S2 Bsf Exam 3: Pregnancy And Lactation

Front 1

what three steps of reproduction occur within the female reproductive tract?

Back 1

internal insemination, internal fertilization and internal gestation

Front 2

What is the placenta composed of?

Back 2

chorion (extraembryonic membranes of the fetus) and decidua (endometrial tissue form mom)

*placenta= new endocrine organ

Front 3

what three endocrine systems are interacting during pregnancy?

Back 3

maternal, fetal and placental

Front 4

what is the purpose of vaginal tenting?


How else does the female reproductive tract facilitate sperm transport?

Back 4

to draw cervix away from vagina to create a local reservoir for sperm.

E provides water mucous & myometrial contractions, oxy aids in uterine contraction, pH is neutralized by vaginal transudate

Front 5

what is capacitation? where does it occur?

Back 5

transient event that must occur before sperm can fertilize the egg. Occurs in oviduct.

Front 6

where do uncapacitated sperm bind? what is the purpose of this?

Back 6

bind epithelium of oviduct; it becomes capacitated & increases the lifespan of the sperm.

Front 7

what are the 4 ways in which capacitation modifies spermatozoa?

Back 7

1) alters membrane fluidity by removal of cholesterol from membrane.
2) removes proteins and/or carbs that may block binding sites for egg
3) changes membrane potential that may assist Ca to enter sperm and facilitate acroosmal rxn
4) protein phosphorylation.

Front 8

What three layers must sperm pass thru?

Back 8

1. cumulus
2. zona pellucida
3. plasma membrane of egg (fusion of sperm, allowing entire sperm to enter)

Front 9

what is the cumulus composed of? how does the sperm get thru this?

Back 9

hyaluronic acid. Sperm has membrane bound hyalurnidase to eat thru that layer.

Front 10

what is the zona pellucida composed of?
what does sperm bind to in this layer?
what does that cause?

Back 10

glycoprotein: ZP1, ZP2, ZP3

sperm binds to ZP3 & triggers acrosome rxn--> blocking all other sperm & digesting zona pellucida
*sperm binds ZP2 to be held in place during digest^

Front 11

how is polyspermy prevented?

Back 11

the egg is metabolically quiesent until sperm egg fusion triggers cortical reaction, hardening zona pellucida, so the same egg cannot be activated by multiple sperm

Front 12

when is the egg finally haploid?

Back 12

when the sperm egg fusion occurs because that triggers the completion of meiosis.

Front 13

what triggers the egg "wakes up" events?

Back 13

Ca release

Front 14

increased Ca stimulates the recruitment of _______ within the egg that will synthesize _____ needed for early embryonic development.

Back 14

stored maternal mRNA; proteins


*Ca also stimulates egg to enter cell cycle

Front 15

what layer of cells separates and forms the chorionic villi that indigitates with the endometrium?

what two hormones are important for this process?

Back 15

the trophoblasts;


prostaglandins and histamine

Front 16

what does the blastocyst secrete? why?

Back 16

secretes immunosuppressive agents to avoid rejection by the maternal immune system.

Front 17

during implantation, what sustains the corpus luteum even though LH is rapidly declining?

what does it act as? what does it promote?

Back 17

human chorionic gonadotropin (hCG).

Acts as an immunosuppresive agent. Promotes trophoblast growth and placental development.

Front 18

during week one, what still encapsulates the embryo?

Back 18

zona pellucida

Front 19

what is present at day 3 of fertilzation and development?

what is formed at days 4-5?

Back 19

16 cell morula.


blastocyst cavity.

Front 20

what are the two cell types of the blastocyst?

Back 20

eccentric inner cell mass and outer, epithelial-like layer of trophoblasts.

Front 21

what is the embryonic pole?

Back 21

trophoblasts cells that are adjacent to inner cell mass.

Front 22

what is required before implantation occurs?

Back 22

hatching- degeneration of the zona pellucida

Front 23

what are the three stages of implantation?

