Repro IV: Pregnancy and Development

Question 1

What are the 3 stages of gestation and how long do they last?

Answer 1

1. germinal stage (1st 2 weeks)
2. embryonic stage (weeks 3-8)
3. fetal stage (weeks 9-38)

Question 2

What happens during the germinal stage of gestation?

Answer 2

zygote becomes morula which becomes a blastocyst which then enters the uterus
once blastocyst is implanted it is called an embryo

Question 3

What happens during the embryonic stage of gestation?

Answer 3

embryo develops 3 primary tissue layers and develops beginnings of organs and organ system
embryo becomes fetus at end of 8th week

Question 4

What are the 3 primary germ layers?

Answer 4

ectoderm
mesoderm
endoderm

Question 5

What two organs/organ systems develop from the ectoderm?

Answer 5

all nervous tissue
epidermis of skin

Question 6

What organs/organ systems develop from the mesoderm?

Answer 6

cartilage, bone, connective tissues
skeletal, cardiac, smooth muscles
blood and lymphatic vessels
epithelium of gonads

Question 7

What organs/organ systems develop from the endoderm?

Answer 7

epithelium of digestive tract
epithelium of respiratory system
epithelium of thyroid, liver, pancreas
epithelium of bladder

Question 8

When does the placenta form>

Answer 8

during 3rd month of gestation

Question 9

What does the placenta develop from?

Answer 9

embryonic chorion and uterine tissue

Question 10

What are the 3 functions of the placenta?

Answer 10

1. site of nutrient, gas, and waste exchange
2. secretes hormones that maintain pregnancy
3. barrier to microorganisms, except some viruses

Question 11

What viruses and substances can pass through the placenta?

Answer 11

AIDS, measles, chickenpox, poliomyelitis, encephalitis
drugs, alcohol

Question 12

What structure connects the embryo and the placenta?

Answer 12

umbilical cord

Question 13

What vessels does the umbilical cord contain?

Answer 13

two umbilical arteries
one umbilical vein

Question 14

What is the maternal portion of the placenta?

Answer 14

decidua basalis of uterus
contains maternal vessels

Question 15

What is the fetal portion of the placenta?

Answer 15

chorionic villi of chorion
contains umbilical cord vessels and amnion, fetal blood vessels

Question 16

What hormone does the chorion of the embryo produce?

Answer 16

human chorionic gonadotropin (hCG)

Question 17

What is the effect of hCG?

Answer 17

rescues the corpus luteum from degeneration until 3/4 months

Question 18

What hormones foes the placenta take over producing from the corpus luteum?

Answer 18

steroid hormones: including estrogens and progesterone

Question 19

At what weeks of pregnancy would hCG levels be the highest?

Answer 19

weeks 4-12

Question 20

At what weeks of pregnanacy would estrogens and progesterone levels be the highest>

Answer 20

end of pregnancy
weeks 32+

Question 21

What are the effects of progesterone and estrogens released from the corpus luteum/placenta?

Answer 21

1. maintain endometrium during pregnancy
2. prepare mammary glands for lactation
3. prepare mother’s body for birth of baby

Question 22

What are the effects of relaxin released from the placenta?

Answer 22

1. increase flexibility of pubic symphysis
2. helps dilate uterine cervix during labor

Question 23

What are the effects of human chorionic somatomammotropin (hCS)?

Answer 23

1. prepare mammary glands for lactation
2. enhance growth by increasing protein synthesis
3. decrease glucose use and increase fatty acid use for ATP production

Question 24

What are the effects of corticotropin-releasing hormone (CRH)?

Answer 24

1. establish timing of birth
2. increase secretion of cortisol

Question 25

What role does cortisol play in fetal development?

Answer 25

maturation of fetal lungs production of surfactant in fetal alveoli

Question 26

What are the 3 stages of birth?

Answer 26

1. stage of dilation 2. stage of expulsion 3. placental stage

Question 27

What is the bp for preeclampsia?

Answer 27

140-160 systolic 90-110 diastolic

Question 28

What accompanies preeclampsia?

Answer 28

proteinuria

Question 29

What is bp for eclampsia?

Answer 29

>160 systolic >110 diastolic

Question 30

What accompanies eclampsia?

Answer 30

proteinuria seizures

Question 31

What causes preeclampsia and eclampsia?

Answer 31

damage to the vascular component of the placenta

Question 32

What is released by the damaged placenta causing damage throughout the body?

Answer 32

pro-coagulant and vasoconstrictive chemicals

Question 33

What tissues/organs/systems are impaired or damaged by pre/eclampsia?

Answer 33

kidney, cardiovascular system, liver, blood cells, central nervous system, placenta

Question 34

What happens when there is impaired placental function due to eclampsia?

Answer 34

blood flow is impaired causing blood to flow into intervillous spaces ischemic placenta produces chemicals causing blood and endothelial cell dysfunction

Question 35

How does eclampsia impair renal function?

Answer 35

1. vasoconstriction of renal blood vessels 2. oliguria (low urine output) 3. increase in blood volume 4. proteinuria as a result of damage to glomerular capillaries and basement membrane

Question 36

How does eclampsia impair cardiovascular function?

Answer 36

significant hypertension increase in preload. increase in cardiac output

Question 37

How does eclampsia impair central nervous system function?

Answer 37

hypertension vascular damage abnormal clotting headaches visual disturbances (retinal damage) seizures

Question 38

How does eclampsia impair liver function?

Answer 38

hemolysis enhanced coagulation hepatic damage liver enlarges elevated liver enzymes from hepatic injury

Question 39

How does eclampsia impair placental function>

Answer 39

restricted nutrient availability diminishes growth of fetus

Question 40

How is eclampsia treated?

Answer 40

inducing labor as soon as fetus is developed enough to be born