Term
| What is the aim of 1st trimester sonography? |
|
Definition
confirm viability
accurately date the pregnancy
diagnose multiple pregnancies
investigate complications |
|
|
Term
| What does the pituitary gland secrestes what happends due to this secretion? |
|
Definition
| FSH and LH - causes the growth of follicles |
|
|
Term
| what is off to one side of the follicle and surrounded by follicular cells |
|
Definition
|
|
Term
| What happens to one follicle? |
|
Definition
| one follicle becomes dominant, bulges on the surface of the ovary, and becomes a mature follicle or a graafian follicle |
|
|
Term
| How long does the graafian follicle continue to enlarge? |
|
Definition
|
|
Term
| what does the developing follicles produce |
|
Definition
|
|
Term
| The _______ level remains relatively low until 4 days before ________ |
|
Definition
|
|
Term
| What does the dominant or active follicle produce during ovulation? |
|
Definition
|
|
Term
| what surge follows the estrogen surge? what does it result in? |
|
Definition
LH and prostaglandin
results in ovulation |
|
|
Term
| ________ follows the LH peak within 12-24 hours |
|
Definition
|
|
Term
| What aids the expulsion of the oocyte from the mature follicle? |
|
Definition
| intrafollicular pressure, possibly contraction of the smooth muscle or enzymatic digestion of the follicular wall |
|
|
Term
| Ovulation occurs on approximately ___ day of the menstrual cycle with expulsion of the _______ from the surface of the ovary |
|
Definition
|
|
Term
| What happenes to the follocle after ovulation? |
|
Definition
| the follicle collapses to form the corpus luteum, which secretes progesterone and to a lesser degree estrogen |
|
|
Term
| what involutes if a pregnancy does not occur? |
|
Definition
|
|
Term
| What happens to the corpus luteum if there is a pregnancy? |
|
Definition
| ivolution of the corpus luteum is prevented by hCG, which is produced by the outer layer of cells of the gestational or chorionic sac |
|
|
Term
| gestation or chorionic sac is aka |
|
Definition
|
|
Term
| What stimulate endomerial cellular proliferation in preparation for implantation and to nourish the blastocyst? |
|
Definition
| progesterone and estrogen |
|
|
Term
| what are the changes in the endometrial called? |
|
Definition
|
|
Term
| How does decidual reaction occur? |
|
Definition
| occurs as a hormonal response regardless of the site of implantation, either ectopic or intrauterine |
|
|
Term
| What is transported into the fimbriated end of the fallopian tube during the ovulation and what picks it up? |
|
Definition
|
|
Term
| What draws the oocyte into the fallopian tube? |
|
Definition
| the sweeping movement of the fimbria, the currents produced by the action of the cillia of the mucosal cells, and the gentle peristaltic waves from contractions of the fallopian musculature draw the oocyte into the tube |
|
|
Term
| Where does the sperm travel to meet the oocyte? |
|
Definition
| sperm must move through the cervical canal and its mucous plug up the endometrial cavity, and down the fallopian tube to meet the awaiting oocyte that is within the ampullary portion of the tube |
|
|
Term
| Fertilization usually occurs within _______ hours after ovulation in the __________ portion of the fallopian tube |
|
Definition
|
|
Term
| Where does the sperm penetrate? what is it called? |
|
Definition
outer layer of the ovum
aka zona pellucida |
|
|
Term
| which day does fertilization occur to form what? |
|
Definition
| fertilization occurs on or about day 14 as the mature ovum and sperm unite to form the zygot in the outer third of the fallopian tube |
|
|
Term
| What does the trophoblast cells differentiate into? |
|
Definition
differentiates into an inner cell layer (cytotrophoblast)
and an outer multicellular later (syncytiotrophoblast) |
|
|
Term
| what does the trophoblast cells produce? what does it do? |
|
Definition
| produces hCG which extends the life of the corpus luteum |
|
|
Term
