Neurons Flashcards
What are the three general regions of neurons?
Dendrites, a cell body and on the axon.
Describe the general idea of dendrites.
Dendrites are an area of a neuron that receives stimuli from the environment or from other neurons. Which contributes to intercellular communication.
Describe the general idea of a cell body
A cell body is an area of a neuron which contains the nucleus and other organelles. Which contributes to intercellular communication.
Describe the general idea of an axon.
An axon is an area on a neuron which carries information towards other cells. Which contributes to intercellular communication.
Describe a dendrite in detail.
Dendrites are highly branched, which each branch bearing fine processes from 0.5 to 1 μm long called dendritic spines. CNS neurons receive most of their information primarily at the dendritic spines.
Describe an axon in detail.
The axon has 5 regions called the axon hillock, the initial segment, the axolemma, the axoplasm and the telodendria.
Describe an axon hillock in detail.
An axon hillock is the origin of the axon from the cell body.
What is the initial segment?
The initial segment of the axon lies distally adjacent to the axon hillock. It is where an action potential is initiated.
What is the axolemma?
The axolemma is a specialized portion of the plasma membrane that surrounds the cytoplasm (axoplasm) of the axon.
What is the axoplasm?
The axoplasm contains neurofibrils, neurotubules, small vesicles, lysosomes, mitochondria, and various enzymes.
Describe a cell body in detail
A cell body consists of two parts- the perikaryon and the two parts of the structure of the perikaryon
What is perikaryon?
The cytoplasm surrounding the nucleus is called the perikaryon. The perikaryon contains organelles that provide energy and synthesize the chemical neurotransmitters that are important in cell-to-cell communication.
What is the structure of the perikaryon?
The perikaryon consists of neurofilaments. Neurofibrils are bundles of neurofilaments that extend into the dendrites and axon, providing internal support for these slender processes.
Describe a telodendria in detail
A telodendria is a bunch of fine extensions from the axon trunk. The telodendria of an axon, end at axon terminals, or synaptic terminals, where the neuron communicates with other cells.
What is axoplasmic transport?
Axoplasmic transport is when materials, including enzymes and lysosomes, travel the length of the axon along neurotubules, it occurs in both directions.
