Topic 3 Flashcards Preview

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Flashcards in Topic 3 Deck (15):
1

-proliferation

-rate of growth of neurons-begins at 5 weeks GA

2

-migration
-integration

-neurons moving to final location (brain stem, cerebellum, etc)
-neurons reach final destination

3

synaptogenisis

neurons spin out axons that connect to each other via dendrites
-anywhere from 1000-100000 connections/neuron
-at the end of the prenatal period, some connections die (if they are inactive) and some strengthen

4

differentiation

occurs AFTER synaptogenesis-separation of function of neurons
-efferent=motor neurons
-afferent=sensory neurons

5

myelination

insulation of neural pathway-occurs at about 20 weeks and continues to age 30 in some areas
-enhanced by physical activity

6

Post-Natal Brain Growth Spurt

-occurs starting at the third trimester and continues to age 4
-at birth, brain 25% of adult weight, at age 3, brain 90% of adult weight-example of cephalo-caudal principle
-attributed to increase in neuron size, branching, and increase in glia and myelin, but highly susceptible to nutrition and extrinsic factors
-allows mother to carry child more easily and may be due to evolutionary explanation-brain too big for pelvic structure at birth

7

activity-independent
activity-dependent

-hardwired processes determined by genetic processes played out in individual neurons (migration, differentiation) [NATURE]
-influence things after axons reach final location and require neural activity (myelination, syaptogenesis) [NURTURE]

8

pruning

connections not made or not stimulated are eliminated (40-70% of original)-keeps system from becoming too confusing
-epilepsy related to this

9

Critical peroids

period of maximum sensitivity to environmental stimuli-a child who misses an opportunity may not develop brain's circuitry to full potential for that aspect of development
1. organism must be in state of readiness
2. if stimulation does not occur in this window, optimal development is lost forever
3. stimulation affects things permanently
4. critical periods exist for all aspects of behavior

10

Electroencephalography (EEG)

-measures electrical activity with electrodes
-measures an average of event-related potentials (ERP)

11

Computed Technology (CT)

-uses x-ray beams to collect cross sectional images of the brain and develops them onto film
-shows structure of brain

12

Positron Emission Tomography (PET Scan)

-detects radioactive material that is injected/inhaled
-shows brain function

13

Magnetic Resonance Imaging

-detects frequency signals produced by displaced radio waves in a magnetic field
-shows anatomical view

14

Functional MRI

-detects change in blood flow to brain
-provides anatomical and functional view

15

Magnetoencephalography

-measures magnetic fields produced by brains electrical activity
-shows function (how brain responds to stimuli)