| What does the corpus luteum secrete? what does this secretion help with? |
|
Definition
| progestrone which helps assure retention of the endometrial lining by stiumating the endometrial tissue. |
|
|
Term
| what does the endometrial tissue become if there is a pregnancy? |
|
Definition
| the endometrial tissue becomes decidualized hence the decidual reaction |
|
|
Term
| what does the trophoblast ultimately create what does it contribute? |
|
Definition
| creates the chorionic membranes and the fetal contribution to the placenta |
|
|
Term
| The male or female reproductive cell (ova or sperm) is called? |
|
Definition
|
|
Term
| A ball of 16 cells, surrounded by the zona pellucida, which is transported through the fallopian tube toward the uterus |
|
Definition
|
|
Term
| an organized collection of cells with a cystic cavity surrounded by trophoblastic cells, it enters the uterine cavity about 7 days afer fertilization and burries into endometrial tissue is called |
|
Definition
|
|
Term
| What does the blastocyst do after it hatches? |
|
Definition
| it begins to invade into the uterine lining to implant |
|
|
Term
| What are the reason to the ER when the blastocyst implant? |
|
Definition
| vaginal bleeding may occur with implantation or burrowing of the blastocyst |
|
|
Term
| what are the 3 germ cell layers that comprise the embryonic disk? |
|
Definition
endoderm - inner layer
mesoderm - middle layer
ectoderm - outer layer |
|
|
Term
| when is the implantation completed? |
|
Definition
| day 23 as the endometrial membrane reforms over the blastocyst |
|
|
Term
| where does the implantation usually occur? |
|
Definition
| in the fundal region of the uterus |
|
|
Term
| decidualized endometrium that closes over and surrounds the blastocyst is called |
|
Definition
|
|
Term
| decidualized endometrium that develops where the blastocyst attaches, it contributes to the maternal portion of the placenta (mom's part of the placenta) |
|
Definition
|
|
Term
| decidualized endometerium that results from hormal influence on the uninvolved endometrial tissue is called |
|
Definition
decidua parietalis
this is part of the endometrium and not involved in the mimplantation area |
|
|
Term
| What is the double decidual sac sign describes as? |
|
Definition
| a method of differentiation between an early intrauterine pregnancy and the decidual cast of an ectopic pregnancy |
|
|
Term
| What are the 2 echogenic ring of the double decidual sac sign? |
|
Definition
one ring is created by the gestational sac and its echogenic outer layer of chorion
the other ring is formed by the echogenic endometrium of the lining of the uterus |
|
|
Term
| What does the placenta contain and what are they derived from? |
|
Definition
both maternal and fetal tissue
maternal component derived from the decidua basalis
fetal component derived from the trophblastic tissue |
|
|
Term
| By the 5th week what does the trophoblast develop into? |
|
Definition
|
|
Term
| what does the chorionic villi do after it is developed? |
|
Definition
| the villi in contact with the decidual basalis rapidly increase in number and vascularity to become the chorion frondosum, which is the fetal part of the placenta |
|
|
Term
| What happens to the rest of the chorion by the 5th week? what is it named? |
|
Definition
| the rest of the chorion undergoes atrophy and becomes smooth and is named the chorion laeve |
|
|
Term
| when does the vasularization of the placenta occur? |
|
Definition
| at the beginning of the 5th week |
|
|
Term
| What is the membrane that is actually the chorionic villi which surrounded the blastocyst but did not further develop into chorion frondosum. It becomes compressed and avascular |
|
Definition
|
|
Term
| The ________ ________ surrounds the gestational sac and extends up to and merges with the edge of the placenta |
|
Definition
|
|
Term
| What are the 3 layers of the chorionic cavity? |
|
Definition
syncytiotrophoblast
cytotrophoblast
extraembryonic mesoderm |
|
|
Term
