Reproduction Flashcards
What is dimorphism
It is what makes people physically distinct from each other
Where is the sex determining gene found
On the Y chromosome without this everyone would be female
What does the malarian duct become
He fallopian tubes, uterus and the upper 1/3 of the vagina
What cell produces sperm cells
The spermatogonium can differentiate into a sperm cell
What effects does testosterone have on men
Promotes male reproductive tract pre birth, promotes growth and maturation of reproductive system during puberty, encourages spermatogenesis, promotes protein anabolic effects and promotes bone growth in puberty
What do the dartos and cremaster muscles do
They contracts to regulate temperature in the cold
What are the 3 phases originating in the autonomic nervous system for the penis
- Emission (contraction I. The epididymis, vas deference and ejaculatory duct)
- Erection
- Ejaculation
How do testosterone levels change with time in men
There is a slight/moderate increase during puberty but otherwise levels remain constant
Describe the process of meiosis that the oogonia undergo’s
- Melodic arrest producing an oocyte
- Then meiosis 1 produces a secondary oocyte and the 1st polar body
- Meiosis 2 completes after fertilisation
When is the luteal phase in the menstrual cycle
Between ovulation and just before menstruation (lasts around 14 days)
What are the phases of the menstrual cycle
The proliferative phase (first 14 days) and the secretory phase (second 14 days)
Where does fertilisation take place
The uterine tube
How long are sperm and oocytes viable for
Sperm = 5 days
Oocyte = 12-24 hours
What happens after a zygote is initially formed
The zygote begins to divide and is entirely totipotent until reaching around 16-32 cells in size when it becomes a blastocyst and a different section becomes the placenta
What are the theee components of a blastocyst
- Trophoblast - outer layer
- Blastocoele - fluid filled sack
- Inner cell membrane
What proportion of births are breech (feet first)
5% although another half of these turn around by themselves during labour
What cervical dilation is required to birth a child
10cm to allow the head to pass through
What causes the water to break before birth and what is the purpose of this
The fetuses head ruptures the amniotic sac lubricating the birth canal
What is the interval and duration of contractions in the first stage of labour
30 minutes to start getting progressively shorter in interval
30 seconds
How many stages of labour are there
3 (first stage with long gaps between contractions, second stage ending with the birth and the third stage is the afterbirth)
What hormones are most greatly effected by the loss of the placenta
Major decrease in maternal progesterone and estrogen
What is parturition
Birthing a child
What do spasmogens do and give an example of one
They increase the force and frequency of contractions
Oxytocin
prostaglandins F2 and E2
What hormones inhibit and what hormones stimulate lactation
Inhibit - estrogen and progesterone
Stimulate - prolactin and oxytocin
What does the corpus luteum do
Essential in maintaining pregnancy in the third trimester
What do low levels of estrogen inhibit during the menstrual cycle
The release of hypothalamic and anterior pituitary gonadotrophins
What can stimulate spermatogenesis in individuals with low sperm counts
Anti-estrogen clomiphene
Which sex starts with a wolffian duct
Males
Which sex starts with a mallerian duct
Females
What hormone causes a wolffian duct to regress
Absence of testosterone
Which hormone causes a Müllerian duct to form
Absence of anti-mullerian hormone
FSH increases the activity of which enzyme in men and what does this cause to happen
Aromatase
Causes the conversion of testosterone into oestradiol in the Sertoli cells
Which endocrinological phase of the menstrual cycle occurs when low estrogen and low progesterone
Proliferative folicular
Which endocrinological phase of the menstrual cycle occurs when moderate estrogen and high progesterone
Luteal post ovulatory
Which endocrinological phase of the menstrual cycle occurs when high estrogen and low progesterone
LH surge
What do leydig cells, Sertoli cells, smooth muscle cells and the blood testis barrier do in the male reproductive system
Leydig cells = secrete testosterone
Sertoli cells = support sperm development
Smooth muscle cells = propel sperm
Blood barrier = maintain tight junctions
During what part of the menstrual cycle does the corpus luteum degenerate
Menstrual phase
Blood supply increases to the uterus in what menstrual phase
Secretory phase
