fetal period

Question 1

9 -12 weeks (more toward the 9th week)

Answer 1

The head constitutes half the crown heel length of the fetus
Broad face, eyes widely separated, ears are low set, eyelids fused
Short legs, small thighs
External genitalia is similar in both sexes
Intestinal coils are clearly visible in the proximal end of the umbilical cord
Liver-major site of erythropoiesis

Question 2

9 -12 weeks (more toward the 12th week)

Answer 2

Growth in body length accelerates. At the end of the 12wk the CRL has more than doubled.
Primary ossification centers appear in the skeleton
Upper limbs almost have reached their final length
Intestines have returned to the abdomen
Erythropoiesis has begun in the spleen and thymus
Urine formation begins, and urine is discharged into the amniotic fluid
Fluid waste is transferrer to the maternal circulation through the placenta
Some amniotic fluid is reabsorbed by swallowing it
Major fetal form established
Sex can be recognized in most cases

Question 3

13-16 weeks

Answer 3

Growth is rapid
The head is relatively small
Lower limbs have lengthened
Slight limb movements
Bones are clearly visible
Slow eye movements occur
Eyes face anteriorly rather than anterolaterally
External ears are close to their definitive position
Week 16 ovaries are differentiated

Question 4

17-20 weeks

Answer 4

Growth slows, but the fetus still increases its CRL by about 50mm
Fetal movements (quickening) are commonly felt by the mother
The skin is covered by a greasy, cheesecake material (vernix caseosa)- skin protection
Brown fat (socialized adipose tissue for heat production) is present
At wk-18 the uterus is formed, and canalization of the vagina has begun primordial follicles containing oogonia are present
Testes have begun to descend, visible head hair, eyebrows and lanugo (body covered by fine downy hair) at 20 weeks

Question 5

21-25 weeks

Answer 5

Substantial weight gain
Wrinkle skin and lean body
Skin is pink to red
Rapid eye movements
lungs start to produces surfactant
Fingernails are present
May survive if born prematurely, but may die because the respiratory system is still immature

Question 6

26-29 weeks

Answer 6

Lungs are capable of breathing air
Eyelids are open
Lanugo and head air are well developed
Subcutaneous fat is present under the skin (smooth skin)
Toenails become visible
Main site of hematopoiesis- spleen
After week 28 hematopoiesis occurs in the bone marrow

Question 7

30-34 weeks

Answer 7

White fat is 8% of body weight
Limbs have chubby appearance
Pupillary light reflex can be elicited

Question 8

35-38 weeks

Answer 8

Exhibit spontaneous to light
Nervous system sufficiently mature to carry out some integrative functions
Pupillary light reflex can be elicited
36 week head and abdominal circumferences are equal after that abdomen is greater that the head
37 week foot is slightly larger that femur
Prominent chat, testes are in the scrotum