The Neuron Flashcards
The neuron (nerve cell) is a …
specialized cell that is directly involved in mental processes and behavior.
In humans, most of the brain’s neurons are …
present at birth.
Neurons die at a rate of about …
10,000 per day.
Because of their enormous initial quantity, …
less than 2% of the original supply of neurons is lost by the age of 70.
There is also evidence that neurons may …
regenerate through adulthood in some areas of the brain.
The creating of new neurons is referred to as …
neurogenesis.
In the human brain, neurogenesis has been observed in the …
hippocampus and caudate nucleus.
Neurons vary in …
shape, size, and function.
Although they vary in shape, size, and function, most neurons consists of three distinct components:
dendrites, cell body (soma), and axon.
The branch-like dendrites …
receive information from other cells and conduct it toward the cell body.
The soma …
integrates information received from the dendrites and passes it on to the axon.
The cell body contains several structures including the …
nucleus, mitochondria, ribosomes, and Golgi complex.
The mitochondria are sites where …
the cell performs its metabolic activities.
Ribosomes are sites at which …
the cell synthesizes new protein molecules.
Where are ribosomes located within the cell?
Some ribosomes float freely within the cell but others are embedded in the smooth endoplasmic reticulum.
The smooth endoplasmic reticulum consists of …
channels that transport proteins to other locations in the cell.
The Golgi complex is a …
system of membranes that prepare neurotransmitters and other substances for secretion.
Finally, the axon …
transmits information from the soma to other cells.
How many axons do most neurons have?
Most neurons have a singe axon that divides into numerous branches (collaterals).
Many axons are covered by a …
myelin sheath.
A myelin sheath is a …
fatty substance that acts as an insulator and speeds up the conduction of nerve impulses.
The myelin sheath is made up of …
glial cells.
Glial cells also serve several other important functions including (1) …
holding neurons together.
Glial cells also serve several other important functions including (2) …
providing neurons with nutrients.
Glial cells also serve several other important functions including (3) …
removing cellular debris.
Communication in the nervous system involves a combination of …
electrical and chemical processes.
What is conduction?
An electrical process in which messages within a neuron are transmitted from the dendrites to the end of the axon.
In its resting state, the inside of the cell is …
negatively charged relative to the outside of the cell.
When the dendrites of the cell receive sufficient stimulation from other cells, …
the electrical balance of the cell is altered.
