Epidemiology
The incidence of infertility in Australia
1 in 6 (11% - 16%) reproductive-age couples
The 4 main phases of spermatogenesis
Mitosis, Meiosis (I & II), Spermiation and Differentiation
The day on which ovulation occurs in a normal menstrual cycle
Day 14
The phase of the ovarian cycle that almost always lasts a fixed 14 days, regardless of the total cycle length
Luteal Phase
The section of the uterine tube where fertilisation is most likely to take place
The ampulla
The most common cause of female infertility
Ovulation disorders - eg. PMOS, Primary Ovarian Insufficiency etc.
What are the names of the main supporting cells for spermatogenesis?
Leydig
Sertoli Cells
What happens during the menstrual phase?
The functional layer of endometrium (stratum functionalis) sloughs off and prostaglandin levels increase, causing vasoconstriction of the spiral arterioles and uterine contractions
The temporary endocrine structure responsible for secreting high levels of progesterone during the second half of the cycle.
Corpus Luteum
The space between the ovaries and the fimbriae
Peritoneal space
Three causes of male infertility
Hormonal disorders, Testicular failure, Abnormal Sperm quality and function, Reproductive tract obstruction
Describe the steps of Spermiogenesis
The Acrosome forms from the Golgi apparatus. Which packages enzymes into acrosome
Acrosome moves to front and centrioles move to the back and Microtubules from centriole elongate
Mitochondria form around the forming flagellum and excess cytoplasm is removed
The phase of the menstrual cycle corresponding with the luteal phase
The secretory phase
The hormone that causes the LH surge prior to ovulation
Estrogen
The area where the placenta attaches in placenta previa
The bottom of the uterus, covering some or all of the cervix
Name four of the risk factors for infertility
Smoking, Excessive alcohol intake, Obesity, Environmental pollutants (heavy metals [lead, cadmium, mercury], endocrine disruptors [BPA, phthalates], and persistent chemicals [PFAS]) , Toxin
Name 2 reasons why testosterone is needed specifically for spermatogenesis?
Meiosis, Blood-testis barrier, cell adhesion, spermation
The phase of the cycle during which cervical mucus things due to rising in oestrogen levels, allowing the passage of sperm into the uterus at the time of ovulation
Proliferative / Preovulatory phase
The hormone that suppresses pituitary FSH production to prevent additional follicles from maturing. (and what secretes it?)
Inhibin (dominant follicle)
The main cell types of the seminiferous tubules and describe their functions
Sertoli cells - involved in germ cell production, Leydig cells - secrete testosterone, Spermatagonia - stem cells from which spermatozoa are derived
Is the rate of infertility in Australia increasing or decreasing? And what is the current birth rate in Australia?
Increasing. 1.48 births per women (which is below the 2.1 births replacement rate needed to maintain population without immigration)
Discuss the hormonal regulation within spermatogenesis touching on release of LH and FSH and their effects on production of sperm
GnRH → LH + FSH
LH → Leydig → testosterone
FSH → Sertoli → ABP + sperm support
Testosterone + Sertoli function → spermatogenesis
Please label each phase on the image.
Menstrual, Proliferative (Preovulatory), Ovulation, Secretory (Postovulatory)
The type of follicle with cuboidal granulosa cells and a new zona pellucida
Primary follicle