2nd/3rd Trimester Anatomy 37% Flashcards
In a normal 4 chamber heart view, what cardiac chamber is closest to the spine?
a. left ventricle
b. right ventricle
c. right atrium
d. left atrium
D
The left atrium is the most posterior cardiac chamber and the right ventricle is the most anterior cardiac chamber in the normal heart.
What cardiac structure is described as having a hockey stick appearance on sagittal views of the chest?
a. aortic arch
b. ductus venosus
c. main pulmonary artery
d. ductus arteriosus
D
The ductus arteriosus is described as having a hockey stick appearance on sagittal views of the chest. The aortic arch is described as having a candy cane appearance in sagittal views. The ductus venosus is located in the abdomen.
Which of the following terms describes the vessel that allows some umbilical blood to bypass the fetal liver in fetal circulation?
a. ductus venosus
b. ductus arteriosus
c. foramen ovale
d. umbilical vein
A
The foramen ovale describes the opening in the interatrial septum that allows normal shunting between the atria. It functions as a shunt for the fetal flow to bypass the fetal lungs. The foramen ovale normally closes very soon after birth. The ductus arteriosus describes the connecting vessel from the main pulmonary trunk to the descending aorta in fetal circulation. If functions as a shunt to bypass the fetal lungs. The ductus venosus describes the vessel that shunts blood flow around the fetal liver in fetal circulation. Both ductus connections also close shortly after birth.
The ductus arteriosus is:
a. a vessel that connects the umbilical vein to the IVC to bypass the liver
b. a vessel that connects the pulmonary artery to the aorta to bypass the fetal lungs
c. a vessel that connects the umbilical artery to the aorta to bypass the fetal lungs
d. an opening between the right and left atrium to shunt flow away from the fetal lungs
B
The ductus arteriosus is a vessel that connects the pulmonary artery to the aorta to allow most flow to bypass the fetal lungs.
Which hormone stimulates the formation of the cervical mucous plug found with pregnancy?
a. bhCG
b. estrogen
c. oxytocin
d. progesterone
D
Estrogen stimulates the cervix to produce mucous just prior to ovulation. Increasing progesterone levels with pregnancy cause the cervical mucous to “dry up” and the cervix to tighten leading to mucous plug formation.
The fetal stomach should be routinely visualized by week ______.
a. 14
b. 12
c. 10
d. 16
A
The fetal stomach should be routinely visualized by week 14.
Average normal heart rate in a 2nd trimester fetus is________.
a. 80-120bpm
b. 100-140bpm
c. 120-160bpm
d. 160-200bpm
C
The average normal heart rate in the 2nd trimester fetus is 120-160bpm.
At what gestational age does the fetus completely take over the amniotic fluid production?
a. 16 weeks
b. 20 weeks
c. 24 weeks
d. 12 weeks
A
Up until 16 weeks gestation, the chorion, amnion and placenta produce the amniotic fluid. After 16 weeks, fetus takes over production of fluid.
What view is used to demonstrate the fetal thymus gland and where is it located?
a. three vessel view, posterior to the sternum at the level of the aorta and pulmonary artery
b. axial cervical spine view, surrounding the larynx and posterior to the esophagus
c. axial cranial view, just below the cisterna magna in the neck
d. transverse abdominal view, in the subphrenic space
A
The thymus gland may be identified in a fetus posterior to the sternum at the level of the great vessels of the heart. It is a hypoechoic structure that bordered by the right and left internal mammary arteries. The thymus is demonstrated on the three vessel view.
__________ refers to a normal finding of sebum and epithelial cells that cause white free-floating debris within the amniotic fluid late in pregnancy.
a. meconium
b. vernix
c. Chadwick’s sign
d. pseudomyxomatous peritonei
B
Vernix refers to a normal finding of sebum and epithelial cells that cause white free-floating debris within the amniotic fluid late in pregnancy. Meconium refers to an abnormal finding of fetal waste, sebum and epithelial cells, that cause hypoechoic free-floating debris within the amniotic fluid late in pregnancy. Normally meconium is visualized in the fetal colon in near term pregnancies. If the fetus has a bowel movement, it is a sign of fetal distress.
The right atrium receives blood from which of the following vessels?
a. SVC
b. pulmonary veins
c. pulmonary arteries
d. ductus arteriosus
A
Blood from the superior and inferior vena cava enters the right atrium. In the fetus, this blood is OXYGENATED blood from the umbilical cord. Flow crosses the tricuspid valve into the right ventricle. In the fetus, the blood will enter the pulmonary artery and ductus arteriosus.
