pregnancy and lactation

Question 1

what is sperms capacitation?

Answer 1

occurs when the female genital tract fluids wash away the inhibitory factors and cholesterol plus calcium enterance into the sperm

Question 2

what is the acrosome reaction?

Answer 2

occurs when the proteolytic enzymes and hyaluronidase opens a penetrating pathway in the ovum corona radiate and zona pellucida

Question 3

what is fertilization?

Answer 3

formation of the pronucleuses and their union to form the zygote

Question 4

What is implantation?

Answer 4

the blastocyst implants into the uterine endometrium aided by the action of proteolytic enzymes secreted by the trophoblast cells

Question 5

What hormones maintain pregnancy for the first trimester until it degenerates at 12 to 17 weeks of gestation?

Answer 5

corpus luteum hormones

Question 6

What ‘takes over’ after the first trimester?

Answer 6

the placenta– it secretes relaxin, progesterone, estrogens, human chorionic gonadotropin and human chorionic somatostatin

Question 7

How long is pregnancy?

Answer 7

280 days plus/minus seven days from the last menstrual period

Question 8

Before implantation, where does the blastocyte obtains its nutrients from?

Answer 8

uterine mil secreted by the uterine endometrial glands

Question 9

Where do nutrients come from after the implantation?

Answer 9

the trophoblast cells digest the decidua to provide the nutrients

Question 10

the trophoblast cells, some of the blastocyst cells and the uterine endometrium cells for the ____.

Answer 10

placenta

Question 11

Trophoblast cells form placental villi into which fetal blood capillaires grow. How does the fetus get blood?

Answer 11

fetal blood flows via two umbilical arteries into the villi capillaries then back to the fetus via the umbilical vein

Question 12

Maternal blood sinuses develop around these placental villi. What is the maternal blood flow track?

Answer 12

Maternal blood flow via the uterine arteries into the maternal blood sinuses then back to the mother via the uterine veins.

Question 13

What is the function of the placenta?

Answer 13

allows for diffusion of nutrients from maternal blood into fetal blood and diffusion of excretory products back into maternal blood

Question 14

What nutrient must use facilitated diffusion to reach the baby via the placenta?

Answer 14

glucose by trophoblasts facilitated diffusion

Question 15

What nutrients/waste move via simple diffusion through the placenta?

Answer 15

oxygen, CO2, FA, sodium, potassium, chloride, urea, uric acid, creatinine

Question 16

The estrogens of the placenta are secreted by what? What are they made from? What do they cause?

Answer 16

• secreted by the syncytial trophoblast cells
• made from androgenic compounds secreted by the mother and fetus adrenal glands
• causes enlargement of the maternal uterus, breasts and external genitalia plus relaxation of the pelvic ligaments

Question 17

The progesterone of the placenta is secreted by what? what effects does it have?

Answer 17

• secreted by the syncytial throphoblast cells
• causes development of the uterine endometriun, development of the breasts alveoli, & decreases uterine muscles contractility during pregnancy thus preventing spontaneous abortion

Question 18

Where is human chorionic somatomammotropin secreted from? What is its function?

Answer 18

• secreted by the placenta at about the fifth week of pregnancy
• decreases glucose utilization by the maternal cells and make it available to the fetus, promotes the release of free fatty acids as an alternative for maternal metabolism, promotes protein tissues formation in the same way as growth hormone

Question 19

Where is relaxin secreted from and what does it do?

Answer 19

• secreted by the corpus luteum and the placenta
• suppresses the release of hypothalamic oxytocin and delays the onset of labor contractions, increases the flexibility of the pubic symphysis, softens the cervix for dilation during parturition

Question 20

what are 7 changes that will occur in pregnancy? (all increases)

Answer 20

increase in endocrine hormones, basal metabolic rate, food intake and weight, nutrients storage, cardiovascualr functions, respiration, renal functions

Question 21

Amniotic fluid formation is derived from what?

Answer 21

fetal renal excretions and the amniotic membrane secretions

Question 22

What is pregnancy-induced hypertension from?

Answer 22

excessive sodium and water reabsorption caused by increased adrenal glands secretion of aldosterone

Question 23

What is preeclampsia?

Answer 23

hypertension, protein urea and impaired vascular functions with arterial spasms

Question 24

What is eclampsia?

