OBS & GYNE Ch. 13 US in First Trimester

Question 1

Acrosome

Answer 1

area in head of sperm contains enzymes to aid penetration of oocyte

Question 2

Amnion

Answer 2

Membrane enclosing amniotic cavity and embryo/fetus

Question 3

Aneuploidy

Answer 3

Abnormal number of chromosomes

Question 4

Blastocyst

Answer 4

Early gestation made up of trophoblast (outer layer cells), embryoblast (inner cell mass) and fluid filled cavity

Question 5

Chorion

Answer 5

Membrane around chorionic cavity made up of trophoblast cells and extraembryonic mesoderm

Question 6

Chorionic villi

Answer 6

Budlike outward growths from trophoblasts, some give rise to fetal portion of placenta

Question 7

Conceptual age

Answer 7

Duration pregnancy, counted from fertilization (conception), AKA embryonic age or postovulatory age

Question 8

Conceptus

Answer 8

Product of fertilization, including all stages from zygote to fetus

Question 9

Corpus luteum

Answer 9

Progesterone-secreting structure formed by follicle after releasing its oocyte

Question 10

Crown-rump length (CRL)

Answer 10

Measurement longest axis of embryo to determine gestational age

Question 11

Estimated date of delivery (EDD)

Answer 11

Due date, calculated by adding 280 days to first day of LMP, aka estimated date of confinement (EDC)

Question 12

Decidualization

Answer 12

Endometrial changes to allow implantation of blastocyst

Question 13

Estrogen

Answer 13

group of hormones, primarily produced in ovaries, affect secondary sex characteristics and menstrual cycle

Question 14

Fertilization

Answer 14

Penetration of oocyte by sperm to form diploid zygote

Question 15

Follicle-stimulating hormone (FSH)

Answer 15

Hormone produced in anterior pituitary, which stimulates maturation of ovarian follicle

Question 16

Gamete

Answer 16

Haploid cell that, when merged with gamete from opposite sex, creates diploid zygote

Question 17

Gestational age (GA, aka menstrual age)

Answer 17

duration of pregnancy, counted from first day of LMP, preg lasts 260 days or 40 weeks

Question 18

First trimester

Answer 18

0 days (first day LMP) to end 13th week

Question 19

Second trimester

Answer 19

14 weeks to end of 27th week

Question 20

Third trimester

Answer 20

28 weeks to delivery

Question 21

Gestational sac

Answer 21

First sonographic evidence of intrauterine preg, fluid-filled blastocyst

Question 22

Gravidity

Answer 22

Number of times woman has been pregnant

Question 23

Human chorionic gonadotropin (hCG)

Answer 23

hormone produced by trophoblasts, extends life of CL in ovary; most preg tests based on this hormone

Question 24

LMP

Answer 24

first day of last menstrual period

Question 25

Luteinizing hormone (LH)

Answer 25

Hormone produced by anterior pituitary, triggers ovulation

Question 26

Mean sac diameter (MSD)

Answer 26

Average diameter of GS, used to determine gest age

Question 27

Morula

Answer 27

Solid cluster undifferentiated cells, formed by repeated cleavage of the single cell resulted from fusion of two gametes

Question 28

Nuchal translucency

Answer 28

Subcutaneous fluid in post region of neck of embryo and fetuses up to 14 weeks gest age; abnormally large risk of chromosomal and structural abnormalities

Question 29

Oocyte

Answer 29

female gamete; aka ovum or egg

Question 30

Parity

Answer 30

Summary of a woman’s pregnancy outcomes.

Question 31

Pregnancy-associated plasma protein A (PAPP-A)

Answer 31

Protein produced by trophoblasts; abnormal levels may be associated with chromosomal abnormalities

Question 32

Progesterone

Answer 32

Hormone produced by CL and placenta

Question 33

Spermatozoon

Answer 33

male gamete

Question 34

Umbilical vesicle (aka yolk sac)

Answer 34

structure within blastocyst cavity, provides nourishment to embryo and produces its first blood cells, the seconday umbilical vesicle is first structure to be sonographically seen within GS

Question 35

Zygote

Answer 35

single cell resulting from fusion of two gametes