Structure & Function of Neurons

Question 1

What are neurons?

Answer 1

• Receivers and transmitters of information to other cells
• Around 100 bn in the spinal cord

Question 2

What is the structure of a neuron?

Answer 2

• Cellular structures all the same but differ in size depending on their function
• Neurons typically consist of a cell body, dendrites and an axon
• Dendrites receive signals from other neurons or sensory receptors
• Cell body carries the impulse along to the axon where it terminates at the axon terminal
• Myelin sheath Coates nerves and allows impulses to be transmitted quicker

Question 3

What are sensory neurons?

Answer 3

• Tell the brain about the test of the environment by processing the 5 senses
• Carry nerve impulses from the receptors to the spinal cord and brain
• Sensory neurons convert information from these sensory receptors to neural impulses
• Converted back to senses when reached brain so van react quickly

Question 4

What are relay neurons?

Answer 4

• Carry messages from one part of the CNS to another
• Connect motor and sensory neurons, allowing them to communicate with each other

Question 5

What are motor neurons?

Answer 5

• Carry signals from the CNS which helps organs, glands and muscles
• When stimulated the motor neuron releases neurotransmitters that bind to receptors and trigger a response from the muscle

Question 6

What is synaptic transmission?

Answer 6

• Process of transmitting messages from neuron to neuron across a synapse

Question 7

What role do chemical transmissions and synapses play?

Answer 7

• Neurons communicate with each other within groups known as neural networks and each neuron is separated by a tiny gap called a synapse
• Signals WITHIN neurons are transmitted electrically
• Signals BETWEEN neurons are transmitted chemically across a synapse
• when electrical impulse reaches end of the presynaptic terminal (giver neuron) it releases neurotransmitters from sacs called synaptic vesicles

Question 8

What role do neurotransmitters play?

Answer 8

• Brain chemicals that are stored within the axon
• Diffuse across a synapse to the postsynaptic receptor site (taker neuron)
• Released by synaptic vesicles that share info from one neuron to the other

Question 9

What is excitation?

Answer 9

• Occurs when a neurotransmitter increases positive charge of the postsynaptic neuron (taker) which increases likelihood that the electrical impulse will be passed on

Question 10

What is inhibition?

Answer 10

• Occurs when a neurotransmitter increases negative charge of the postsynaptic neuron (taker) which decreases the likelihood that the electrical impulse will be passed on