Nervous System
Nerve Cells
Neuron  designed to _______to surrounding environment
Axons and Dendrites
Small branches called ___________ receive chemical or
electrical input from the body. Neurons have _________
dendrites
Large branches are called _____________________, which
carry information away from the cell in the form of a nerve
impulse. Neurons commonly have only ____________
____________ are simply bundles of axons. Axons are
surrounded by a “Band-Aid” of cells called ____________.
Multiple layers of these cells create __________________,
around the axon called a ______________________.
The myelin sheath, allows for the __________________ of
nerve impulses. Nerves that are mylenated appear ______.
Mylenated nerves are used to ______________ over long
distances.
Unmylenated nerves appear________ (like gray matter in
the brain) and are often used for _______________nerve
information
Nerve Communication
Neurons communicate to each other by sending _______
______________to one another. These chemicals are
called neurotransmitters.
_____________________ leave one neuron, travel through
a small intercellular space, to another neuron. That space is
called a ______________.
At the end of each neuron is a _____________that
monitors the internal condition of the body
Receptors transmit information down the dendrite, to the
__________. Information is processed and sent out of the
axon, ___________________________
The ____________ consists of millions of communicating
neurons, neurotransmitters, receptors, and synapses.
Division of the Nervous System
Central Nervous System _________________________
Peripheral Nervous System  All other _______________
Somatic Nervous System Nerves that are controlled
___________________
Autonomic Nervous System Nerves that are controlled
________________
Types of Neurons
Sensory Neuron  Neurons with ___________on the end.
Send signals to the __________.
Motor Neurons  Carry nerve impulses to from the brain
to your _______________
Interneurons Reside in the _________________.
Connect ___________ neurons to _________ neurons
Conduction of a Nerve Impulse
Nerve impulse in a human travels more than ____________
per second
Resting nerve cells tend to have lots of ______________
________________ in them, and therefore have a negative
charge to them (-65mv).
Resting nerve cells also have lots of ______________
inside the cell.
They also have lots of _____________ just outside the cell
Cell Membrane (Action) Potentials
______________________ describe how a nerve impulse
is generated and conducted throughout the body
The ________________________ by an electric current,
change in pH, or a pinch, causing an action potential
Upon stimulation, ______________ in the nerve cell
membrane open and sodium _________________. This
rush of positive ions causes the cell’s charge to rise and
spike (from -65mv to +40mv). This process is called
_____________________.
After the initial rush, the sodium _____________ (stopping
sodium movement) and potassium ______________.
Potassium then rushes ___________________. The loss of
these positive ions causes the cell to return to its resting
charge (-65mv). This is called _________________.
Eventually, the sodium which rushed into the cell and the
potassium which rushed out of the cell are pumped out of
the cell (Na) and into the cell (K). This is done by the
__________________________.
During this time the nerve is in its ___________________.
Brain
Parts of the Brain
Brain Stem
Brain Stem contains the ________________ and the ________.
Located at junction of ____________________________
Medulla Oblongata contains clusters of neurons that
control __________________________________. Also
contains neurons that control reflexes like swallowing,
_____________________________
Pons Means _________. Mostly aids in sending
messages from MO to spinal cord. Also has limited tactile,
visual, and auditory function
Diencephalon
Hypothalamus Maintains ________________; Regulates
hunger, thirst, body temperature, and _____________.
Hypothalamus also controls the ______________ (growth)
Thalamus: Post office of the brain. Receives incoming
messages from the spinal cord and _________________,
sends the information to the appropriate part of the brain
Cerebellum
2 portions separated by the brain stem
Cerebellum functions in _________________ coordination;
maintaining ________________________. Receives
information from the inner ear
Cerebrum
Surface area of the brain
Area of the brain devoted to ___________________.
4 surface areas: Frontal, Parietal, Temporal, and Occipital
Frontal Lobe: formation of conscious _________________
Parietal Lobe: Sensations: ________________________
Temporal Lobe: ____________________________
Occipital Lobe: __________________________
Other Interesting Parts of the Brain
Corpus callosum Part of the frontal lobe that splits into right
and left sides. Over excitation of CC can cause
________________________.
Limbic System Lies below the cerebrum in the frontal lobe.
Controls emotions such as ____________________________,
etc... Also controls sense of memory (long and short term)
Destruction of neurons in the limbic system leads to
___________________________
Most ______________________ affect neurons in the limbic
system