1. Intro to Embryology

Question 1

when is the critical period? Why at that time and not at conception?

Answer 1

week 3-8 ; when fetus is sensitive to teratogens. at this point the baby is now joined with the mother and shares her blood supply

Question 2

embryonic age vs menstrual age. time of each?

Answer 2

embryonic age goes from conception to birth and is 38 or 266 days weeks or 3 trimesters while

menstrual age goes from last period which adds 2 weeks and makes it 40 weeks or 280 days

Question 3

conceptus

Answer 3

1-2 weeks from conception

Question 4

embryonic period

Answer 4

3-8 weeks (coincides with critical period)

Question 5

fetal period

Answer 5

9-38 weeks

Question 6

perinatal

Answer 6

period around birth

Question 7

neonatal

Answer 7

birth to 4 weeks

Question 8

infancy

Answer 8

birth to 1 year

Question 9

childhood

Answer 9

1 yr to 12/13 yrs

Question 10

adolescence

Answer 10

13-17

Question 11

adulthood

Answer 11

18-21/25

Question 12

gender differences in developmental periods

gender differences in gamtogenesis?

Answer 12

females hit puberty first and mature earlier so childhood is 1-12/13 and adulthood is 18-21/25

men begin making sperm in puberty
by 5 months women are born with all eggs

Question 13

conception

Answer 13

where sperm meets egg

Question 14

what are the 2 phases of pregnancy

Answer 14

1) embryonic period: up to 8 weeks after fertilization and

2) fetal period: from 9th week till birth. growth occurs during this period

Question 15

trimesters

Answer 15

divided into equal 12.6 week periods

Question 16

what 6 factors influence development?

Answer 16

1) genetics 2) cell potency 3) cell-cell interactions 4) apoptosis 5) differential growth rates 6)environments

Question 17

which side of the embryo grows fastest

Answer 17

dorsal side grows faster

Question 18

differentiate mitosis and meiosis

Answer 18

-both are replication methods-both start with a diploid cell

meiosis is for sex cell and mitosis is for somatic cells

Steps of mitosis:
Before mitosis: G1, synthesis (double dna),
G2 1) dna replication–> 2n + 2n2)
cell division — > 2n 3) diploid product (2n)

Meiosis:
1) dna replication –> 2n + 2n2) two cell divisions (crossing over in prophase I gives probability and variation; metaphase I separates homologous pairs; metaphase II separates sister chromatids)* yields 4 haploid products; females only have 1 egg and 3 polar bodies

Question 19

describe meiosis in female and how it coincides with embryology

Answer 19

female has all eggs at birth (pretty much by 5 months of gestation) and finishes meiosis I at puberty- one egg at a time.

1) primary oocyte is arrested in prophase I at birth. it grows as a follicle in the ovary and completes meiosis I and is released during ovulation
2) when released at ovulation, a polar body comes off
3) secondary oocyte now arrested in meiosis II until it is fertilized by sperm. if not…disinegrates
4) if fertilized by sperm, another polar body comes off (hallmark sign) and completes meiosis

Question 20

define capacitation; where does it occur

Answer 20

sperm must reside in female reproductive tract and mature for several hours to be able to fertilize the oocyte; occurs in ampulla

Question 21

when is the best time for a couple to have sex?

Answer 21

24-48 hours before ovulation bc sperm can mature for 1-2 days prior to fertilizing the dropping egg

Question 22

___ sperm are deposited into the ___ per ejaculate but only ___ get to the uterus and ___ make it to oocyte

track the travel of the sperm

where does FERTILIZATION HAPPEN?

Answer 22

250,000,000 in the fornix; 100,000 make it to uterus; 50 or so make it to oocyte

fonrix of vagina—> uterus—> remains in ampulla for a couple days; day 2-3 it is in the isthmus of uterine tube; day e 3-4 enters uterine cavity and day 6-7 it implants

fertilization is in the ampulla

Question 23

what are causes of female infertility

Answer 23

1) ovulation problems which can be treated with clomiphene citrate treatments: stimulate FSH, & LH and many follicles to increase the incidence of multiple pregnancies2) fertilization blockage- uterine scare/blockage3) hormonal problems in menstrual cycle can affect implantation

Question 24

what are reasons for male infertility?

Answer 24

1) low sperm count (meaning less than 50 million (instead of the 250 million) per ejaculate or less than 10 million per ml)2) sperm shape, motility3) scrotal varicocoele infection diseaselow testoerone levels4) obesity can lower sperm count

Question 25

give overview of menstrual cycle with uterine and hormonal

Answer 25

menstrual phase: 4-5 days of sloughing off of the compact and spongy endometrium layer. estrogen is low.

proflieration: restore the uterine wall. estrogen increasing ( but it inhibits FSH, LH). at the end of this phase is ovulation with LH surge

secretory phase: corpus luteum releases progesterone and estrogen to get ready.

pre-menstrual phase: corpus luteum doesn’t get fertilized so begins to disintegrate.

Question 26

what are the 3 endometrial layers. which is superficial and deep? which layer sloughs off during menstrual flow?

Answer 26

superficial –> deep is 1) compact (2) spongy both of which make up the functional layer that sloughs off and

(3) is basal which is the deepest. has the spiral artery progenies that retract and release fluids if no baby

Question 27

types of developmental disorders

Answer 27

• genetic
• chemical/drug
• nutrition
• gestational
• infectious agens
• molecular signaling or gradients

Question 28

parturition

Answer 28

birth

Question 29

prenatal

Answer 29

conception to birth