Reproduction Flashcards
(33 cards)
What are the male gonads and what do they produce?
- Testis and they produce testosterone, and sperm.
What are the female gonads and what do they produce?
- Ovaries and produce oestrogen and eggs.
What does the reproductive tract do?
- Provides passage and supportive secretions for gametes - consists of ducts and glands.
What kind of function do the glands in the reproductive tract have?
- Endocrine.
Can women function without functional gonads?
- Yes: menopause, function of ovaries ceases - no longer producing sufficient hormones therefore reproductive function of women ceases.
What are the two major parts of gonads?
- primordial germ cell (PGC), these cells produce gametes, gametes carry important information.
- mesenchymal tissue, this firms a matrix around the gonads.
Which cells “nurse” and “foster” the primordial cell line and assist maturation and movement through reproductive tract?
- In males: sertoli.
- In females: granulosa.
In males what is the PGC and what are the cells present in mesenchymal tissue?
- PGC = spermatozoa and the cells present in mesenchymal tissue are: Sertoli cells (close to spermatozoa) and leydig cells (further removed).
In females what is the PGC and what are the cells present in mesenchymal tissue?
- PGC = oocyte (egg) and the cells present in the mesenchymal tissue are theca cells (more peripheral) and granulosa (surrounding oocytes).
What kind off cell division takes place in primordial germ cell?
- Meiosis.
When is the gender of offspring determined and when can it be seen?
- At point of fertilisation and if you look at structure between 3 and 7 weeks following fertilisation cannot determine gender based on structure.
What are the names of the male and female genital ducts that develop on either side of gonads?
- Male: wolffian.
- Female: mullerian.
When are the wolffian and Müllerian ducts fully developed?
- Male: wolffian.
- Female: mullerian.
- Both developed fully within 18-20 weeks following fertilisation.
What is an important difference between male and female genitalia in fetus?
- You do not require a positive hormonal influence to get female pattern of reproductive hormones.
For both sexes the steroid sex hormones (testosterone and oestrogen) are regulated by which hormones and where are these hormones produced?
- LH = lutenising hormone.
- FSH = follicle stimulating hormone.
- both are produced in the anterior pituitary.
What do LH and FSH do?
- Act by activating cell membrane receptors.
- LH stimulates leydig (male) and theca (female) cells to lead to production of steroid based hormones.
- LH activates an enzyme known as 20,22 desmolase enzyme.
- FSH activates ovarian granulosa cells and testicular cells to increase activity of aromatase enzyme. It converts testosterone -> oestrogen.
Anterior pituitary gonadotropins are regulated by what?
- Hypothalamus.
What regulates gonadotrophin hormones?
GnRH - gonadotrophin hormone releasing hormone - decapeptide which is released phasically by neurones
What are the male gonads?
Testis - oval, about 4-5cm long and are suspended external to individual in scrotal sac, this sac is made up of cremaster muscle - has ability to contract when temp cold and relax when temp high
Why are testis external?
Sperm tissue is unable to develop at body temp, spermatogensis most efficient at 2-3 degrees lower than body temp
Where is sperm produced and stored?
Spermatozoa is produced in testis, stored in epididymis and delivered by penis
What are the ducts of the testis called?
Seminiferous vesicles/tubules
Which cells are inside and which are outside the seminiferous tubule?
Inside - sertoli and sperm
Outside - leydig
Function of vas deferens?
Connects testis to rest of the body, joins the urethra and prostate glands and then to a set of other organs referred to as seminal vesicles
