Reproductive system Flashcards
What is the testis surrounded by?
The testis is surrounded by the tunica vaginalis to keep cool
What do male and female Gonads produce?
Females produce oocytes (eggs) by oogenisis and males produce sperm by spermatogenisis
What is the function of the Uterus?
Used for the implantation of the fertilized ovum and growth of the foetus.
Describe the steps in the Hypothalamic Pituitary Gonadal Axis
Hypothalamic signaling horomone releases Gonadotrophin releasing horomone (GNRH). That interacts with pituitary horomones Lutenising Horomone (LH) and Follicle stimulating Horomone (FSH)
Which areas of the hypothalamus are involved in ovarian control?
Preoptic and supra optic nucleus (both secret GNRH)
What is GnRH and its function?
Peptide horomone that stimulates the synthesis and secretion of the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH).
How is GnRH released
It is released in pulses
How does GnRH get to the pituitary gland from the hypothalamus
Portal circulation to the anterior pituitary ganotrobes
What do Gonadotrobes secrete?
FSH, LH
What do Ovaries have inside of them
Oocytes
What are the types of follicles and which types secrete hormones?
Early and latter follicles and latter follicles secrete hormones
Where can you find Theca cells in a follicle?
Theca cells are found on the superficial layer of follicles
What is the function of a Theca cell?
They convert cholesterol into pregnenolone and produce androstenedione and testosterone
What receptors do Theca and Granulosa cells have?
Theca has LH recpetors and Granulosa cells have LH and FSH receptors
Where can you find Granulosa cells in a follicle?
You find them in the deep layers of the follicle
When is the oocyte released from the follicle?
During ovulation
What does the Granulosa cell do?
They convert cholesterol into pregnenolone and activates aromatase
What does aromatase do?
Facilitates the formation of estradiol
3 main oestrogens
Oestradiol, oestrone and oestriol
What do ovaries produce?
Oestregins and progestins
What does estrogen and progestins do?
It regulates LH and FSH secretions. It changes from a negative feedback to positive feedback during the mid-cycle
What are the 2 cycles that the menstral cycle include?
Ovarian and Endometrial cycle
Describe the Ovarian cycle
- Follicular phase: Follicles grow
- Luteal phase: After ovulation and oocyte is released. It secretes estrogen and progesterone
If no fertilization occurs then the corpus luteum degrades
Describe the Endometrial cycle
If no fertilization, menstruation cycle starts and endometrial lining is replaced with vasoconstriction of the spiral arteries.
Proliferative cycle, endometrial is thickening
Maturation phase, Prepares oocyte to come in
Prolactin function:
Milk production
Oxytocin function:
Milk let down
What do Testis contain?
Leydig cells that produce testosterone, blood vessels and semiferous tubules (produce sperm and Sertoli cells)
Where are the testicular endocrine functions?
In the Leydig and Sertoli cells
Describe Oogenesis
It starts in the fetus, it starts producing oogonia which then matures into oocytes until it reaches its max number and starts to slowly decline.
Descibe spermatogenisis
Starts from Spermatogonia to primary spermatocytes to secondary spermatocytes to spermatids to spermatoza. Regulated by testosterone
Testosterone secretion regulation
Progesterone regulates the secretions
What part of the pituitary gland causes what for milk production
Anterior pituitary gland creates prolactin which creates milk production and the posterior pituitary gland creates oxytocin which makes the milk let down for the baby to take in the milk.