Fetal Development

Question 1

Pre-embryonic

Answer 1

Fertilization - 2 weeks

Question 2

Embryo

Answer 2

2-8 weeks gestational age

Question 3

Fetus

Answer 3

8 weeks to birth

8 weeks - extremities

Question 4

Neonate

Answer 4

Birth to 2 months of age

Question 5

Infant

Answer 5

3 weeks to 12 months of age

Question 6

Menstrual age

Answer 6

Age counted from date of mothers last period - full term is 40 weeks

Question 7

Gestational age

Answer 7

Age counted from the time of fertilization (mid cycle of mother)
Full term is 38 weeks

Question 8

Full term

Answer 8

range of 38-42 weeks

premature is 36 weeks

Question 9

Chronological age

Answer 9

Begins at time of birth

vs. adjusted age

Question 10

First month of fertilization

Answer 10

Moves down fallopian tubes
Mitosis
Trophoblast
Blastocyst

Question 11

First month of fertilization - day 4

Answer 11

Arrives in uterus

Question 12

First month of fertilization - day 14

Answer 12

implants onto wall of uterus- embryo stage week 2-8

Question 13

First month of fertilization - week 2.5

Answer 13

Neural plate - beginning of CNS
Primitive placenta has formed
Heart - paired heart tubes bulge into midline, become a single tube in coelom

Question 14

First system to develop in the embryo

Answer 14

heart

Critical period of heart development is day 20-50 after fertilization

Question 15

First month of fertilization - week 3.5

Answer 15

Neural groove - closes except for neuropores

Question 16

First month of fertilization - week 4
Length
Head region
Brain and spinal cord

Answer 16

Length = 1/5 in
Head differentiated and 1/3 of length
Brain and spinal cord are developing
Rudimentary eyes, ears, and nose
Body with head, trunk, tail
Heart
Branchial (gill) arches - give rise to mandible, hyoid, larynx
Arm buds
Initial brain development

Question 17

Week 5

Answer 17

1/2 in long
Head is more erect
Fingers visible
Placenta developing
Umbilical cord
Hear differentiating with atria and ventricles

Question 18

Week 6

Answer 18

Cerebrum makes curve in the forehead, development of hemispheres
Hands develop fingers
Heart and liver separated by diaphragm
Liver is now producing blood cells 
Two vertebral arteries
No vertebrae
Deciduous teeth developing

Question 19

Somite

Answer 19

will end up being a nerve root

Question 20

Week 8

Answer 20

Length 1-1.6 in
Weight 2/3 ounce
All adult parts and organs become function
Eyelids forming, ears take shape, pigment in eyes, cartilage for skeleton
Startle reflex

Question 21

Week 9

Answer 21

Amniotic sac
Muscle movement in mouth and jaw
Muscles in UE and LE respond to tactile stimulation

Question 22

Week 11-12 = third month

Answer 22

length - 2.4 to 3 in
Weight 3/4 ounce
Inc activity, primitive reflexes noted (grasp)
Heart is complete
Lips open and close, head turns, forehead wrinkles
yolk sac will soon loosen all blood produced by liver and spleen
Bones - shaft of limb bones are ossified

Question 23

Week 12 - 13 - end of first trimester

Answer 23

All major systems are developed
Umbilical cord and amniotic sac established for nourishment
Determine sex between 12-20 weeks
Isolated movement of hand to mouth and above head
Production of urine

Question 24

Week 13-14 month 4

Answer 24

Mother begins to feel movement
Isolated elbow flex/ext, finger flex/ext, LE reciprocal movement
Bone development continues

Question 25

Foot/hand development

Answer 25

6 week - hand further developed than foot 11 week - nail beds and AROM 5 month - complete

Question 26

Week 16

Answer 26

``` Length 6 in Weight 4 ounces Finger prints appear Weak thumb suck Ears stand out from head ```

Question 27

Month 5

Answer 27

``` First sigh Touches foot, isolated finger movement Turns and moves Swallows, hiccups Sleep/wake cycle Stronger suck Heart beat regular Lanugo, groove in fat layer protecting skin Vestibulocochlear system myelinated ```

Question 28

Week 22

Answer 28

initial myelination of CNS and PNS

Question 29

Month 6

Answer 29

``` Length 10-12 in Weight 2 pounds hair grows thicker Hears in utero Sx fetal distress if HR doesn't inc to noise End of 2nd trimester ```

Question 30

25 weeks of gestation

Answer 30

the child is viable to live outside of the womb

Question 31

Prematurity - appearance

Answer 31

Global hypotonia Extremities in ext, abd, versus midline flexion (lack of muscle tone) Minimal random movements

Question 32

Prematurity - medically unstable

Answer 32

Temp regulation and resp problems Complications - BPD, hyaline membrane disease, IVH Feeding problems

Question 33

Week 26-30

Answer 33

Dislike bright lights Length 16 in Weight 2.5 lbs

Question 34

Week 26-30 premature

Answer 34

Primitive reflexes seen: rooting, suck/swllow, moro, crossed extension, flexor withdrawal, plantar grasp Suck/swallow present but safe nippling wont occur until weeks 33-35 when coordinated gag reflex stronger

Question 35

Week 32-36 in utero

Answer 35

Strong growth phase Getal movement begins to slow Turns head to diffuse light Reflexes = galant, neonatal NOB, BOB, positive support, stepping

Question 36

Week 32 premature

Answer 36

``` More pronouced state differentiation Mvt dominated by trunk will creep in isolette Dec in clonic mvt Attempt hand to mouth and erect head Dec in hip hypotonia ```

Question 37

Week 36 premature

Answer 37

Vigorous sustained cry Inc in co-contraction of muscles UE and trunk more hypotonic than LE

Question 38

Week 38-40 full term State cycles Brain Reflexes

Answer 38

Organized state cycles of active, quiet, transitional Brain is 25% of adult wt and size Brain cells and synapses will be selectively eliminated with age No myelinated fibers extend to cerebral cortex PNS not myelinated Reflexes DTR, superficial skin reflexes

Question 39

Week 38-40 premature

Answer 39

Improved state differentiation More organized spontaneous movement Tone is normalizing but still less than full term, more ROM, poorer flex/ext balance of head and neck More reactive startle, tremore, brisk reflexes

Question 40

Factors that effect development

Answer 40

Teratogen - causes or mechanisms and patterns of abnormal development 20% of deaths in N America caused by birth defects Genetic Environmental

Question 41

Genetic causes

Answer 41

Huntington - breakdown of brain cells Sickle cell anemia Muscular dystrophy Chromososomal disorders

Question 42

Environmental causes

Answer 42

Drugs

Question 43

Chemicals

Answer 43

Organic mercury Lead Polychlorinated biphenyls

Question 44

Infections

Answer 44

``` Rubella Cytomegalovirus Herpes simplex virus Varicella HIV Toxoplasmosis Listeria Congenital syphillis ```

Question 45

Maternal factors

Answer 45

``` Maternal health Maternal age SES Rh blood compatibility Uncontrolled diabetes PKU ```

Question 46

Non-teratogenic agents

Answer 46

Non-ionizing radiation - microwave ovens, UV light | Prenatal vitamins

Question 47

Critical times - CNS

Answer 47

Week 3-5

Question 48

Critical times - Heart

Answer 48

Week 3-6

Question 49

Critical times - UE and LE

Answer 49

Weeks 4-8

Question 50

Critical times - Eyes

Answer 50

Week 4-8

Question 51

Critical times - Ears

Answer 51

Week 4 -12

Question 52

Critical times - teeth and palate

Answer 52

Weeks 6-12