Which of the following describes the normal fetal diaphragm?
a. hypoechoic dome shaped structure with the top of the dome facing cephalad
b. hyperechoic dome shaped structure with the top of the dome facing cephalad
c. hypoechoic cup shaped structure with the bottom of the cup facing caudal
d. hyperechoic linear structure that separates the abdomen from the chest
A
The normal fetal diaphragm is demonstrated on ultrasound as a hypoechoic dome shaped structure with the top of the dome facing cephalad.
Which of the following terms describes the opening in the interatrial septum that allows normal shunting between the atria?
a. patent ductus arteriosus
b. foramen ovale
c. muscular septal defect
d. patent ductus venosus
B
The foramen ovale normally closes very soon after birth. The ductus arteriosus describes the connecting vessel from the main pulmonary trunk to the descending aorta in fetal circulation. It functions as a shunt to bypass the fetal lungs. The ductus venosus describes the vessel that shunts blood flow around the fetal liver in the fetal circulation. Both ductus connections also close shortly after birth.
If two fetuses are different genders, this indicates:
a. monozygous twins
b. monomaniotic twins
c. identical twins
d. dizygous twins
D
Fetuses of the same gender can be dizygous or monozygous. Fetuses of different gender must always be dizygous.
The cisterna magna is enlarged if it measures more than:
a. 5mm
b. 7mm
c. 10mm
d. 12mm
C
A cisterna magna with an AP dimension greater than 10mm can indicate Dandy-Walker malformation or mega cisterna magna. If the AP measurements is less than 2mm, Arnold Chiari II malformation could be present.
What is the function of the choroid plexus?
a. the choroid plexus is responsible for releasing multiple types of hormones that control fetal circulation and blood pressures
b. the choroid plexus is responsible for releasing multiple types of hormones that control fetal lung maturation
c. the choroid plexus is responsible for production of cerebrospinal fluid
d. the choroid plexus is responsible for releasing multiple types of hormones that control fetal growth and metabolism
C
The choroid plexus is responsible for production of cerebrospinal fluid.
Which cranial structure is considered abnormal if it increases in size between ultrasound exams performed at 20 and 28 weeks?
a. choroid plexus
b. thalamus
c. cerebellum
d. lateral ventricle
D
The lateral ventricles are usually consistent in size throughout pregnancy. An increase in size between serial exams can indicate a developing problem with CNS drainage.
The proximal pulmonary artery and aorta demonstrate a normal appearance when:
a. the aorta crosses anterior to the pulmonary artery as they both exit the heart
b. the diameter of the aorta is at least 2X the diameter of the pulmonary artery
c. the pulmonary artery crosses anterior to the aorta as they both exit the heart
d. they exit the heart parallel to one another
C
The proximal pulmonary artery and aorta demonstrate a normal appearance when the pulmonary artery crosses anterior to the aorta as they both exit the heart. The PA is the same as or slightly larger in diameter than the aorta in the 2nd and 3rd trimester fetus. Parallel great vessels OR the aorta crosses anterior to the pulmonary artery = transposition of the great vessels.
The normal anterior-posterior renal pelvic diameter (APRPD) in a second trimester fetus is ________ and in a 3rd trimester fetus ________ is considered normal.
a. less than 2mm, less than 4mm
b. less than 8mm, less than 16mm
c. less than 4mm, less than 7mm
d. less than 10mm, less than 20mm
C
The normal anterior-posterior renal pelvic diameter (APRPD) in a second trimester fetus is less than 4mm and in a 3rd trimester fetus less than 7mm is considered normal pyelectasis. Severe hydronephrosis is indicated in the 2nd trimester with an APRPD of more than 10mm. Severe hydronephrosis is indicated in the 3rd trimester with an APRPD of more than 15mm. An increase in the APRPD between the second and third trimesters indicates higher possibility of postnatal abnormalities.
During renal development, the kidneys normally migrate ___________.
a. from the upper abdomen into an inferior retroperitoneal location
b. from the pelvic region superiorly into the lower abdomen
c. from the lower right side of the spine superiorly and separate once the fetus reaches 11 weeks
d. from their origination point centrally in the abdomen to a more lateral location adjacent to the ribs
B
During renal development, the kidneys normally migrate from the pelvic region superiorly into the lower abdomen. A pelvic kidney occurs when the kidney fails to migrate superior/posterior into the proper location.
