Reproduction Flashcards
testicles are what cunt
external
3 male excessory glands
seminal vescible
bulbarurethral gland
prostate gland
in fetal life, the balls are what where?!?!?!
testes are formed near the kidneys
then they descend into scrotum
guided by gubernaculum
what are undescended testes called
cryptochidism, this results in infertility, cause testis, and gametogensis is highly sensitive to temperature,
temperature in the balls
2-3 degrees lower than the body temperature, controlled by muscles,
muslces that move the balls
cremaster muscle
dartos muscle
pampiniform plexus what is it cunt
facilitates heat exhcange within the blood that is flowing into the testis, following a simple counter current system.
tubes in the testis proper are what
each of these coiled up tubes are the seminiforus tubules, this is where gamete production takes place. they move to the rete testis, then go to the efferent ductules, then to epidydmis, then the vas deferens
the epidydmis is what (4) (4) (4)
single, highly-coiled tube
2-6 day passage
sperm maturation (gain mobility, metabolic changes, cell membrane changes, ) storage (?) and or transport
androgen dependant
the vas deferens is what (4)
35 cm long , thick muscular wall
sperm storage and transport
palpable
vascetomy - sterilisation
the bulbourethral glands is what
paired glands
< 5% seminal fluid
alkaline
pre-ejaculatory fluid
why tf do u need cum fluid? (40
urethra is acidic, cause of urine, re-ejaculatory fluid brings it more to a alkaline type environment, better for sperm.
seminal vesicles what are they (4) (4)
paired glands
~65% of the seminal fluid
alkaline (this is to protect sperm in urethra and in vagina)
prostaglandins, clotting proteins, fructose.
prostate gland what is it (4) (last part)
single gland
~30% of the sseminal fluid
has liquefying enzymes
this enables sperm transport in the pussy
prostate fluid is slightly acidic not alkaline
penis function
to deposit male gametes into female reproductive tract to facilitate fertilisation to take place (to get freaky freaky)
main erectile tissue and erectile tissue surrounding urethraa
main = corpus cavernosum
urethra = corpus spongiosum
erection (boner) what tf is it cunt
a vascular event
- sexual arousal
- nerves in the penis release nitric oxide (which causes vasodilation)
- vasodilation - increase blood flow to corpora cavernosa -> erection
- erectile dysfunction - increases with age due to an increase in vascular disease
functions of female reproductive tract
produces gametes, transport for fertilisation;
provides a receptacle for fertilisation, embryogenesis, and fetal development, give birth, nurture the newborn.
things to know about female reproductive tract
Uses correct anatomical terminology to describe the main structures of the female reproductive tract
- Relate structure to function
- Relate events of the ovarian cycle to those of the menstrual cycle
- Describe the effects of ovarian steroids on female reproductive tissues
- Relate differences in male and female anatomical form to differences in reproductive function
follicles (4) (4)
structures that house each developing oocyte, also know what the corpus luteum does too
what do ovarian follicles secrete in first half of cycle (4) (4)
ovarian follicles secrete oestradiol and inhibin in first half of cycle under stimulation by gonadotrophins
what happens to the follicles at ovulation (4)
one of the follicles gets really large and essentially burst and rupture, releasing the oocyte, the remnants of the follicle forms the corpus luteum
cyclic changes in ovarian activity
gonadotrophins from anterior pituitiary gland (LH & FSH)
Ovarian activity
ovarian steroids (oestradiol & progesterone)
what do fimbriae do (4)
they lay over the ovary and capture the ovulated oocyte
be able to identify these (4)
primordial follicle
preantral (primary follicle)
antral (secondary) follicle
mature follicle characteristics (4)
is very large
has a very large antrum
corpus luteum (4)
formed after a reuptured follicle (i.e. after ovulation)
secretes progesterone, oestradiol, and inhibin
in absence of pregnancy CL regresses after 10 - 12 days -> scar tissue (corpus albicans)
uterine tube
gets smaller and smaller from the ovary to the uterus.
