Anatomy/Physiology
Trimester's
Bioeffects
100

What are the 4 parts of the fallopian tubes?

Intramural, Isthmus, Ampulla, Infundibulum 

Fimbriae (bonus +1)

100

What is the reason M-mode is used instead of Doppler, in 1st trimester?

Doppler has higher intensity and greater thermal bioeffect risk under ALARA; it is safer

100

What does ALARA stand for?

As Low As Reasonably Achievable 

200

What 2 functions does the female reproductive system have?

Endocrine - produces estrogen & progesterone

Reproductive - produces the oocyte 

200

Which weeks make up the 3rd trimester?

27-40

200

To prevent thermal bioeffects, output power should be set at ___.

<100%

300

What is implanted after fertilization, and where?

The blastocyst implants in the functional layer of the endometrium of the uterus, about 5–6 days after fertilization

300

Which obstetric study is performed between 11wk and 13wk 6d?

Nuchal Translucency 

300
What value should the mechanical index (MI) be kept under in OB ultrasound?

<1.9

400

These vessels are seen in the periphery of the uterus (basal zone) and shouldn't be mistaken for pathology.

Arcuate Vessels

400

Which obstetric study has the most images and is the most tedious?

Second-trimester anatomy/morphology ultrasound at 18–22 weeks

400

What is cavitation?

The creation, oscillation, and collapse of air bubbles

500

Which hormones are used to sustain pregnancy until the placenta is formed?

Progesterone from the corpus luteum sustains pregnancy; 

hCG maintains the corpus luteum until the placenta takes over

500

This cardiac abnormality is better seen in the third trimester once the fetus is larger (demonstrated on the four-chamber view with color Doppler).

VSD - Ventricular Septal Defect 

500

Which thermal index setting should be used before and after 8 weeks' gestation?

TI s = soft tissue (<8 weeks)

TI b = bone (>8 weeks)

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