Spermatogenesis & Oogenesis
during spermatogenesis how many gametes are produced
4 sperm
what is the role of LH in the female
A surge in LH causes ovulation and the secondary oocyte is released into a fallopian tube.
when does capacitation occur
Capacitation involves removal of steroid (e.g. cholesterol) and seminal glycoproteins from the head of the sperm by the vaginal fluid. This exposes the acrosomal head of the sperm and allows greater binding between sperm and oocyte
role of estrogen
Estrogens are responsible for the development and maintenance of the female secondary sex characteristics
what is the role of FSH in female
FSH is secreted from Day 0 through 14 of the reproductive cycle and causes the primary oocyte (primary follicle) to mature and develop into secondary oocyte (secondary follicle).
What happens to the primary oocyte during puberty
FSH stimulaes about a dozen of primary oocytes to resume meiosis I. Only one egg will proceed and halt at metaphase of meiosis II, where it is now a secondary oocyte
what is considered a follicle
Follicle = egg + epithelial cells (granulosa cells) that surround the egg
what happens to the corpus luteum if there is no implantation/fertilization
If implantation does not occur by Day 24, the corpus luteum degenerates (becoming the corpus albicans), and levels of progesterone (and estrogen) decline dramatically.
role of progesterone
Progesterone prepares the endometrium of the uterus for preganacy.
what is the role of seminiferous tubules
Seminiferous tubules are tightly packed tubules located within lobules of the testes. The seminiferous tubules are the functional units of the testis, where spermatogenesis takes place
what is spermiogenesis
Spermiogenesis involves major changes in a spermatid's internal and external structures. head body flagellum
what secretes estrogen in the female
The developing follicle secretes estrogen (granulosa cells)
what happens to the follicle left in the ovary after ovulation of the ovum
The follicle that is left in the ovaries after ovulation becomes the corpus luteum, which secretes progesterone
what is the role of leydig cells
They are responsible for secreting the male sex hormones (testosterone).
when does meiosis II resume in the female
after fertilization occurs, then it produces the second polar body
why are polar bodies produces
all of the cytoplasm goes to one ovum to ensure that at least on egg will have enough cytoplasm to support the zygote until the placenta has formed after fertilization
what is the follicular phase of the ovarian cycle
day 1 -14
what is the luteal phase of the ovarian cycle
day 14-28
what happens to the secondary oocyte
during LH surge, the secondary oocyte is ovulated from the ovary into the uterus. It will remain arrested in metaphase II until fertilization
what are polar bodies
during meiosis in female there is unequal cytokinesis where at the end of Meiosis I, one ovum gets all the cytoplasm and sheds one polar body. At the end of Meiosis II, one ovum gets all the cytoplasm and sheds the second polar body.
what are the layers to the uterus
endometrium - inner most layer myometrium - muscular layer perimetrium - visceral covering
what is the function of epididymis
epididymis is the primary site of storage of sperm cells i.e. as spermatozoa are transported into the epididymis, they are stored there.
when is estrogen levels high in the blood during menstration
estrogen secretion increases beginning with day 0 of the reproductive cycle until day 14. During this period the level of estrogen in blood is high
when estrogren levels decrease, what happens to progestrone levels
estrogren is high day 1-14. progestrone levels are high day 14-24 so the corpus lueteum to prepare body for pregnancy
what are the phases of the menstral cycle
menstral phase (days 1 - 5) proliferation phase (days 6 - 14) secretory phase (days 15 - 28)
what is the overall sequence of speramtogenesis
mitosis meiosis spermiogenesis
are the spermatozoa that are in the epididymis mature?
not they are immature and immobile
when does sperm become mobile and mature
once they undergo capacitation
What happens to the primary oocyte from birth to until puberty
primary oocytes undergo meiosis and soon halts at prophase I until puberty
what stage of spermatogenesis undergoes meiosis
primary spermatocyte (meiosis I) secondary spermatocyte (meiosis II)
what is a primordial follicle
primordial follicles contains a primary oocyte with a single layer of epitheilal cells.
what stage of meiosis is the female egg arrested in
prophase II
what are the layers of the scrotum/testes starting with superficial to deep
skin scrotal fascia cremaster muscle tunica vaginalis tunica albuginea testes
what stage of spermatogenesis undergoes spermiogenesis
spermatid
what is the sequence of spermatogenesis
spermatogonia primary spermatocyte secondary spermatocyte spermatid spermatozoa
what stage of spermatogenesis undergoes mitosis
spermatogonia divides into two daughter cells
what is the role of FSH in male
stimulates sertoli cells in the testes and initiates spermatogenesis in the germinal epithelium of seminiferous tubules
what is the role of LH in male
stimulates the Leydig cells to produce male sex hormones (testosterone).
What is the role of sertoli cells
support and nourish the spermatogenic cells, secrete androgen-binding protein, secrete inhibin, maintain the blood-testis barrier.
in oogenesis how many gametes are produces
1 ovum with 2 polar bodies