A local anesthetic such as Novocaine decreases membrane permeability to Na+
ions. The use of this anesthetic will
Block sensory input into the CNS
The sensory (afferent) division of the peripheral nervous system
Conveys action potentials to the CNS
During depolarization of the plasma membrane,
sodium ions move rapidly into the cell
Neurotransmitters are released from the
presynaptic terminal
The peripheral nervous system includes the
cranial nerves
An action potential
occurs when the local potential reaches threshold level
Neurons that have a single axon and a single dendrite are
bipolar
Chemical synapses are characterized by
the release of neurotransmitter by the presynaptic terminal
There are _______ pairs of cranial nerves and ______ pairs of spinal nerves
12; 31
Depolarization of the nerve cell membrane occurs when there is a rapid influx
(inflow) of
sodium ions
The junction between two neurons is a
synapse
Which of the following substances must pass through the blood-brain barrier in
order for neurons to survive?
glucose
The brachial plexus supplies nerves that function to contract which of the
following?
muscles of the arm and forearm
Gap or interruptions in the myelin sheath are called
nodes of Ranvier
A local potential
increases of decreases in direct proportion to the stimulus strength
The plasma membrane of a neuron is more permeable to potassium ions because
there are more non-gated channels for K+ than Na+
Digestion of food is regulated by the
parasympathetic division of the ANS
The spinal cord
links the peripheral nervous system to the brain
Reflexes function in
A. removing the body from painful stimuli
B. keeping the body from falling
, C. maintaining blood pressure
D. maintaining blood CO2 levels
E. ALL OF THESE CHOICES ARE CORRECT
The blood-brain barrier
protects neurons from toxic substances in the blood
Dendrites
are the input part of the neuron
Motor (efferent) division of the peripheral nervous system
transmits impulses from the CNS to skeletal muscles
The nervous system
A. monitors internal and external stimuli
B. transmits information in the form of action potentials
C. interprets or assesses information
D. maintains homeostasis
E. ALL OF THESE CHOICES ARE CORRECT
The central nervous system
is the site for processing information
A stimulus either causes an action potential or it doesn't. This is called
an all-or-none response
Neurotransmitter is being released at a synapse. Which of the following occurs
last?
an action potential is produced in the postsynaptic membrane
Which of the following is responsible for problem-solving skills?
central nervous system
When repolarization of a neuron is complete, the
original polarity of the neuron is restored
The central nervous system includes the
spinal cord
Which of the following combinations indicates the correct distribution of spinal
nerve pairs?
8 Cervical; 12 Thoracic; 5 Lumbar; 5 Sacral; 1 coccygeal
Neurotransmitters
cause the production of action potentials in the postsynaptic membrane
A stimulus that results in a local potential that does not reach threshold is called
a
subthreshold stimulus
Which of the following situations occurs in electrically excitable cells?
depolarization causes voltage-gated sodium ion channels to open
Reflex arcs
are capable of receiving a stimulus and yielding a response
Which of the following is NOT a lobe of the cerebrum?
sphenoidal
The cerebrum has an outer surface of gray matter that is called the
cortex
If an animal has had its cerebrum removed, it cannot
see