Vertebrate Nervous System

Question 1

How are higher vertebrates brains different to lower

Answer 1

Have a more folded cerebral cortex
Have a more layered neocortex
have a larger cerebellum
have a reduced olfactory system (less need for small)
Parts of the brain that are more needed are larger

Question 2

Which areas of human brain are especially more developed

Answer 2

Pre frontal cortex
Cortical areas involved in ;
Manual dexterity 
Speech 
Facial expression

Question 3

What is white matter

Answer 3

Myelinated axons

Question 4

What is grey matter

Answer 4

Neurone cell bodies

Question 5

Give three examples of the evolution of function of the vertebrate CNS

Answer 5

Swimming in fish
Walking on land by amphibians and reptiles
Birdsong

Question 6

What are central pattern generators

Answer 6

Helps fish swim
Present on both sides of the spinal cord and generate a basic rhythm for locomotion
There are connections between L and R to ensure coordination
Controlled by locomotor command centres in the brain stem that are controlled by the basal ganglia in the cerebral hemisphere

Question 7

Describe the startle response in fish

Answer 7

Mediated by maunther neurones, helps fast acceleration from ‘standing’ fish
- detects vibration by sensory input from lateral line
- axon crosses midline and extends throughout the spinal cord
- collaterals contact interneurones and motor neurones at all spinal levels
- unilateral muscle contraction takes place
Switches sides repeatedly and generates rhythmic pattern

Question 8

How was it discovered that locomotive activity doesn’t require the brain

Answer 8

Cats placed on treadmill and communication cutoff between brain and spinal cord. Cats carried on walking.

Question 9

What’s the leg (4 of them) sequence in walking

Answer 9

LH, LF, RH, RF

Question 10

What are the 2 phase of the leg whilst walking

Answer 10

1. Swing - leg flexed, raised off ground, swung forward and extended
2. Stance - leg is in contact with ground moving backwards in relation to direction of body

Question 11

What is needed for walking

Answer 11

Spinal reflexes
Inhibition/stimulation of antagonist is muscle groups; flexors and extensors
Co-ordination of movement of multiple joints
Sensory feedback (controls rate of stepping)
Supra-spinal control (ascending pathways run form spinal cord to sensory cortex in cerebral hemisphere)

Question 12

What connections influence locomotion in reptiles and amphibians

Answer 12

1. Cerebral cortex and the spinal cord
2. Evolving basal ganglia, the cortex and the brain stem
3. The cerebellum and spinal cord

Question 13

What are the three major pathways that evolve to connnect the neocortex with other parts of the CNS in mammals

Answer 13

1. Corticostriate pathway (basal ganglia)
2. Cortico-cerebellar pathway
3. Corticospinal tract