describe the differences between unipolar, bipolar and multipolar neurons.
Unipolar-one process coming off the cell body(afferent nerves),bipolar-two processes (neurons in the retina),multipolar-many processes(efferent, motor neurons..
the system that transmits action potentials from the CNS to the skeletal muscles
compare the frequency of the action potentials of when you touch something hot vs something warm.
The frequency is greater when you touch something hot than when you touch something warm.
Name a toxin that can cross the blood brain barrier?
alcohol and street drugs (p204)
Compare the maximum potential difference of each action potential when you tough something hot vs something warm?
no difference, action potentials work on the all or nothing principle
What is Saltatory conduction?
(from the Latin saltare, to hop or leap) is the propagation of action potentials along myelinated axons from one node of Ranvier to the next.increased velocityo
What are spinal nerves?
PNS nerves that originate from the spinal chord (Cranial nerves are nerves that start in the brain)
What do schwann cells do?
They insulate the axons in the PNS, so the action potential can travel more efficiently
If a stimulus causes an all or nothing action potential, how can we feel the difference between something warm and something hot?
The frequency of the action potentials
What neurons can heal and under what conditions?
PNS, nerves with Schwann cells, provided the cell body is alive and the axon is relatively lined up. (p208)
Where is, and how large is your sciatic nerve?
The size of your little finger, and from your lower back, through your butt and down your leg. It is the largest nerve in your body
What is the difference between the sympathetic and parasympathetic nervous systems.
Sympathetic - fight or flight, parasympathetic - rest and repose (digestion, urination)
synapse diagram name b, l, e, i, d.
b-neurotransmitter(NT) in a synaptic vesicle.l-NT released from presynaptic neuron,e-synaptic cleft,i- NT bound to a receptor, d-post synaptic neuron
Why can’t oligodendrocytes heal neurons in the CNS?
Oligodendrocytes cover many neurons, many schwann cells cover one neuron, so the schwann cells can create a path for the axon to regrow.
What household event does the author relate the all or nothing action potential to?
A toilet flush
Give an examples of where these circuits might be found. Convergent, divergent, oscillating
convergent-many inputs to one motor neuron (your biceps) divergent-one sensor on the skin sends a signal to the brain and to the muscles. oscillating-breathing,
What do neurotransmitters do?
They pass an action potential across a synapse. Neuron to neuron or neuron to muscle (p211)
What is the difference between the afferent and efferent nervous system?
Afferent receives information from sensory receptors to the CNS, Efferent sends information from the CNS to the effector organs
Why can’t an action potential flow both ways down an axon?
Immediately after the action potential, that part of the axon is in its absolute refractory period (a time when no action potential can be stimulated)
Does the sodium potassium pump require energy? If so why?
Yes because it is pumping ions from areas of low concentration to areas of high concentration.
What neuroglia make cerebrospinal fluid?
Ependymal cells (non ciliated) ependymal cells line the passages in the brain where CSF flows (p203) ciliated move the fluid around
Where are the oligodendrocytes located?
they are neuroglia in the CNS that create the myelin sheath around the neurons in the CNS. One connects many neurons together
neuron diagram. label f, i, d, j, c, b ?
f - nucleolus, i - cell body, d - golgi body, j - axon hillock, c - collateral axon, b - node of ranvier
Why might a stimulus not result in an action potential.
the stimulus was sub threshold or it occurred during the absolute refractory period
What is the difference between depolarization and repolarization
depolarization- Na channels open in response to a stimulus. Na rushes into the cell. Repolarization -Na channels close and K rush out of the cell.
Why is it important that we have an intact blood brain barrier? What cells do this for us?
Many normal substances in the blood are toxic to neurons, astrocytes.
Are there more neurons or neuroglia (glial cells)?
Neuroglia 9:1 according to the book, 10:1 according to the video.
Does a neuron at rest have a potential difference between the inside and the outside of the cell?
Yes according to the book a typical potential difference is -85mV, according to the video an average potential difference is -70mV
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