| The embryo is lying inside its closely fittting _______ sac which lies inside the much larger ________ sac |
|
Definition
amniotic sac
chorionic sac |
|
|
Term
| Which membrane forms from cells that originated from the inner blastocyst. It initially forms opposite the secondary yolk sac, and is attached to the embryonic disk |
|
Definition
|
|
Term
| Where does the amniotic membrane remain attached to the embryo? |
|
Definition
| at the umbilical cord insertion site |
|
|
Term
| when do we start seeing the amnion membrane? |
|
Definition
|
|
Term
| when does the amnion and chorion being to fuse? |
|
Definition
|
|
Term
| the formation of the neural plate and its closure to form the nural tube is called? |
|
Definition
|
|
Term
| when and where does neurulation being? |
|
Definition
| begins in the 5th week in the thoracic region and extends caudally and cranially resulting in complete closure by the end of 6th week |
|
|
Term
| failure of the closure of the neural tube will result in _______ |
|
Definition
|
|
Term
| Describe when and how the heart is developed? |
|
Definition
during the 5th week, 2 cardiac tubes (primitive heart) develop. By the end of the 5th week, these tubes begin to pump into a primitive paired vascular system
by the end of the 6th week, blood flow is unidirectional and by the end of the 8th week, the heart attains its definitive form |
|
|
Term
| when does the primitive gut form? |
|
Definition
|
|
Term
| when does the midgut form? |
|
Definition
| the midgut herniates into the umbilical cord from week 8 through the end of week 12 |
|
|
Term
| The _______ separates from the ________ sinus by the end of 8th week and the _______ membrane perforates by the end of week 10 |
|
Definition
| rectum / urogenital / anal |
|
|
Term
| The primitive _______ (aka _________) ascend from the pelvis starting at approx. week 8, but do not reach their adult position until week 11 |
|
Definition
|
|
Term
| When does the external genitalia form? |
|
Definition
| external genitalia do not reach mature fetal form until the end of week 14 |
|
|
Term
| when does nearly all congenital malformaions, except for genitalia abnormalities originate? |
|
Definition
| before or during the embryonic period |
|
|
Term
| ___________ is a protein produced by ___________ which is detectable in maternal serum and urine |
|
Definition
| Human chorionic gonadotropin (hCG) / trophoblastic tissue |
|
|
Term
|
Definition
| hCG supports the corpus luteum, thereby assuring a continuous supply of progesterone in the 1st trimester |
|
|
Term
| when is hCG first detected? |
|
Definition
| 3 weeks after the LMP or 7-10 days after ovulation |
|
|
Term
| what happens to the hCG every 2-3 days? |
|
Definition
|
|
Term
| what happens to the hCG around 8-9 weeks? |
|
Definition
| it plateau's around 8-9 weeks, then declines |
|
|
Term
| which 2 ways can the beta hCG be done? |
|
Definition
qualitative - urine results are either + or -
quantitative - blood results provide specific levels of the protein present, namely alpha-feto protein, which is produced by the fetal liver |
|
|
Term
| greater than expeted levels of hCG are associated with? |
|
Definition
incorrect dates
gestational trophoblastic disease
multiple gestations |
|
|
Term
| less than expected levels of hCG are associated with |
|
Definition
incorrect dates
ectopic pregnancy
embryonic demise |
|
|
Term
| second internaltional standard (2IS) or second international reference preparation = __________ |
|
Definition
| International reference preparation (IRP) ÷ 2 |
|
|
Term
| First international reference preparation (IRP) = |
|
Definition
|
|
Term
| what is the first sonographic evidence that a normal, intrauerine pregnancy is present? |
|
Definition
| the identification of a gestational sac within the endometrial cavity |
|
|
Term
| what are the normal sonographic observations of a gestational sac? |
|
Definition
double sac sign
round, oval well defined borders
position in the fundus or mid uterus
echogenic, intact borders
grows - 1 mm per day
