Anatomy Ch 29 Pregnancy selections

What are the trimesters of pregnancy

1. first trimester - first 3 months

   • zygote becomes embyro and then early fetus

2. second trimester - 4-6 months

   • grwoth of fetus

3. third trimester - 7-9 months

   • fetus grows rapidly and mothers body prepares for labor and deliveyr

What is the prenatal period

begins with fertilization and ends wiith birth

composed of 3 periods

1. pre-embryonic period

2. embryonic period

3. fetal period

the pre-embryonic period is the ____ weeks after fertilization

ends when ______ implants in uterine lining

3

blastocyst

what is the embryonic period

weeks 3-8 of development

primary organ development

Sperm are attracted to the ovulated oocyte via _________

this icnludes ____ and ____

chemoattractants

progesterone and allurin (from fallopian tubes)

what part of the sperm pierces the zona pellucida

acrosome cap

Secondary oocyte completing second meiotic division forms the ____

ovum

Nucleus of sperm and ovum fuse to become _____ nucleus which is now called a ______

diploid

zygote

what is cleavage

series of mitotic division

cells increase but size remains same

16 cell phase is morula

Last stage of cleavage is blastocyst

Trophoblast forms the ______ and is the outer ring of blastocyst

Embryoblast forms ______ proper and has ________ cells

chorion

embryo

pluripotent

Implantation occurs when?

more info??

end of first week

zona pellucidum breaks down and blastocyst burrows into endometrium

by day 9 blastocyst is implanted

the blastocyst produces ____________ which signals that implantation occurs and the corpus luteum secretes what

human chorionic gonadotropin

progesterone and estrogren

By day 8 the membrnaes start to dvelop to protect/nourish fetus

This includes ____ and ________ and _______

The yolk- early blood cell and vessel formation

Amnion - amniotic fluid keeps membrane from drying out

Chorion - outermost embryonic membrane

• eventually forms placenta

The placenta diffuses ___ from maternal blood to fetal blood

diffuses ___ from fetal blood to maternal blood

O2 and CO2

What is gastrulation

occurs during 3rd week

epiblast forms 3 primary germ layers forming embryo

epiblast is where all body tissues devlop from

what are the 3 layers of the epiblast

1. Ectoderm - skin and nerves

2. Mesoderm - muscle and tissue

3. Endoderm - completes msot organs

Organogenesis generally in the first ____ weeks of pregnancy

extra sensitive to_____ during this time

8 weeks

teratogens

The pre-embryonic period lasts for:
A: One month
B: One week
C: Three months
D: Two weeks

B 2 weeks

The embryonic cells that develop into all muscles of the body
are the:
A: Mesoderm
B: Endoderm
C: Ectoderm
D: Chorion

A- mesoderm

What are false labor contractions

Braxton Hicks Contractions

do not lead ot cervical changes

When labor occurs, the placenta secretes __________ which widen and soften the cervix and contractions

prostaglandins

Is true labor negative or positive feedback

positive

What are the stages of labor

1. Dilation phase'

2. Expulsion phase

3. placental stage

what is the term for women who have given birth versus not

nulliparous - have not given birth

parous - have given birth

The dilation stage of labor ends when the cervix is ________ (thinned) d dilated to 10cm

This is the longest of the stages

effaced

what is an episiotomy

surgical incision to aid in getting babty out

if a baby is born premature it may ahve to go on a ventilator because of a lack of __________

surfactant in the lungs

Lactation is stimulated by _____ and inhibited by ______

prostaglandins

dopamine

colostrum is rich in ________

purpose

immunoglobulins

aids in baby’s first bowel movement

Inhibition of the secretion of which hormone allows for milk
production?
A: Oxytocin
B: Dopamine
C: Prolactin
D: Estrogen

B

How long does the pre-embryonic period last

embryonic?

pre-Embryonic - 2-3 weeks

embyonic - 3-8 weeks

When is the morula stage of development?

when dividied into 16 cells

What is the difference between trophoblast and embryoblast cells

trophoblast - makes chorion (makes bld vessels and cells)

embryoblast - makes embryo

What do chorion cells become

placenta

•Be able to explain the ectoderm, endoderm, and mesoderm

ectoderm - skin

endoderm - organs

mesoderm - msucles