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BIO 75 FINAL PINON
bio 75 final
59
Biology
Undergraduate 2
03/21/2012

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Term
viviparity
Definition
means that the development of the fertilized egg takes place inside the mother; all humans are viviparous
Term
prebirth stages
Definition

3 major stages:

1. pre-embryonic

2. embryonic

3. fetal stages

Term
pre-embryonic stage
Definition

first 2 weeks of fertilization, includes the pre-implantation & periimplantation periods; culmnates with foramtion of bilaminar embryo

 

 

Term
embryonic
Definition
covers the 3rd through 8th week; most complex of the stages; all of the tissue & organ system of the body are formed during this period
Term
fetal stage
Definition
begins at week 9; characterized by continued growth and maturation of all organs
Term
parturition
Definition
represents the birth after the 9 month long pregnancy
Term
normal time for pregnancy
Definition
266 days, 38 weeks; divided into 3 trimesters
Term
placenta
Definition
incorporates both fetal and maternal tissues; fetal portion develops from teh chorion; the maternal portion is known as decidua
Term
decidua
Definition
the layer of the endometrium from the maternal portion of the placenta; it separates from the uterus at the time of birth
Term
decidual cells
Definition
large cells connected to each other by tight junctions that form around the invading conceptus in a change known as decidual reaction
Term
decidual reaciton
Definition
when the decidual cells form around the invading conceptus
Term
conceptus
Definition
the embryo & other membranes
Term
the three decidual regions
Definition

1. decidual basalis

2. decidua capsularis

3. decidua parietalis

Term
decidual basalis
Definition
marks the region in which the placenta will develop
Term
decidua capsularis
Definition
is present in the early stages of implantation, but eventually disappears
Term
decidua parietalis
Definition
the endomaterial regions far from the site of implantation
Term
implantation
Definition
the proces by which the newly formed embryo establishes contact with the uterus and initiates the development of the placenta
Term
fetal and maternal stages, do they remain separate or together?
Definition
they remain separate
Term
what is the placenta defined by?
Definition
the decidua basalis (maternal portion) & chorion frondosum (fetal portion)
Term
chorion frondosum
Definition
another name for the fetal portion
Term
amniotic sac
Definition
defines the region in which the embryo and later the fetus develops
Term
umbilical cord
Definition
connects the embryo/fetus to the placenta
Term
principle function of the placenta?
Definition
ensure the well being of the developing fetus, bitch
Term
what does the placenta do to ensure the well being of the developing fucking fetus?
Definition

1. regulates maternal protein and energy metabolism

2. requires the pregnant female to increase her dietary intake

3. prepares the mammary glands so that the nutrional needs of the baby post-birth are met

Term
estrogen function (placential hormone)
Definition
maintain estrogen-dependent tissues; regulated by CRH; stimulates uterine growth & blood flow; stimulates growth of boobies
Term
progesterone (placential hormone)
Definition
maintains endometrial stability; inhibits maternal H-P-O axis; mammary gland development
Term
hCG (placential hormone)
Definition
maintains corpus luteum function during the first 8 weeks of pregnancy; may stimulate embryonic & fetal pituitary; initiated by CRH
Term
hPL & hPGH (placential hormone)
Definition
regulates fetal growth, maternal and fetal energy utilization
Term
CRH (placential hormone)
Definition
stimulates hCG production; regulates plcental estrogen production; initiues parturition; may be the clock that regulates the length of human pregnancy
Term
the feto-placental unit
Definition
the coordinated activity of the placenta and the fetal adrenals and liver in producing steroid hormones in the pregnant female
Term
dizygotic twins
Definition
a fancy/bitch way of saying fraternal twins; when two oocytes are ovulated simultaneously and each is fertilized (come from two different zygotes/eggs)
Term
monozygotic twins
Definition
the fancy/fag way of saying identical twins; arise from splitting of the inner cells mass into two groups of cells; each inner cell mass develops into a separate embryo
Term
location of high twinning rates (highest to lowest)
Definition

1. africia

2. europe

3. hawaii, japan, taiwan

Term
labor
Definition
the sequence of events that begins with voluntary uterine contractions and ends with the expulsion of the fetus & placenta from the uterus
Term
dilation stage
Definition
begins with the onset of regular contractions of the uterus that are less than 10 minutes apart, culminates with the dilation of the cervix; usually 7 to 12 hours long
Term
expulsion stage
Definition
begins when the amniochorionic membrane ruptures and the fetus passes through the dilated cervix and pussy; much shorter than the dilation stage
Term
placental stage
Definition
refers to the expulsion of the placenta; results in bleeding
Term
recovery stage
Definition
begins after the expulsion of the placenta; takes 2 to 3 hours
Term
what triggers labor?
Definition
the relatively sharp increase in the estriol/progesterone ratio; a result of the rate at which placenta CRH is released into the maternal and fetal circulations
Term
cortisol
Definition
ensures that the infant's lungs undergo the final changes required for breathing air and helps maintain CRH production by the placenta
Term
lactation
Definition
important contributer to fertility control
Term
mammary gland composition
Definition

1. adipose (fatty) stroma permeated by blood vessels and nerves

2. lactiferous ducts

Term
lactiferous ducts
Definition
breast epithelial tissue involved in the synthesis or transport of milk
Term
mammary gland development begins when?
Definition
4th week of gestation
Term
lactiferous sinuses
Definition
the convergence of the ducts which drain different alveolar clusters
Term
what happens if suckling doesn't take place (suckling is when the baby gets dat milk from the mommy's tit)
Definition
proacltin levels decrease and milk production slowly diminishes over a 3-to-4 week period
Term
what is necessary for prolactin release?
Definition
nipple stimulation
Term
what's in breast milk?
Definition
a complex mixture of fat, protein, carbohydrates, vitamins and minerals
Term
when does milk production begin? and with what?
Definition
it begins at birth with the removal of placental hormones
Term
why does fetal loss and birth defects occurs?
Definition
result of disturbances in the development program that converts the zygote into a fully developed infant
Term
teratology
Definition
study of developmental disorders
Term
factors of distrubances in normal development
Definition

1. intrinsic (genetic)

2. extrinsic (evironmental)

3. maternal factors

Term
intrinsic factors
Definition
defects in the conceptus itself, consequences of chromosmal aberrations
Term
extrinsic factors
Definition
maternal nutrional deficiency, exposure to environemntal agents known as teratogens (radiation, drugs, chemicals)
Term
maternal factors
Definition
result in the inability of the mother to support a pregnancy to term; endocrine disorders, malformations of the uterus...ect.
Term
what account for a very large percentage of sponstaneous abortions?
Definition
chromosome aberrations
Term
when is the embryo most sensitive to teratogenic effects?
Definition
weeks 3-8 of gestation (when all of the organ systems develop)
Term
fetal loss
Definition
refers to the termination of a pregnancy due to "natural causes"; i.e. miscarriages/spontaneous abortions
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