Pregnancy

Question 1

When can fertilization occur?

Answer 1

-2 days before ovulation
- 24 hours after ovulation

Question 2

Can freshly deposited sperm in vagina penetrate an oocyte? why?

Answer 2

No, sperm must spend time with egg before they can penetrate
- uterine secretions + washings needed to help sperm penetrate egg –> fertilization

Question 3

What are the 5 steps for accomplishing fertilization. ZP (zona pellucida)

Answer 3

1. Approach
   - sperm eats away at granulosa cells of corono radiate with the help of enzymes
2. Acrosome reaction
   - triggered by: binding of sperm to ZP3 receptors causes inc Ca2+ levels in sperm
   - each sperm digests holes through ZP to clear a path to oocyte membrane
3. Binding
   - Sperm membrane binds to oocyte’s “SPERM BINDING RECEPTORS”
4. Fusion:
   - Membranes fuse and sperm contents enter oocyte
5. Blocks to polyspermy
   - Cortical reaction: inc Ca2+ in oocytes cytoplasm
   - This causes ZP to harden + sperm binding receptors are clipped off; this ensure 1 sperm can enter each egg

Question 4

What does gravidity mean?

Answer 4

of times a woman is pregnant

Question 5

What are the stages of embryonic development in the uterus (names of cells)?
0 days
2 days
3 days
4 days
7 days

Answer 5

0 days (fertilized egg)
- Zygote (at ampula)

2 days (4 cells)
- blastomere

3 days (16+ cells)
- Morula

4 days
- Early blastocyte
- Hollows out & fills with fluid; then “hatches” from ZP

7 days
- Implanting blastocyst (hatched)
- Consists of trophoblast + inner cell mass
- floats unprotected for 2-3 days (not self-like)

Question 6

What is the role of trophoblast cells and inner cell mass of the blastocyst?

Answer 6

Trophoblast
- aids in implantation (invades endometrium)
- participate in placenta formation
- Immunosuppressive

Inner cell mass
- future embryo

Question 7

When does implantation begin?

Answer 7

6-7 days after ovulation
a week before ovulation

Question 8

What are the 2 layers that form when trophoblasts proliferate in the endometrium

Answer 8

1. Syncytiotrophoblast
   - cells in outer layer those their PM and digest endometrium
2. Cytotrophoblast
   - inner layer of trophoblast cells

Question 9

How long does it take for implantation to finish?

Answer 9

12 days

Question 10

What is the purpose of the human chorionic gonadotropic hormone (hCG). When is it secreted?

Answer 10

Secreted by trophoblasts after implantation is complete (12 days after ovulation

Purpose
- prevent ovulation by suppressing FSH & LH
- Prompts corpus luteum to secrete progesterone and estrogen
- progesterone prevents shedding of endometrium (keeps you pregnant)

Question 11

What is the process of gastrulation? When does it occur?

Answer 11

Goes from 2 to 3 layers
- allows an organism to be made
- forms extraembryonic membrane to support
- Occurs week 3

Question 12

What is the order of the 3 layers in gastrulation

Answer 12

1. Endoderm
2. Mesoderm
3. Ectoderm (remain on embryo’s dorsal surface)

Question 13

What do each layers of gastrulation do?

Answer 13

Ectoderm
- forms CNS and Integumentary system
Mesoderm
- everything else
Endoderm
- Lines inside of body tubes, digestive and respiratory

Question 14

When does the folding of embryonic occur? What does it do?

Answer 14

Week 4 after gastrulation
- the reason why respiratory and digestive tubes end up inside the boy

Question 15

Extraembryonic Membranes: Role of amnion

Answer 15

Comes from epiblast
- Surrounds baby, maintains pregnancy

Question 16

Extraembryonic Membranes: role of yolk sac

Answer 16

Original source of blood cells
- after 1st trimester, placenta takes over

Question 17

Extraembryonic Membranes: role of allantois

Answer 17

• structural base for umbilical cord
• Waste storage (bladder)

Question 18

Extraembryonic Membranes: role of chorion

Answer 18

Helps form the placenta
- combination of mesoderm + trophoblast

Question 19

What changes is in a 16-day embryo?

Answer 19

Trophoblast associated mesoderm become chorion (placenta) + chorionic villi are elaborating

Question 20

What is the placenta made of?

Answer 20

Chorionic villi + decidua basalis

Question 21

What do maternal arteries and veins carry? What do umbilical arteries and veins carry?

Answer 21

Maternal arteries: carry oxy blood from heart to placenta
Maternal veins: carry DEXOY blood from placenta to heart

Umbilical arteries: carry oxy blood from placenta to embryo
Umbilical veins: carry DEOXY blood from embryo to placenta

Question 22

What hormone is secreted by the placenta that causes most glucose to go to fetus instead of mother? What else does it do?

Answer 22

human placental lactogen
- Maturation of breasts for lactation
- fetal growth

Question 23

What is the role of the human chorionic thyrotropin that the placenta releases?

