Physiology

Question 1

Gestational Age

Answer 1

The time from the Mother’s first day of the last menstrual period, including the two weeks of fertilisation = Embryonic Age +2 weeks
- Full term in this timeline = 40 weeks

Question 2

Embryonic Age

Answer 2

The time from fertilisation/conception = minus 2 weeks from Gestational age

Question 3

Chronological Age

Answer 3

The time from birth (Ex: 2 days old)

Question 4

Post-Menstrual Age (PMA)

Answer 4

Gestational Age + Chronological Age (to account for prematurity or delayed delivery)
- Ex: 35 week pregnancy and the baby is 2 weeks old = 37 week old baby in PMA

Question 5

What gestational age is considered extremely premature?

Answer 5

24-27 weeks

Question 6

What gestational age is considered very premature?

Answer 6

28-30 weeks

Question 7

What gestational age is considered moderately premature?

Answer 7

31-33 weeks

Question 8

What gestational age is considered late premature?

Answer 8

34-36 weeks

Question 9

What gestational age is considered full term?

Answer 9

37-40 weeks

Question 10

Brain development stages from first trimester through to third

Answer 10

First trimester (0-12 weeks):
- Neural tube formation (initial structure that eventually becomes the brain and spinal cord)
- Neuronal proliferation (neural tube begins to produce neurons)
Second trimester (13-26 weeks):
- Neural migration (new neurons migrate to their correct position in the brain)
- Differentiation (neurons take on specialised roles ex: sensory/motor, etc.)
- Cortical development (outer layer of brain develops)
Third trimester (27-40 weeks):
- Synaptogenesis (neurons form synapses so they can communicate w/ each other)
- Myelination initiation (myelin forms allowing more efficient communication)
- Establishment of neural networks (complex networks form that allow movement, breathing, etc.)