Fetal development

Question 1

Explain proliferation

Answer 1

Massive production of neurons and glia from the thickened layers of the neural tube & neural crest

Question 2

What is Migration?

Answer 2

Glia assist the the movement of neurons to establish the grey matter areas of the brain and spinal cord. (3-5months)

Question 3

Explain myelinization

Answer 3

Formation of myelin around CNZ (Sensory then motor) and PNS neurons (mortor first followed by sensory). (4-5months onwards)

Question 4

What is organization?

Answer 4

Integration of neural functions via formation of complex neural networks and synaptic connections which are continuously refined. (6months onwards)

Question 5

What sensory abilities does the foetus have at 28weeks?

Answer 5

Smell, taste and hearing

Question 6

Motor abilities start at what point?

Answer 6

• Twitching at 10weeks
• Independent limb movement at (10-12w)
• Hand and face(12-13)
• Limb, head and torso(12-16)
• movement complexity from 16ws
• All movements at 18weeks.

Question 7

What are the 5 blood components?

Answer 7

• RBC
• WBC
• Platelets
• Coagulation factors
• Plasma

Question 8

Explain Hematological development

Answer 8

• Begins in embryonic period
• Precursos to first blood cells appear in yolk sac and begin hematopoiesis to produce the first blood cell for circulation.
• Stem cells migrate to the developing liver and hematopoiesis takes place in the liver from 6-18 fetal weeks.
• Hematopoiesis also begins within the spleen and bone marrow during the fetal period, with the bone marrow becoming the major site for hematopoiesis from 30 weeks onwards

Question 9

What is hematopoiesis?

Answer 9

Immature precursor cells develop into mature blood cells.

Question 10

What is Erythropoiesis?

Answer 10

Development of RBC independant of mother under the influence of erythropoietin initially produced by the liver, then the kidneys. By week 10-12 the dominant type is fetal hemoglobin (fHb) high affinity for oxygen, facilitating increased transfer across the placenta

Question 11

Development of WBC

Answer 11

Produced in significant numbers beginning in fetal period in the liver and spleen, but also occurs in the thymus & lymph nodes.

Question 12

Development of Platelets

Answer 12

Production steadily increases during fetal period and into postnatal period.

Question 13

Development of Coagulation factors

Answer 13

Coagulation proteins are present in significant amounts and coagulation & fibrinolytic activity is demonstrated by 10-13 fetal weeks. Thromboplastin from the whenua initiates the clotting cascade in the fetus, if required. Vitamin K levels are initially low, but rise to 50% of adult values by term, thus Vit K dependent clotting factors are reduced.

Question 14

Development of Plasma

Answer 14

Total body fluid volume continues to increase in the baby, with overall increases in both ECF and ICF volumes, however, ECF volume decreases relative to ICF volume during the fetal period as fluid compartment volumes and osmolarity become established.

Question 15

What are the 5 structural differences of the fetal cardiovascular system?

Answer 15

• Umbilical arteries
• Umbilical vein
• Ductus venosus
• Foramen ovale
• Ductus arteriosus

Question 16

Umbilical arteries

Answer 16

Takes blood from the Abdominal aorta to the placenta

Question 17

Umbilical vein

Answer 17

Takes blood from placenta to ductus venosus

Question 18

Ductus venosus

Answer 18

Takes blood from Umbilical vein to inferior vena cava bypassing liver

Question 19

Foramen ovale

Answer 19

Take blood from the right atrium to the left atrium bypassing the lungs

Question 20

Ductus arteriosus

Answer 20

Takes blood from the pulmonary trunk to the Aortic arch bypassing the lungs