Answer 23

Increase maternal metabolism

Question 24

Placenta releases relaxin for?

Answer 24

Relaxes pelvic ligaments & pubic symphysis

Question 25

What week are all organ systems recognizable?

Answer 25

8th week

Question 26

What main event occurs at the end of the 8th week?

Answer 26

Cardiovascular system fully functional

Question 27

What main event occurs at the end of the 12th week?

Answer 27

Lungs been to develop; fetus inhales and exhales amnionic fluid to practice - ultrasound sex determination

Question 28

What main event occurs at in the 2nd trimester?

Answer 28

- Fetal position (body flexed anteriorly) because of space restrictions - limbs reach near-final proportions

Question 29

What main event occurs in the 3rd trimester?

Answer 29

Skin is wrinkled; nails are complete

Question 30

What occurs in first 2 weeks of pregnancy

Answer 30

- No implantation, just floating - Not compatible with life, no malformations will occur, just a miscarriage

Question 31

Why are parathyroid hormone & vitamin D levels high throughout pregnancy?

Answer 31

For fetus to grow bones

Question 32

What occurs in the reproductive system in pregnancy?

Answer 32

- Chadwick's sign: vagina & cervix develop purpulish hye - increased discharge - Cervix closed by mucus plug

Question 33

What occurs in the cardiovascular system in pregnancy?

Answer 33

- BV and CO increases 40% - BP decreases mid-pregnancy then normal during 3rd trimester

Question 34

What occurs in the integumentary system in pregnancy?

Answer 34

- Melasma (increase pigmentation of facial skin) - Decrease hair loss - Stretch marks

Question 35

What occurs in the Musculoskeletal system in pregnancy?

Answer 35

- Relaxin causes pelvic ligaments to relax (not good for stability) - Increase risk of falls - Leg cramps

Question 36

What occurs in the nervous system in pregnancy?

Answer 36

- Insomnia for frequent urination at night or baby picking - faintness & dizziness - eye dryness & vision changes - Sciatica (sharp posterior pain)

Question 37

What occurs in the GI system in pregnancy?

Answer 37

- Heart burn - Food aversion (not wanting to eat) - Constipation (increase physical restrstriction)

Question 38

What occurs in the urinary system in pregnancy?

Answer 38

- Physical stress on bladder - UTI more common (warm area for bacteria to live in)

Question 39

What occurs in the respiratory system in pregnancy?

Answer 39

- Estrogens may cause nasal edema & congestion - Increase thorax diameter - incrase min. ventilation (inc. tidal volume) - dec of Functional residual capacity (FRC) due to dec in ERV and RV

Question 40

What causes the placenta to release more estrogen in the last few week of pregnancy (for initiation of labour?

Answer 40

Fetal secretion of adrenocorticol hormones

Question 41

What does fetal oxytocin cause?

Answer 41

Causes placenta to release prostaglandins - both cause powerful uterine contractions

Question 42

What is the role of surfactant protein A (SP-A)?

Answer 42

Softens cervix for baby for birth

Question 43

What is the natural adhesive protein that binds placental fetal & maternal tissues together called?

Answer 43

Fibronectin

Question 44

What are the 3 stages of labour? Describe them briefly

Answer 44

1. Dilation - longest stage (6-12hrs+) - contractions are 15-30 min apart, 10-30 sec long - cervix softens and dilates to 10 cm - amnion fluid is released 2. Expulsion - 2 hours long - strong contractions every 2-3 min, 1 min long - Crowning occurs 3. Placental - Delivery of afterbirth (placenta + membranes)

Question 45

Define episiotomy

Answer 45

Episiotomy: surgically cut (lateral) parts of vulva, * to direct a tare if it is going toward anus or clitoris Usually they let you rip, stitch you up after

Question 46

What score is used to assess physical status after birth?

Answer 46

APGAR Activity Pulse Grimace Appearance Respiration

Question 47

What process does the first breath of an infant exhibit

Answer 47

inc CO2 --> Central Acidosis

Question 48

Since no blood needs to go lungs, what allows blood to go from right atrium to left atrium directly

Answer 48

Forman Ovale

Question 49

What is the first milk that is produced and rich in vitamin A

Answer 49

Colostrum

Question 50

What causes uterine to contract and go back to pre-pregnant size

Answer 50

Oxytocin

Question 51

What does prolactin do?

Answer 51

Makes more milk for future feeds

Question 52

What are some advantages of breastfeeding

Answer 52

- Fats & iron are easily absorbed; AA more easily metabolized (compared with cow's milk) - Natural laxative to help eliminate meconium - Protect from infections - Promote skin-skin contact - Promote healthy bacteria in large intestine

Question 53

What are some maternal advantages of breastfeeding

Answer 53

- Delay in resumption of ovulation (birth control) - Reduction of cancer risk - reduced risk of postpartum blood loss - Cost savings