Back 23

1. apposition
2. adhesion
3. invasion

Front 24

1. Apposition
where it occur?
why does it occur there?

Back 24

at site where zona pellucida lysed

makes it possible for cell membranes of the trophoblast & endometrium to make direct contact.
(inner cell mass points toward endometrium)

Front 25

2. Adhesion occurs via receptor ligand interaction, on the intracellular side what do ligands interact w.?

on the extracellular side?

Back 25

cytoskeletal elements


receptors for matrix proteins (collagen, laminin and fibronectin).

Front 26

3. Invasion
what happens during this phase of implantation?

Back 26

trophoblasts differentiate into two layers: syncytiotrophoblasts (outer) and
cytotrophoblast (inner)

Front 27

Describe the syncytiotrophoblast (outer layer of trophoblast)

Back 27

-multinucleated w/o cellular boundaries
-long protrusions extend btwn uterine epithelial cells (decidual lining).

Front 28

what is eventually penetrated by the decidual lining of the syncytiotrophoblast?

what happens after penetration?

Back 28

the basement membrane of uterine epithelial cells.


the decidual cells degenerate; lipids & glycogen are released to provide nutrients to the embryo

Front 29

Describe the cytotrophoblast (inner layer of trophoblast)

Back 29

initially provides a layer of continuously dividing cells.

Front 30

when does endocrine function begin?


What does hCG do?

Back 30

at implantation when synctiotropholasts begin secreting hCG

maintains corpus luteum & P secretion

Front 31

what is the first detectable sign of pregnancy?

Back 31

plasma level of hCG

Front 32

at ten weeks, what do the syncytiotrophoblasts start producing? why?

Back 32

they start making progesterone independent of the corpus luteum because they have become steriodogenic

& enzymes that modify & convert hormones

Front 33

syncytiotrophoblasts take on the function of what three activities?

Back 33

gas transfer
facilitated transport
pinocytosis / transcytosis.

Front 34

what is decidualization?

Back 34

enlargment and engorgement of stromal cells as they fill with lipid and glycogen

Front 35

what does the decidua forms?


What does it secrete?

Back 35

an epithelial sheet w/ adhesive junctions to inhibit migration of implanting embryo.

factors that moderate activity of syncytiotrophoblastic-derived hydrolytic enzymes-->regulating invasion of the embryo & placenta so it never reaches the myometrium.

Front 36

what are the layers of the chorionic membrane?

Back 36

-outer syncytiotrophoblasts
-inner cytotrophoblasts, mesenchyme and fetal blood vessels.

Front 37

where is maternal blood trapped?

Back 37

in the intervillous space, between th decidua capsularis (mom side) and the villi (fetal).

Front 38

what types of arteries, in the mature placenta, empty directly into the intervillous space?

what drains these arteries?

Back 38

spiral arteries;

maternal veins

Front 39

early nutrition & absorption for the placenta is from what?

later nutrition is from what?

Back 39

early nutrition from trophoblastic digestion& absorption of nutrients form the endometrium

later nutrition from diffusion through placental membrane

Front 40

near the end of pregnancy, what is the mean PO2 of maternal blood in placental sinus?
what is the mean PO2 of fetus after oxygenation?

Back 40

~50 mmHg;

30 mmHG

Front 41

T/F
Fetal Hb has higher O2 affinity than adult Hb.

Back 41

True

*allows fetus to get enough O2

Front 42

what kind of shift is caused by the fetus's demand for O2?

Back 42

double bohr shift

(fetus has 50% greater Hb concentration)

Front 43

what are the 5 endocrine functions of the placenta?

Back 43

1) maintain pregnant state of uterus
2) stimulate lobuloalveolar growth & fxn of breast
3) adapt maternal metabolism & physiology to support growing fetus
4) regulate portions of fetal development
5) regulate timing/progression of partuition (birth)

Front 44

What types of hormones are secreted from cytrophoblasts (CT)?

what types of hormones are secreted by syncytial trophoblasts (SCT)?

