89. nerve tissue and development

Question 1

what are the 2 major divisions of the nervous system

Answer 1

Central nervous system (CNS)- brain and spinal cord

Peripheral nervous system (PNS)- cranial, spinal, peripheral nerves

Question 2

cells found in both central and peripheral nerve tissue

Answer 2

neurones- responds to stimuli

glial cells- support and protect neuron

Question 3

Which embryonic layer does nerve tissue develop from

Answer 3

ectoderm beginning third week of development

Question 4

how does ectoderm form into tissue

Answer 4

• ectoderm thickens to form the epithelial neural plate
• sides of plate fold up and grow to form neural tube. This forms entire CNS including neurons and glial cells
• neural tube separates from ectoderm. Neural crest separates from neural epithelium and becomes mesenchymal
• neural crest cells migrate and differentiate as cells of PNS

Question 5

What is an action potential

Answer 5

membrane depolarization
stimuli received then is propagated across length or nerve plasma membrane