Reproduction Flashcards
what are the 2 main functions of gonads
Produce gametes
Produce reproductive hormones
Oestradiol
is formed by the granulosa from puberty to menopause and is the main orchestrating component of femininity
Oestrone
Is the male/female reproductive component
Oestriole
made in the placenta, prior to labour causes softening of the cervix
Progesterone
Major steroidal hormone of the corpus luteum and of the placenta
associated with the preparations for pregnancy and its maintenance
Difference between Sex Determination
and Sex Differentiation
Sex determination: Commitment of the gonad to a testis or an ovary
Sex differentiation
The phenotypic development of genital structures due to the action of hormones produced by the gonad
Why is the develpment of the female system slower
its slow because there is no active hormone driving the process.
In the absence of SRY, the embryo develops into a female
What do the wolffian duct develop into
Vas Deferens
Seminal vesicle
Epididymis
What do the Internal female genitals develop into
The fallopian tube,
uterus
Upper third vagina
Describe the male differentiation of external genitals
GULU control
Fusion ofthe urethral folds enclosing the urethral tube forming the shaft of the penis
Labioscrotal swellings fuse in the midline forming the scrotumn
The genital tubercle expands forming glans penis
Describe female differentiation
The urethral folds and the labioscrotal swellings remain separate, thus forming the labia minora and majora
The genital tubercle forms the clitoris
Androgen insensitivity syndrome
Basically Campbell
The person is XY, but all the external genitals are female,
this causes mutation in their androgen receptor gene which prevents androgen function
Puberty
It is the reawakening of the reproductive endocrine systems which leads to full secondary sexual maturation with the capacity for repro
Puberty stages for female
1) Breast
2) Pubic hair
3) Peak height spurt
4) Menarche
Oestrogen iis what leads to the breast bud, then the breast mound, the
Sexual hair development
happens 1 year after pubic hair
happens due to exposure of hair follicles to androgens
Growth spurt
happens in females 11-12, boys 13-15
Growth is stimulated by steroid hormones (oestrogen and androgen) with epiphyseal closure ( bony ends) by oestrogen
Why does the first ovulation take place 6-9 months after menarche
Because the positive feedback mechanisms of oestrogen have not developed
Why do testicles enlarge
Leydig cells enlarge and secrete testosterone, giving rise to increased testicular size
Elongation of penis begins within a year of enlargement
What ages constitute as precocious puberty
7 yrs in girls
9 years in boys
This is usually due to a GnRH dependent problem, often due to a hypothalamic tumour
Delayed puberty
lack of appearance of the physical and hormonal signs of puberty, 13 in girls
14 in boys
Menopause is
consequence of ovaries running out of follicles
The last episode of natural menstrual bleeding signifies the end of her reproductive life and is referred to as menopause
How much do the oestrogen level drop compared to previous in menopause
about 1/10 of previous
Mostly produce oestrone
Perimenopausal symptoms
Vasomotor( Hot flush, night sweat)
Gastrourinary( Vaginal dryness)
Bone metabolism ( osteoporosis)
Behavioral changes( Depression, tension, anxiety, mental confusion, libido)
What is the function of the vagina
1) Elimination of Menstrual fluid
2) Holds spermatozoa as they pass through into the uterus
3) Forms lower portion of birth canal through which the foetus passes
Cervix
Mucus that prevents anything from passing through which only changes for the entry of sperm
The internal os is the opening to the uterus
The external os is the cervical OPENING to the vagina
Uterus
Fundus ( top of vagina), the fundal height is the top of the uterus from the pubic bone, and you can roughly tell what the gestational period is
Provides nutritional support, waste removal, and contracts to eject the fetus at birth,
it is the source of menstrual fluid
Endometrium for implantation and source of menstrual fluid
Stratum functionalis
the zone that is lost in the menstrual cycle
its increased growth is due to oestradiol
it is responsible for the secretory phase, that is driven by progesterone because this stratum is where many of the secretory glands are
