Explain how insulin and glucagon regulate the balance (i.e, homeostasis) between
glycogen and glucose when epinephrine (i.e., adrenalin) is not involved.
... [Show More] -----CORRECT
ANSWER-------Glucagon and Insulin work in a negative feedback loop together to keep
your blood sugar in a normal range (in a healthy person). Insulin works when your
pancreas detects when you have high levels of glucose in your blood stream. Insulin
binds to the cells, and some use glucose as energy, and others, like your liver store it as
glycogen. Glucagon is the opposite of insulin. After you haven't eaten in a while, your
blood glucose levels lower and glucagon signals the cells that have the stored glycogen
(liver and muscle cells) to then turn it back into glucose for the other cells to use for
energy.
How do the glial cells (i.e., myelin sheath) speed up the firing of neurons? -----
CORRECT ANSWER-------The cell wraps extensions of a fatty insulating substance
(myelin) around the axons of neurons which increase the speed because the action
potential jumps from each node of ranvier rather than going down the entire length and
firing each Na+K+ pump.
Briefly explain why the action potential flows only from the axon hillock to the terminal
web. -----CORRECT ANSWER-------The action potential originates from the axon hillock
which initiates the flow of the action potential because of the presence of higher density
voltage-gated ion channels.
List the 4 types of glial cells and list a phrase to describe their function. -----CORRECT
ANSWER-------- Microglia: Are part of the cellular immune system to protect the brain
since the humoral immune system usually cannot cross the BB barrier.
- Astrocytes: Contribute to the blood brain barrier
- Schwann Cells: myelinates axons of the neurons in the PNS
- Oligodendrocytes: Myelinates axons of the neurons of the CNS
T/F Excitatory synapses cause hyperpolarization of post-synaptic cells. -----CORRECT
ANSWER-------False
The resting potential of neurons is: -----CORRECT ANSWER--------60 mv (The answer
is not on this list.) [Show Less]