Chapter 9

Question 1

An embryo develops into a fetus over a time span of…

Answer 1

8 weeks

Question 2

Three stages of development after conception

Answer 2

Zygote, embryo, fetus

Question 3

When does brain development begin?

Answer 3

At the point of conception.

Question 4

Differentiation

Answer 4

Various types of cells are created during the embryonic and fetal period

Question 5

Layer of cells that forms linings of the body (lungs, intestines, liver, etc)

Answer 5

Endoderm

Question 6

Layer of cells that forms connective tissue (muscle, cartilage, bones)

Answer 6

Mesoderm

Question 7

Layer of cells that forms the nervous system, epidermis, and parts of the eyes and ears

Answer 7

Ectoderm

Question 8

Neural plate

Answer 8

Thickened ectodermal layer

Question 9

Neural folds

Answer 9

Push up to form the neural groove

Question 10

Neural tube

Answer 10

Place from which the brain and spinal cord develop

Question 11

When embryonic layers thicken, they form into…

Answer 11

The neural plate, neural folds, and neural tube.

Question 12

Neural tube defect: how and types

Answer 12

When a neural tube fails to close.

Types= spina bifida, anencephaly, Down syndrome

Question 13

Anencephaly is a neural tube defect that results in…

Answer 13

Stillborn, or death shortly after birth (literally means no brain)

Question 14

Spina bifida results in_______and can be prevented how?

Answer 14

Paralysis, limb deformities, and mental retardation. Can be prevented with supplemental folic acid.

Question 15

Ectodermal cells along the inner surface of the neural tube tighten to form the…

Answer 15

Ventricular layer

Question 16

The ventricular layer divides into…

Answer 16

Daughter cells, which go to marginal layer or intermediate layer

Some become neurons or glia

Question 17

Between the marginal and intermediate layers is the…

Answer 17

Cortical plate

Question 18

The cortical plate develops into…

Answer 18

Neurons and glia of the cerebral cortex

Question 19

The subventricular layer cells become…

Answer 19

Glia or interneurons

Question 20

The formation of new neurons is called…

Answer 20

Neurogenesis

Question 21

What do radial glial cells do?

Answer 21

Guide migrating daughter cells.

Question 22

Neurons grow toward organs or other neurons called…

Answer 22

Target cells

Question 23

The swollen end of the developing neuron from which the axon emerges

Answer 23

Growth cone

Question 24

Spines that extend from the growth cone

Answer 24

Filopodia

Question 25

How do neural connections form?

Answer 25

The filopodia finds a target cell and pulls the growth cone which lengthens the axon while the cell body remains in place

Question 26

Two types of neural depth

Answer 26

Necrosis and apoptosis

Question 27

The first to travel a route and interact with guidance molecules

Answer 27

Pioneer growth cones

Question 28

Cells that redirect axon growth to target cells and serve as a “topographic map”

Answer 28

Guidepost cells

Question 29

The brain volume ____________ between birth and maturity.

Answer 29

Quadruples

Question 30

Rapid brain growth is due to what factors?

Answer 30

Synaptogenesis, myelination, and increased dendritic branches

Question 31

Symptoms of autism

Answer 31

Diminished ability to interpret emotions and intentions of others

Poor social skills

Preoccupation with a single activity or object

Delayed language and social development

Question 32

Potential causes of autism

Answer 32

Genetics or environment

Question 33

Three layers of cells found in the embryo

Answer 33

Endoderm, mesoderm, ectoderm