The Fetus And Placenta

Question 1

The period from the 💡beginning of the ninth week to 💡birth is known as the

It is characterized by 💡maturation of tissues and organs and 💡rapid growth of the body.

Answer 1

Fetal period.

Question 2

The 💡length of the fetus is usually indicated as the?

Answer 2

Crown-rump length (CRL) (sitting height)

Question 3

The measurement from the 💡vertex of the skull to the 💡heel (standing height).

Answer 3

Crown-heel length (CHL)

Question 4

💡Growth in length is particularly striking during the?

Answer 4

Third, fourth, and fifth months

Question 5

Increase in weight is most striking during the?

Answer 5

Last 2 months of gestation

Question 6

The length of pregnancy is considered to be __ after the onset of the last normal menstrual period (LNMP) or, more accurately, __ after fertilization.

Answer 6

280 days, or 40 weeks

266 days or 38 weeks

Question 7

One of the 💡most striking changes taking place during fetal life is the?

Answer 7

Relative slowdown in growth of the head

Question 8

During the __, the face becomes more human looking

Answer 8

Third month

Question 9

💡Primary ossifícation centers are present in the long bones and skull by the __.

Also, 💡external genitalia develop to such a degree that the sex of the fetus can be determined by external examination (ultrasound)

Answer 9

12th week

Question 10

By __ intestinal loops cause a large swelling (herniation) in the umbilical cord, but by the __, the loops have withdrawn into the abdominal cavity.

Answer 10

Sixth week

12th week

Question 11

During the __, the fetus lengthens rapidly, and at the end of the first half of intrauterine life, its CRL is approximately 15 cm, about half the total length of the newborn.

Answer 11

Fourth and fifth months

Question 12

The fetus is covered with fine hair, called?

Answer 12

Lanugo hair

Question 13

During the __, 💡movements of the fetus can be felt by the mother.

Answer 13

Fifth month

Question 14

During the __,weight increases considerably, particularly during the last 2.5 months, when 50% of the full term weight (approximately 3,200 g) is added.

Answer 14

Second half of intrauterine life

Question 15

During the __, the skin of the fetus is 💡reddish and has a 💡wrinkled appearance because of the 💡lack of underlying connective tissue.

Answer 15

Sixth month

Question 16

At what month the fetus has a CRL of about 💡25 cm and weighs approximately 💡1,100 g. If born at this time, the infant has a 90% chance of surviving.

Answer 16

7 months

Question 17

At what month the fetus is 💡well-rounded contours as the result of 💡deposition of subcutaneous fat

By the end of intrauterine life, the skin is covered by a whitish, fatty substance (vernix caseosa) composed of secretory products from sebaceous glands.

Answer 17

8th month

Question 18

It is a 💡whitish, fatty substance which is composed of secretory products from 💡sebaceous glands.

Answer 18

vernix caseosa

Question 19

At what month where the 💡skull has the largest circumference of all parts of the body, an important fact with regard to its passage through the birth canal.

The weight of a normal fetus is 💡3,000 to 3,400 g, its CRL is about 💡36 cm, and its CHL is about 💡50 cm. 💡Sexual characteristics are pronounced, and the 💡testes should be in the scrotum.

Answer 19

Ninth month

Question 20

It is the action of giving birth to young

Answer 20

Parturation

Question 21

The date of birth is most accurately indicated as __, after fertilization.

Answer 21

266 days, or 38 weeks

Question 22

The obstetrician calculates the date of birth as __ from the first day of the LNMP.

This method is accurate among women with regular 28-day menstrual periods

Answer 22

280 days or 40 weeks

Question 23

Most fetuses are born within __ of the calculated delivery date.

Answer 23

10 to 14 days

Question 24

If the fetuses are born much earlier, they are categorized as

Answer 24

Premature

Question 25

If the fetuses are born later, they are categorized as

Answer 25

Postmature

Question 26

It is a valuable tool which can provide an accurate (1 to 2 days) measurement of CRL during the 7th to 14th weeks.

