Final Flashcards
List two general (non-localizing) symptoms of brain tumors
headache nausea vomiting mental dullness decreased arousal (somnolence) seizures
What are the most benign neoplasms discussed in class?
Meningiomas
True or False: There are several types of neurons
True.
Sensory neurons
Motor neurons
Interneurons
The ion channels that are involved in depolarization during the action potential open in response to a change in ______
voltage
What structure is primarily responsible for maintaining the resting potential?
Sodium-potassium pumps
The axon ______ “decides” whether an action potential is created, or whether the neuron will pass along information or not
hillock
Name one specific type of cell responsible for myelination
Oligodendrocytes
Schwann cells
How is the resting potential maintained?
Inside neuron - negatively charged
Extracellular fluid - positively charged
Result is resting potential of ~70mV inside cell
Surplus of potassium ions inside cell
Deficit of sodium ions inside cell
Sodium ions pumped out to counter effect of diffusion across concentration gradient
Potassium ions pumped in to counter effect of diffusion across concentration gradient
Sodium-potassium pumps actively transport sodium out and potassium in at 3:2 rate
This active transport maintains the resting potential
Which ion is responsible for repolarization during the action potential?
Potassium (K+)
Dendrites transmit the signal _____ the cell body
toward
Axons typically have _____ terminal button(s) / end bulb(s)
more than one
True or False: The purpose of myelin is to increase the speed at which the electrical impulse travels
True
Potassium (K) channels are faster to open and close than sodium (Na) channels
False
List three symptoms of multiple sclerosis, one involving sensory function, one involving motor function, and one other symptom
Sensory function - Loss of vision
Motor function - Uncoordinated movement, weakness, leg dragging, stiffness.
Other symptom - Squeezing sensation around the torso
What complicates chemotherapy for brain tumors?
The action of the blood-brain barrier does not allow for chemicals in the blood stream to enter most parts of the brain
The element of the cytoskeleton that mediates axonal transport are called ______
microtubules
List two differences between axons and dendrites in a typical neuron
Dendrites exhibit arborization while axons are consistent in diameter and consist of a single tube
Dendrites pass information toward the soma while axons pass impulses away from the soma
What happens if the membrane at the “beginning” of the axon, near the soma, does NOT reach threshold?
The resting potential is maintained
True or False: During repolarization the neuron cannot fire an action potential.
True
The depolarization (rising) phase of the action potential is primarily caused by which of the following?
a. sodium flowing in
b. sodium flowing out
c. potassium flowing in
d. potassium flowing out
a. Sodium (Na) flowing in
The unmyelinated regions of myelinated axons are called nodes of ________
ranvier
What part of the neuron is involved in multiple sclerosis (MS)?
Axons
Which of the following would be the best way to make a pathway in your brain faster?
Reduce the number of synapses
True or False: The most common neurotransmitter in the human nervous system is an amino acid
True
Glutamate