Uterine tube
Fimbriae, contain cilia, and they beat constantly, thereby collecting oocytes
Uterine tube have glycogen and lipids
Whay causes the oocyte to move up the fallopian tube
1) peristaltic contraction, and cilia causes the stuff to move
essentially things that don’t allow the cilia to beat so well is what causes ectopic pregnancy, with things like age and smoking
Outer ovarian cortex
contains ovarian follicles
Central ovarian medulla
Consist of ovarian stroma and steroid producing cells
Inner hilum
which acts as a point of entry for nerves and blood vessels
Zona Pellucida
made of glycoprotein and contain a form of receptors
it binds with spermatozoa
Granulosa cells
responsible for secretion of some stuff, it eventually forms the corona radiata and cumulus oophorus
Theca externa
fibrous capsule for structure in growing follicle
Theca interna
Vascular and glandular, that help produce oestradiol,
Both of the theca cells and the granulosa cells help form the corpus Luteum
Corpus Luteum is rescued from degeneration by the
hCG from the embryo
How long is the luteal phase
14 days, it is always 14 days
A long menstrual cycle is due to the differing time of the follicular phase
These describe the ovarian cycle
What are the 3 phases of the endometrial cycle
1) Menstruation
2) Preovulatory
3) Ovulation
4) Postovulatory
Assymetric meaning
for spermatogonia, 1 daughter cell remains undifferentiated to maintain stem cell population
Sertoli Cells are found
in the seminiferous tubule and are in direct contact with spermatogonia,
ABP testosterone in testes so spermatogonia can develop even if testosterone isn’t in there
IVF
oocytes are harvested and fertilised ex vivo, requires approx 50000 motile sperm
function of oxytocin
Smooth muscle contraction
Contraction of uterus in childbirth
Milk ejection
Labour
Semen content
10%sperm
30%prostatic fluid
60%seminal vesicle fluid
The pathway
1) Sperm are produced in the seminiferous tubules
2) move in the rete testis
3) epididymis
4) vas deferens
The Ducts
ability to be motile and to fertilize while in the epididymis
reabsorbs liquid from around the sperm making it more concentrated
Sperm then move to the vas deferens where sperm may be stored for several months
Vas deferens ampulla
site where we concentrate store of sperm
Prostaglandin
Smooth muscle contraction Uterus
Clotting protein
Coagulum glue sperm into female reproductive tract
The last part of the ejaculate
comes from the seminal vesicles
Milky colour
due to phosphate and calcium
what do the prostate secrete
citrate, calcium, phosphate
PSA,
psa breaks down post ejaculation coagulum
UTI
travels back to kidneys and urinary infections
Treatments for the enlarged prostate
Finasteride
Dutasteride
Surgery
Prostatic urethral lift
Erection
release of NO and Prostaglandin E1 causes the smooth muscle of corpora cavernosa to relax
8x the volume of blood
Engorgement of corpora reduces venous outflow adding to the engorgement
Viagra
Relaxation of smooth muscle requires cGMP
phosphodiesterase breaks down GMP
viagra inhibits phosphodiesterase
Scrotumn
temperature
contract to get it closer to body so testes can absorb body heat
Blood testis barrier
prevents an immune response against spermatogonia which have different antigens
Sertoli function
nourish, phagocytose
release sperm into lumen of seminiferous tubule but also produce fluid for sperm transport
Secrete inhibin which stops FSH from secreting
so if there is less inhibin, there would be more spematogenesis
Symmetry
sperm mature at the same time, and are linked in mitosis
Spermatogenesis
length 65-75 days
spermatogonia squeeze through tight junction of blood testis barrier
Primary spermatocytes replicates its DNA, then meiosis begins
Meiosis I forms secondary spermatocytes
Meiosis II forms spermatid
No replication of DNA occurs in secondary spermatocytes
Before Birth development
testosterone
dihydrotestosterone
Testosterone is internal genitalia
Dihydrotestosterone is external genitalia
Sex drive is driven by
Androgens
and Androgens stimulate bone growth
epididymis
site where sperm mature and acquire the ability to fertilise an ovum
What are the phases called
Menstruation
Proliferative
Secretory
Menstrual phase
preovulatory phase
ovulation
postovulatory phase