Answer 24

extreme degree of preeclampsia with vascualr spasms, seizures and coma

Question 25

Age based terminology for the developing baby

Answer 25

blastocyst- less than 2 weeks old embryo- 2 to 8 weeks old fetus- 9 weeks to birth neonate- newborn to 6 weeks old

Question 26

Parturition is preceded by increased uterine excitability and contractibilty caused by what?

Answer 26

- increased estrogens-progesterone secretion ratio - increased maternal and fetal oxytocin secretion - stretch of the uterine musculature - stretch and irritation of the cervix - initiation of a positive feedback mechanism

Question 27

What is the positive feedback mechanism of parturition?

Answer 27

baby's head stretches the cervix--> cervical stretch excites fundic contraction--> fundic contraction pushes baby down and stretches the cervix some more--> cycle repeats over and over

Question 28

What causes labor?

Answer 28

oxytocin stimulates uterine contractions to cause the forcible expulsion of the fetus in three stages

Question 29

What are the three stages of labor?

Answer 29

dialtion- cervix dilates and water breaks expulsion- baby delivery via the vagina placental- ejection of the afterbirth

Question 30

What are early labor pains caused by?

Answer 30

hypoxia of the uterine muscles transmitted by the hypogastric nerves

Question 31

What are late labor pains caused by?

Answer 31

cervical, perineal, and vaginal stretch or tear transmitted by the somatic nerves

Question 32

What is involution (postpartum)?

Answer 32

the shrinking of the uterus during the period which is achieved by autolysis of the uterine cells by their own lysosomal enzymes

Question 33

What is lochia (postpartum)?

Answer 33

the vaginal discharge produced by this autolysis

Question 34

breast feeding promotes uterine involution because...

Answer 34

lactation suppresses estrogen secretion whihc usually keeps the uterus flaccid and it stimulates oxytocin secretion whcih causes uterine myometrium contractions that firm up the uterus

Question 35

What are the milk secreting units in the mammary glands?

Answer 35

alveoli

Question 36

suspensory (Cooper's) ligaments attach the breast tissues to the ___ ____ ___.

Answer 36

pectoralis major muscle

Question 37

What is the role of estrogens in development of the breasts?

Answer 37

- stimulates growth of the ductal system - increase growth of breast stroma & fat deposition in stroma - inhibits actual secretion of milk

Question 38

What is the role of progesterone in the development of the breasts?

Answer 38

- stimulates development of the breats lobule-alveolar system - causes budding of more new alveoli - stimulates development of the secretory characteristics in the alveoli epithelial cells - inhibit the actual secreiton of milk

Question 39

What is the role of prolactin in the development of the breasts?

Answer 39

- stimulates colostrum synthesis during late pregnancy - stimulates milk synthesis by the alveoli eptihelial cells soon after birth - prolactin surges occur with each nursing

Question 40

What provide nutrients for milk synthesis?

Answer 40

growth hormone, cortisol, insulin and parathyroid hormone

Question 41

What is the role of oxytocin in the develpment of the breasts?

Answer 41

- stimulates contraction of the alveoli wall myoepithelial cells - milk is squeezed from the alveoli into the lacitferous sinuses and ducts to the nipple during suckling - milk ejection can be stimulated or inhibited by psychogenic factors or sympathetic system stimulation - powerful positive feedback system

Question 42

What is the positive feedback system of oxytocin and breast feeding?

Answer 42

receptors in nipples are stimulated--> impulses propagated to spinal cord--> stimulation of hypothalamic nuclei--> oxytocin released--> milk ejected

Question 43

What is colostrum?

Answer 43

fluid synthesized and secreted by the alveoli during the last days of pregnancy and the first days after birht promoted by prolactiin stimulation

Question 44

Colostrum contains....

Answer 44

same concentration of proteins and lactose as milk but one-third less fats, contain immunoglobulin (IgA mainly) for the newborn protection

Question 45

What is the lactation cost on the mother?

Answer 45

50 g fat, 100 g glucose and 3 g calcium phosphate a day

Question 46

What causes bone decalcification to provide enough calcium and phosphate for the newborn bones calcification?

Answer 46

parathyroid hormone

Question 47

Breast feeding suppresses the ovarian cycle via____ by the nipple nerve signals during suckling and the high prolactin levels during lactation.

Answer 47

inhibition of gonadotropin releasing hormone