Integration Properties of Nerve Centers

Question 1

What are the types of synapse depending on the function?

Answer 1

There are 2 types of synapse:
1. Excitatory synapse: When the action potential of the presynaptic neuron causes hypo polarization (or action potential) in the post synaptic membrane

2. Inhibitory synapse: When the action potential of the presynaptic neuron causes hyperpolarization (no action potential) in the post synaptic membrane

Question 2

What the chemical cause for the synapse to be excitatory?

Answer 2

When the neuro transmitters sit on the receptors that correspond to Na+ channels. This causes hypo polarization and the synapse is excitatory

Question 3

What is the chemical cause for the synapse to be inhibitory?

Answer 3

When the neurotransmitters sit on the receptors that correspond to K+ or Cl- channels, there is hyperpolarization and the synapse is inhibitory

Question 4

What are the types of channels?

Answer 4

1- Voltage dependent channels:
When the channels open under the effect of stimulation, they are called voltage dependent
channel such as sodium channels that open under the effect of stimulation causing
depolarization.

2. Chemical dependent channels:
   When the channels open by chemical substances, they are called chemical dependent
   channels such as sodium channels of the postsynaptic membrane that open by
   neurotransmitters

Question 5

Explain the integrating role of a neuron?

Answer 5

Motor neuron has an integrating role where it receives many sensory
messages whether excitatory or inhibitory, it adds them up and gives a
corresponding response.

Question 6

Temporal Summation

Answer 6

When the motor neuron receives many messages after applying
successive stimulation on the same presynaptic fiber. Then there is
temporal summation.

Question 7

Spatial Summation

Answer 7

When the motor neuron receives many messages after applying at the
same time , stimulation on many sensory fibers. Then, there is spatial
summation

Question 8

1- After applying series of successive/repeated stimulations at the pre synaptic neuron, the Motor neuron receives the successive PSPs ( excitatory and inhibitory post synaptic potentials) and summed up to produce depolarization or hyperpolarization

2- After applying simultaneous stimulations on many presynaptic neurons , the motor neuron receives many EPSPs and/or IPSPs at the same time to sum them up to produce hyperpolarization or depolarization or resting potential

Derive an indication for both and a general deduction

Answer 8

1- Motor neuron performs temporal summation of the successive EPSPs and IPSPs received from the presynaptic neuron in a short delay

2- Motor neuron performs spatial summation of the EPSPs & IPSPs received from the different presynaptic neuron

Deduction: Motor neuron has an integrative property