RDA Flashcards
Label the following diagram of the male reproductive system
Where are sperm produced
Sertolli cells in the seminiferous tubules
What is produced by Leydig (interstitial cells) ?
Tetosterone
What is the path of sperm on ejaculation ?
Sperm are stored in the epididymis.
On ejaculation sperm pass through the two Vas Deferens (which are contractile), and are mixed with fluid from the seminal vesicles.
The fluid then leaves the ejaculatory duct, and passes into the urethra where it mixes with secretions from the prostate gland”
Label the following diagram of the female reproductive system
Summarise the main regulatory pathways within the adult human male reproductive system
FSH +ive on Sertolli cells
LH +ive on Leydig cells = Testosterone production = +ive on Sertolli cells
Testosterone -ive on Hypothalamus and Pituitary
Inhibin (from Seminifeous tubule)= -ive on Pituitary
What is ovarian follicle atresia ?
Ovarian follicle atresia is the periodic process in which immature ovarian follicles degenerate and are subsequently re-absorbed during the follicular phase of the menstrual cycle. Typically around 20 follicles mature each month but only a single follicle is ovulated. The rest undergo atresia. That single dominant follicle becomes a corpus luteum following ovulation
Explain what a corpus luteum is?
The corpus luteum (Latin for “yellow body”; ) is a temporary endocrine structure in female ovaries that is involved in the production of relatively high levels of progesterone, moderate levels of estradiol and inhibin A. It is the remains of the ovarian follicle that has released a mature ovum during a previous ovulation
What is the function of the corpus luteum if ovum is fertilized?
If the egg is fertilized and implantation occurs, the syncytiotrophoblast (derived from trophoblast) cells of the blastocyst secrete the hormone human chorionic gonadotropin (hCG, or a similar hormone in other species) by day 9 post-fertilization.
Human chorionic gonadotropin signals the corpus luteum to continue progesterone secretion, thereby maintaining the thick lining (endometrium) of the uterus and providing an area rich in blood vessels in which the zygote(s) can develop. From this point on, the corpus luteum is called the corpus luteum graviditatis.
At what point in oogenesis does the oocyte become haploid?
When it becomes a secondary oocyte.
What is folliculogenesis /
the maturation of the ovarian follicle, a densely packed shell of somatic cells that contains an immature oocyte.
What are the stages of folliculogenesis?
Primordial follicle - Dormant, small, only one layer of flat granulosa cells
Primary follicle Mitotic cells, cuboidal granulosa cells. Zona pellucida forms
Secondary follicle Presence of theca cells, multiple layers of granulosa cells
Antrum formation. The formation of a fluid-filled cavity adjacent to the oocyte called the antrum designates the follicle as an antral follicle, also called a Graafian follicle.
Tertiary follicle Fully formed antrum, no further cytodifferentiation, no novel progress
Ovulating follicle
Corpus Luteum
What are the two phases of the female mentrual cycle called
Follicular phase
Luteal phase
Why does LH remain low despite high GnRH levels rising During the follicular phase?
Follicles produce oestrogen which at low concentrations inhibit LH release
What is the relationship between FSH release and oestrogen levels?
FSH is released in response to low oestrogen levels. So as Oestrogen rises from the follicles, FSH starts to fall.
What is the relationship between oestrogen and LH
At low concentrations its inhibitory but at high concentrations oeastrogen stimulates LH release.
Wht are the three hormones secreted by the corpus luteum
Oestrogen
Inhibin
Progesterone
Which is the pathway in the brain is relevant to reward and pleasure?
mesolimbic dopaminergic system
What are the changes during male erection?
- Initiated by: increased parasympathetic activity releasing acetylcholine.
- The acetylcholine increases the activity of Nitric Oxide Synthase (NOS), and hence nitric oxide (NO) in vascular endothelial cells
- NO increases production of cyclic GMP which induces dilatation of pudendal artery smooth muscle.
- counteracts sympathetic-maintained myogenic tone
- increases blood flow in corpus cavernosum
- which compresses the dorsal vein, restricting the outflow of blood
- The urethra is protected from increased pressure by surrounding corpus spongiosum (less turgid)
Why is it important to state whether gestational age is from LMP or embryological view from moment of fertilization?
These dates can differ by +/- 2weeks
What is the overall average weight gain in pregnancy?
10-15kg
What is the main hormone of pregnancy in the first 10 weeks ?
HCG (human Chorionic Gonadotrophin)
What are the main three hormones seen in the second and third trimesters of pregnancy ?
Progesterone
Oestrogens (mainly oestriol)
Placental lactogen
These parallell the increased size of the placenta