Chapter 4 - Physical Development in Infancy

Question 1

Why is myelination important?

Answer 1

increase speed of neural impulses, which improves information transmission between cells.

Question 2

What accounts for increases in brain weight in the first two years?

Answer 2

synaptogenesis - the development of connections - synapses - between neurons through the growth of axons and dendrites. First 6 months - 100,000 new synapses every second, by 2 - 1 neuron to 10,000 connections.

Question 3

Describe the general pattern of physical growth (proximodistal and cephalocaudal)

Answer 3

Proximodistal - from center of body outward.

cephalocaudal - from top of head down.

Question 4

How does experience relate to brain differentiation and specialization?

Answer 4

Brain Plasticity
~ Experience-expectant processes - prewired processes in the brain.
~Experience-dependent processes - involve the active formation of new synaptic connections in response to experience .

Question 5

What are reflexes and what are the primary reflexes in infancy?

Answer 5

Reflexes - simple, involuntary responses to certain stimuli that have(or had) adaptive significance.
Primary Reflexes in infants:
approach - intake; breathing, rooting, sucking, and swallowing.
avoidance - coughing, sneezing, and blinking.
other - palmar grasp (tighten grip when held) & moro (swing arm across body as if around caregiver).