Answer 26

Ultrasound

Question 27

Measurements commonly used in the 💡16th to 30th weeks are:

Answer 27

``` Biparietal diameter (BPD), Head and abdominal circumference Femur length. ```

Question 28

It is the 💡organ that facilitates nutrient and gas exchange between the maternal and fetal compartments.

Answer 28

Placenta

Question 29

FUNCTIONS OF PLACENTA

Answer 29

1. Exchange of metabolic and gaseous products between maternal and fetal bloodstreams. 2. Transmission of Maternal Antibodies (IgG) 3. Hormone Production (Progesterone)

Question 30

The fetal component of the placenta is derived from the __ and __ (the chorionic plate); the maternal component is derived from the __.

Answer 30

Trophoblast Extraembryonic mesoderm Uterine endometrium

Question 31

These are formed when 💡syncytium becomes very thin, and large pieces containing several nuclei may break off and drop into the intervillous blood lakes. They 💡enter the maternal circulation and usually 💡degenerate without causing any symptoms.

Answer 31

Syncytial knots

Question 32

The 💡villi on the embryonic pole continue to grow and expand, giving rise to the? It is the 💡only portion of the chorion participating in the 💡exchange process

Answer 32

Chorion frondosum (bushy chorion)

Question 33

Villi on the abembryonic pole degenerate, and by the third month, this side of the chorion, now known as the known as the?

Answer 33

Chorion laeve

Question 34

It is the 💡functional layer of the endometrium, which is 💡shed during parturition.

Answer 34

Decidua

Question 35

The 💡decidua over the chorion frondosum which consists of a compact layer of 💡large cells, 💡decidual cells, with 💡abundant amounts of lipids and glycogen.

Answer 35

Decidua basalis

Question 36

It is 💡tightly connected to the chorion

Answer 36

Decidual plate

Question 37

It is the 💡decidual layer over the abembryonic pole. | With growth of the chorionic vesicle, this layer becomes stretched and degenerates.

Answer 37

Decidua capsularis

Question 38

It is the 💡uterine wall where the chorion laeve comes into contact on the opposite side of the uterus, and the two fuse, obliterating the uterine lumen.

Answer 38

Decidua parietalis

Question 39

Chorion frondosum + Decidua basalis

Answer 39

placenta

Question 40

Amnion + Chorion It is this 💡membrane that ruptures during labor (breaking of the water).

Answer 40

Amniochorionic membrane

Question 41

By the beginning of the 💡fourth month, the placenta has two components:

Answer 41

Fetal portion Maternal portion

Question 42

It is formed by the 💡chorion frondosum

Answer 42

Fetal portion

Question 43

It is formed by the 💡decidua basalis

Answer 43

Maternal portion

Question 44

It 💡borders the placenta on the 💡fetal side.

Answer 44

Chorionic plate

Question 45

It 💡borders the placenta on the 💡maternal side

Answer 45

Decidual basalis

Question 46

This is where 💡trophoblast and 💡decidual cells 💡intermingle. This zone is characterized by 💡decidual and syncytial giant cells, is rich in amorphous extracellular material.

Answer 46

Junctional zone

Question 47

During the fourth and fifth months, the decidua forms a number of __, which project into intervillous spaces but do not reach the chorionic plate These septa have a 💡core of maternal tissue, but their surface is covered by a layer of 💡syncytial cells, so that at all times, a syncytial layer separates maternal blood in intervillous lakes from fetal tissue of the villi.

Answer 47

Decidual septa

Question 48

They 💡divide the placenta into a 💡number of compartments as a result of the 💡decidual septum formation

Answer 48

Cotyledons

Question 49

It is a 💡discoid with a diameter of 💡15 to 25 cm, is approximately 💡3 cm thick, and weighs about 💡500 to 600 g.

Answer 49

Full-Term Placenta

Question 50

When the placenta is viewed from the maternal side, 15 to 20 slightly bulging areas, the cotyledons, covered by a thin layer of decidua basalis, are clearly recognizable. Grooves between the cotyledons are formed by decidual septa.

Answer 50

True

Question 51

The __ of the placenta is covered entirely by the 💡chorionic plate.

Answer 51

Fetal surface

Question 52

It separates maternal and fetal blood, is initially composed of four layers: (1) The endothelial lining of fetal vessels (2) The connective tissue in the vlllus core (3) The cytotrophoblastic layer (4) The syncytium

Answer 52

Placental membrane | Placental barrier

Question 53

It is the oval line of reflection between the amnion and embryonic ectoderm (amnio-ectodermal junction)

Answer 53

Primitive umbilical ring

Question 54

At the end of pregnancy, a number of changes that occur in the placenta may indicate reduced exchange between the two circulations. These changes include:

Answer 54

(1) An increase in fibrous tissue in the core of the villus (2) Thickening of basement membranes in fetal capillaries (3) Obliterative changes in small capillaries of the villi (4) Deposition of fibrinoid on the surface of the villi in the junctional zone and in the chorionic plate.

