Chapter 2 gametogenesis Flashcards
primitive sex cords
supporting cells plus the germ cells
genital ridges
areas where the gonads are going to form
What are the supporting cells of the female ?
follicular cells
what are the supporting cells of the male?
sertoli cells
In male gametogenesis, primordial germ cells lay dormant until when ?
puberty
What hormone and cells places an important role in male gametogenesis
LH and leydig cells
When does spermatogenesis stop ?
when the person dies
What hormone do the leydig cells secrete?
testosterone
what starts the process of spermatogensis?
secretion of testosterone by the leydig cells
spermiogenesis
conversion of spermatids into mature sperm
What four steps occur in spermiogenesis?
lose the cytoplasm, condense nucleus, neck+ tail added and acrosome added
maturation of the sperm occurs where ?
vagina of the female
at week 12 what major step happens in female gametogenesis
population of oogonia after their first meiotic prophase become dormant until puberty!
ovarian follicle
capsule and the follicle
What do the follicular cells secrete that prevent further progression of the cell cycle in female gametogenesis ?
OMI-oocyte aturation inhibitor helps arrest the process and puts the break in meiosis
What are the two stages of the ovarian cycle ?
follicular stage and the luteal phase
in 5-12 primordial follicles what happenes as a result of FSH and LH ?
the follicular cells begen to thicken to cuboidla cells and it becomes a primary follicle
zona pellucida
a glycoprotein coat sereted by the follicular cells and the oocyte together
graafian follicle
the structure that is formed that has an antrum (take up of fluid and space) when the main follicle continues to develop
what hormone secretes HcG
SYNCYTIOTROPHOBLAST
what hormone does the corpus luteum secrete
progesterone until the placenta takes over
malformations
occur during organogenesis in the embryonic period and result in abnormal structure
disruptions
result from external influence that causes alterations of completely formed structures
deformations
abnormal form resulting from mechanical forces (club foot is an example)
dysplasia
abnormal organization of cells into tissue (sacrococcgela teratome)
what percentage of congenital abnormalities is caused by genetic factors ?
28%
agenesis
absence of an organ
aplasia
cells to form an organ never formed
association
anamalies occuring together without determiend cause
atresia
absence of an opening or lumen
hyperplasia
overgrowth of an organ
hypoplasia
underdevelopment of an organ
syndrome
a group of anomalies, occurring together with a common cause
teratogen
subtance affecting migration, proliferation or interaction of cells; results in congenital anomalies
What does the G1 phase do?
monitors the environment and the cell size to make sure its appropriate for replication
pachytene
crossing over event (exchange of genetic material that results in unique genetic combinations
where do the germ cells arise from
the epiblast from primary ectoderm
when the primordial follicle gains a zona pellucida and has now become multilaters it is now called the_________–
primary follicle
What are the two layers of the vesicular follicles or graafian follicles called
theca exerna and theca interna
what does the theca interna become
steroid secreting cells !
the granulose cells of the ruptured follicle after ovulation begin to proliferate to what type of cells
luteal cells
what is the function of the corpus luteum
serves to maintain the uterine endometrium in a condition ready to receive an embryo
what is the role of the menstrual cycle ?
to produce a single female gamete each month
what is the cumulus oophorous
connects the oocyte to the rest of the graffian follicle
what does the corpus luteum become if implantation does NOT occur
corpus albicans
FSH
rises during first half follicular phase, peaks prior to ovulation, declines during luteal phase, functions to stimulate the development of ovarian follicles and production of estrogen
LH
rises during first half of follicular phase, peaks just prior to obulation, declines at luteal phase and functions to trigger ovulation and production of progesterone
estrogens
low at first half of follicular phse, rises during 2nd half of follicular phase and peaks before LH surge and decline sat beginning of luteal phase but then increases
progesterone
low during folliuclar phase, increases prior to ovulation, in prenancy levels remain high, no pregnancy means rapid decline of progesterone due to degeration of corpus luteum
what are the three phases of uterine progresstion
meststrual, proliferative, secreory, ischemic
thecal cells from the theca externa secrete
estrogen
trisomy 18
intellectual disability, congenital heart defects, low set ears, flextion of fingers and hands, renal abnormalities, microagnathi (small jaw) a, syndactyly, and malformations of skeletal system, three copies of trisomy 18
trisomy 21
down’s syndrome, growth retardation, varying degrees of intellectual disability, craniofacial abnormalities, extra skin folds, flat faces, small ears, hypotonia, premature aging risk of leukemia, thyroid disease and infection three copies of 21
trisomy 13
intellectual disability, holoprosencelphly, heart defects, deafness, cleft lip, palate and eye defects microphthalmia(small eye), anophthalmia (missing and eye) and coloboma(hole in eye)
klinefelter syndrome
found only in males usually detected by amnioentesis, sterility, testicular atrophy, 47 chromosomes, XXY, barr body is also present,
turner syndrome
X karyotype, only monosomey compatible with life, absence of ovaries, short statur, webbed neck, lymphedema, broad chest and wise spaced nipples
Triple X
often undergo undiagnosed, frequently have speech problems
Angelman syndrome
microdeletion on the long arm of chromosome 15 on the maternal chromosome, cannot speakm poor motor development and unprovoked laughter
prader willi syndrome
microdeletion on the long arm of chromosome 15 that occurs on the paternal chromosome, hypotonia, obesity, intellectual disability, hypogonadism, and undescended testes
