Structure of a neuron

Question 1

What is a cell body

Answer 1

contains the nucleus, cytoplasm and organelles of a neuron. these organelles carry out normal cell functions, such as growth and metabolism

Question 2

What are dendrites

Answer 2

cytoplasmic extensions of the cell body. the dendrites bring nerve impulses into a nerve cell (pick up stimuli/neurotransmitters)

Question 3

What is an axon

Answer 3

an extension of the cell body that carries a nerve impulse from the cell body toward the terminal branches. axons vary in length from millimeters to about one meter. axons are sometimes called nerve fibers. these fibers often occur in bundles called nerves

Question 4

What are schwann cells

Answer 4

surround the axon and produce layers of a white fatty substance called myelin which wraps around the axon, forming a myelin sheath. the myelin sheath insulates the neuron and helps to speed up impulses along the axon. neurons with this myelin sheath conduct impulses at a faster rate

Question 5

What are nodes of ranvier

Answer 5

gaps in the myelin sheath which expose the axon to the surrounding environment. helps speed up nerve impulses

Question 6

What are terminal branches/axon terminals

Answer 6

branches that form at the end of an axon. they almost touch the dendrites of the next neuron. the terminal branches contain synaptic knobs, which secrete special chemicals called neurotransmitters. these carry the nerve impulse across the gap between a nerve cell and a muscle is called the neuromuscular junction

-nerve impulse is not an electric current