Reproductive Physiology Flashcards
what does Biological Sex distinguish and what is it the result of
gender
It is the result of chromosomes
and results in the production of gametes
what does sexual reproduction do
produces offspring that differ genetically from both parents.
what is sexual intercourse
Sexual intercourse is required for sexual reproduction; involves sexual activity and
pleasure.
Also, human bonding.
what pathways are associated with pleasure
Pathways for reward and pleasure in mesolimbic dopaminergic system.
what other pathways are involved in procreation, role in human bonding and parental
behaviours
Neuroendocrine pathways regulating fertility and parenting;
Control of movements by nigrostriatal tract;
what do these systems do
link human bonding with
reproduction and parenting
what is the role of the brain
controls gamete production via the hypothalamic-pituitary-
gonadal axis.
what is penile erection controlled by
brain via the spinal cord and efferent nervous system.
what direct interaction can cause erection
Tactile stimulus can activate the afferent system via the pudendal nerve; a more direct
interaction between spinal cord and penis.
what changes occur during erection (which limb of ANS dominates)
increased parasympathetic activity to smooth muscle of pudendal artery
Increase NO activity = increase blood flow in corpus cavernosum
which vein is compressed restricting outflow of blood
dorsal vein
how it the urethra protected from increased pressure
surrounding corpus spongiosum
how does viagra work
Cyclic GMP is normally de-activated by a phosphodiesterase enzyme
Viagra inhibits the phosphodiesterase, thus potentiating the effects of cyclic GMP.
what is the female erectile tissue called
clitoris
main functions of male reproductive system are
the provision of androgens and the production of mature sperm!
role of testis
contains seminiferous tubules which produce sperm
and leydig cells which produce testosterone.
role of epididymis
sperm released from testes and stored here prior to ejaculation
what happens at ejaculation
sperm passes through the vas deferens and mixed with fluid.
Fluid leaves ejaculatory duct and passes to urethra where it mixes with secretions from prostate gland.
how does Spermatogenesis change over life
normally continues through adult life after it starts at puberty.
Quality and quantity of sperm may decline with age
what are Key tissues for reproductive function
Ovary, Fallopian tube, Uterus
role of ovary
produces gametes (oocytes)
and steroids (progesterone and estrogens)
role of Fallopian tube
oocyte reaches the uterus via this; providing an appropriate environment to maintain either an oocyte or conceptus (fertilized oocyte).
IN THE AMPULLA
role of uterus
conceptus normally implants here and is supported throughout pregnancy
what are Thecal cells responsible for
responsible for the production of the androgenic precursors
what produces oestrogen’s and progesterone during the second half of the ovarian cycle
granulosa cells
define key phases of the menstrual cycle.
Part 1= Endometrial cycle:
Part 2= Ovarian cycle:
what are the stages of the endometrial cycle
- menstrual phase (5 days),
- repair and proliferative phase (9 days),
- secretory phase (13 days).
what are stages of the ovarian cycle
- follicular phase (14 days),
* luteal phase (14 days)
what happens to basal body temp during mensturation
rises slightly around the time of ovulation.
what hormonal changes cause ovulation
Within HPG axis, change from negative to positive feedback to cause LH surge and ovulation.
what happens during the Menstrual phase
shed blood and endometrial lining; remaining basal endometrium is very thin.
what happens during Repair and proliferative phase
stimulation of endometrial cell proliferation; increase in thickness, number and length of glands/ arteries.
Secretory phase
production of nutrients and other factors. Epithelial glands widen, endometrium thicken, increased coiling of arteries.
how does the number of follicles in ovary vary until birth
Ovaries contain around 6 million primordial follicles at 20 weeks of development. By delivery of the infant, this has fallen to around 1 million per ovary.
how many follicles will be ovulated during the reproductive life-time
Around 400 follicles
how many sperm do testes produce per day
100 million sperm per day, from puberty onwards
describe passage of sperm from deposition to meeting egg
- Sperm are deposited near the cervix
- Passage of sperm through the uterus and into fallopian tube
- Sperm swims from fallopian tube to ampulla; capacitation is essential preparation before sperm meets oocyte
- Meeting of egg with sperm
describe how seem fuses with egg
acrosome reaction, calcium influx,
resumption of meiosis and release of second polar body
change in zona pellucida to prevent additional sperm fusing with zygote
initiation of mitotic divisions in embryo.
how many hours post ovulation does egg fusion occur
within 24 hours post ovulation
what forms a physical barrier to sperm
Cervical mucus is normally hostile to sperm
Cervical mucus changes at mid-cycle
what happens in gonadotrophin independent growth
primordial follicle pool - primary follicles - preantral follicles
what happens in gonadotrophin dependent growth
small antral follicle - large antral follcile - preovulatory follcile
how many chromosones in primary oocyte and secondary oocyte
primary - 2n
secondary - n (becuase first polar body has been released)
summarise oogenesis
Ovulation = release of mature oocyte (egg) from the ovary
Oocyte is 2n at this stage, in meiotic arrest (metaphase II)
Enters the Fallopian tube
how quickly does the oocyte need to be fertilised before it degenerates
within 24 hours
what happens after fertilisation to maternal and paternal chromosones
Meosis of maternal chromosomes resumes, forming female pronucleus (23 chromatids), and 2nd polar body
Sperm chromosomes decondense to form male pronucleus - 23 chromatids
what are the barriers to fertilisation
Corona radiata
Zona Pellucida
Plasma membrane
