Central Nervous System
The Central Nervous system contains which two parts?
The brain and spinal cord
The peripheral nervous system consists of what?
All of the nerves that branch off of your spine
What does a neuron (nerve cell) do?
Responds to stimuli and transmits signals.
These cells are most abundant and versatile glial cells. They anchor neurons to their blood supply and govern the exchange of materials between neurons and capillaries.
Astrocyte
Satellite cells
These neurons transmit impulses from sensory receptors and towards the central nervous system. These are mostly unipolar.
Sensory neurons
Somatic (voluntary) nervous system does what?
Rules skeletal muscle movement
What percent of daily caloric intake is consumed by your brain?
About 25%
This glial cell provides immune defense against invading micororganisms in brain and spinal cord.
Microglial cells
Wrap around axons and make an insulating myelin sheath.
Schwann cells
Transmit impulses away from the central nervous system and out to the body's muscles and glands. Mostly multipolar.
Motor neurons
Autonomic (involuntary) system does what?
Keeps organs functioning
This is the neuron's life support, the central part of the cell containing mitochondria, nucleus, DNA, ribosomes and cytoplasm.
Soma (cell body)
Ependymal cells
Live in the central nervous system and transmit impulses between sensory and motor neurons
Interneurons
Within the autonomic system is the sympathetic and parasympathetic divisions. What does each division do?
Sympathetic- Responds to threats
Parasympathetic- Relaxes the body
This branches off of the soma's cell body- bushy, branch like things projecting off which act as listeners, picking up messages from other cells and conveying them to the body.
Dendrites
These cells wrap around neurons, producing insulating barrier called myelin sheath.
Oligodendrocytes
Extension of a dendrites, can be long or short, can even run a full meter down your spine to your ankle. Transmit electrical impulses away from the cell body to other cells.
Axons