Chapter 1 ( Nervous System Organization And Development )

Question 1

Skeletal motor neurons develops from ?

Answer 1

Neural tube

Question 2

Sensory neurons develop from ?

Answer 2

Neural crest

Question 3

All the ganglia of PNS are derived from ?

Answer 3

Neural crest

Question 4

When does neurulation begin ?

Answer 4

In the third week of development

Question 5

Alpha fetoprotein is elevated in ?

Answer 5

Gastroschisis
Omphalocele
Spina bifida with myeloschisis

Question 6

AFP are low in ?

Answer 6

Pregnancy of down syndrome

Question 7

What induces the formation of nervous system ?

Answer 7

Notochord releasing inducers such as Sonic Hedgehog

Question 8

Rostral neuropore closes at ?

Answer 8

Day 25

Question 9

Caudal neuropore closes at ?

Answer 9

Day 27

Question 10

Adult derivatives of secondary brain vesicles ?

Answer 10

1- Telencephalon: cerebral hemispheres and most of basal ganglia , lateral ventricles
2- Diencephalon : thalamus , hypothalamus , subthalamus , epithalamus , retina and optic nerve , third ventricle
3- Mesencephalon : midbrain , cerebral aqueduct
4- Metencephalon : pons and cerebellum , forth ventricle
5- Myelencephalon : medulla and spinal cord , central canal

Question 11

Mechanism of anencephaly ?

Answer 11

Failure of the rostral neuropore to close