Comparative nervous systems Flashcards Preview

Building the nervous system > Comparative nervous systems > Flashcards

Flashcards in Comparative nervous systems Deck (13):
1

How does a sponge regulate the flow of water through its body

Water flows in through the body wall
Flows out via the osculum (the main opening in the sponge)
Regulation of flow down to myocytes - contract or relax

2

How are myocytes independent effectors

Cells produce a response without the intervention of neurons - produce response when directly stimulated

3

What causes the flow of water through the sponge

Flagella

4

What are the key characteristics of the Hydra body plan

Radially symmetrical - associated with a nerve net rather than a CNS
Hydra wall consists of a number of neurons - cells derived from cells that would normally have been skin ectoderm

5

Do Hydra show input from sensory neurons

Yes - sensory neurons relay info to effector cells and other motor neurons
Interneurons lie between sensory and motor neurons
this means they are able to respond to physical contact and detect food and other chemicals but can't detect the source of the stimulus

6

What do both segmented and non segmented worms have in common

Both show bilateral symmetry - two nerve cords , one on each side of the body

7

What's an example of a segmented worm and what neuronal characteristics do they show

Flatworms - clustering of neurons - gangliation, cephalization, fasciculation, commissures (allow for co-ordination of both sides of the body)

8

What is an example of a non-segmented worm and what neuronal characteristics do they have

Fusion of longitudinal nerve cords - suprapharyngeal ganglia (where the cephalic neurons cluster is intimately associated with the mouth)

9

How many neurons does C.elegans have

302

10

How many glia does C.elegans have

56

11

What cells are most neurons derived from

AB cells

12

What is the process of neuronal cells migrating inwards from the ectoderm

Delamination

13

How are neurons formed in drosophila

Delamination of ectoderm forms neuroblasts - neuroblasts form ganglion mother cells - ganglion mother cells form neurons and glia