Anatomy: Neural Tissue
the approximate resting potential of a typical neuron is...
-70 mV
two parts of the cns
1. brain 2. spinal cord
two major subdivisions of the nervous system
1. central nervous system (cns) 2. peripheral nervous system (pns)
the speed of an impulse is based upon what two factors
1. diameter of an axon 2. degree of myelination
three functions of the nervous system
1. gathers sensory information 2. makes decisions on what should be done at each moment (integration) 3. effects a response by activating effects organs
three classifications of neurons based upon their functions
1. motor neurons 2. sensory neurons 3. interneurons
three classifications of neurons based upon their structure
1. soma 2. dendrites 3. axons
depolarization of a membrane will shift the membrane from -70 mV to...
30 mV
what is ACh broken down by?
AChE
the period during which the neuron cannot respond to a second stimulus...
absolute refractory period
the most common excitatory neurotransmitter is...
acetycholine
what is the sequential depolarization of the membrane along an axon that causes transmission of the nerve impulse?
action potential
the all-or-none law states that...
an action potential will happen completely or not at all
conducts impulses away from the soma
axon
impulses are carried towards the soma of a nerve cell by the...
axon
longer processes (up to 3-4 feet long)
axon
releases neurotransmitters
axon terminal
during rabies, what symptom causes the mammal to foam at the mouth?
build up of saliva
associative neurons (interneurons) are found in the...
central nervous system (cns)
conducts local currents towards the soma
dendrite
shorter branches that taper off the cell body
dendrite
the neurotransmitters cause ____________________ to occur in the post-synaptic membrane
depolarization
where are bipolar neurons found in the body?
eyes
during rabies, what symptom causes the mammal to act crazy?
hallucinations and muscle spasms
what is the function of myelin sheaths around the axons?
insulation
sodium-potassium pumps transport K...
into the cell
what neuroglial cell is responsible for the presence of white matter in the brain?
microglia
what neurons are attacked in the infection polio?
motor neurons
causes white matter of the brain
myelin sheath
location of the nucleus
myelin sheath
multiple sclerosis is an autoimmune disorder that destroys the...
myelin sheaths
what are chemicals that are released by the axon knob?
neurotransmitters
what are the spaces between the myelin sheaths?
nodes of ranvier
what cells produce myelin sheaths in the cns?
oligodendrocytes
sodium-potassium pumps transport Na....
out of a cell
what is the movement of the membrane potential back to the resting potential level?
repolarization
the latin phrase for the "leaping" of axon impulse over the myelin sheaths is known as...
saltatory conduction
what cells produce myelin sheaths in the pns?
schwann cells
what type of neuron carries impulses to the brain and spinal cord?
sensory neurons
summation is the adding of _________________ stimuli until a minimum level is reached thus causing depolarization
subthreshold
what is the junction or space between the axon of one neuron and the dendrite of the next neuron?
synapses
what is the space between the axon knob and the receptor membrane called?
synaptic cleft
rabies is a viral infection the is absorbed through the...
synaptic knob
what is the minimum level of a stimulus at which depolarization of an axon will occur?
threshold stimulus