site of fertilisation
ciliated and secretory (peg) cells
transports oocyte / embryo to uterus
early nourishment of embryo
ampulla (4)
ampulla is typically the site in which fertilisation takes place
what is the myometrium
outer muscle wall
what is the endometrium
inner lining
endometrium & the menstrual cycle
- rich blood supply, highly glandular
- undergoes cyclical growth, loss and repair -> menstrual cycle
- influenced by cyclic changes in estradiol and progesterone
proliferative phase (4)
the first half of the ovarian menstrual cycle
under influence of estradiol, endometrium is growing, ovulation takes place and we get an enormous amount of progesterone being secreted
secretory phase (4)
what happens is endometrium enters the secretory phase,
characterised by the maximal amount of growth, but also the production and formation of these uterine glands, they are waiting for a fertilised embryo to implant themselves into it.
what is inside the uterine glands
“uterine milk” which is nourish implanting embryo (if that takes place)
early menstrual phase
if pregnancy implantation doesn’t occur, the CL regresses and we get the loss of progesterone ,which is supporting the secretory phase, so if you get a loss of support the structure essentially breaks down.
then its shed,
what is the first half of the menstrual cycle called (4)
follicular phase
the follicular phase with estrogen is paired with the proliferative phase in the endometrium
what is the second half of the menstrual cycle called (4)
luteal phase
the luteal phase is paired with the secretory phase
the menstral cycle (4) (4)
first day of menses (bleeding) = day 1 of cycle
length of cycle = interval between consecutive menses
average interval = 28 days
common variation = 21 - 35 days
reflects ovarian activity
luteal phase usually constant = 12-14 days, life of CL follicular phase varies in length
therefore ovulation occurs ~12-14 days prior to the next menses
variation has implications for failure of natural family planning methods
cervix tissue types
the tissue (in the womb) above the cervix is simple colomnar epithelium, the tissue of the cervix is stratified squamous epithelium
cervical glands function
secrete cervical mucus , which is under the influence of those ovarian steroids during the cycle
describe the vaginal epithelia
epithelial cells accumulate glycogen
-> converted to lactic acid
-> acidic pH
-> inhibits pathogen growth
made of stratified squamous epithelium, for the wear and tear of sex.
greater vestibular gland (4
is it a homologous structure ig to the male bublourethral gland
it has a secretory product which aids in the lubrication of the vagina to help faciliate sexual reproduction.
shit u need to know about hormones
List the main groups of reproductive hormones and give examples of each
- Explain the function, control, and action of GRH, gonadotrophins, estradiol, progesterone, testosterone and inhibin
- Explain positive and negative feedback
- Describe the hormonal control of the testicular and ovarian axis
- Apply the above to explain action of hormonal contraceptive and effects of anabolic steroids
under the influence of oestrodiol, the mucus has a large water component relatively thin, allows sperm to pass through
under the influence of progesterone (in the secoind half of the cycle), water content of the mucus decreases dramatically, mucus become a lot more viscous, almost impenetrable.
steroid examples (4)
testosterone, estradiol, progesterone, cortisol
three main types of hormones
peptides
steroids
eicosanoids
hormones
chemical messengers, produced by endocrine glands/cells, act on target cells/tissues, target cells express specific receptors (membrane bound or intracellular)
peptide examples
GnRH, LH, FSH, hCG, inhibin, oxytocin, prolactin
eicosanoid examples
prostaglandins
peptide hormones
peptide hormones bind to membrane-bound receptors and require action of second messengers, this is typically refered to as a g protein mechanism.
when ligand binds tog the membrane bound receptor is activatee these g proteins and then activate adenal cyclise, that leds to a production of cyclic amp cAMP, leading a cellular response
steroid hormones
have no problem crossing cell membranes or nuclear membranes, when they enter cell, they bind to their receptors, when this happens, they form a receptor hormone complex, which acts a a transcription factor, (a transcription factor is a molecule that will influence gene transcription)
types of hormone action
endocrine
paracrine, cell that is producing the hormone also has the receptor for that hormone
autocrine
exocrine
control of the endocrine system
positive feedback
negative feedback, osselates above and beow the set level, endochrine gland with secrete a hormone, that horemone with have an effect at a targert tissue, that target tissue with have a response, and that response will have a negative feedback effect at that gland, leds to a decrease in the horomone productyion, then a decrease in hormone provided to the target tissue, then a decreased response, then the negative feedback will be released, then initiatial hormone production from the gland will increase, (always increases and decreases )
LH effecting androgens, testorsterone (4)
anterior pitutary glands produces LH, efffecting leydig cells, leads to production of testosterone, testosterone has a negative feedback effect on the anterior pituitary, this leads to less LH being produced, less LH rpovudied to leydig cell,s less testosterone being the final about put, then the release of that negative feedback
positive feedback
gland producing a hormone, having an effect at a target tissue, it has its reponse, the response is positive to that initial gland.
