Nervous System Development

Question 1

ectoderm

Answer 1

this is the outermost layer of cells or tissue of the developing embryo

Question 2

neurulation

Answer 2

this is the folding process that ultimately leads to the neural tube

this begins when the ectoderm overlying the notochord begins to furrow forming a neural groove surrounded by two neural folds

Question 3

notochord

Answer 3

this is a cartilaginous structure in embryos that supports the body of embryos

this stimulates the overlying ectoderm to fold over

Question 4

neural crest

Answer 4

this is a region at the leading edge of the neural fold and the cells here will migrate throughout the body and form disparate (different) tissues
ex. dorsal root ganglia, melanocytes, and calcitonin producing cells

Question 5

neural tube

Answer 5

• after the neural furrow closes it forms this
• this will become the central nervous system
• contains the alar plate and basal plate

over time, the neural tube will enfold on itself and become the 3 brain swellings of the embryonic brain and then eventually the 5 brain swellings of the mature brain

Question 6

alar plate

Answer 6

this is part of the neural tube and differentiates into sensory neurons

Question 7

basal plate

Answer 7

this is part of the neural tube and differentiates into motor neurons

Question 8

primitive reflexes

Answer 8

these are reflexes that exist in infants and should disappear with age

most serve a protective role and can reappear in certain nervous system disorders

Question 9

rooting reflex

Answer 9

the infant will turn its head toward anything that brushes the cheek

Question 10

moro reflex

Answer 10

the infant extends the arms, then slowly retracts them and cries in response to a sensation of falling

Question 11

babinski reflex

Answer 11

the big toe extended and the other toes fan in response to the brushing of the sole of the foot

Question 12

grasping reflex

Answer 12

the infant grabs anything put into his or her hand