A&P 1- CHapter 12 learnsmart
the nervous tissue of a young adult may contain up to ______ glial cells
1 triliion
which of the choices is an acronym which is used to describe a postsynaptic graded potential in which the membrane becomes more negative on the inside
IPSP
before a vesicle of neurotransmitter can be released which of the following must occur
action potential reaches synaptic knob, voltage gated calcium channel open
the term ______ means "inflowing"
afferent
sensory ______ neuron carry information ______ the central nervous system
afferent, towards
the components of the somatic sensory division are
hearing, taste, pain
the nervous system collects information through
receptors
which of the following statements describes the flow sodium ions in the meylinated regions of an axon
sodium diffuses through the axoplasm
______/_______ pumps are needed to maintain the resting membrane potential
Na/K
a substance synthesize at the cell body must undergo ______ transport to reach the synaptic knobs
anterograde
the plasma membrane of an axon is called the
axolemma
the nervous system is composed of the ______, spinal cord, nerves, and ganglia
brain
the central nervous system is made of the ______ and spinal ______
brain, cord
the ependymal cells help produce
cerebrospinal fluid
unequal distribution of a substance across a membrane creates a ______ gradient
chemical
what is the basic function of a neuron?
conduct nerve impulses
______ nerves extend from the brain, which ______ nerves extend from the spinal cord
cranial, spinal
a positive change in the membrane potential is called ______
depolarization
which of the following processes are occurring during the synaptic delay
diffusion of neurotransmitter, binding of neurotransmitter to receptors, release of neurotransmitter
the net diffusion of a given ion is dependent upon is ______ ______
electrochemical gradient
the "E" in EPSP stands for ______, meaning that the potential makes the inside of the postsynaptic cell more ______
excitatory, positive
an increase in the response of a postsynaptic neuron to a neurotransmitter is known as
facilitation
true or false: ion channels use the energy of ATP to maintain concentration gradients across neuron membrances
false
when chemically or voltage gated channels open, there is a change in ion ______ across a membrane
flow
neurons are classified ______ depending on the direction the nerve impulse travels
functionally
a cluster of neuron cells bodies found along a peripheral nerve is known as a ______
ganglia
nervous tissue is made of neurons and ______ cells
glial
negatively charged proteins and other large organic molecules are found in
greater amounts inside a neuron
_______ occurs when the inside of a cell becomes more negative than the resting membrane potential
hyperpolarization
following the repolarization of an action potential the membrane undergo ______ before returning to the resting membrane potential
hyperpolarization
if you were moving across a neuron's membrane from the receptive segment toward the transmissive segment, where would you first encounter large number of voltage gated Na+ and K+ channels
initial segment
the electrical gradient in a resting neuron is such that the ______ of the cell is negative relative to the ______
inside, outside
nerves are usually ______ and neurons are usually ______
macroscopic, microscopic
the difference in charge formed from the electrical gradient is referred to as the
membrane potential
which glial cells acts as phagocyte
microglial cell
the autonomic division of the nervous system is part of the ______ nervous system
motor
which functional division of the nervous system consists of all axons that transmit a nerve impulse from the CNS to a muscle or gland
motor nervous system
the sequential opening of voltage gated sodium channels is followed by the sequential opening of voltage gated ______ channels
potassium
voltage is a measure of relative ______ energy
potential
what type of neuron transmits an impulse through its axon toward the synapse
presynaptic neuron
______ are specialized nervous system structures that detect stimuli
receptors
during ______ ______ an axon is either incapable of generating an action potential or requires a larger than normal stimulus
refractory period
which of the following are functions of astrocytes
replaces damaged neurons, helps form the blood brain barrier, regulates the composition of interstitial fluid
the opposition to the movement of electrical charge is known as ______
resistance
which of the following are considered types of effectors?
skeletal muscle, glands, cardiac muscle
which of the following are true of neurolemmocytes
they create the myelin sheath in the PNS, they are also called Schwann cells
sensory nerves carry information
to the central nervous system
true or false: graded potentials vary in size depending on stimulus
true
pseudounipolar is another name for a ______ neuron
unipolar
which of the following are structural classification of neurons?
unipolar, multipolar, bipolar
which division of the nervous system transmits nerve impulses from blood vessels and viscera to the central nervous system
visceral sensory division
which of the following is essential for the generation of an action potential
voltage gated channels
according to Ohms law, current is directly related to ______, and inversely directed to _____
voltage, resistance
the somatic nervous system (SNS) is another name for the _______ division of the nervous system
voluntary
the movement of charge particles can be harnessed to do
work
______ nerves always relay information to the CNS
Sensory
the endoneurium is made of
areolar connective tissue
a fascicle is a bundle of
axons
the main activity of ______ is nerve impulse conduction
axons
a synpase is a junction
between a neuron and another cell
satellite cells are found surrounding
cell bodies
a soma is another name for the
cell body
dendrites branch off of the
cell body
which structural division of the nervous system contains the brain
central nervous system
the epineurium is made of ______ connective tissue
dense irregular
tissue that responds to neural input by changing its activity is called
effector
tissues that receive nerve impulses from motor neurons are called
effectors
the motor nervous system is also referred to as the ______ division
efferent
what type of neuron is also called an association neuron
interneuron
the autonomic nervous system is also known as the
involuntary nervous system
the resting membrane potential is measure in
millivolts
which type of neurons is most common/
multipolar
synapses occur where axons contract
muscle cells, gland cells, other neurons
which cell type is considered "nerve glue"
neuroglial cells
the regulation of the response of neurons to neurotransmitters is known as
neuromodulation
nervous tissue is composed of glial cells and
neurons
______ are chemicals released from synaptic knobs and bind to receptors on postsynaptic membrances
neurotransmitters
______ are large cells that ensheath many different axons
oligodendrocytes
bipolar neurons have one axon and ______ dendrite
one
a graded potential caused by the opening of chemically gated channels on a postsynaptic membrane is known as
postsynaptic potential
flow of which ion is the most common cause of repolarzation
potassium
_____ are membrane molecules that use the energy of ATP to move ions against a concentration gradient
pumps
the peripheral nervous system is a ______ division of the nervous system
structural
a change in membrane potential insufficient to cause an action potential is known as a
subthreshold value
the process by which postsynaptic potentials are added together at the initial segment is known as
summation
a junction between an axon and another cell is called a
synapse
if several EPSPs occur at a synapse over a shot period of time, they undergo ______ at the initial segment
temporal summation
the myelin sheath covers
the axon
the all or none law refers to the fact that action potentials will only occur if the initial segment reaches ______
threshold