Fetal Development/Genetics

Question 1

What must happen with the female for conception to occur?

Answer 1

A healthy ovum is released from the ovary, passes into an open fallopian tube, and starts its journey downward

Question 2

What is the area where fertilization takes place?

Answer 2

Sperm from the male is deposited into the vagina and swims approximately 7 inches upward to meet the ovum at the outer most portion of the fallopian tube

Question 3

How long does it take for the ovum to reach the cervix?

Answer 3

an hour

Question 4

How long does the process of fertilization typically take?

Answer 4

5 hours

Question 5

Pre-embryonic Stage

Answer 5

fertilization through the second week

Question 6

What are the 3 stages of fetal development during pregnancy?

Answer 6

• Pre-embryonic
• Embryonic
• Fetal

Question 7

When does fertilization typically occur?

Answer 7

around 2 weeks after the last normal menstrual cycle

Question 8

Morula

Answer 8

16 cells appearing as a solid ball of cells
“little mulberry”
Reaches the uterine cavity about 72 hours after fertilization

Question 9

Blastocyst

Answer 9

appears within the morula as an off-centered, fluid filled space, transforming into a hollow ball of cells
-inner surface will form the embryo and amnion

Question 10

Trophoblast

Answer 10

outer layer of cells surrounding the blastocyst cavity

Question 11

What will the trophoblast develop into?

Answer 11

one of the embryonic membranes, the chorion, and helps to form the placenta

Question 12

What will the inner surface of the blastocyst develop into?

Answer 12

Will form the embryo and amnion

Question 13

What will attach its self to the endometrium for implantation?

Answer 13

trophoblast

Question 14

Where does implantation typically occur?

Answer 14

Fundus

Question 15

What are the 3 embryonic layers of cells formed?

Answer 15

Ectoderm
Mesoderm
Endoderm

Question 16

Ectoderm

Answer 16

forms the central nervous system (CNS), special senses, skin, and glands

Question 17

Mesoderm

Answer 17

forms the skeletal, urinary, circulatory, and reproductive systems

Question 18

Endoderm

Answer 18

forms the respiratory system, liver, pancreas, and digestive system

Question 19

What two fetal membranes form the fluid-filled amniotic sac?

Answer 19

Amnion and chorion

Question 20

How much fluid can the amniotic sac hold at full term?

Answer 20

1 L

Question 21

What is amniotic fluid derived from?

Answer 21

Maternal blood and fetal urine

Question 22

Embryonic Stage

Answer 22

begins at day 15 after conception and continues through week 8

Question 23

Week 3 Gestation

Answer 23

Beginning development of brain, spinal-cord, heart, and GI tract
-Leg and arm buds appear and grow

Question 24

Week 4

Answer 24

Brain differentiates

Stomach, pancreas, and liver begin to form

Question 25

Week 5

Answer 25

Heart beat has regular rhythm
Beginning structures of eyes and ears
Some cranial nerves visible
Muscles innervated

Question 26

Week 6

Answer 26

Beginning of lungs
Fetal circulation 
Liver produces RBC's
Primitive skeleton forms
CNS forms
Brain waves detectable

Question 27

Week 7

Answer 27

Straightening of trunk
Nipples and hair follicles form
Elbows and toes visible 
Arms and legs move
Diaphragm formed 
Heart beat can be heard 
Mouth with lips and early tooth buds

Question 28

Week 8

Answer 28

Rotation of intestines
Facial features develop
Heart development complete
Resembles a human being

Question 29

Weeks 9-12

Answer 29

Sexual differentiation continues 
Buds for all 20 temporary teeth formed
Digestive system shows activity 
Head comprises is nearly half the fetus size 
Face and neck are well formed
Urogenital tract complete 
Red blood cells produced in liver 
Urine is produced and excreted
Fetal gender can be determined 
Limbs long and thin; digits formed

Question 30

Weeks 13-16

Answer 30

Lanugo hair 
Fetal skin is almost transparent 
Bones become harder
Sucking motions
Amniotic fluid is swallowed 
Fingernails/toenails
Weight quadruples 
Mom can feel movement

Question 31

Weeks 17-20

Answer 31

Rapid brain growth
Fetal heart tones heard w/ stethoscope 
Vernix ceseosa covers the fetus 
Eyebrows and head hair 
Sebaceous glands
Brown fat
Muscles well developed

Question 32

Weeks 21-24

Answer 32

Eyebrows and eyelashes 
Grasp and startle reflex 
Alveoli forming in lungs 
Skin is translucent and red
Lungs begin to produce surfactant

Question 33

Weeks 25-28

Answer 33

Fetus reaches length of 15 inches
Rapid brain development 
Eyelids open and close 
Nervous system controls some functions 
Fingerprints are set 
Blood formation shifts from spleen to bone marrow 
Usually assumes head-down position

Question 34

Week 29-32

Answer 34

Rapid increase in body fat 
Increased CNS control
Rhythmic breathing movements occur
Lungs are not fully mature
Stores iron, calcium, phosphorus

Question 35

Week 33-38

Answer 35

Testes are in scrotum of male fetus 
Lanugo begins to disappear 
Increase body fat
Small breast buds present
Mother supplies fetus w/ antibodies 
Considered full term at 38 wks 
Fills uterus

Question 36

Oligohydramnios

Answer 36

too little amniotic fluid (< 500 mL)

Question 37

What can happen due to oligohydraminos?

Answer 37

uteroplacental insufficiency, fetal renal abnormalities, higher risk of surgical births, and low birth weight