positive feedback is highly unstable, you need some kind of stimulus to stop the positive feedb ack cycle from occuring.
exampels of positive feedback in reproductive biology
the LH surge during ovarian cycle, the catacyltmic event that stops that is ovulation taking place, 2. what is happening during childbirth
what is happening during childbirth
positive feedback loop, posterior pituitary gland is producing oxytocin, which affects the myometrium of the uterus, leading to contractions, those contractions lead to a nervous signal that has a positive feedback.
hierarchy of control (4)
hypothalamus - gonadotrophins releasing hormone GnRH
pituitary - gonadotrophins (LH & FSH)
gonads (ovary and testis) - estradiol, progesterone, testosterone, inhibin.
endocrine control of spermatogenesis
differences in males and females function reflected in feedback mechanisms
female fertility is episodic: cycle of ovarian activity
male gamete and steroid production is continuous from puberty
difference reflected in feedback mechanisms of gonadal steroids on gonadotrophins
-> males -ve feedback
-> females -ve AND +ve feedback
spermatogenesis three main processes
- mitotic proliferation
- meiotic division
- cell remodelling (spermiogenesis)
spermatogonium
spermatogonium at the onset of puberty will undergo mitosis, will be continuously proliferating at the
basement membrane of that seminifeous tubule.
there are two types of spermatogonium
type A and type B spermatogonium
type A will only ever be spermatogonium, and they will undergo to mitosis to generate more spermatogonium, of which, you will have type B spermatogonium
type B will enter the subsequent phases of maturation
primary spermatocyte
from type B spermatogonium, they will become a primary spermatocyte, this is the completion of mitosis, then they will enter the first meiotic division.
spermatogonium *(they are stem cells) enter into spermatogenesis approximately every 16 days
secondary spermatocytes
after first meiotic division, primary spermatocytes (which are 2n) become secondary spermatocytes (which are n)
spermatids
secondary spermatocytes enter the 2nd meiotic division and become spermatids (which are n), resulting is 4 cells from an initial 1 primary spermatocyte
how is spermatogenesis organised (4) (4)
by sertoli cells, at all stages of spermatogenesis, the cells are in contact with a sertoli cells, this is imoportant because the sertoli cells provide the nutrients required to support theses cells as they are maturing, they also coordinate that spermiogenic waves, and they also create a blood-testis barrier
spermatogenesis takes ~74 days to complete
spermatozoa
spermatids undergo spermiogenesis to form spermatozoa
male sperm count is constant, this is achieve through what is known as the spermatogenic wave,
why is there a blood-testis barrier
because cells undergoing spermatogenesis cells have haploid chromosomes, so they are technically foreign cells, so if male immune system detects those cells, it will attack them.
spermiogenesis (4)
(Its helpful to look at a diagram of this) golgi apparatus differentiate into a acrosomal granule, and will migrate and lay over the top of the nucleus forming the acrosomal vesciel, then the more mature acrosome.
there are black spots in the nucleus which are centrioles, one of those centrioles will migrate to the distal portion of the nucleus, (opposite to the acrosome) and it will differentiate and forms a flagella.
primary macronutrients in sperm are glucose and fructose, and will convert it into ATP. there are the mitochondria in nucleus, all mitochondria migrate towards the end of the flagella, and line up and go on to form the middle piece of the sperm.
the remaining cytoplasm in the cell is phagocytosed and removed from the cell through a residual body
the nuclear material become incredibly condensed.
end of spermiogenesis
sperm still need to mature to obtain their swimming capabilities, and they don’t have the complete fertilising potential yet. they obtain this complete fertilisation potential when fertilisation of the female egg is about to occur.
oogenesis three stages
- mitotic proliferation
- meiotic division
- cell remodelling
oogenesis
begins with 1 oogonium (which is 2n), which undergoes mitotic proliferation to form 1 primary oocyte (which is 2n), which then undergoes first meiotic division and forms 1 secondary oocyte and 1 1st polar body, that secondary oocyte will under a second meiotic division, forming 1 ovum (which is n) and 1 2nd polar body.