Back 44

releasing & inhibiting hormones (hypothalamic action)

gonadotropin like hormones (LH and FSH); hCG and hCS (pituitary action)

Front 45

how many days does it take for hCG from placental (SCT) cells to appear in serum?

Back 45

at most 9 days

*first key hormone of pregnancy

Front 46

What are the two subunits that hCG consists of? what is the difference between the two?

Back 46

alpha and beta.

Alpha is identical for FSH, LH & TSH
Beta subunit only 80% homology to subunit of LH

Front 47

how is hCG secreted by the placenta?

Back 47

The CT layer secretes the LHRH which then stimulate the SCT to secrete hCG via paracrine action.

Front 48

what is responsible for morning sickness in some people?

Back 48

rapid rise in hCG

(hCG peaks at 9-12 wks, then plateaus)

Front 49

T/F
no hCG enters fetal circulation.

Back 49

FALSE
a very small amount enters 1%-10%

Front 50

what does hCG stimulate in male fetuses?

Back 50

leydig cells to produce the testosterone critical for sexual differentiation.

Front 51

what is detected in maternal plasma at 5 weeks?

(continues to rise throughout pregnancy in proportion to the weight of the placenta)

Back 51

human chorionic somatomammotropin (hCS)

Front 52

what is hCS?

what does it cause?

Back 52

protein hormone w/ similar fxns as prolactin &GH

-causes decrease insulin sensitivity & glucose utilization in the mother, increasing serum glucose--> directs larger flow of glucose to fetus.
-stimulates the development of mammary glands
-increases protein synthesis--> enhance growth

Front 53

what does relaxin do?

Back 53

relaxes pubis and helps dilate cervix

Front 54

what enzyme do SCT cells lack?

Back 54

17 alpha hydroxylase

Front 55

what kind of receptors do SCT cells have?

Back 55

LDL receptors

(allows more uptake of cholesterol for progesterone production)

Front 56

what is required to maintain quiescent myometrium and pregnant uterus?

Back 56

large amounts of progesterone

(produced by placenta)

Front 57

T/F
progesterone production by the placenta is completely independent of the fetus and is regulated.

Back 57

FALSE

it is not regulated

Front 58

how does progesterone quiet uterine contractions?

Back 58

by inhibiting prostaglandins

Front 59

what affect does progesterone have on the mother?

Back 59

increases capacity of alveolar pouches to hold milk

Front 60

what role does progesterone play in regards to the respiratory center?

Back 60

stimulates respiratory center to get rid of excess CO2 produced by fetus.

Front 61

what produces estrogen during pregnancy?

Back 61

SCT cells

Front 62

where do androgens come from?

Back 62

fetal adrenal cortex

Front 63

T/F
The fetal zone of adrenal cortex expresses little or no 3B-HSD

Back 63

true

Front 64

what is released from the fetal zone of the adrenal gland during gestation?

Back 64

androgen DHEA-S

Front 65

what is the production of DHEA in the fetus is dependent on?

what organism can convert DHEA to estriol?

Back 65

release of ACTH from fetal pituitary


placenta ONLY
*thus estriol can be used to ***** fetal well being

Front 66

what affect does estrogen have on placental blood flow?
LDL receptors?
partuition?

Back 66

increase placental blood flow

increase LDL receptor in SCT layer

induce factors involved in partuition.

Front 67

What is estrogen's role in the uterus?

Back 67

stimulates growth of uterine muscle,
softens pelvis along with relaxin and
causes enlargement of external genitalia

(also increases duct system in breast)

Front 68

T/F
estrogen inhibits Progesterone synthesis.

Back 68

FALSE
augments

Front 69

what conversion does estrogen stimulate in the placenta?

Back 69

cortisol to cortisone.

Front 70

initially where does DHEA come from?

Back 70

adrenals of the mother


(as fetus grows, fetal adrenals can produce DHEA)

Front 71

why do prolactin levels in the mother rise?

Back 71

due to increases in estrogen

Front 72

why does LH and FSH decrease with the maternal endocrine?