The ratio of kidney diameter to the abdominal diameter should stay between _______ for the entire pregnancy.
C
The ratio of kidney diameter to the abdominal diameter should stay between 0.23 - 0.27 for the entire pregnancy. An increased kidney diameter will lead to an abnormally increased ratio. Mass formation or cystic disease are potential causes for increased kidney size.
In a normal pregnancy, the placental thickness should be relatively equal to the:
a. fetal head circumference
b. gestational age in weeks
c. gestational age in weeks + 10mm
d. length of the cervix
C
In a normal pregnancy, the thickness of the placenta in mm should be equal to the weeks of gestation + 10mm
EX: a 20 week pregnancy should have a thickness of 20 + 10 = 30mm
The corpus callosum should be completely formed by which week of gestation?
a. 12
b. 14
c. 16
d. 18
D
The corpus callosum should be completely formed by 18 weeks. If it is not identified after 18 weeks, agenesis should be suspected.
Which of the following terms describes the connecting vessel from the main pulmonary trunk to the descending aorta found in fetal circulation?
a. foramen ovale
b. ductus arteriosus
c. ductus venosus
d. left atrial appendage
B
The foramen ovale describes the opening in the interatrial septum that allows normal shunting between the atria. It functions to as a shunt for the fetal flow to bypass the fetal lungs. The foramen ovale normally closes very soon after birth. The ductus arteriosus describes the connecting vessel from the main pulmonary trunk to the descending aorta in fetal circulation. It functions as a shunt to bypass the fetal lungs. The ductus venosus describes the vessel that shunts blood flow around the fetal liver in fetal circulation. Both ductus connections also close shortly after birth.
Which type of breech position is defined as fetus with one or both feet in the lower uterine segment?
a. complete
b. footling
c. partial
d. frank
B
Frank breech = butt down legs straight up in front of abdomen
Complete breech = butt down legs folded, knees bent, ankles crossed
Footling breech = feet down, baby “standing” on cervix
What is the lateral bone of the foramen called?
a. fibula
b. humerus
c. ulna
d. radius
D
When describing upper extremity anatomy it is assumed the patient is in anatomic position. The palms of the hands are turned forward which indicates the radius is on the lateral aspect of the arm.
Where is Wharton jelly found?
a. fossa of Waldeyer
b. umbilical cord
c. cervical mucous plug
d. amniotic fluid
B
The umbilical cord is composed of 2 arteries and 1 vein surrounded by Wharton jelly and covered by amnion.
At what gestational age do the fetal kidneys begin to produce urine?
a. 10
b. 12
c. 14
d. 16
B
The fetal kidneys begin producing amniotic fluid around 12 weeks gestation and completely take over fluid production by 16 weeks.
In a small amount of adults, Meckel’s diverticulum can be identified as a remnant of fetal embryology. What causes this anatomic variation?
a. the gestational sac persists as a diverticulum in the ileum portion of the bowel
b. the placental umbilical cord attachment persists as a diverticulum in the ileum portion of the bowel
c. the yolk sac persists as a diverticulum in the ileum portion of the bowel
d. the placenta persists as a diverticulum in the ileum portion of the bowel
C
Meckel’s diverticulum refers to when the yolk sac persists into adult life as a diverticulum in the ileum portion of the bowel.
Peristalsis of the fetal bowel should normally be identified ___________.
a. after 35 weeks gestation
b. before the midgut herniation retracts
c. just after midgut herniation retracts
d. in the late 2nd trimester
D
Peristalsis of the fetal bowel should normally be identified late in the 2nd trimester.
The fetal heart normally sits at a __________ degree angle in the chest with the apex pointed toward the left anterior chest wall.
a. 30
b. 45
c. 60
d. 90
B
The fetal heart normally sits at a 45 degree angle in the chest with the apex pointed toward the left anterior chest wall.
Twins will exhibit the same fetal growth pattern as a fetus in a singleton pregnancy until _________ weeks.
a. 30
b. 24
c. 33
d. 36
A
Twins will exhibit the same fetal growth pattern as a singleton pregnancy until 30 weeks. Twin growth rate will decrease in the last trimester compared to the growth rate of a fetus in a singleton pregnancy.
