ch.12 A&P
Which part of the nervous system controls smooth muscle, cardiac muscle, glands, and adipose tissue subconsciously?
The autonomic nervous system
The axon is connected to the soma at the synapse. synaptic knobs. collaterals. axon hillock. telodendria.
axon hillock.
Schwann cells are glial cells responsible for
producing the myelination around peripheral axons
The neurotransmitter glutamate opens channels that are permeable to sodium ions. What effect does glutamate produce on a postsynaptic neuron?
EPSPs
What type of neuroglial cell myelinates axons in the peripheral nervous system?
Schwann cells
Which functional class of neurons carries electrical signals that control the contractions of smooth muscle and cardiac muscle?
Visceral motor neurons
Poliomyelitis is caused by a virus that spreads easily in human populations. Most people with polio infections show no symptoms of disease. However, in a small percentage of victims, the virus enters the central nervous system and attacks the motor neurons of the spinal cord. Motor neurons are an example of what type or class of neuron?
a multipolar neuron that has two or more dendrites and a single axon
Both poliomyelitis and Guillain-Barré syndrome can involve paralysis where control over skeletal muscle function is lost. What is the neurotransmitter that a motor neuron uses to communicate with a skeletal muscle?
acetylcholine
Rachel decides to go swimming, but when she sticks her big toe into the water, she changes her mind because the water is too cold. The sensory neurons responsible for sending the message about the cold temperature of the water are
exteroceptors
Sensory (ascending) pathways distribute information
from peripheral receptors to processing centers in the brain
Collections of nerve cell bodies outside of the central nervous system are called: nuclei nerves ganglia tracts
ganglia
Voltage regulated channels can be found: at the motor end plate on the surface of the dendrites in the membrane that covers axons on the soma of neurons along the perikaryon of neurons
in the membrane that covers axons
Schwann cells in the PNS are functionally similar to _____ in the CNS. oligodendrocytes astrocytes ependymal cells microglia
oligodendrocytes
The period after an initial stimulus when a neuron is not sensitive to another stimulus is the: resting period repolarization period depolarization period refractory period
refractory period
Axons terminate in a series of fine extensions known as: telodendria synaptic knobs collaterals hillocks synapses
telodendria
A node along a myelinated axon represents an area where
there is an absence of myelin
Sensory neurons are responsible for carrying impulses
to the CNS
Compared to type A axons, type C axons are
unmyelinated slower propagating smaller diameter
The generation of an action potential in a neuron requires the presence what type of membrane channels?
voltage-gated channels
Which of the following is not a function of the neuroglia? secretion of cerebrospinal fluid maintenance of blood-brain barrier phagocytosis memory support
Memory
Which type of neuroglial cell functions in the central nervous system to engulf cellular debris, waste products, and pathogens?
Microglia
Which structural class of neurons consists of neurons with one axon and one dendrite?
Bipolar neurons
Rabies is a viral disease contracted from the bite of an infected animal. Rabies bypasses many immune system defenses by traveling in peripheral neurons to reach the CNS. Which method of transport is NOT used by the rabies virus to reach the CNS?
Anterograde flow
What part of the neuron is a long cytoplasmic process capable of propagating an action potential?
Axon
Which anatomical division of the nervous system consists of the brain and spinal cord?
Central nervous system
Which part of the nervous system performs the higher-order thinking required to complete a practice exam?
Central nervous system
What part of the neuron consists of the cytoplasm that surrounds the nucleus?
Perikaryon
Efferent pathways consist of axons that carry impulses
away from the CNS
Functions of astrocytes include all of the following, except forming a three-dimensional framework for the CNS. guiding neuron development. maintaining the blood-brain barrier. responding to neural tissue damage. conducting action potentials.
conducting action potentials
Myelin limits the movement of ions across the axon membrane, so the action potential "jumps" from node to node along the axon. This is an example of what type of propagation?
saltatory
Interneurons are responsible for
analyzing sensory inputs and coordinating motor outputs
EPSPs and IPSPs summate at the
axon hillock
An inhibitory postsynaptic potential (IPSP) is associated with: a change in sodium ion peremeability hyperpolarization opening of voltage-gated channels lowering the threshold for an action potential to occur
hyperpolarization
The sodium pump: pumps three sodium ions outside the cell and two potassium ions inside pumps two sodium ions outside the cell and three potassium ions inside pumps three sodium ions intside the cell and two potassium ions outside pumps two sodium ions intside the cell and three potassium ions outside
pumps three sodium ions outside the cell and two potassium ions inside
Glial cells that surround the neurons in ganglia are astrocytes. satellite cells. oligodendrocytes. ependymal cells. microglia.
satellite cells.
