Developmental

Question 1

How many neurons does the adult brain comprise?

Answer 1

The adult brain comprises of 80 billion neurons.

Question 2

At what rate are neurons added during early embryonic life?

Answer 2

Neurons are added at a rate of 250,000 neurons/min.

Question 3

What percentage of adult brain size is achieved by 2 years after birth?

Answer 3

Growth at 2 years after birth is 80% of the adult size.

Question 4

How many other cells does a single neuron interact with on average?

Answer 4

A single neuron interacts with an average of 15,000 other cells.

Question 5

What happens to the brain’s surface area from 5 to 9 months?

Answer 5

The brain at 5 months is quite smooth; by 9 months it starts growing the surface area.

Question 6

What are the three parts of gastrulation?

Answer 6

Ectoderm, Mesoderm, and Endoderm.

Question 7

What does the ectoderm develop into?

Answer 7

The ectoderm becomes your CNS, PNS, and skin.

Question 8

What does the mesoderm develop into?

Answer 8

The mesoderm develops into the skeletal system, muscles, and vascular region.

Question 9

What does the endoderm develop into?

Answer 9

The endoderm develops into the gut, lungs, and liver.

Question 10

When does the neural tube start forming?

Answer 10

The neural tube starts forming at 4 weeks.

Question 11

What does the neural tube form?

Answer 11

The neural tube forms the basis of the brain and spinal cord.

Question 12

What develops from the rostral front part of the neural tube?

Answer 12

The rostral front part develops into 3 chambers that eventually become the ventricles.

Question 13

What does the hindbrain form?

Answer 13

The hindbrain forms the cerebellum.

Question 14

What are the three stages of neurodevelopment?

Answer 14

Neurogenesis, Neural migration, and Neural differentiation.

Question 15

What happens during neurogenesis?

Answer 15

Progenitor (stem) cells divide by mitosis in the neural tube.

Question 16

What is the process of neural migration?

Answer 16

Neurons migrate to the outside of the tube, guided by radial glia cells.

Question 17

What occurs during neural differentiation?

Answer 17

Immature neurons differentiate into different types of specialized neurons.

Question 18

What is synaptogenesis?

Answer 18

Over-production of synapses, redundancy, beginning from about 17 weeks after conception but mostly postnatal.

Question 19

What is apoptosis in the context of neurodevelopment?

Answer 19

Clearing of neurons whose axons don’t find their targets, activated by genetic processes.

Question 20

When does synapse reorganization occur?

Answer 20

Synapse reorganization occurs from 26 weeks until after birth.

Question 21

What is myelination?

Answer 21

Myelination is produced by glial cells and involves a gradual increase in the myelin sheath surrounding the axons.

Question 22

What is DNA?

Answer 22

DNA is packed into chromosomes in the nucleus of our cells and contains our genetic information

Question 23

How many pairs of chromosomes do humans have?

Answer 23

Humans have 23 pairs of chromosomes.

Question 24

What is a gene?

Answer 24

A gene is an area of DNA which codes RNA.

Question 25

What do genes code for?

Answer 25

Genes code proteins, not behavior.

Question 26

What are examples of genetically controlled characteristics?

Answer 26

Height and eye color.

Question 27

What are examples of environmentally controlled characteristics?

Answer 27

Religion and language skills.

Question 28

What are family studies in measuring heritability?

Answer 28

Histories recorded for family members compared as a function of relatedness.

Question 29

What are adoption studies?

Answer 29

Comparing twin pairs raised together and separated at birth to remove environmental factors.

Question 30

What are twin studies used for?

Answer 30

To assess heritability by comparing monozygotic (MZ) and dizygotic (DZ) twins.

Question 31

What are genetic linkage studies?

Answer 31

Studies that require DNA collection to screen for regions associated with a disorder.

Question 32

What are brain tumors?

Answer 32

Abnormal growth of cells affecting normal functions.

Question 33

What are the two ways brain tumors affect normal functions?

Answer 33

Compression and infiltration.

Question 34

How are brain tumors graded?

Answer 34

Graded according to aggressiveness from 1 to 5 by the WHO.

