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52 Cards in this Set
- Front
- Back
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What are the cells from which gametes initially develop?
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Primordial germ cells
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Primordial germ cells (PGCs) are known as what once they have migrated to the gonads in the developing organism?
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Oogonia
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What are the cells that surround oogonia as they undergo mitosis?
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Follicular cells
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When an oogonia enters prophase of meiosis I, what is it called?
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Primary oocyte
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What is a primordial follicle?
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A primary oocyte surrounded by follicular cells.
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What stage of cell division do primary oocytes pause in prior to female puberty?
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Prophase I of meosis
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What causes primary oocytes to arrest until puberty? Where is this produced?
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oocyte maturation inhibitor produced by follicular cells
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What is the other name for the stage in which oocytes arrest until puberty?
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diplotene stage
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What is the sequence of follicle development?
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primary follicle to secondary (antral/Graffian) follicle to preantral follicle
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What type of cells release a glycoprotein coat around a maturing oocyte?
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Granulosa cells
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What is the name of the glycoprotein coat produced by granulosa cells which surrounds the developing oocyte?
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Zona pellucida
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What are the two layers of cells which surround the basement membrane (granulosa cells)?
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theca interna and theca externa
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What is the difference between the theca interna and externa?
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The interna is secretory while the externa is a fibrous capsule.
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How many follicles are recruited for each ovarian cycle? How many reach full maturity?
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15-20. Only 1 (usually)
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What hormone is released when a follicle reaches maturity?
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Leuteinizing hormone (LH)
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What is the impact of a release of LH on a mature follicle?
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Meiosis I finishes and the primary oocyte develops into a secondary oocyte and a polar body.
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What are the three main layers of the uterus? What are the cell types of these tissues?
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perimetrium (connective tissue), myometrium (muscle), and endometrium (epithelial)
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What are the three layers of the endometrium?
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Compact, spongy, and basal
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Which layers of the endometrium slough during each ovarian cycle?
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compact and spongy
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What hormones cause spermatogenesis to begin?
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testosterone and dihydrotestosterone
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When primordial germ cells begin undergoing meiosis in males they become known as what?
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spermatogonia
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Where are spermatogonia found?
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Located along the basal membranes of the seminiferous tubules
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After two rounds of meiosis on a spermatagonia, what and how many are formed?
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Four spermatids are formed
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What is spermatogenesis?
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The maturation of spermatogonia into spermatid.
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What is spermiogenesis?
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The maturation of spermatid into spermatozoa.
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What are the key helper cells in spermiogenesis?
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Sertoli cells
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What are the three roles of the Sertoli cells in spermiogenesis?
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Reduction of gamete cytoplasm and formation of structures (head [acrosome], tail, mitochondrial midpiece)
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What is spermiation?
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Cytoplasmic bridges between spermatozoa and Sertoli cells are broken and spermatozoa are released into the lumen of the seminiferous tubules.
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How long does a round of spermatogenesis take to occur?
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64 days
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What is the process that prepares a spermatozoa for fertilization called?
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Capacitation
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When does capacitation occur?
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As the spermatozoa travel from the seminiferous tubules to the fallopian tubes.
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Once spermatozoa are produced, where are they stored?
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The coiled region of the vas deferens called the epididymis.
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Where does fertilization usually occur?
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The ampulla of the fallopian tubes.
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What occur when a spermatozoa cell reaches the zona pellucida of an oocyte?
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The spermatozoa binds to human-specific glycoprotein-sperm receptors.
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What is released when spermatozoa bind human-specific glycoprotein-sperm receptors? Why is this important?
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Degredative enzymes which allow the spermatozoa to penetrate the zona pellucida.
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Once spermatozoa and oocyte cell membranes occur, what is released? Where is it released and why is this important?
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cortical granules are released into the space between the oocyte membrane and the zona pellucida. This inhibits human-specific glycoprotein-sperm receptors preventing more spermatozoa from fusing with the oocyte and causing polyspermy.
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When does an oocyte undergo meiosis II?
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Only after it has fused with a spermatozoa.
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After fertilization but prior to the fusion of male and female genetic material where is this information found?
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male and female pronuclei
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What is cleavage?
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Cell divisions after fertilization that increase the number of cells but not the size of the zygote.
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What is a blastomere? Where are they found?
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The type of cells produced by cleavage. Inside the zona pellucida.
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A group of blastomeres together is called what?
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A morula
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What is the impact of compaction on a morula?
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It becomes a blastocyst.
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How does compaction change the shape of a morula?
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Cell-cell adhesion is maximized in outer cells and minimized in inner cells. This causes the outer cells to become convex and inner cells
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Which side of the blastocyst will implant in the uterine mucosa?
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The embryonic pole.
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What are the two types of trophoblast? Which one invades and erodes the uterine mucosa?
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Syncytiotrophoblast and cytotrophoblast. The synctytiotrophoblast.
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What is the Gravid uterus?
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The state of the uterus after fertilization which prepares it for implantation.
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What occurs to the uterus between fertilization and implantation?
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Endometrial glands secrete mucus and glycogen and arteries become more twisted forming a capillary bed.
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What are the most common sites of blastocyst implantation?
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The anterior or posterior uterine wall.
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What is placenta previa?
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Implantation occurs near the os of the uterus. Makes examination difficult. Can lead to severe bleeding.
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What are the possible sites of ectopic pregnancy?
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Placenta previa, abdominal pregnancy (pouch of Douglas/ recto-uterine pound, mesentary, or kidney), tubal pregnancy (fallopian tube).
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What is a secondary implantation?
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A tubal pregnancy that is expelled and becomes an abdominal pregnancy.
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What is a simultaneous implantation?
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A normal intrauterine pregnancy masks the presence of an ectopic pregnancy.
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