Anatomy: Neural Tissue
The approximate resting potential of a typical neuron is ____ mv
-70
Depolarization of a membrane will shift the membrane potential from ______ mv to ____ mv
-70 +30
Name the 2 parts (organs) of the CNS
A) brain B) spinal cord
Name the 2 major subdivisions of the nervous system
A) central nervous system B) peripheral nervous system
The speed of an impulse is based upon what 2 factors
A) diameter of axon B) degree of myelination
What are the 3 functions of the nervous sytem
A) gathers sensory information B) makes decision of what shold be done at each moment C) effects responsible by activating effector organs
During rabies, what symptom causes the mammal to.... A) act "crazy" B) foam at the mouth
A) hallucinations B) saliva build-up
What are the 3 classifications of neurons based upon their structure
A) multipolar B) bipolar C) unipolar
What are the 3 classifications of neurons based upon their functions
A) sensory B) motor C) association
Ach is broken down by ______ (abbreviation)
AchE
Conducts impusles away from the soma
Axon
Longer Processes (up to 3-4 feet long)
Axon
Releases neurotransmitters
Axon terminal
Conducts local currents towards the soma
Dendrite
Shorter branches that taper off the cell body
Dendrite
The resting membrane potential consists of a cell cytoplasm that contains a higher concentration of ______ ions and a lower concentration of ____ ions than the surrounding extracellular fluid
K Na
Oligodendrocyte
Location: CNS Function: cover the fibers of the CNS neurons with myelin sheaths
Microglia
Location: CNS and PNS Function: phagocyte cell that protect neurons form invading microorganism
Astrocytes
Location: CNS and PNS Function: star-shaped cell that connect neurons to capillaries and help exchange nutrients between capillaries and neurons
Schwann Cells
Location: PNS Function: cover the fibers of the PNS neurons with myelin sheaths
Causes white matter of the brain
Myelin Sheath
Formed by the Schwann cells in the PNS
Myelin Sheath
Increases the speed of impulse transmission
Myelin Sheath
Gaps in the myelin sheath
Node of Ranvier
The spaces between the myelin sheaths are called
Nodes of Ranvier
What cells produce myelin sheaths in the CNS
Oligodendrocyte
What cells produce myelin sheaths in the PNS
Schwann
Location of the nucleus
Soma
Junction between nerve cells
Synapse
The most common excitatory neurotransmitter is _________
acetycholine
Impulses are carried towards the soma of a nerve cell by the
dendrites
the neurotransmitters cause ______ to occur in the post-synaptic membrane
depolarization
Motor (_________) neurons carry impulses _______ from the CNS and ________ muscles or glands.
efferent away towards
What is the function of myelin sheaths around the axons
increase the speed of impulse transmission
associative neurons are also called _______ and are found in the ____.
interneurons CNS
Rabies is a viral infection that is absorbed through the synaptic _______
knob
Polio is a viral infection that attacks _______ neurons
motor
Damaged during multiple sclerosis
myelin sheath
Multiple sclerosis is an autoimmune disorder that destroys the _______
myelin sheaths
Chemicals that are released by the axon knob and the receptor membrane called
neurotransmitters
What neuroglial cell is responsible for the presence of white matter in the brain
oligodendrocytes
Sodium-potassium pumps transport Na ____ of a cell and K ______ of a cell
out of into
The movement of the membrane potential back to the resting potential level is called
repolarization
Where are bipolar neurons found in the body
retina of the eye and the olfactory mycosa
The Latin phrase for the "leaping" of axon impulse over the myelin sheaths is known as __________
saltatory conduction
What type of neuron carries impulses to the brain and spinal cord
sensor
Summation is the adding of ______ stimuli until a minimum level is reached thus causing depolarization.
subthreshold
The junction or space between the axon of one neuron and the dendrite of the next neuron is called a _______
synapses
What is the space between the axon knob and the receptor membrane called
synaptic cleft
The minimum level of a stimulus at which depolarization of an axon will occur is called the ______ stimulus.
threshold