Saltatory conduction is made possible by: the myelin sheath large nerve fibers diphasic impulses rapid conduction of local potentials nissil bodies
the myelin sheath
What type of neuroglial cell participates in the production and circulation of cerebrospinal fluid?
Ependymal cells
The concentration of _______ is higher inside than outside the cell.
K+
The membrane is more permeable to
K+
The resting membrane potential is maintained by Na+-K+ pumps that actively transport _____ into and _____ out of the cell.
K+; Na+
Which of these ions is actively transported through the cell membrane to establish a resting potential? Cl Mg Ca K Na
Na
The concentration of ____ is higher outside than inside the cell.
Na+
Certain details about Mr. Roosevelt's case call into question whether he really suffered from polio. The pathological features that Mr. Roosevelt experienced were much more characteristic of Guillain-Barré syndrome, an autoimmune disease that involves the demyelination of peripheral nerves. Which neuroglia cells form the myelin sheath of motor nerves?
Schwann cells
Which functional division of the nervous system controls skeletal muscle contractions?
Somatic nervous system
A resting neuron is an unstimulated neuron that is not presently generating an action potential. The resting membrane potential is the separation of the relative positive and negative charges across the membrane of a cell at rest.
The separation of charges creates a voltage (electrical potential difference), which can be measured using a voltmeter. The resting membrane potential of a neuron averages -70mV (millivolts). All neural activities begin with a change in the resting membrane potential of a neuron.
The following are the main steps in the generation of an action potential. 1. Sodium channels are inactivated. 2. Voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization. 3. Sodium channels regain their normal properties. 4. A graded depolarization brings an area of an excitable membrane to threshold. 5. A temporary hyperpolarization occurs. 6. Sodium channel activation occurs. 7. Sodium ions enter the cell and depolarization occurs. The proper sequence of these events is
4, 6, 7, 1, 2, 3, 5
Tyson decides to travel overseas, but he does not get all the needed vaccines before he goes on the trip. While on his trip, he contracts diphtheria. Which type of glial cells are particularly at risk from this disease?
Schwann cells
The cranial and spinal nerves make up what part of the nervous system?
The peripheral nervous system
The main functional difference between the autonomic nervous system and the somatic nervous system is that the activities of the ANS
are primarily involuntary, or under "automatic" control
The neuroglia cells that help supply neurons with nutrients are the
astrocytes
The part of a neuron that conducts impulses away from its cell body is called a(an): axon dendrite neurolemma soma nissil body
axon
The part of the neuron that performs the metabolic work of the cell to keep the neuron alive and functioning properly is the
cell body or soma
The portion of a neuron that primarily receives communication is the
dendrite
Opening of sodium channels in the membrane of a neuron results in: depolarization repolarization hyperpolarization increased negative charge inside the membrane reestabllishing the resting potential
depolarization
Ciliated CNS neuroglia that play an active role in moving the cerebrospinal fluid are: ependymal cells Schwann cells oligodendrocytes astrocytes satellite cells
ependymal cells
The most abundant class of neuron in the central nervous system is bipolar. pseudopolar. multipolar. anaxonic. unipolar.
multipolar
Saltatory propagation occurs in _________ axons, in which action potentials _________.
myelinated; move from one node of Ranvier to another
Adrenergic synapses release the neurotransmitter: acetylcholine norepinephrine dopamine serotonin GABA
norepinephrine
Which of the following are a type of glial cell found in the peripheral nervous system? astrocytes microglia ependymal cells satellite cells oligodendrocytes
satellite cells