Structure and Function of the Nervous System

Question 1

How does a Neuron generate Signals?

Answer 1

1. Energy is needed
2. Energy is elctrical potential across the membrane
3. Difference in voltages depends on the concentrations of potassium, sodium, and chloride ions as well as on charged protein molecules both inside and outside of the cell

Question 2

What is the resting potential of a neuron?

Answer 2

The resting state is defined by the differences in elctrical potential in the cell compared to outisde of the cell. It is typically -70 millivolts

Question 3

Why is the neural membrane important?

Answer 3

It separates intracellular and extracellular ions and electrical charge. It is made up of particular proteins that allow neural communication by allowing ions to move across. Ion channels and Ion pumps

Question 4

What is permeability?

Answer 4

• Permeability is the extent to which ions can move across ion channels. Ion channels are more susceptable for some ions than others (Na+ , K-).
• Neurons are excitable. That means that they can change their permeability

Question 5

What is an action potential?

Answer 5

Action potential is the rapid depolarisation and repolarisation of a small region of the membrane caused by openings and closings of the ion channels.

Question 6

How is the intensity of a stimulus represented in the Neuron?

Answer 6

The intensity of a sensory input can be expressed by measuring the firing rate of the action potentials

Question 7

Describe how neurons communicate with each other

Answer 7

• Using Action Potential
• At the axon terminal, it causes depolarisation of the presynaptic membrane
• Triggers Neurotransmitter release
• Neurotransmitters transport the signal to the next neuron across the synaptic cleft (gap between neurons at the synapse)

Question 8

Two different ways neurons communicate with each other

Answer 8

• through neurotransmitters
• through electrical signal

Question 9

What are neural circuits?

Answer 9

Groups of interconnected neurons that process specific kinds of information.

Question 10

What do neural circuits do?

Answer 10

• They take in information
• Evaluate this information
• Convey results to other neurons

Interestingly, some neural circuits show plasticity. The patterns of activation within a neural circuit can change. This is what happens with learning and during development.

Question 11

What are different types of neural circuits?

Answer 11

• Diverging Circuit ( One input - Multiple Output, Motorcontrol)
• Converging Circuit (Multiple Inputs - One Output, Sensory information)
• Reverberating Circuit (Feedback loops, rythmic activities like walking or breathing)
• Parallel After-Discharge Circuit (Complex Brain Acitivities)

Question 12

What are different types of neural processing?

Answer 12

• Serial Processing ( reflex)
• Parallel processing ( synthesizing information , high level complex brain activities)

Question 13

What is the nervous system composed of?

Answer 13

• The CNS ( Brain and Spinal Cord)
• PNS (Nerves and Ganglia)

The CNS is the commander. The PNS is the executive function of the CNS.

The PNS delivers sensory input information to the CNS and carries motor control information from the CNS to the muscles.

Question 14

What is the automatic nervous system composed of?

Answer 14

sympathetic branch and parasympathetic branch

using different neurotransmitters

Question 15

What accounts for increased abilities?

Answer 15

• Its not the amount of neurons but their connectivity
• dendritic tips of the front lobe neurons do have more branches
• NOT every neuron can be connected to every other neuron (Size problems)