LECTURE II Flashcards
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describe the process of spermatogenesis?
spermatogonium to secondary spermatocyte after mitosis and meiosis then to the spermatid after meiosis II and then differentiation to sperm
what are the stages in oogenesis?
oogonium
primary oocyte
secondary oocyte
ovum
in oogenesis, we start with the primordial germ cell in embryo which differentiates into?
oogonium
in this part of oogenesis, there is the differentiation of the oogonium and onset of meiosis I to produce?
primary oocyte
in this stage of oogenesis, the primary oocyte undergoes completion of meiosis I and the beginning of meiosis II to produced?
secondary oocyte and the first polar body
when the secondary oocyte undergoes ovulation, what is then produced?
ovum and the second polar body
this gene is required for ovarian development and its expression inhibits SOX9 activity?
DAX1
this gene is located on the Y chromosome and its expression inhibits DAX1 activity?
SRY
we on chromosome 9, XY sex reversal with loss of this gene?
DMRT1
this male hormone aids in the development of the penis and prostate but expression of androgen receptors must happen first
DHT
this region of the chromosome is present in XX males and deleted in XY females?
Yp pseudoautosomal region
what are the three phases of spermatogenesis?
spermatogenial
spermatocyte
spermatid
these cells nourish developing sperm
sertoli cells
these cells secret androgen (testosterone)
leydig cells
outside tubules produce testosterone
interstitial cells
what part of the endometrium sloughs off?
stratum functionalis of the endometrium, the other part, stratum basalis of the endometrium
in the stages of Oogenesis, this is arrested in prophase of meiosis I and present at birth?
primary oocyte, however completion of meiosis I and the onset of meiosis II leads to the formation of the secondary oocyte arrested at metaphase II
when is meiosis II completed?
ovulation
these cells make androgen?
theca cells
these cells convert those androgens into estradiol and estrogen?
granulosa cells
how many ovum are ovulated?
1
this hormone favors pregnancy?
progesterone
this hormone induces: estrus corticosterone cortisol aldosterone
estrogen
this type of contraception:
suppression of FSH- no dominant follicle
increase in progesterone-reduced progesterone dose
decreases likelihood of implantation
feedback inhibition of GnRH, FSH and LH release
continuous high estrogen
prevents ovulation by suppressing LH surge
thickens cervical mucus
decreases likelihood of implantation
feedback inhibition of GnRH, FSH, and LH release
continuous high progesterone
high dose of progesterone or high dose progesterone and estradiol-no ovulation
morning after pill
Mifepristone or RU 486 blocks the activity of progesterone
effective up to week nine
decidual degeneration
reduced hCG
RU-486
in the male reproductive life cycle changes, what are the stages of the cycle?
embryonic
prepubertal birth
pubertal
post pubertal
in the male reproductive life cycle changes, this happens during what stage?
response to testosterone
receptors for testosterone must be present on tissue
embryonic
in the male reproductive life cycle changes, this happens during what stage?
at birth, testosterone decreases to undetectable levels at about one week
testosterone and LH increase in males from 1-6 months
at 7 months, testosterone falls to insignificant levels and stays there until puberty
prepubertal birth
in the male reproductive life cycle changes, this happens during what stage?
decrease in melatonin
decreased feedback sensitivity of gonadotropin-gonadostatin, increased GnRH secretion, increased pituitary cell sensitivity to GnRH
increased LH:FSH in response to GnRH, increased Leydig cell sensitivity to LH: increased testosterone synthesis and cessation of division, activation of Sertoli cells
sequential development of testes and secondary sex characteristics
stimulation of spermatogenesis and spermiogenesis
Pubertal
in the male reproductive life cycle changes, this happens during what stage?
tonic hypothalamic center controls more or less continuous release of FSH and LH
testes provide more or less continuous synthesis of testosterone
add to adrenal produced testosterone 33% higher than female
gradual decline of testicular function and test levels from around age 40-45
post-pubertal
what are the stages in the female reproductive life cycle changes?
embryonic pre-pubertal pubertal post-pubertal peri-and post-menopause
in the female reproductive life cycle changes, this happens during what stage?
differentiation occurs in the absence of increased test levels
estrogen required for full differentiation and development of uterus and vagina
embryonic
in the female reproductive life cycle changes, this happens during what stage?
low levels of estrogen throughout childhood
increasing levels in late childhood leads to ovarian development
high sensitivity of the negative feedback effect of gonadal steroids
pre-pubertal
in the female reproductive life cycle changes, this happens during what stage?
reduction of sensitivity of the negative feedback effect of gonadal steroids-gonadostat hypothesis
pubertal
in the female reproductive life cycle changes, this happens during what stage?
cyclic hypothalamic center controls periodic surges of LH and FSH
progressive shortening of menstrual cycle with increasing age-follicular phase
post pubertal
in the female reproductive life cycle changes, this happens during what stage?
around age 45, shortening of the follicular phase with increase in FSH at mid cycle surge
estradiol secretion from ovary progressively declines
other tissue maintain estrogen levels
menopausal symptoms due to estrogen deficiency
peri- and post- menopause
in mitosis, the life cycle of somatic cells, what phase does DNA synthesis occur?
S phase
what phase of mitosis is the cell in listed below?
RNA and protein synthesis
cell growth
nucleus growth
G1 phase
what phase of mitosis is the cell in listed below?
DNA synthesis
histone synthesis
centriole duplicates
S phase
what phase of mitosis is the cell in listed below?
multiplication of cell organelles
cell growth
nucleus growth
biochemicals for m-phase
G2 phase
what phase of mitosis is the cell in listed below?
PMAT (Karyokinesis) and cytokinesis
M-phase
how is progression through parts of the cell cycle affected?
via specific cyclins
this cyclin triggers cells to move from G0 to G1 and from G1 into S phase?
cyclin D
this cyclin prepares the cell for DNA replication in the S phase?
Cyclin E
this cyclin activates DNA replication inside the nucleus in the S phase?
Cyclin A
this cyclin promotes the assembly of the mitotic spindle and other tasks in the cytoplasm to prepare for mitosis?
Cyclin B
purpose of meiosis?
reduction of the number of chromosomes from diploid to haploid
reassortment of paternal and maternal chromosomes
redistribution of maternal and paternal genes through translocation
what are the different types of chromosomal abnormalities/aberrations?
numerical and structural
Euploidy, Aneuploidy, XXY, Triploidy, Tetrapolidy are what kinds of chromosomal aberrations?
Non-disjunction
what are specific diseases due to Aneuploidy?
Klinefelter syndrome (47,XXY;48,XXYY)
(48,XXXY;49,XXXXY)
Turner Syndrome (45,XO)
Trisomy 21
what are the types of abnormal structures or gene arrangement on one or more chromosomes?
balanced rearrangements
unbalanced rearrangements
these are the characteristics for what type of structural abnormality?
individual with balanced rearrangement has a full complement of genetic information
may be no phenotypic abnormalities
may not be detected until progeny show abnormalities
Balanced rearrangements
these are the characteristics for what type of structural abnormality?
phenotypic abnormalities are likely due to deletions or duplications
frequent fetal abnormalities
duplications=partial trisomy
deletions=partial monosomy
unbalanced rearrangments
