Brain Development Flashcards

Question

Anacephaly

Answer 1

- failure to close at the top of the neural tube | - fatal

Answer 2

neural stem cells line the neural tube -Extensive capacity for self-renewal -Give rise to progenitor (precursor) cells -Eventually produce neuroblasts and glioblasts (nondividing) -Begins early in gestation (approx. day 40) Complete by midgestation

Answer 3

- Neurons multiplying during this period - Number of neurons increases by hundreds of thousands every minute throughout pregnancy - Concentrated period of proliferation occurring between 6 and 17 weeks after conception - As a result, young infant has around 100 billion neurons

Answer 4

- supportive and nutrient role in NS | - Enable regeneration of damaged nerves

Answer 5

- Form blood-brain barrier - Direct migration of neurons - Clean up & plug injury sites

Answer 6

speed up transmission of neural impulses, coat axons with myelin

Answer 7

clean up tissue around injury sites, especially grey matter

Answer 8

- Birth of glial cells begins after most neurons are born; continues throughout life - Normal adult function is attained only after myelination is complete - Myelination useful as a rough index of cerebral maturation - MRI analyses used to look at myelin development

Answer 9

- Neurons move to particular locations throughout the brain where they will become part of specialized functioning units. - Influenced by genetic instructions and the biochemical environment. - Some neurons migrate passively (brain stem & thalamus), others actively (cerebral cortex).

Answer 10

Last 4 ½ months of gestation, the brain is especially delicate and extremely vulnerable to injury or trauma, including asphyxia. The brain can more easily cope with injury during neuron generation than it can during cell migration and differentiation.

Answer 11

Most neurons are produced in the ventricular zone (VZ) and migrate radially from the VZ in the center of the brain out to the developing neocortex.

Answer 12

Cells travel along “roads” made of cells - radial glial cells - fiber extending from the ventricular zone to the surface of the cortex The cells from a given region need to follow the glial road and they will end up in the right location As the brain grows, the glial fibres stretch, but they still go to the same place

Answer 13

Brain fails to form sulci and gyri and corresponds to a 12-week embryo – can be caused by a virus, lack of blood supply or genetic causes

Answer 14

The process in which neuroblasts become specific types of neurons. Every neuron starts with the potential to become any specific type of neuron. What each neuron becomes depends on where it migrates to. essentially complete at birth but maturation continues for years

Answer 15

neurons must begin the process of growing dendrites to provide the surface area for synapses with other cells Axons also extended to appropriate targets to initiate the formation of other synapses Axons have specific targets that they must reach if the neuron is to survive and become functional Process can be disrupted leading to behavioural disturbances

Answer 16

- axons may be blocked | - axonal development can be disrupted if the axonal system's target is damaged (system may degenerate)

Answer 17

Synaptogenesis not equal throughout brain, or at same time 1st in primary motor and sensory areas Then association areas; and prefrontal cortex (PFC) This order is sensible to function – infant needs basic motor and sensory skills in place before more complex mental abilities can develop

Answer 18

- elimination of synapses - happens very rapidly - lose up to 200 axons per second

Answer 19

Initial over-production allows brain to be maximally responsive to environment Depending on this input, certain connections become important while others are irrelevant Allows brain to fine-tune and specialize itself

Answer 20

naturally occurring cell death

Answer 21

First regions to be myelinated = regions NB for vital functions (eg spinal chord, medulla) 1st year after birth basic sensory and motor systems become myelinated Later childhood myelination between brain regions occurs Myelination of corpus collosum continues into early 20’s

Answer 22

Structural changes in both the major grey and white matter continue through childhood and adolescence. Parallel changes in functional organization that are also reflected in behavior. The brain increases four-fold during the preschool period, reaching approximately 90% of adult volume by age 5.

Answer 23

- The functions controlled by the two hemispheres diverge - Typically, the left cerebral hemisphere controls the right side of the body - -language processing - Typically, the right hemisphere controls the left side of the body - -understanding spatial information and for processing visual-motor information and the emotional content of information - The hemispheres are connected by the neurons that make up the corpus callosum - Signs of lateralization are evident at birth - Direction the head is turned, grasp reflex, hemispheric response to speech sounds

Answer 24

the brain's ability to change as a result of experience | -greatest in childood

Answer 25

Captures the idea that the early experience of the organism plays an essential role in normal brain development, particularly in the early postnatal period and functional organization of the developing brain.

Answer 26

Behaviour altered as a result of learning from the environment

Answer 27

- neural networks are streamlined, especially in prefrontal cortex and limbic system (emotions) - upsurge of dopamine

Answer 28

- Helps control the brain’s reward and pleasure centers - Helps regulate movement and emotional responses, and it enables us not only to see rewards, but to take action to move toward them - too much = psychotic

Answer 29

- neural networks become more efficient - Some loss of neurons, diminished functioning of neurons, and changes to related tissues, such as myelin - Greatest loss in the areas that control sensory and motor activities - Decrease in brain weight and volume - Transmission of signals by atrophied neurons is less effective - Declines in levels of neurotransmitters - Formation of “senile plaques” - Reduced blood flow to the brain

Answer 30

a gradual loss of cognitive abilities that accompanies abnormal brain deterioration and interferes with daily functioning

Answer 31

- sequential processing - analytic thought - logic - language - science and health

Answer 32

- simultaneous processing - holistic thought - intuition - creativity - art and music

Answer 33

Volume of grey matter increases, peaks and then decreases through teen years

Answer 34

Increases in a linear fashion as a result of steady progression of mylination of axons.

Brain Development Flashcards

(58 cards)