Question 35

What are common symptoms of brain tumors?

Answer 35

Unexplained behavioral/psychiatric symptoms followed by neurological examination.

Question 36

How are brain tumors diagnosed?

Answer 36

Diagnosed with brain imaging, such as MRI or CT.

Question 37

What is a stroke?

Answer 37

A condition where blood supply to part of the brain is interrupted or severely reduced.

Question 38

What are the types of strokes?

Answer 38

Haemorrhagic stroke, Ischemic stroke, and Transient ischemic attack.

Question 39

What are risk factors for stroke?

Answer 39

High blood pressure, smoking, diabetes, obesity, and family history.

Question 40

What are common symptoms of strokes affecting the frontal lobe?

Answer 40

Loss of flexibility in thinking, mood changes, sequencing problems, and inability to focus.

Question 41

What are symptoms of strokes affecting the temporal lobe?

Answer 41

Language problems, agnosia, and attention/memory problems.

Question 42

What are symptoms of strokes affecting the parietal lobe?

Answer 42

Alexia, agraphia, apraxia, and difficulties in hand-eye coordination.

Question 43

What are symptoms of strokes affecting the occipital lobe?

Answer 43

Color/motion blindness, prosopagnosia, visual field loss, and blindsight.

Question 44

What are symptoms of strokes affecting the cerebellum?

Answer 44

Dysergia, problems sequencing and coordinating rapid movement, and dysmetria.

Question 45

What is Chronic Traumatic Encephalopathy (CTE)?

Answer 45

A disease affecting those with repeated concussive or sub-concussive brain injuries.

Question 46

What are the characteristics of CTE?

Answer 46

Mood disorder, memory disturbances, behavioral changes, and dementia.

Question 47

What is a traumatic brain injury (TBI)?

Answer 47

Injury caused by vehicle accidents, sports injuries, falls, and acts of violence.

Question 48

What are the two mechanisms of TBI?

Answer 48

Direct strike to the head or sudden acceleration/deceleration causing diffuse shear forces.

Question 49

What is Fragile X Syndrome?

Answer 49

The most common inherited form of intellectual disability.

Question 50

What are symptoms of Fragile X Syndrome?

Answer 50

Delayed speech, mild to moderate intellectual disability, ADHD symptoms, and seizures.

Question 51

What is Down Syndrome?

Answer 51

A chromosomal condition that occurs when there are 3 copies of chromosome 21.

Question 52

What are the effects of Down Syndrome?

Answer 52

Mild to moderate intellectual disability, delayed language, and a variety of birth defects.

Question 53

What is foetal alcohol syndrome (FAS)?

Answer 53

A disorder caused by alcohol intake during pregnancy affecting 1 in 1000 lives.

Question 54

What are the effects of FAS?

Answer 54

Distinctive facial features, low height/weight, low brain volume, and brain damage.

Question 55

What is Autism Spectrum Disorder?

Answer 55

A diagnosis based on persistent deficits in social communication and restricted behaviors.

Question 56

What are genetic factors in Autism Spectrum Disorder?

Answer 56

High heritability within symptom groups and complex multi-gene interactions.

Question 57

What environmental factors are associated with Autism Spectrum Disorder?

Answer 57

Paternal age, toxin exposure, and maternal infection/autoimmune diseases.

Question 58

What genes are thought to be involved in autism?

Answer 58

Genes linked to GABA and oxytocin are thought to be involved in autism.

Question 59

What hampers research on autism?

Answer 59

Research is hampered by the very diverse aetiology of autism, leading to small and inconsistent sample sizes.

Question 60

What environmental factors are suggested to be linked to autism?

Answer 60

There are many suggested environmental factors with mixed evidence, such as gestational diabetes and birth order.

Question 61

What environmental factors have clearer evidence linked to autism?

Answer 61

Paternal age, toxin exposure, and maternal infection/autoimmune diseases have clearer evidence linked to autism.

Question 62

What neurological symptoms are associated with ASD?

Answer 62

ASD is associated with a range of neurological symptoms, including motor problems, sleep disorders, and epilepsy.