Back 72

due to negative feedback from high estrogen and progesterone
(higher ratio of P to E)

Front 73

what happens to the mother's thyroid gland during pregnancy?

what affect does estrogen have on thyroxine binding globulin?

Back 73

increases in size and level of T4 and T3 can double.


increases globulin---> increased hormone binding

Front 74

The first trimester changes of TSH are in parallel with what?

Back 74

changes in hCG

Front 75

what happens late in pregnancy in regards to cortisol production? why is that important?

Back 75

there is a serge in cortisol production, which is important for the initiation of lactation.

Front 76

how many days from ovulation is pregnancy? from last menstrual period?

Back 76

ovulation: 266 days; menstrual: 280 days

Front 77

how much does cardiac output increase during 1st trimester? when does it increase again?

Back 77

35-40%; slowly until term

*mostly due to increased stroke volume

Front 78

where is the majority of CO distribution targeted?

Back 78

40% increase in renal flow; 15% in uterine flow.

Front 79

why is than an increase in CO flow to the skin and breasts?

Back 79

skin= heat dissipation; breast- mammary glands

Front 80

what three organs experience NO change in flow (cardiac) during pregnancy?

Back 80

brain, gut or skeleton

Front 81

How does pregnancy affect MAP? why?

Back 81

MAP decreases during mid-pregnancy w/ an increase in 3rd trimester.

Due to a decrease in peripheral vascular resistance & the vasodilating effects of P & E

Front 82

what position gives the highest CO of the mother?

Back 82

lateral recumbent

Front 83

what will happen to venous return if the mother is supine?

Back 83

the fundus of the uterus rests on the inferior vena cava near L5 impeding venous return.

Front 84

what is the increase in blood volume during pregnancy due to?

which trimesters are specifically affected?

Back 84

due to an increase in plasma volume and erythrocytes (necessary to meet demands of hypertrophied vascular system in pregnant uterus)

2nd and 3rd trimester.

Front 85

what affect does pregnancy have on the diaphragm?

Back 85

the diaphragm rises ~4 cm due to relaxing effects of P

(diameter of thoracic cage also increases)

Front 86

T/F
Pregnancy alters the Mother's vital capacity.

Back 86

FALSE

there is a net decrease in residual volume with no appreciable change in vital capacity.

Front 87

what affect does pregnancy have on alveolar ventilation?

what does this create for the mother?

Back 87

increased alveolar ventilation (and tidal volume)


pulmonary resistance falls facilitating airflow--> a decrease in maternal PCO2 (from 40-32)

Front 88

why is additional protein necessary during pregnancy? how much is necessary?

Back 88

protein is for the fetus, placenta, uterus, breasts and BV. need an additional 30 grams.

Front 89

why do you need an additional amount of iron during pregnancy? how much? how much do you need to absorb per day?

Back 89

to support maternal Hb mass, the placenta and the fetus.

Need a net gain of ~800 mg. per day: 7.0 mg/day

Front 90

why is folate necessary during pregnancy?

Back 90

required to make additional RBC; lowered plasma folate can cause neural tube defects in fetus.

Front 91

in regards to maternal weight gain, how much can be attributed to intra-uterine things such as the fetus, placenta and amniotic fluid?

what is the rest due to?

Back 91

5 kg;

9 kg maternal gain such as the uterus, blood, breast and adipose/interstitial fluid.

Front 92

what is partuition?

Back 92

process of uterine contraction leading to childbirth

Front 93

what are the 3 stages of Parturition?

Back 93

1)Dilation
initiation, increasing intensity & duration of contractions (several hours)
2)Expulsion
Delivery of fetus (~ 1 hour)
3)Placental
Delivery of placenta (> 10 min)

Front 94

which stage of labor is the fastest?

Back 94

delivery of the placenta

Front 95

what three things does increased cortisol from the fetus lead to?

Back 95

1) maturation of lungs
2) increase in liver glycogen stores
3) increase in intestinal transport and digestion

Front 96

what stimulates the contraction of uterine smooth muscle cells?