why is the shuttling of cytoplasmic content to one cell in oogenesis important?
two reasons, if fertilisation takes place we need, within the cytoplasm, support for the early cleavage or cellular proliferation of that embryo. important consequence of this is that the gamete is relatively large and unable to transport itself, so its up to the sperm and the oviduct to facilitate transport.
because of unequal divison of cytoplasm and cellular contents, this could be seen. as quality control as only one is made, where has males focus on quantity of sperm.
differences in cellular remodelling steps in males and females
in males the meiotic divisions, division of the cytoplasm and the cellular contents was equal, in females the division of the cytoplasm and cellular contents is not equal, resulting in polar bodies.
what is the polar body
the expulsion of half the genetic content
the timing of the relative stages of oogenesis and folliculogenesis
in males, process starts at the onset of puberty and mitosis just continues on.
In females, this process begins during fetal life. primary oocytes are all surrounded by a primordial follicle and will end the first phase of meiosis, and will arrest or stop at that first meiotic division.
female will then enter puberty, they are still arrested. at puberty, a follicle starts to mature, there still is a primary oocyte in that follicle
that follicle will then form a antral follicle , primary ooctye is in that antral follicle, the only way that the meiotic division can complete is if ovulation takes place. the trigger for this is the first LH surge, just before ovulation the first meiotic division is completed and the 1st polar body is extruded.
at ovulation the 2nd oocyte arrests in second meiotic division, the only way that the second meiotic division can complete is if fertilisation occurs, where by second meiotic division completes and 2nd polar boy is extruded
other big difference in cellular remodelling between males and females
the timing
two processes needed for sperm to leave the male tract
emission and ejaculation
emission
smooth muslce contractions of the prostate, vas deferens, seminal vesicles,
contents into posterior urethra,
emission is essentially the initial stages of ejaculation
sperm in female tract
sperm is depositied in the vagina, they swim all the way to the fertilisation site,
what processes to sperm need to undergo in the female reproductive tract? (4)
- capacitation (acquire capacity to fertilise) helps get through cumulus oophorus
- acrosome reaction (head modification) helps get through zona pellucida
characteristics of sperm of the seminal fluid that aid in sperm transportation through the female reproductive tracts barriers
humans are bipedal, initial coagulation stops seminal deposition from falling out , and provides some protection for the sperm against the acidic environment of the vagina, seminal fluid is alkaline, which neutralises the environment,
liquifying agents , after the initial coagulation occurs, its broken, so the sperm are now potentially able to cross the cervix, also remember the characteristics of the cervical mucous can greatly impact sperms ability to do this.
cervical mucous filters sperm, only the strongest swimming sperm are able to do this.
transported to the ampulla (actions of flagella, uterine contractions)
one of the ingrediants of cum is prostaglandins, they faciliate smooth muscle contractions of the myometrium of the uterus.
only a couple hundred (<0.0001%) sperm make it to the ampulla
sperm can survive in the reproductive tract for 3-4% days
how do sperm know where tf do go ( find the oocyte)?
(this is mostly theoretical) sperm seem to be able to sense temperature, and tend to swim from cooler temperatures to warmer temperatures, the ampulla temp is deeper in the female body, so its closer to the 37 degrees of average body temp.
ejaculation
- internal urethral sphincter contracts
-> prevents seminal fluid into bladder / urine into the urethra - smooth muscle of urethra contracts
- skeletal muscles of pelvic floor
barriers to the union of sperm and oocyte
- cumulus oophorus (granulosa cells)
- zona pellucida
capacitation
- sperm attain their fertilisinbg capacity
- occurs in the uterine tube under the influence of estrogen
this is characterised by:
- change in mobility (hyperactivated tail, more vigorous movement)
- change in cell surface membrane
fertilisation
outer membranes fuse
stimulates completion of 2nd meiotic division of oocyte (i.e. 2nd polar body extrunded)
ovum formed
block to polyspermy
sperm nucleus decondenses and forms male pronucleus
results of fertilisation
DNA replication occurs in male and female pronuclei
pronuclei fuse - diploid number of chromosomes restored
new individual (zygote)
1 degree of sex determination (XX or XY)
initiation of cleavage (mitosis) (formation of 2-cell embryo)
