Invertabrate brains 1

Question 1

How many neurons does the human CNS contain?

Answer 1

8.6 x 10^13

(86 billion)

Question 2

Up to how many synapses can come from a single neurone?

Answer 2

100,000

Estimates more than a trillion synpases in the brain

Question 3

What are the 4 main cellular processes in (invertabrate) development?

Answer 3

• Cell specification/determination
• Cell proliferation
• Cell migration
• Cell differentiation

Question 4

What sort of NS do sponges have?

Answer 4

no NS

Question 5

What sort of NS do Cnidarians have?

Answer 5

(e..g sea anenomy)

Radia symmetry/nerve net –> randomly orientated

Question 6

What sort of NS does a sea star have?

Answer 6

A neural ring

Respond to stimuli in their arms - radially symmetric

Question 7

What sort of NS does a flatworm have?

Answer 7

More developed, showed key differences:

1 - Ladder like CNS into a trunk structure

2 - SHow accumulations of neurons at anteriorr end of the animal (brain like region)

Question 8

What sort of NS do squids have?

Answer 8

Like a flatworm it has an accumulation of neurons at one end resembling some sort of a brain