Brain Development

Question 1

Neural tube —> brain

Answer 1

Week 4/5

Question 2

Neurulation

Answer 2

process in which the neural plate bends up and later fuses to form the hollow tube that will eventually differentiate into the brain and the spinal cord of the central nervous system

Question 3

Neurulation in humans occurs in two distinct phases, what are they?

Answer 3

1.) Primary neurulation
2.) Secondary neurulation

Question 4

Primary neurulation

Answer 4

during weeks 3 and 4 of gestation leading to development of the brain and spinal cord

Question 5

Secondary neurulation

Answer 5

during weeks 5 and 6, with formation of the lower sacral and coccygeal cord

Question 6

What is the purpose of brain development?

Answer 6

• creation of neural tube (brain and spinal cord)
• establishment of brain specific regions

Question 7

Establishment of brain specific regions:

Answer 7

1.) Neural tube
2.) Primary Brain Vesicles
3.) Secondary Brain Vesicles
4.) Postnatal CNS

Question 8

Postnatal CNS

Answer 8

• establishment of cranial nerves
• establishment of peripheral nerves

Question 9

3rd and 4th week of development

Answer 9

• embryo body folding into “C” shape
• 3-Part brain is formed
• at head end –> cephalic and cervical flexures are formed

Question 10

At the beginning of week 5, cervical flexure doubles back on itself and is the boundary between _________ and __________ ______

Answer 10

hindbrain; spinal cord

Question 11

Later, the __________ flexure separates the mesencephalon and myelencephalon

Answer 11

pontine

Question 12

“encephal” =

Answer 12

brain

Question 13

3 primary vesicles formed during primary neurulation

Answer 13

1.) Prosencephalon
2.) Mesencephalon
3.) Rhombencephalon

Question 13

Primary Vesicles (3rd and 4th week of development)

Answer 13

As the anterior end of the neural tube starts to develop into the brain, it undergoes a couple of enlargements; the result is the production of sac-like vesicles. Similar to a child’s balloon animal, the long, straight neural tube begins to take on a new shape

Question 14

Prosencephalon

Answer 14

forebrain

Question 15

Mesencephalon

Answer 15

midbrain; also the site of the cephalic flexure

Question 16

Rhombencephalon

Answer 16

• “Rhomb” means a geometric figure with four equal sides
• hindbrain

Question 17

Secondary Vesicles (5th to 6th week of development)

Answer 17

The brain continues to develop, and the vesicles differentiate further during a process called secondary neurulation

Question 18

By the 5th-6th week, the three primary vesicles become _____ secondary vesicles

Answer 18

5

Question 18

5 secondary primary vesicles

Answer 18

1.) Telencephalon (distant)
2.) Diencephalon (2)
3.) Mesencephalon (middle)
4.) Metencephalon (beyond)
5.) Myelencephalon (spinal cord)

Question 19

Growth between cervical flexure and midbrain –> produces _________ flexure and this divides __________

Answer 19

Pontine; hindbrain

Question 20

The prosencephalon enlarges into two new vesicles called what?

Answer 20

1.) Telencephalon
2.) Diencephalon

Question 21

The telencephalon will become what?

Answer 21

cerebrum

Question 22

The diencephalon gives rise to what adult structures?

Answer 22

1.) Dorsal thalamus
2.) Hypothalamus

Question 23

In the embryonic diencephalon, a structure known as the _____ ____ also develops, which will eventually become the _____

Answer 23

eye cup; retina

Question 24

The mesencephalon does or does NOT differentiate into any finer subdivisions?

Answer 24

does NOT

Question 25

The _______ is an established region of the brain at the primary vesicle stage of development and remains that way

Answer 25

midbrain

Question 26

The rhombencephalon develops into what two structures?

Answer 26

1.) Metencephalon 2.) Myelencephalon

Question 27

Metencephalon

Answer 27

corresponds to the adult structure known as the pons and also gives rise to the cerebellum

Question 28

Cerebellum

Answer 28

(from the Latin meaning little brain) accounts for about 10 percent of the mass of the brain and is an important structure unto itself

Question 29

The most significant connection between the cerebellum and the rest of the brain is at the _____ because this and the cerebellum develop out of the same vesicle

Answer 29

pons

Question 30

Myelencephalon

Answer 30

corresponds to the adult structure known as the medulla oblongata

Question 31

Embryonic telencephalon

Answer 31

- cerebral cortex - basal ganglia - hippocampus - olfactory bulb - basal forebrain

Question 32

Embryonic diencephalon

Answer 32

- dorsal thalamus - hypothalamus

Question 33

Embryonic mesencephalon

Answer 33

- midbrain

Question 34

Embryonic metencephalon

Answer 34

- cerebellum - pons

Question 35

Embryonic myelencephalon

Answer 35

- medulla oblongata

Question 36

The brain is developing from the ________ neural tube

Answer 36

anterior

Question 37

The spinal cord is developing from the ________ neural tube

Answer 37

posterior

Question 38

The spinal cord does not differ from the basic layout of the neural tube; it is a long straight cord with a small, hollow space down the center; as the neural tube separates from the rest of the ectoderm, the side closest to the surface is _______ and the deeper side is _______

Answer 38

dorsal; ventral

Question 39

As the spinal cord develops, the cells making up the wall of the neural tube proliferate and differentiate into the ________ and glia of the spinal cord

Answer 39

neurons

Question 40

Dorsal tissues

Answer 40

associated with sensory functions

Question 41

Ventral tissues

Answer 41

associated with motor functions

Question 42

______ ______ houses within brain stem (midbrain, pons, medulla oblongata)

Answer 42

Motor nuclei