Question 55

It is a 💡clear, watery fluid that is produced in part by 💡amniotic cells but is 💡derived primarily from 💡maternal blood which filled the 💡amniotic cavity.

Answer 55

AMNIOTIC FLUID

Question 56

Functions of AMNIOTIC FLUID:

Answer 56

(1) Absorbs jolts (2) Prevents adherence of the embryo to the amnion (3) Allows for fetal movements.

Question 57

The amount of fluid increases from approximately 30 mL at __ of gestation to 450 mL at __ to 800 to 1,000 mL at __.

Answer 57

10 weeks 20 weeks 37 weeks

Question 58

The volume of amniotic fluid is replaced every __.

Answer 58

3 hours

Question 59

During 💡5th month, what will happen to the fetus and the amniotic fluid?

Answer 59

1. The fetus swallows its own amniotic fluid | 2. Fetal urine is added daily to the amniotic fluid

Question 60

They result from simultaneous shedding of 💡two oocytes and fertilization by 💡different spermatozoa.

Answer 60

Dizygotic (Fraternal) Twins

Question 61

It develops from a 💡single fertilized ovum

Answer 61

Monozygotic (identical) Twins

Question 62

Labor itself is divided into three stages:

Answer 62

(1) Effacement (thinning and shortening) and dilatation of the cervix (this stage ends when the cervix is fully dilated) (2) Delivery of the fetus (3) Delivery of the placenta and fetal membranes

Question 63

It is a term applied to infants who 💡do not attain their optimal intrauterine growth. These infants are 💡pathologically small and at risk for poor outcomes. Caused by mutations in the 💡IGF-I gene.

Answer 63

Intra-uterine growth restriction (lUGR)

Question 64

It is a term applid to infant who have a birth weight that is 💡below the l0th percentile for their gestational age. These babies may be 💡pathologically small (they may have lUGR) or they may be 💡constitutionally small (healthy but smaller in size).

Answer 64

Small for gestational age (SGA)

Question 65

Babies with lUGR have been shown to have a greater chance as adults to develop a metabolic disorder later in life, such as obesity, hypertension, hypercholesterolemia, cardiovascular disease, and type 2 diabetes

Answer 65

Barker hypothesis

Question 66

It is the 💡major growth-promoting factor during development before and after birth. Mitogenic and anabolic effects

Answer 66

Insulin-like growth factor-l (IGF-I)

Question 67

This hormone binds to its receptor [GHR], activating a signal trans- duction pathway and resulting in 💡synthesis and 💡secretion of IGF-I.

Answer 67

Growth hormone (GH)

Question 68

Mutations in the 💡GHR It is characterized by marked 💡short stature, and sometimes 💡blue sclera. These individuals show 💡little or no lUGR because IGF-I production does not depend on GH during fetal development.

Answer 68

Laron dwarfism

Question 69

It is a condition characterized by 💡maternal hypertension and 💡proteinuria due to reduced organ perfusion and occurs in approximately 5% of pregnancies.

Answer 69

Preeclampsia

Question 70

Hemolytic disease of the fetus and newborn RH incompatibility

Answer 70

Erythroblastosis fetalis

Question 71

It happens when the anemia is so severe causing edema and effusions into the body cavities

Answer 71

Fetal hydrops

Question 72

This compound produced 💡clear cell carcinoma of the vagina and abnormalities of the cervix and uterus in females and in the testes of males in individuals who were exposed to the compound during their intrauterine life

Answer 72

Diethyistilbestrol (DES],

Question 73

Length of a cord reflects the amount of intrauterine movement of the fetus, and shortened cords have been observed in fetal movement disorders and with intrauterine constraint.

Answer 73

True

Question 74

Tears in the amnion It may encircle part of the fetus, particularly the limbs and digits causing amputations, ring constrictions, and other abnormalities, including craniofacial deformations.

Answer 74

Amniotic Bands

Question 75

It is the term used to describe an excess of amniotic fluid (1,500 to 2,000 mL)

Answer 75

Hydramnios or polyhydramnios

Question 76

It refers to a decreased amount (<400 mL] of amniotic fluid.

Answer 76

Oligohydramnios

Question 77

It refers to rupture of the membranes before uterine contractions begin.

Answer 77

Premature rupture of the membranes (PROM)

Question 78

It refers to the 💡death of one fetus. This disappearance, which occurs in the 💡first trimester or the 💡early second trimester, may result from resorption or formation of a 💡fetus papyraceus

Answer 78

Vanishing twin

Question 79

One twin is larger, and the other has been compressed and mummified.

Answer 79

Fetus papyraceus

Question 80

Placental 💡vascular anastomoses produced unbalanced blood flow to the two fetuses.

Answer 80

Twin transfusion syndrome

Question 81

-

Answer 81

Thoracopagus twins

Question 82

-

Answer 82

Pygopagus twins

Question 83

-

Answer 83

Craniopagus twins