ASU BIO 181 EXAM 3

ASU BIO 181 EXAM 3 LATEST ACTUAL EXAM 160 QUESTIONS
AND CORERCT DETAILED ANSWERS
Excitatory synapses make the post-synaptic cell less likely to fire. - ANSWER: False

The neural tissues are: - ANSWER: Spinal cord, sensory neurons, and brain

How do the glial cells (i.e., myelin sheath) speed up the firing of neurons? - ANSWER:
The cell wraps extensions of a fatty insulating substance (myelin) around the axons
of neurons.

The action potential is: - ANSWER: A result of the movement of ions.

Receptors are made from membrane-bound polyribosomes. - ANSWER: True

List the 4 types of glial cells and list a phrase to describe their function. - ANSWER:
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

Acetylcholine exocytosed from the presynaptic cell travels to the postsynaptic cell to
start the action potential in the postsynaptic cell. - ANSWER: True

When the presynaptic cell contacts a muscle cell, the synapse area is called a motor
end plate. - ANSWER: True

Potassium ions are at high concentrations inside of cells including in neurons. -
ANSWER: True

The membrane potential (resting potential) is largely set by the Na-K- ATPase pump.
- ANSWER: True

Fast neurons as described in lecture are fast because they are surrounded by a type
of glial cell that results in a myelin coating. - ANSWER: False

Voltage-gated ion channels open when a protein binds to the receptor. - ANSWER:
False

The cell body refers to the part of the neurons that begin at the dendrites and
extend to the axon terminal. - ANSWER: False

Only pre-synaptic neurons are coated with myelin. - ANSWER: False

The post-synaptic cell can be: - ANSWER: In glands, muscle cells, neurons

, Fast neurons as described in lecture require cytoplasmic signal transduction to open
an ion channel. - ANSWER: False

Acetylcholine esterase breaks acetylcholine into muscarinic acid - ANSWER: False

Excitatory synapses cause hyperpolarization of post-synaptic cells. - ANSWER: False

Excitatory synapses cause depolarization of the post-synaptic cell. - ANSWER: True

The axon hillock in the pre-synaptic neuron fires based on temporal and spatial
summation of inputs. - ANSWER: True

The receptors in post-synaptic cells are the basis on which the synapse can be
defined as inhibitory or excitatory. - ANSWER: False

The resting potential of neurons is: - ANSWER: The answer is not on this list

Draw a neuron, and label all the parts as described in lecture. - ANSWER:

The central nervous system (CNS) contains: - ANSWER: There is no correct answer

The terminal web: - ANSWER: is a site of exocytosis

In the motor end plate, the event that is the immediate trigger for exocytosis is: -
ANSWER: Calcium ions

The autonomic nervous system contains the sympathetic and the parasympathetic
nervous system. - ANSWER: True

The axon from a pre-synaptic cell contacts the axon of another neuron. - ANSWER:
False

Briefly explain why the action potential flows only from the axon hillock to the
terminal web. - 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.

Explain how insulin and glucagon regulate the balance (i.e, homeostasis) between
glycogen and glucose when epinephrine (i.e., adrenalin) is not involved. - ANSWER: -
blood glucose rises
-> b-cells of pancreas release insulin
-> insulin stimulates cells to use glucose and convert glucose to glycogen and fat
- blood glucose falls
-> pancreas stops releasing insulin
-> cells use glycogen and fat for energy
- blood glucose falls too low
-> a-cells release glucagon