A&P I- Chapter 12
Which of the following are considered types of effectors? - bone tissue -skeletal muscle -cardiac muscle -glands
-skeletal muscle -cardiac muscle -glands
The time when there is complete insensitivity of the plasma membrane to another stimulus.
Absolute Refractory Period
What catalyzes hydrolysis of ACh to remove it from the synaptic cleft.
Acetylcholinesterase
Which glial cell is starlike in shape and helps form the blood-brain barrier?
Astrocytes
Which glial cell acts as a phagocyte?
Microglial cells
_______ neurons are most common
Multipolar
Many dendrites and a single axon
Multipolar Neuron
EPSPs are caused by the movement of
Na+ into the cell
What type of cells produce the myelin sheath in the central nervous system (CNS)?
Oligodendrocytes
Includes cranial nerves, spinal nerves, and ganglia
PNS
Classify the given items with the appropriate group. More Abundant in Cytosol:
Phosphate Negatively charged proteins Potassium
Myelin sheaths mainly consist of which part of the glial cells that form them?
Plasma membranes
A time when there is a decrease in the sensitivity of the plasma membrane to further stimulation.
Refractory Period
The time when a stronger-than-threshold stimulus is needed to initiate another action potential.
Relative Refractory Period
What is the basic function of a neuron?
To transmit nerve impulses
A substance synthesized at the cell body must undergo _____ transport to reach the synaptic knobs.
anterograde
The _________ is the functional division of the nervous system that controls involuntary movement of smooth muscle.
autonomic motor nervous system
A difference in the number of charged particles between two sides of membrane forms a(n)
electrical gradient
The electrochemical gradient is formed from a combination of the ______ gradient and the _____ gradient
electrical; chemical
The glial cells that help produce and circulate CSF in the CNS are
ependymal cells
A cluster of neuron cell bodies found along a peripheral nerve is known as a(n)
ganglion
A(n) _______ is a cluster of neuron cell bodies with the PNS
ganglion
At an electrical synapse, presynaptic and postsynaptic membranes interface through
gap junctions
Negatively charged proteins and other large organic molecules are found in
greater amounts inside a neuron
The functions of astrocytes are to
help form the blood-brain barrier, assist neuronal development, and regulate the composition of the interstitial fluid
Which neurons are located only within the CNS?
interneurons
Neuronal pools are composed of
interneurons.
The component of nervous tissue that conducts electrical impulses is (are)
neurons
Neurolemmocytes produce myelin in the _____ nervous system.
peripheral
A graded potential that occurs in a postsynaptic neuron is known as a
postsynaptic potential
The opposition to the movement of electrical charge is known as
resistance
The relative difference in charge across the plasma membrane of a resting neuron is known as the
resting membrane potential
What type of neural circuit results in a repeating, cyclical response?
reverberating
As a result of a neurotransmitter opening up chemically gated sodium channels on the postsynaptic membrane,
sodium ions enter the cell.
A change in membrane potential insufficient to cause an action potential is known as a
subthreshold value
The junction between an axon and another cell is called a
synapse
A typical synapse in the CNS consists of a presynaptic neuron and a postsynaptic neuron, separated by a narrow space called the
synaptic cleft.
When threshold is reached, depolarization occurs with the same amplitude of potential change. This is known as
the all-or-none principle.
One dendrite and one axon
Bipolar Neuron
What neurons are: Special senses
Bipolar Neurons
Consists of the brain and spinal cord
CNS
Which terms are used for the structural classification of nerves?
Spinal & Cranial
Which segments of a neuron contain large numbers of voltage gated potassium channels and voltage gated sodium channels?
The initial segment and the conductive segment
Before a vesicle of neurotransmitter can be released which of the following must occur?
Voltage-gated calcium channel open and action potential reaches synaptic knob
A positive charge in the membrane potential is called
depolarization
The _____ functional division of the nervous system transmits info from the viscera to the CNS
visceral sensory division
An action potential is generated when threshold is reached, at which time
voltage-gated Na+ channels open
Categorize the following neurotransmitter/neuromodulator as to its effect on the postsynaptic neuron. Some neurotransmitters may belong to more than one category: INHIBITORY
Dopamine, Acetylcholine, GABA, Glycine
Categorize the following neurotransmitter/neuromodulator as to its effect on the postsynaptic neuron. Some neurotransmitters may belong to more than one category: EXCITATORY
Dopamine, Norepinephrine, Acetylcholine, Glutamate, Substance P, Nitric Oxide
Which ions have leak channels on the plasma membrane?
K+ and Na+
What neurons are: Most common type; innervate muscles and glands
Multipolar Neurons
____ are large cells that ensheath many different axons.
Oligodendrocytes
The cell body of a neuron does all of the following except: A. Release neurotransmitter into the synaptic cleft B. Produce synaptic vesicles containing neurotransmitter that are subsequently transported to the synaptic knob C. Conduct graded potentials to the axon hillock D. Receive graded potentials from dendrites
Release neurotransmitter into the synaptic cleft
What are the functional classes of neurons?
Sensory, Motor, and Interneurons
Classify the given items with the appropriate group. More Abundant in ISF
Sodium Chloride
One process with two branches; one extending to the CNS, one extending to the periphery
Unipolar Neuron
What neurons are: Most neurons in the PNS
Unipolar Neurons
The _______ is a period when a membrane cannot respond to another stimulus (no matter how strong).
absolute refractory period
A recently depolarized area of a cell membrane cannot generate an action potential because of the
absolute refractory period.
A flow of electrical current called a(n) _________ is generated within the initial segment of a neuron
action potential
The plasma membrane of an axon is called the
axolemma
Neurons that have only two processes attached to the cell body are called
bipolar
The nervous system is composed of:
brain, spinal cord, nerves, and ganglia
Ependymal cells help produce
cerebrospinal fluid.
The main activity of the _________ is propagation of an action potential along the axolemma
conductive segment
Which of the following is part of the PNS? a. microglia b. spinal cord c. brain d. neurolemmocyte
d. neurolemmocyte
A message traveling from one presynaptic neuron to multiple postsynaptic neurons is an example of a ____ circuit.
diverging
An axon with a large diameter transmits an impulse ____ than an axon with a smaller diameter.
faster
The components of the somatic sensory division are:
hearing, taste, joints, and muscles
Voltage is a measure of relative ______ energy
potential
Which type of Neuronal pool utilizes feedback to repeatedly stimulate the circuit?
reverberating circuit
An excitatory postsynaptic potential (EPSP) causes
the postsynaptic neuron's membrane potential to become more positive.