Reproduction Flashcards
how does the reproductive system differ from other body systems?
the rest of the body’s systems work to ensure the survival of the individual animal they are part of, whereas the reproductive system works to ensure the survival of the species of animal
why is the reproductive system of an individual animal considered only half a system?
because it requires a second animal (of the opposite sex) to fully carry out its function
mitosis
starts with 1 cell that duplicates its DNA, then spilts 1x to yield 2 diploid cells
meiosis
starts with 1 cell that duplicates its DNA then splits 2x to yield 4 haploid cells
what is haploid chromosomes?
the reduced number of chromosomes in the gamete which results from a reduction division called meiosis
what is diploid chromosomes?
the total number of chromosomes in the nucleus of each body cell is the same
what is the haploid chromosome number ensuring?
that a fertilized ovum from the union of a ova and spermatozoa have a diploid number
which gamete determines the genetic sex of the offspring when fertilization occurs?
the spermatozoon
how does cell division by meiosis differ form cell division by mitosis?
in mitosis, the chromosomes duplicated are the same, they are split between 2 daughter cells; in meiosis, a random half of the total chromosomes go to each daughter cell to ensure genetic diversity
how does spermatogenesis differ from oogenesis?
spermatogenesis is designed to produce large number of sperm at a time, oogenesis only needs to produce a small number of mature ova at a time
what is spermatogenesis?
the production of spermatozoa in the seminiferous tubules of the testes; specifically the rete testis within the seminiferous tubules
what is the principle androgen produced by the interstitial cells?
testosterone
what do the sertoli cells do?
they support developing spermatids and shield them from the body’s immune system; they respond to FSH
what do interstitial cells do?
they respond the LH and produce androgens; they are aka nurse cells
where are the spermatozoa stored before ejaculation?
the epididymis
what structures do spermatozoa pass through from their site of production to their eventual deposition in the female reproductive tract?
through the seminiferous tubules, rete testis, efferent ducts, epididymis, vas deferens (including the ampulla in some species), and urethra
what are 2 main types of hormones produced in the ovary?
estrogens and progestins
where are estrogens produced?
by the cells of the developing ovarian follicles
where are progestins produced?
principally progesterone, are produced by the corpus luteum, which develops from the empty follicle after ovulation
after ovulation has occurred, what cells in the ovary multiply to form the corpus luteum?
granulosa cells
when ovulation occurs, what causes the ovum to enter the oviduct?
the ovum is “caught” by the fimbriae of the infundibulum
where is the urethral opening located in the female?
the urethra opens on the floor (ventral portion) of the vestibule, which is part of the vulva (the part that is considered the entrance to the vagina)
what is the order of stages of the estrous cycle?
proestrus, estrus, metestrus, diestrus, anestrus
what animals are induced ovulators?
cats, camels, rabbits and ferrets
what hormones control the estrous cycle?
FSH and LH
what are the intervals of the estrous cycle?
polyestrous, seasonally polyestrous, diestrous, and monoestrous
polyestrous
cycle continuously throughout the year if they are not pregnant; cattle, swine
seasonally polyestrous
cycle continuously during certain times of the year and not at all during others; horses, sheep, cats
diestrous
2 estrous cycles per year, usually spring and fall; dogs
monoestrous
only 1 cycle each year; foxes and minks
proestrus
the period of follicular development in the ovary; getting ready to become pregnant
estrus
the heat period or the period of sexual receptivity; ovulation
what animals do not ovulate until they have been bred?
camels, cats, ferrets and rabbits
metestrus
the period after ovulation when the corpus luteum devlops
diestrus
waiting for embryo development; when the corpus luteum has reached maximum size and exerts its maximum effect
anestrus
a period of temporary ovarian inactivity
corpus luteum
a solid endocrine structure that forms from the empty ovarian follicle after ovulation; the granulosa cells left in the now empty follicle begin to multiply under continued stimulation of LH to form the corpus luteum
what is the order of sperm duplication?
spermatogonia (mitosis) primary spermatocytes (meiosis I) secondary spermatocytes (mitosis) spermatids (meiosis II) sperm
what is the order of oocytes duplication?
primary oogonia (mature) primary oocyte (meiosis I/ovulation) secondary oocyte (meiosis II) ovum (fertilization)