yolk sac is present when the mean sac diameter is ≥ 13mm |
|
|
Term
| about how fast does the gestational sac grow? |
|
Definition
|
|
Term
| when does the yolk sac appear? |
|
Definition
|
|
Term
| when does the embryo first appear adjacent to the yolk sac? |
|
Definition
|
|
Term
| when does the embryo first appear adjacent to the yolk sac? |
|
Definition
|
|
Term
| When can a mean sac diameter be used? why? |
|
Definition
| mean sac diameer can be used to date an early 1st trimester preganancy. Because several extrinsic facors can alter sac dimensions, MSD is best used prior to identification of a crown rump length |
|
|
Term
| How is a mean diamter calculated? |
|
Definition
from 3 planar section
ap + long + trans |
|
|
Term
| When does the primary yolk sac (aka primitive) formed? |
|
Definition
|
|
Term
| what happens to the primary yolk sac? what does it result in? when? |
|
Definition
| the primary yolk sac is pinched off and extruded, which results in the formation of the secondary yolk sac, forming at approx. 27-28 days |
|
|
Term
| which yolk sac is visible in ultrasound? |
|
Definition
|
|
Term
| where is the yolk sac located? |
|
Definition
|
|
Term
| what is the first structure we see within the gestational sac? |
|
Definition
|
|
Term
| when is the yolk sac always seen? |
|
Definition
|
|
Term
| when is the yolk sac seen ev and trans abd? |
|
Definition
endo vaginal - 5 weeks
trans abdominal - 7 weeks when the MSD is 20mm |
|
|
Term
| when the embyonic demise how is the yolk sac seen? |
|
Definition
| calcified yolk sacs are only see with embryonic demise |
|
|
Term
| what can be helpful in determining amnionicity of the pregnancy? |
|
Definition
| the number of yolk sacs present |
|
|
Term
| the number of yolk sacs will be the same as |
|
Definition
|
|
Term
| what is the normal diameter of a yolk sac? |
|
Definition
| should never exceed 5.6mm |
|
|
Term
| what does enlarged yolk sac have? |
|
Definition
|
|
Term
| which measurement is the most accurate of all thoughout the pregnancy, and is accurate for dating to within 3-5 days if measured properly? |
|
Definition
|
|
Term
| What is the correct measurement for a crown rump lenght? |
|
Definition
| is obtained from the top of the head to the bottom of the rump (excluding legs) |
|
|
Term
| what is the embryonic growth rate? |
|
Definition
|
|
Term
| which growth rate is the same as embryonic growth rate? |
|
Definition
| gestational sac growth rate |
|
|
Term
| what is the rule of thumb to get the gestational age? |
|
Definition
|
|
Term
| which is the single most important feature for the confirmation of embryonic and fetal life? |
|
Definition
| the identification of cardiac activity |
|
|
Term
| __________ the embryo and embryonic cardiac activity can be reliably and consistently identified earlier than ____________ |
|
Definition
| transvaginally / transabdominally |
|
|
Term
| __________ ultrasound can identify a normal embryo without cardiac activity |
|
Definition
|
|
Term
| it is abnormal to identify an embryo without cardiac activity with ________ ultrasound |
|
Definition
|
|
Term
| which the first organ to function within the embryo? |
|
Definition
|
|
Term
| when does the embryonic heart starts beating? |
|
Definition
| approx 35 days, when the endocardial heart tubes fuse to form a single heart tube |
|
|
Term
| when does the heart obtain its adult configuration? |
|
Definition
|
|
Term
| what is the heart rate for 6 week and 9 week embryo? |
|
Definition
90-115 bmp - 6 weeks
140-160 - 9 weeks |
|
|
Term
| when is umbilical cord formed? |
|
Definition
|
|
Term
| how is the umbilical cord formed? |
|
Definition
| the amnion expands and envelops the connecting stalk, the yolk stalk and the allantois |
|
|
Term
| what does the umbilical cord contain? |
|
Definition
|
|
Term
| the umbilical cord is embedded in ___________ |
|
Definition
|
|
Term
| what does the umbilical cord contain? |
|
Definition
| allantois, yolk sac aka vitelline duct, 2 arteries, 1 vein |
|
|
Term
