1- Development of the Nervous System

Question 1

Gastrulation

Answer 1

2 weeks gestation

Single layer of cells begin infolding to form multiple layers (ecto, meso, endoderm)

Question 2

Ectoderm

Answer 2

Nervous System

Skin

Question 3

Mesoderm

Answer 3

Muscle

Bone

Question 4

Endoderm

Answer 4

Future lining of gut and some organs

Question 5

Neuroepithelial Cells

Answer 5

Found in ventricular zone
Undergo rapid cell division
Produce precursors, post-mitotic neurons, glial cells

Question 6

Encephalopathy

Answer 6

Any disease or disorder of the brain

Can have many different causes

Question 7

Creutzfeldt-Jakob Disease

Answer 7

Mad cow disease

Caused by misfolded proteins (prions)

Prions come into contact with brain tissue, disrupts siganling cascade

Question 8

Lyme Encephalopathy

Answer 8

Caused by lyme disease bacteria

Causes neurodegeneration

Question 9

HIV Encephalopathy

Answer 9

Atrophy of white matter due to HIV not being treated properly

Question 10

Microecephaly

Answer 10

Head circumference is smaller than normal

Associated with defect during early brain development

Possible causes include genetic abnormalities, exposure to teratogens

Question 11

Symptoms of Microcephaly

Answer 11

Delayed motor and speech
Intellectual disability
Seizures
Facial distortion
Hyperactivity
Balance/coordination problems

Question 12

Macrocephaly

Answer 12

Overly large head (circumference is more than 2 SD above average)

Too many neurons

Can be benign or associated with intellectual disability, epilepsy

Associated with tumours, infections, genetic abnormalities

Question 13

Cowden Syndrom

Answer 13

Caused by loss of function mutation in PTEN gene

Autosomal dominant

Can also be caused by a de novo mutation (during formation or egg or sperm cell)