Module 13-14 Flashcards
Briefly explain why the action potential flows only from the axon hillock to the terminal web.
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.
Acetylcholine esterase breaks acetylcholine into muscarinic acid
False
The action potential is:
A result of the movement of ions.
Potassium ions are at high concentrations inside of cells including in neurons.
True
Receptors are made from membrane-bound polyribosomes.
True
How do the glial cells (i.e., myelin sheath) speed up the firing of neurons?
Provides insulation for the axons.
Voltage-gated ion channels open when a protein binds to the receptor.
False
Acetylcholine exocytosed from the presynaptic cell travels to the postsynaptic cell to start the action potential in the postsynaptic cell.
True
Excitatory synapses cause depolarization of the post-synaptic cell.
True
The post-synaptic cell can be:
In glands, muscle cells, neurons
Only pre-synaptic neurons are coated with myelin.
False
Fast neurons as described in lecture require cytoplasmic signal transduction to open an ion channel.
False
The terminal web:
is a site of exocytosis
The central nervous system (CNS) contains:
There is no correct answer
Draw a neuron, and label all the parts as described in lecture.
…
The resting potential of neurons is:
The answer is not on this list
-60mV
The cell body refers to the part of the neurons that begin at the dendrites and extend to the axon terminal.
False
In the motor end plate, the event that is the immediate trigger for exocytosis is:
Calcium Ions
The axon from a pre-synaptic cell contacts the axon of another neuron.
False
Fast neurons as described in lecture are fast because they are surrounded by a type of glial cell that results in a myelin coating.
False
The autonomic nervous system contains the sympathetic and the parasympathetic nervous system.
True
Excitatory synapses make the post-synaptic cell less likely to fire.
False
Excitatory synapses cause hyperpolarization of post-synaptic cells.
False
Draw an action potential in the axon of a neuron and indicate which ions flow into the neuron and out of the neuron as the action potential passes at the point where the electrodes are in the cell. Be sure to assign on the Y-axis the mV of each of these areas. This should be as described in my lectures.
…
The neural tissues are:
Spinal cord, sensory neurons, and brain
The axon hillock in the pre-synaptic neuron fires based on temporal and spatial summation of inputs.
True
When the presynaptic cell contacts a muscle cell, the synapse area is called a motor end plate.
True
The receptors in post-synaptic cells are the basis on which the synapse can be defined as inhibitory or excitatory.
False
List the 4 types of glial cells and list a phrase to describe their function.
- Microglia: cleans up cellular debris
- Astrocytes: support and repair neurons
- Schwann Cells: myelinates axons of the neurons in the PNS
- Satellite: form the brain-blood barrier within the CNS
The membrane potential (resting potential) is largely set by the Na-K- ATPase pump.
True
When the Sympathetic nervous system is triggered glycogen is broken down to glucose to provide more energy.
True
When epinephrine is released it triggers activation of which part of the Autonomic Nervous System?
Sympathetic Nervous System
Explain how insulin and glucagon regulate the balance (i.e, homeostasis) between glycogen and glucose when epinephrine (i.e., adrenalin) is not involved.
Insulin and glucagon work in a negative feedback loop to keep your blood glucose balanced. During digestion, carbohydrates from food you eat are converted into glucose which end up in your blood stream raising your blood glucose levels. This triggers a release of insulin, so your cells will take in glucose from your blood making your blood glucose levels go down. Some of the glucose is used for energy and some is stored as glycogen. When blood glucose is low, it triggers the production of glucagon which tells the body to take stored glycogen into glucose and release it into your bloodstream. This raises your blood glucose.
Your mom came back from her medical appointment and said that the M.D. told her she had low bone density. What medical problem could this cause and what hormones/endocrine glands in the body are involved?
Osteoporosis can be caused by low testosterone in the ovaries. Is also linked to hyperthyroidism and hypopituaritism.
What could the stress of taking an exam do to your glucose levels in various parts of the body?
Stress releases epinephrine into your system triggering the fight or flight response of the SNS. The resulting changes in blood pressure and heart and breathing rates draws glucose from the liver and muscles, stopping glycogen production.
Vitamin D is really a hormone.
True
The medulla of the adrenal gland produces epinephrine (i.e., adrenaline).
True
Insulin is a ligand.
True
The Parasympathetic Nervous System is triggered to act by exposure to epinephrine.
False (Sympathetic Nervous System)
Where do fats in the body play a role in balance between glucose and glycogen?
When blood glucose levels fall, the pancreas stops releasing insulin and cells switch to using glycogen and fats for energy.
Vitamin D causes the parathyroid to inhibit new PTH synthesis.
True
Vitamin D is synthesized from cholesterol
True
Insulin is produced by alpha cells.
False (produced by islet cells from the pancreas)
