Brain Development

Question 1

What is the second brain of the body and describe

Answer 1

-> enteric nervous system (gut) is regarded as the second brain in our body
-> seems that the brain has outsourced digesting to the digestive system.
-> However, there is still communication between the brain and the gut through the vagus nerve.

Question 2

When is normally regarded as the first brain growth spurt

Answer 2

last 3 months before birth to 2 years old

Question 3

name the types of neurons

Answer 3

sensory neurons = send signals to the sensory receptors from the brain
motor neurons = send signals to the muscles and glands from the brain
inter neurons = connecting the sensory neurons and the motor neurons

Question 4

what are the characteristics of neurons

Answer 4

neurons migrate along the pathways laid down by the guiding cells
very adaptive. if there are guided to the visual cortex, become a neuron in the visual system
(specialisation for different neural functions)

Question 5

Why are glial cells important

Answer 5

1. strengthens synapses
2. produces myelin that speeds up electrical signals transportation
3. have their own system

Question 6

names and the functions of glial cells

Answer 6

astrocytes: common, mop up excessive neurotransmitters
oligodendrocytes: speeds up the electrical signal transport. Wraps the tip of the neurons and produce myelin. white matter
schwann cells: wraps up the axons. same function as the oligodendrocytes in the peripheral system
Microglia cells: the immune system of the brain
NG2+ cells: precursor

Question 7

Explain myelination and continues from when till when. Also, in what direction does myelination grow

Answer 7

-> Myelins (mostly lipids) wrapping the axon
-> to prevent action potentials leaking out from the axon
-> speeds up and more effective the electrical signals
-> Starts from the back of the brain to the frontal lobe
-> continues from 7 months of gestation to early adulthood

Question 8

why is myelination important?

Answer 8

-> growth of teenagers = mature myelination = better decision-making, better concentration, better emotional control

Question 9

What are the three items in the brain that grow

Answer 9

increase surface area of the brain
increase neurons
increase synapses

Question 10

Explain apoptosis and synaptic pruning and when does it end

Answer 10

apoptosis = die out of unsufficiently used neurons
synaptic pruning = die out of unsufficiently used synaptic connections.

vital so that the brain is not overpopulated withunused neurons and synaptic connections.
child’s brain has high plasticity. experience determines the scale of apoptosis and synaptic pruning

-> ends at mid/late 20s