nervous system through development

Question 1

what are the layers of tissue called at ~17 days old?

Answer 1

• endoderm = lining of viscera
• ectoderm = skin and nervous system (neural plate)
• mesoderm = bones and muscles

Question 2

what happens during neurulation (~22 days old)?

Answer 2

neural plate folds to form neural tube (CNS) neural crest (PNS) which gets pinched off
- middle of neural tube becomes ventricular system

Question 3

why are women advised to take folic acid when trying to conceive and during pregnancy?

Answer 3

• failure to appropriately close the neural tube
• folic acid results in 90% reduction in birth defects (anencephaly and spina bifida)

Question 4

main stages of nervous system development

Answer 4

• neurulation
• differentiation

Question 5

what happens during differentiation?

Answer 5

gives rise to 3 primary brain vesicles and then secondary brain vesicles of the forebrain

Question 6

what are the 3 primary brain vesicles in differentiation?

Answer 6

• prosencephalon/forebrain
• mesencephalon/midbrain
• rhombencephalon/hindbrain

Question 7

what are the 3 secondary brain vesicles of the forebrain?

Answer 7

• telencephalic vesicles (cerebral hemispheres)
• diencephalon
• optic vesicles (optic stalk and optic cup)

Question 8

what does the telencephalon become?

Answer 8

• cerebral cortex
• basal telencephalon (contains nuclei involved in emotional and fear regulation)

Question 9

what does the diencephalon become?

Answer 9

• thalamus (relay center controls what goes in and out of cerebral cortex)
• hypothalamus

Question 10

midbrain differentiation

Answer 10

• cerebral aqueduct (connects third ventricle to fourth ventricle)
• tegmentum surrounds cerebral aqueduct
• tectum on top

Question 11

what is the role of the midbrain in sensory processing and voluntary movement?

Answer 11

• receives inputs and produces outputs to the eye
• receives inputs from auditory system
• control of pain
• control of muscles

Question 12

hindbrain differentiation

Answer 12

• pons
• cerebellum
• medulla

Question 13

structure of the cerebelllum

Answer 13

• two cerebellar hemispheres
• cerebellar cortex in the middle
• deep cerebellar nuclei

Question 14

where does the cerebellum receive input from?

Answer 14

• vestibular system (inner ear) about balance and posture
• spinal cord, to know where limbs are
• cerebral cortex

Question 15

through where does information enter and leave cerebellum?

Answer 15

input via pons (specifically pontine nuclei)
output via deep cerebellar nuclei

Question 16

what are the key functions of the cerebellum?

Answer 16

co-ordination of movement, balance, posture