Biopsychology - Structure & Function of Neurons

Question 1

How many neurons are there in the nervous system and how many of them are in the brain?

Answer 1

There are roughly 100,000,000,000 neurons in the nervous system 80% of them are in the brain.

Question 2

How does the nervous system provide the primary form of communication?

Answer 2

The neurons transmit signals chemically and electrically.

Question 3

What are the three types of neurons and what do they do?

Answer 3

Sensory Neurons – carry messages from the peripheral nervous system to the central nervous system they have long dendrites and short axons.
Relay Neurons – connect sensory neurons and motor neurons have short dendrites and long axons.
Motor Neurons – connect the central nervous system to affecters and have short dendrites and long axons.

Question 4

What is the basic structure of a neuron?

Answer 4

A cell body contains the nucleus and genetic material.
Dendrites, branch like, which protrude from the cell body and carry impulses.
Axons carry impulses away from the cell body and are covered in a fatty layer of myelin sheath but with breaks called nodes of ranvier to protect it and speed up transmissions.
Terminal buttons at the end of the axon to communicate with the next neuron in the chain across the synapse.

Question 5

How do electrical transmissions cause the neuron to fire?

Answer 5

At rest the inside of the cell in a neuron is negatively charged compare to the outside. When the neuron is activated the inside becomes positively charged for a second which causes an action potential to occur sending an electrical impulse down the axon.