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17 Cards in this Set
- Front
- Back
PREGNANCY, GROWTH, AND DEVELOPMENT
Define "Growth" Define "development" Define pregnancy |
growth is an INCREASE in SIZE.
Development is the process of changing from one life phase to another. Pregnancy is the presence of a developing offspring in the uterus. |
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Preg2
A male deposits ____ in the vagina during sex. How to sperm cells move within the female reproductive tract? Where in the female reproductive system does fertilization normally take place? |
semen.
Sperm cell lashes its tail to move. It is aided by muscular CONTRACTIONS in the female reproductive tract. Uterine tube. |
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Preg3
During fertilization, an ____ helps a sperm cell penetrate the ____ ______. When a sperm cell penetrates an egg cell membrane, changes in the _____ and ____ _____ prevent entry of _____ _____ _____ Fusion of the _____ of a sperm cell and an ____ _____ completes fertilization. The product of fertilization is a _____ with ____ chromosomes. |
enzyme, zona pellucida
membrane, zona pellucida, additional sperm cells nuclei, egg cell zygote, 46 |
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Preg4
Briefly describe fertilization |
1)penetration of zona pellucida of egg cell by sperm cell (enzyme helps)
2)changes in egg cell membrane to prevent entry of additional sperm cells 3)fusion of the nuclei of a sperm cell and egg cell ->zygote |
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Preg5
Describe the process of cleavage What else happens during cleavage. Once it reaches the uterine cavity, what happens? |
Starting from the zygote, the cells undergo MITOSIS, giving rise to SMALLER and smaller cells.
The developing offspring MOVES down the uterine tube to the uterus (about 3 day trip) In the cavity, the developing offspring remains free, but eventually IMPLANTS in the endometrium (at this point it is called a blastocyst) |
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Preg6
define embryo Define fetus. |
The term given to the developing offspring from the embryonic stage up to the end of 8 weeks (when the basic structural form of the human body is recognizable).
Fetus is the term given after embryo, up until birth. |
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Preg7
Describe the formation of the placenta. What are its functions? |
Eventually, cells surrounding the embryo, with cells of the endometrium, form a complex vascular structure called the PLACENTA. (therefore, EMBRYONIC and MATERNAL cells form the placenta)
The placenta 1)exchanges nutrients, gases, and wastes between maternal blood and the embryo's blood. 2)secretes hormones. |
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Preg8
Which hormone produced during pregnancy maintains the corpus luteum. Where is that hormone produced? |
Human chorionic gonadotropin (hCG) is produced by the embryonic cells.
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Preg9
Name the hormones produced by the placenta, and their function. What other hormonal changes happen in pregnancy? |
1)estrogens and progesterone - maitain the uterine wall, and inhibit FSH and LH secretion
2)progesterone and relaxin inhibit uterine contractions 3)estrogens cause enlargement of the vagina 4)relaxin helps relax the ligaments of the pelvic joints 5)placental lactogen stimulates development of maternal breasts and mammary glands 1)increased aldsterone - retention of sodium and body fluid. 2)increase PTH - high concentraiton of maternal blood calcium. |
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Preg10
The embryonic stage extends from the beginning of the _____ week through the ____ week of development. During the embryonic stage, the ____ and the main internal and _____ body structures develop. |
second, eighth
placenta, external |
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Preg14
Name the primary germ layers How do they form? |
endoderm, mesoderm, and endoderm.
THey form from the inner cell mass (the group of cells in the blastocyst stage, near time of implantation, that go to form the offspring) |
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Preg15
List the major body parts derived from the primary germ layers. |
1)ectodermal cells - nervous system, special sensory organs, epidermis, hair,nails, glands of skin, linings of mouth/anal canal
2)mesodermal cells - muscl, bone, bone marrow, blood, blood and lymphatic vessels, connective tissues, internal reproductive organs, kidnesy, epithelial linings of the body cavities 3)endodermal cells - intestines, respiratory tract, urinary bladder, and urethra |
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Preg16
What is the placental membrane made of. What structures does it separate? What happens across the placental membrane? |
Placental membrane = the epithelium of the chorionic villi and epithelium of the capillaries inside the villi.
It separates embryonic blood in the capillaries of a villus from the maternal blood in lacunae. Across this membrane, oxygen and nutrients diffuse FROM MATERNAL blood into fetal blood. Carbon dioxide and other wastes diffuse in FROM FETAL blood into maternal blood. |
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Preg17
Distinguish between the chorion and amnion. |
During the blastocyst stage (pre-embryo), cells from the outer blastocyst form a layer of cells called the trophoblast. Another layer of cells develops and lines the trophoblast, called the CHORION. The trophoblast later helps form the placenta.
While the placenta forms, around the second week, another membrane called the AMNION envelops the tissues attached to the underside of the embryo. Between the amnion and the embryo, AMNIOTIC FLUID develops. |
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Preg13
Embryonic stage (continued) The _____ extends from the yolk sac into the connecting stalk. The connecting stalk attaches the _____ disc to the developing _____. The allantois gives rise to the umbilical ____ and _____ By the beginning of the eighth week, the embryo is recognizable as ____ |
allantois, embryonic, placenta, arteries, veins
human |
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Preg11
Embryonic stage (continued) During the embryonic stage, the cells of the ____ ___ mass organize into _____ ____ ____. The ____ ____ becomes cylindrical, and attaches to the developing _____ |
inner cell, primary germ layers
embryonic disc, placenta |
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Preg12
Embryonic stage (continued) a fluid-filled ____ develops around the embryo The _____ ______ forms as the amnion envelops the tissues attached to the ______ of the embryo. The ____ sac forms on the _____ of the embryonic disc. |
amnion
umbilical cord, underside yolk, underside |