the neuron

Question 1

what is an axon?

Answer 1

• the part of the neurone that carries electrical impulses (information) away from the cell body towards the axon terminals
• they develop axon collaterals, so one neurone can pass info onto several others

Question 2

what are axon terminals?

Answer 2

• the hair-like ends of the axon containing neurotransmitters
• they (AT’s) make synaptic contact with the next neurone in the chain
• here, electrical messages turn into chemical signals, which communicate with the next group of nerve cells, muscle cells or organs

Question 3

what the role of the cell body?

Answer 3

• contains the genetic information from the nucleus
• maintains the neuron’s structure
• contains mitochondria, so it provides energy to drive activities
• initiates an action potential

Question 4

what are the role of dentrites?

Answer 4

• finger–like extensions, containing DNA, that recieve information from other neurons
• this information turns into electrical signals and are then taken to the cell body, in order to trigger an action potential

Question 5

what is the role of the myelin sheath?

Answer 5

• the fatty substances that surrounds the axon to protect nerve fibres
• insulates and enhances conduction speed of nerve impulses along axons
• made from schwann cells
• helps speed up the rate of transmissions so that the electrical impulses can jump from one node (of ranvier) to the next
• prevents the loss of ions and helps maintain electrochemical gradient

Question 6

what are schwann cells?

Answer 6

• a type of gilal cell that surrounds neurons, keeping them alive, and produce myelin around the nerve fibres
• they can be myelinating (providing insulation and enhances the speed of nerve impulse transmission) or non-myelinating (wrapping around many axons without forming a myelin sheath)

Question 7

what is the node of ranvier?

Answer 7

• many gaps in the myelin sheath
• they allow the generation of fast electrical impulses along the axon

Question 10

what is the role of the nucleus in the neuron?

Answer 10

• controls and regulates the activities of the cell
• helps create instructions for making protein, which is essential for transmitting mesages between neuons

Question 11

what are terminal buttons?

Answer 11

• small structures at the end of neuron branches
• they release neurotransmitters into synapses, facilitating communication between neurons