| what is the vitelline duct aka? |
|
Definition
omphalomesenteric
yolk sac |
|
|
Term
| what grows into the body stalk? |
|
Definition
|
|
Term
| what fuse to become the umbilical cord? |
|
Definition
|
|
Term
| what does the umbilical vein carry? and how? |
|
Definition
| carries oxygenated blood from the placenta to the fetus through the ductus venosus into the IVC and the heart |
|
|
Term
| what does umbilical vein become in a new born? |
|
Definition
| ligamentum teres, left portal vein and the ligamentum venosum |
|
|
Term
| what does the allantois become after the baby is born and what is it associated with? |
|
Definition
| associated with bladder development and becomes the urachus and the median umbilical ligament |
|
|
Term
| what does the yolk sac connect? |
|
Definition
| the primitive gut to the yolk sac |
|
|
Term
| ________ and _____________ within the umbilical cord have been described to occur in the 1st trimester |
|
Definition
|
|
Term
| when are the cysts within the umbilical cord usually seen and when does it disappear? |
|
Definition
| seen in the 8th week and disappear by the 12th week |
|
|
Term
| how does a cysts in the umbilical arrise? |
|
Definition
| may originate from remnants of the allantois and usually resolve in utero |
|
|
Term
| Around the 6th week of gestation, 3 primary brain vesicles develop. what are they? |
|
Definition
1 prosencephalon
2 mesencephalon
3 rhombensephalon |
|
|
Term
| the rhombencephalon divides into? |
|
Definition
|
|
Term
| what forms when the rhombencephalon divide? when can it be imaged? |
|
Definition
the cystic rhomboid fossa forms
imaged routinely from the 8th - 11th week of gestation |
|
|
Term
| what does the midgut, derived from the primitive gut develop into? |
|
Definition
| develops and form the majority of the small bowel, cecum, ascending colon, and proximal transverse colon |
|
|
Term
| how does the yolk stalk form? |
|
Definition
| because the midgut is in direct communication with the yolk sac, amniotic cavity expansion pulls the yolk sac away from the embryo, forming the yolk stalk |
|
|
Term
| how does the midgut herniate into the base of the umbilical cord? |
|
Definition
| as amniotic expansion occurs, the midgut elongates faster than the embryo is growing causing the midgut to herniate into the base of the umbilical cord |
|
|
Term
| how does the small bowel appear within the base of the umbilical cord? |
|
Definition
| appears as an echogenic mass within the base of the umbilical cord |
|
|
Term
| when must the herniation of the bowel be diagnosed as abnormal? |
|
Definition
| after 14 weeks of gestation |
|
|
Term
| what is nuchal translucency? |
|
Definition
| nuchal translucency is an abnormal fluid collection behind the fetal neck that is reported as a late first trimester finding between 10-14 weeks of gestation |
|
|
Term
| what is an abnormal thickness of a nuchal translucency? |
|
Definition
|
|
Term
| what is nuchal translucency associated with? |
|
Definition
| aneuploidy, which is an abnormal number of chromosomes, and is seen in trisomy 13, 18, 21, ripoloidy and turner's syndrome |
|
|
Term
| when is limb buds that are embryologically recognizable? |
|
Definition
| during the 6th week of gestation |
|
|
Term
| when is the spine develop? |
|
Definition
| 5th - 7th week of gestation |
|
|
Term
| when does the skeletal system develop? give the order of development |
|
Definition
| the skeletal system begins to develop during the 6th week with the upper limbs forming first, followed by the lower limbs. The hands and feet develop later but are completely formed by the end of the 10th week. Fingers and toes are regonized with transvaginal sonography at 11 weeks |
|
|
Term
| when does the embryonic face form? |
|
Definition
| the embryonic face undergoes significant evolution starting in the 5th week, with palate fusion beginning around the 12th week of gestation |
|
|
Term
| which feature of the face is seen as brightly echogenic structures during 9th week? |
|
Definition
|
|
