
What is the oviduct and its function?
- It is a tube connecting each ovary to the uterus
- It is lined with ciliated cells to push the ovum down
- Fertilisation occurs in the oviduct
What are the functions of the ovaries?
There are two ovaries
- They produce and contain ova
- They mature and release eggs when hormones are released
Ova is plural of ovum (the female gamete)
In women, what is the urethra and its function?
It connects the bladder and the hole, allowing urine to be released
The hole where urine comes out is seperate from the vagina
What is the uterus and its function?
It is a muscular bag, where the zygote (fertilised egg) implants itself to develop into a foetus
What is the cervix and its function?
- It is a ring of muscle at the lower end of the uterus, in between the vagina and the uterus
- It keeps the foetus in place during pregnancy
What is the vagina and its function?
- It is a muscular tube with an opening which leads to the uterus
- It is where the penis enters during sexual intercourse and deposits sperm
How long is the average menstrual cycle?
28 days
What happens on the first 5-7 days on the menstrual cycle if fertilisation of the oviduct did not happen?
Menstruation occurs, where the lining of the uterus is broken down in preperation for the next cycle which lasts 5-7 days
What happens between day 7 and day 14 of the menstrual cycle?
The uterine lining begins to thicken and is built up in preparation for possible zygote implantation
What happens on day 14 of the menstrual cycle?
Ovulation occurs
Ovulation is the release of the egg
What happens from day 14 to day 28?
The lining continues to build up and is maintained
If implantation occurs, the lining will stay, if not the cycle starts over again at day 28 with menstruation
How do oestrogen levels change during the menstrual cycle?
- Levels rise from day one (stimulated by FSH), and peak shortly before day 14 to stimulate LH (ovulation)
- They drop after ovulation, rise slightly to maintain the lining and then drop for menstruation
How do progestrone levels change during the menstrual cycle?
- Levels stay low from day 1-14
- They rise signifigantly once ovulation has occured, stimulated by LH, to maintain and thicken the lining, and then drop, causing menstruation
How do LH levels change during the menstrual cycle?
- Levels are low from day 1-12
- They rise at day 13, stimulated by oestrogen, and peak at day 14 for ovulation
- They then drop, and are low for the rest of the cycle as progestrone inhibits it
How do FSH levels change during the menstrual cycle?
- Levels are high between day 1-12 to mature the egg and stimulate oestrogen production
- Levels drop shortly before ovulation as oestrogen peaks
- They are low for the rest of the cycle as progestrone + oestrogen inhibit it to ensure only one egg is fully matured
What are the roles of oestrogen in the menstrual cycle?
- Stimulates the uterus to begin to build up a lining
- Stimulates the production of LH at its peak
- Inhibits FSH production to stop the maturation of another follicle
Oestrogen is produced in the ovaries
What are the roles of progesterone in the menstrual cycle?
- Maintains the lining of the uterus
- Inhibits the production of LH and FSH to stop the maturation and release of another egg past day 14
Progesterone is produced by the corpus leutem, which is a dead follice left behind after ovulation
