a specialized type of nuclear division which occurs in the ovaries and testes during gametogenesis. in order to produce gametes with the reduced chromosomal number
the gametes produced in the gonads that have only half the normal chromosome number than seen in all other body cells
the process of gamete formation which involves the reduction of the chromosome number by half
sperm production that begins at puberty and continues without interruption throughout life. It occurs in the seminiferous tubules of the testes.
the primitive male stem cells found at the tubule periphery. before puberty all of these are mitotic divisions that produce more of itself.
the product of a mitotic division of a spermatogonium under the influence of FSH (follicle-stimulating hormone) after puberty. this cell is destined to undergo meisosis. it under goes a growth phase and then meiosis I takes place (DNA replicates before the division)
the result of meiosis I of the primary spermatocyte is this haploid which is smaller in size. two are made out of one primary spermatocyte, they are destined to undergo meiosis II (DNA is not replicated before division)
haploid cells that are the actual product of meiosis, and they are not functional gametes. they are nonmotil;e cells and have too much excess baggage to function well in a reproductive capacity.
the process that follows meiosis, and strips away the excess cytoplasm from the spermatid and converts it to a sperm
aka Leydig cells, cells lying external to and between the seminiferous tubules. LH and ICSH (interstitial-cell stimulating hormone) promotes these cells to produce testosterone and acts synergistically with FSh to stimulate sperm production
the genetic region of the sperm, it contains the DNA of the chromosomes. essentially it is the nucleus of the spermatid
the metabolic region of the sperm. there is a centriole which gives rise to the filaments that structure the sperm tail. wrapped tightly around the centriole are mitochondria that provide the ATp needed for contractile activity of the tail.
located anterior to the nucleus, this contains enzymes which contains enzymes involved in sperm penetration of the egg
the primitive stem cells that begin oogenesis. during fetal development, these undergo mitosis thousands of times until their number reaches two million or more
when the female is born, her oogonia have increased in size and are known as... The number of these are determined by the time you are born, and they remain quiescent until puberty. Becaue of FSH one or more of the follicles begin to undergo maturation every 28 days.
the name of the grown follicle...its epithelium changes from squamous to cuboidal. It begins to produce estrogens, and the primary oocyte completes its first maturation division, which results in two haploid daughter cells that are disproportionate in size.
one of the haploid daughter cells formed by the primary oocyte's first maturation division. it contains nearly all of the cytoplasm of the primary oocyte. as the follicle for this continues to enlarge, blood levels of estrogens rise.
first polar body
one of the two haploid daughter cells that results from the primary oocyte's first maturation division. it is tiny in comparison to the secondary oocyte. It often produces two more polar bodies but they eventually disintegrate for lack of sustaining cytoplasm
the stage of the follicle in the middle of the 28 day cycle. by this point rising estrogen levels become highly stimulatory and a sudden burstlike release of LH triggers ovulation. this causes the secondary oocyte to be extruded and journey down the uterine tube to the uterus. if pemetrated en route by a sperm, the secondary oocyte will undergo meiosis II, producing one large ovum and a tiny second polar body. if sperm penetration does not occur, the secondary oocyte simply disintegrates.
the result of the sperm and egg. when the second matyration division is complete, the chromosomes of the egg and sperm combine to form the diploid nucleus of the fertilized egg
the ruptured follicle is transformed when the secondary oocyte is expelled from the ovary and LH transforms the follicle into this.... It begins producing progesterone and eestrogen. It appears as a solid glandular structure that contains a scalloped lumen that develops from the ruptured follicle.
the scar tissue that replaces the corpus luteum. it is caused by the drop of LH levels in the blood at the end of the 28 day-cycle. as soon as progesterone production ends, the corpus luteum begins to degenerate and is replaced by this.
one or a few layers of cuboidal follicle cells surrounding the larger central developing ovum
several layers of follicle (granulosa) cells surrounding the central developing ovum. beginning to show evidence of fluid accumulation and antrum formation. follicle development may take more than one cycle
at this stage of development, the follicle has a large antrum containing fluid produced by the grranulosa cells. The developing secondary oocyte is pushed to one side of the follicle and is surrounded by the corona radiata
A capsule of several layers of granulosa cells that surrounds the developing secondary oocyte. this remains intact for when the secondary oocyte enters the uterine tubes