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10 Cards in this Set
- Front
- Back
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What is the relationship between cortisol and transcortin during pregnancy?
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Cortisol, is highly bound to plasma proteins. especially transcortin. Increased plasma levels of transcortin, such as occur during pregnancy, tend to decrease free cortisol concentration, but feedback results in increased ACTH secretion, which stimulates cortisol secretion until free plasma levels of the steroid return to normal levels. Thus, in a steady state, total plasma cortisol conc.(bound plus free) is elevated, but free cortisol conc. is normal.
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In target tissues, nuclear receptors, for thyroid hormones have a greater affinity for T3 than for T4. TRUE/FALSE
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TRUE. The secretion rate, plasma conc, half life and onset of action are all greater for T4 than for T3.
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What is the relationship between cortisol and transcortin during pregnancy?
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Cortisol, is highly bound to plasma proteins. especially transcortin. Increased plasma levels of transcortin, such as occur during pregnancy, tend to decrease free cortisol concentration, but feedback results in increased ACTH secretion, which stimulates cortisol secretion until free plasma levels of the steroid return to normal levels. Thus, in a steady state, total plasma cortisol conc.(bound plus free) is elevated, but free cortisol conc. is normal.
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By age 45 yrs, only a few primordial follicles remain in the ovaries to be stimulated by gonadotropic hormones, and the production of estrogen decreases as the number of follicles approaches zero. TRUE/FALSE
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TRUE. When estrogen production falls below a critical value, it can no longer inhibit the production of gonadotropic hormones from the anterior pituitary. FSH and LH are produced in large quantities, but as the remaining follicles become atretic, production by the ovaries falls to zero.
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The cell bodies of magnocellular neurons are found where?
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In the paraventriculat and supraoptic nuclei. In contrast to the local actions of neurotransmitters at nerve endings, neurohormones circulate in the blood before producing biological effects at target tissues. Oxytocin is synthesized from magnocellular neurons whose cell bodies are located in the paraventricular and supraoptic nucle and whose nerve terminals terminate in the posterior pituitary gland. Targets for oxytocin are the breast and uterus.
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In target tissues, nuclear receptors, for thyroid hormones have a greater affinity for T3 than for T4. TRUE/FALSE
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TRUE. The secretion rate, plasma conc, half life and onset of action are all greater for T4 than for T3.
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How does the blastocyst obtain nutrition obtain nutrition during the first week after implantation?
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As the blastocyst implants, the trophoblast cells invade the decidua, digesting and imbibing it. The stored nutrients in the decidual cells are used by the embryo for growth and development. During the 1st week after implantation, this is the only means by which embryo can obtain nutrients. This is the case for app the 1st 8 weeks, although the placenta begins to provide nutrition after about the 16th day beyond fertilization.
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By age 45 yrs, only a few primordial follicles remain in the ovaries to be stimulated by gonadotropic hormones, and the production of estrogen decreases as the number of follicles approaches zero. TRUE/FALSE
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TRUE. When estrogen production falls below a critical value, it can no longer inhibit the production of gonadotropic hormones from the anterior pituitary. FSH and LH are produced in large quantities, but as the remaining follicles become atretic, production by the ovaries falls to zero.
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The cell bodies of magnocellular neurons are found where?
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In the paraventriculat and supraoptic nuclei. In contrast to the local actions of neurotransmitters at nerve endings, neurohormones circulate in the blood before producing biological effects at target tissues. Oxytocin is synthesized from magnocellular neurons whose cell bodies are located in the paraventricular and supraoptic nucle and whose nerve terminals terminate in the posterior pituitary gland. Targets for oxytocin are the breast and uterus.
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How does the blastocyst obtain nutrition obtain nutrition during the first week after implantation?
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As the blastocyst implants, the trophoblast cells invade the decidua, digesting and imbibing it. The stored nutrients in the decidual cells are used by the embryo for growth and development. During the 1st week after implantation, this is the only means by which embryo can obtain nutrients. This is the case for app the 1st 8 weeks, although the placenta begins to provide nutrition after about the 16th day beyond fertilization.
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