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42 Cards in this Set
- Front
- Back
Meiosis |
Formation of gametes. Maintains chromosome number from generation to generation because it reduces the number to one copy of each chromosome (23 total) in each sperm and each egg so that at fertilization there are 46. |
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Spermatogenesis |
The process of taking an immature spermatagonia through two mitotic divisions and reducing chromosome number by half. Results in 4 spermatids connected by cytoplasm. |
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Spermiogenesis |
Final maturation process of spermatids, shedding cytoplasm and forming flagella and acrosome. |
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Acrosome |
Head piece of sperm containing hydrolytic enzymes needed to penetrate the egg. |
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Capacitation |
Softening of the head of the sperm (the acrosome), releasing hydrolytic enzymes allowing the sperm to penetrate the egg. |
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Hormones involved in sperm development |
Hypothalamus releases gonadotropin releasing hormone (GnRH) which stimulates anterior pituitary to release LH and FSH. Leutinizing hormone (LH) released by anterior pituitary stimulates interstitial cells in testes to secrete testosterone. Follicle stimulating hormone (FSH) causes maturation of spermatagonia. Testosterone is important in sperm production and secondary sex characteristics. |
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Where is sperm stored? |
Epididymis |
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Pathway from testicles to urethra |
Testes --> efferent ductules --> epididymis --> vas deferens --> ejaculatory duct --> urethra |
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Oogenesis |
While spermatogenesis results in 4 sperm cells, oogenesis results in only one egg. Process of egg development. Meiosis II only occurs if fertilization occurs. |
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Hormones involved with ovum development |
Same as for sperm development, but LH stimulates development of estrogen and progesterone, and FSH stimulates development of oocyte. |
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HcG |
Produced by embryo. Maintains corpus luteum beyond the normal ten days (for up to 3 months) until the placenta is formed. |
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Mechanisms for maintaining the lower temperature in scrotum |
1. Dartos muscle 2. Cremaster muscle 3. Pampiniform plexus |
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Ovarian ligament |
Connects the ovary to the uterus. |
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Endometrium |
Stratum functionalis is shed during menstruation. Stratum basalis builds up stratum functionalis.
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Glands producing secretions for semen |
60% from seminal vesicles, 30% prostate gland (sperm activator), 10% bulbourethral glands |
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Ovulation |
On Day 14 of monthly cycle, an LH surge from the anterior pituitary causes the egg to be released (ovulation). Mittelschmerz is a twinge of pain sometimes felt at ovulation. 1 to 2% of ovulation result in an egg being released from both ovaries (which can lead to fraternal twins). |
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Menstrual cycle |
Monthly cycle associated with the maturation of an egg. Follicular phase: (Days 1-14) Luteal phase: (Days 14-28) Ovulation on day 14. |
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Role of corpus luteum |
Secrete progesterone and estrogen to maintain stratum functionalis. If conception occurs, HcG released by the fetus helps maintain the corpus lutein until a placenta is formed. If it does not, the corpus luteum breaks down after about 10 days, leaving only a scar known as the corpus albicans. |
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Location of fertilization |
Distal end of fallopian tube |
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Function of GnRH |
Released from hypothalamus, stimulates anterior pituitary to release FSH and LH. |
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Stages of labor |
Dilation stage Expulsion stage (delivery of baby) Placental phase (delivery of placenta) |
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Major cause of testicular cancer |
Cryptorchidism (undescended testicles) |
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Prolactin |
Stimulates milk production |
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Progesterone's job is to ______________ if pregnancy occurs. |
Maintain the uterine lining |
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Prostate cancer |
Second most common cancer in men. Easily treated if it's encapsulated, so early detection is key. |
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Apgar score |
Scale rating how healthy the baby is on birth. 0 to 2 points each for heart rate, respiration, color, muscle tone, reflexes. |
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Blocks to polyspermy |
1. Membrane depolarization 2. Zonal inhibiting proteins (ZIPs) Polyspermy results in a non-viable zygote. |
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Embryonic development stages |
Zygote (fertilized egg) --> Cleavage (rapid division of cells) --> morula (3 day old embryo - 16 or more cells --> Blastocyst --> implantation |
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Primary germ layers |
Ectoderm (forms nervous system and skin), endoderm (forms epithelial linings of digestive, respiratory, and urigenital systems), mesoderm (forms all other tissues) |
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Gastrulation |
Formation of germ layers. Sets the stage for organogenesis. By the 8th week of pregnancy all organ systems are recognizable. |
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Amnion (upper part) |
Epiblast cells transform into a transparent membranous sac. This sac will eventually fill with amniotic fluid and will completely encase the embryo. |
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Ectopic pregnancy |
Development of embryo outside uterine cavity. |
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Yolk sac (lower part) |
Hypoblast cells that form a sac on the central surface of the embryo. |
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At what point do the cells become an embryo? |
At completion of embryogenesis (about 16 days) when germ layers are formed. |
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Purpose of uterus |
Receive, retain and nourish a developing embryo. |
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Purpose of inner cell mass? |
That is the embryo |
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Embryonic membranes |
1. Amnion - from epiblast cells, accumulates amniotic fluid (about 1 L by the time the baby is born). 2. Yolk sac - bottom part, forms part of digestive tube along with the endoderm. 3. Allantois - spot that goes into umbilicus 4. Chorion - trophoblasts. The baby's contribution to the placenta. |
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What has happened by end of first trimester? |
Bones are ossified, limbs are formed, heart is beating. |
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Teratogens |
Anything that can cause birth defects |
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Problems affecting premature infants |
Lack of surfactant on lungs, liver not being fully functional |
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Aneuploidy |
Presence of an abnormal number of chromosomes in a cell |
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When does implantation occur? |
Between 6 and 14 days after ovulation. |