week 4

Question 1

What are three approaches to development of brain and behaviour

Answer 1

Brain development-predicts-behavioural development
Behavioural development-predicts-brain development
Experience injury effects behavioural development and brain development, and Behavioural development effect brain development

Question 2

What is the journey of the egg

Answer 2

Step 1: egg leaves ovary and enters fallopian tubes
Step 2: sperm enters egg and unites with nucleus
Step 3: Fertilised egg divides
Step 4: cells attach to uterus

Question 3

What happens in the Germinal stage

Answer 3

contraception to 3 weeks
from conception until implantation in the wall of the uterus
0-2 weeks from contraception: zygote travels down fallopian tube to uterus
Cells multiply rapidly from 2 cells to 90 cells 5 days later
cells differentiate as they divide

Question 4

What happens in embryonic stage

Answer 4

3 weeks- 9 weeks
period of rapid cell division and differentiation. embryo takes on a human shape. Three key structure emerge: amniotic sac, Placenta, umbilical cord
Divides into three layers:
Ectoderm: Hair, teeth, outer skin layer and nervous system
Mesoderm: inner skin layer, skeleton, muscle
Endoderm: vital organs, glands and gastrointestinal tract

Question 5

Foetal stage

Answer 5

9 week- birth
Period of continuous growth for major structure and systems, culminating in birth
Major feature= brain development not complete at birth

Question 6

What happens from conception to first the 3 weeks

Answer 6

Ectoderm thickens and become neural plate by day 18 of gestation. The sphere of dividing cells flattens, and the outer layers thicken lengthways
The neural plate folds to form the neural groove, which then closes over to form and a fluid-filled cylinder- the neural tube

Neural tube defect: Anencephaly: Neural tube fail to completely close over- underdevelopment skull and brain; life-limiting condition 5/10,000 birth

Question 7

What happens from week 4 to birth

Answer 7

Embryo: up to 10 weeks foetus: week 10-birth
By week 4- the main divisions of CNS are formed: forebrain, midbrain, hindbrain and spinal cord

By mid-pregnancy cerebral hemispheres have expanded to cover the rest of the brain

By 6 months, cell proliferation-infolding-sulci and gyri on surface of cortex. Lobes can be differentiated

Question 8

How many stages are there in development

Answer 8

7 Stages

Question 9

What is stage 1

Answer 9

Cell birth: neurogenesis
Non-neuronal cells divide by mitosis to produce neurons.
Single layer of cells along inner surface of neural tube- ventricular zone.
All neurons and glial cells come from here.

Question 10

What is stage 2

Answer 10

Cell migration: newly formed cells move from the ventricular zone to the correct destination in the nervous system.
Travel along radial glial cells which act as guides

Question 11

Stage 3

Answer 11

Cell differentiation
Cells acquire distinctive characteristic
Cells reach their destinations and start to express particular genes.
Cell-cell interaction coordinates development- ensure right type of neuron for that part of the brain

Question 12

What is stage 4

Answer 12

Cell maturation: dendrite and axon growth

Question 13

What is stage 5

Answer 13

Synaptogenesis: formation of synapses

Question 14

What is stage 6

Answer 14

cell death and synaptic pruning
Cell death aka apoptosis
Use it or lose it: synaptic connections that do not become part of a functional neural network are lost.

Question 15

What is stage 7

Answer 15

Myelination: axon become wrapped in fatty sheath
speeds the conduction of electrical signals
some prenatally; rapid shortly after birth; continues into adulthood

Question 16

What continues after birth

Answer 16

1. neurogenesis only in the hippocampus
2. synaptogenesis
3. cell death and synaptic pruning
4. myelination

Question 17

What factors influence brain and behaviour development

Answer 17

Intrinsic factors
extrinsic factors

Question 18

What are intrinsic factors

Answer 18

originating within the developing organism

Question 19

What is extrinsic factors

Answer 19

outside the developing organism

Question 20

What are the intrinsic factors

Answer 20

Chromosomal changes: down syndrome: extra chromosome, physical properties, developmental delays and intellectual disability, behavioural dysfunction varies, abnormal dendritic spine in the cerebral cortex

Question 21

What are some extrinsic factors

Answer 21

Changes in the visual cortex depending on experience -sensitive period during which visual experience crucial for proper development of vision. Human: cataracts: blurry vision until 6 months (then corrected) impaired face perception at 9 years, lazy eye

Enriched environments: studied by rats with simple or complex cages , increased dendritic branching with complex environment

Social-economic status and brain development in humans: family income is positively related to cortical surface are, particularly in temporal, frontal and prefrontal regions

Injury and recovery: Humans in the womb or soon after birth- most dramatic consequences, first two years- may produce no behaviour consequences, Adulthood- severe behavioural consequences

Foetal alcohol: prenatal exposure to alcohol- distinct facial features, changes in neuroanatomy, most common non-genetic cause of learning difficulties

Zika virus: transmitted through mosquito bites, mild symptoms: fever, rash, headache. Infection during pregnancy= microencephaly abnormal brain development and loss of brain tissue

Question 22

Changing demographics

Answer 22

1900: 4% 65 plus
2030: 20% 65 plus

Question 23

Dementias affect

Answer 23

1-6% of over 65s
10-20% of over 80s

Question 24

What are the two types of dementias

Answer 24

Non-degenerative- mostly caused by problem in the cardiovascular system
Degenerative- primary cause in the nervous system, thought to have a degree of genetic transmission

Question 25

What is Alzheimer

Answer 25

65% of all dementias, begins as a loss of memory for recent events, progresses to being unable to answer basic Qs, atrophy of the cerebral cortex, particularly temporal and frontal areas. Cellular changes in the hippocampus which impair synaptic function
Risk factors: Apoe4 gene
Increase of senile/amyloid plaques, increase in neurofibrillary tangles

Question 26

What is Parkinson’s

Answer 26

loss of cells in substantia nigra and consequent loss of the neurotransmitter dopamine
Key symptoms in motor behaviour: tremor at rest, loss of spontaneous movement, rigidity, posture disturbances, cognitive slowing
risk factors: environmental pollutants
treatments: physical therapy; L-dopa deep brain stimulation

Question 27

What is Neuroplasticity

Answer 27

The potential of the nervous system to change across the life-span as an adaptation to the environment