Exam #3 Flashcards
ch. 47-52 (99 cards)
MSD: meaning and formula
*Mean Sac Diameter
MSD = L + W + H / 3
TA MSD: __ mm should see yolk sac
20 mm
TA MSD: __ mm should see embryo
25 mm
In a TA MSD, a normal yolk sac should never exceed _ mm
6 mm
In a TA MSD, what should be suspected if you do not see an embryo by 25 mm?
anembryonic pregnancy
(gestational sac is empty)
TV MSD: __ mm should see the yolk sac
8-10 mm (acc. to Radiopaedia)
TV MSD: __ mm should see embryo
16-18 mm
CRL
*Crown Rump Length
- the most accurate measurement in in 1st trimester to predict due date
What are the two main parameters for gestational dating in the 1st trimester?
- crown rump length
- mean sac diameter
FHT
*Fetal Heart Tone/Rate
- seen with TV at 5-6 weeks
What is the normal heart range?
100-180 bpm
Tachycardia is heart rate…
over 180 bpm
Bradycardia is heart rate…
under 100 bpm
In the 1st trimester of pregnancy, what indicates a poor pregnancy outcome?
a heart rate <90 bpm
Ductus Venosus
- umbilical vein –> IVC during fetal development
- blood bypasses the liver
Ductus Arterious
- fetal pulmonary artery –> aorta during fetal development
- blood bypasses pulmonary circulation
Foramen Ovale
- blood moves from R. –L. atrium
- blood bypasses lungs
Zygote
the union of M and F cell at fertilization
Gamete
M and F germ cell
Morula
16 cell ball
Blastocyst
early stage of an embryo that develops 5-6 days after fertilization
Trophoblast
- the outer layer of cells of the blastocyst
- provides nutrition to developing embryo
Trophoblast: two layers
- cytotrophoblast: inner layer
- synctiotrophoblast: multilayered
- fx: prod. BhCG, keeps Corpus Luteum growing
Eventually the trophoblast cells become the _____
placenta