Action potential
Transmission of the depolarization wave along the neuron's membrane
depolarization
state in which the resting potential is reversed as sodium ions rush into the neuron
polarized
electrical condition of the plasma membrane of a resting neuron
potassium ions
the chief positive intracellular ion in a resting neuron
refractory period
period of repolarization of the neuron during which it cannot respond to a second stimulus
repolarization
period during which potassium ions diffuse out of the neuron
sodium ions
when the neuron's action potential is released, these positively charged ions are rushing into the axon through openings on the membrane
sodium potassium pump
process by which ATP is used to move sodium ions out of the cell and potassium ions back into the cell; completely restores the resting conditions of the neuron
meningeal layer
outermost covering of the brain, composed of tough fibrous connective tissue
pia mater
innermost covering of the brain; delicate and vascular
arachnoid villi
structures that return cerebrospinal fluid to the venous blood in the dural sinuses
arachnoid mater
middle meningeal layer; like a cobweb in structure
dura mater
its out layer forms the periosteum of the skull
axon
Generally conducts impulses away from the cell body
axonal terminal
releases neurotransmitters
dendrite
conducts electrical currents toward the cell body
myelin sheath
increases the speed of impulse transmission
cell body
location of the nucleus
Neurons
***demonstrate irritability and conductivity, and thus transmit electrical messages from one area of the body to another area
***are amitotic
Neuroglia
***support, insulate, and protect cells
***release neurotransmitters
***able to divide; therefore are responsible for most brain neoplasms
autonomic nervous system
**Subdivision of the PNS that regulates the activity of the heart and smooth muscle, and of glands; it is also called the involuntary nervous system
**A major subdivision of the nervous system that interprets incoming information and issues orders
central nervous system (CNS)
**Nervous system subdivision that is composed of the brain and spinal cord.
peripheral nervous system (PNS)
Nervous system subdivision that is composed of the cranial and spinal nerves and ganglia
Somatic nervous system
**subdivision of the PNS that controls voluntary activities such as the activation of the skeletal muscles
**A major subdivision of the nervous system that serves as communication lines, linking all parts of the body to the CNS
somatic reflex(es)
**patellar (knee-jerk)
**effectors are skeletal muscles
**flexor reflex
Autonomic reflex(es)
**pupillary light reflex
**effectors are smooth muscle and glands
**regulation of blood pressure
**salivary reflex