Back 96

prostaglandin from uterus, placenta and fetal membranes.

Front 97

what potentiates contractions induced by oxytocin? how?

Back 97

PG by forming gap jxns between smooth muscle cells.

Front 98

what affect does PG have on the cervix?

Back 98

softening, dilation and thinning of the cervix

Front 99

what stimulates PG production? how?

Back 99

oxytocin by binding to the receptor on decidual cells

Front 100

T/F
Maternal oxy is thought to initiate labor

Back 100

False
Maternal oxy is NOT thought to initiate labor but maintains labor

(stimulates contractions of uterine smooth muscle)

Front 101

when does fetal oxytocin rise?

Back 101

at the beginning of labor

Front 102

what hormone is relaxin related to?
what produces it?

Back 102

insulin;
corpus luteum, placenta and decidua.

Front 103

what is the job of relaxin? when does production increase?

Back 103

keeps uterus quiet during pregnancy, relaxes pelvic area prior to labor. Production increases during labor to help dilate cervix.

Front 104

what affect does estrogen have on the oxytocin receptors? where?

Back 104

increases the number of oxytocin receptors in myometrium and decidual layers.

Front 105

by how much does the oxy receptor number rise during early labor?

Back 105

200 fold

Front 106

what are the four steps involved with the theory for the onset of strong contractions during labor?

Back 106

1) baby's head stretches cervix
2) cervical stretch excites fundic contraction
3) fundic contraction pushes baby down and stretches cervix some more
4) cycle repeats over and over again

Front 107

what is mammogenesis?

Back 107

proliferation of alveolar and duct cells

Front 108

what is lactogenesis?

What hormone stimulates this?

Back 108

milk production by alveolar cells

*relies on prolactin

Front 109

what is galactorrhea?

Back 109

excessive or continued secretion of milk even after suckling has stopped

Front 110

what is lactation?

what hormone stimulates this?

Back 110

lactogenesis and milk let down

oxytocin

Front 111

T/F

Alveolar duct & alveoli production are stimulated by the same hormone

Back 111

FALSE

diff hormones

Front 112

where does the lactiferous duct carry secretions during lactation?

Back 112

outside

Front 113

during prenatal development of mammary glands, what are the mammaries sensitive to?

Back 113

estrogen

Front 114

what is present, in regards to mammary glands, at birth?

Back 114

rudimentary duct system

Front 115

what is present or developing, in regards to mammary glands, from birth until puberty?

Back 115

some growth of secretory tissue and development of supporting adipose tissue

Front 116

what happens to the mammary glands during puberty? why?

Back 116

sudden growth due to an increase in estrogen. The ducts grow, lobules and epithelial buds form at ductus terminus and there is an increase in CT and adipose tissue.

Front 117

what happens to the mammary glands during the menstrual cycle (folliculuar and luteal)?

Back 117

follicular: duct maintenance
luteal: lobular/alveolar maintenance

Front 118

during pregnancy, what is high? what does that cause?

Back 118

high estrogen, progesterone and hCS which causes max growth of lobular/alveolar and duct system

Front 119

what is prolactin essential for?

Back 119

P and E to have mammotropic effects

Front 120

what does Prolactin stimulate? what prevents it?

Back 120

lactogenic apparatus; prevented by excess P and E

Front 121

why is milk synthesis initiated after parturition?

Back 121

due to decreased P and E

Front 122

what maintains high levels of prolactin after birth?

Back 122

sucking

Front 123

what can prevent subsequent ovulations (and therefor pregnancies) while lactating?

Back 123

high prolacting which can inhibit GnRH keeping LH low.

(ONLY very high levels, not a good birth control)

Front 124

what is milk?

Back 124

milk is an emulsification of fats in an aqueous solution containing sugar, proteins and inos

Front 125

What changes does the uterine myometrium undergo before parturition?

Back 125

increase in gap junctions*
increased actin & myosin