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BIO 201 Exam 4 LATEST 2025 100% COMPLETE FULL
LENGTH TEST WITH ACCURATE ANSWERS
In multiple sclerosis, the cells that are the target of an autoimmune attack are the _________.
- neurons
- muscle cells
- Schwann cells
- oligodendrocytes oligodendrocytes Which mechanism allows the rabies virus to gain access to the central nervous system (CNS)?
- Rabies virus moves through the blood vessels to the CNS.
- The rabies virus uses retrograde movement along the neuronal axon. - The rabies virus uses anterograde along the neuronal axon.
- The rabies virus enters the Schwann cells of the peripheral nervous system and uses salutatory movement to move toward the CNS. the rabies virus uses retrograde movement along the neuronal axon
People with multiple sclerosis (MS) experience many challenging symptoms. Which statement best explains one cause of these difficulties?
- Damage to ependymal cells results in stagnation of cerebrospinal fluid, damaging neurons.
- A loss of astrocytes causes leaked neurotransmitters and K+ to accumulate, impairing generation of action potentials.
- Loss of oligodendrocytes in the central nervous system results in absence of the myelin sheath of neuronal axons, impairing rapid saltatory conduction.
- An increase in the number of oligodendrocytes in the central nervous system results in an overgrowth of the myelin sheath of neuronal axons, resulting in abnormally large action potentials. Loss of oligodendrocytes in the central nervous system results in absence of the myelin sheath of neuronal axons, impairing rapid saltatory conduction People who have hydrocephaly often have an issue with which of these glial cell types?
- Oligodendrocytes
- Ependymal cells
- Astrocytes
- Microglia Ependymal cells
The term central nervous system refers to the ________.
- spinal nerves
- somatic nerves
- sensory (afferent) nerves
- brain and spinal cord brain and spinal cord A neuron that has as its primary function the job of connecting other neurons is called a(n) ________.
- efferent neuron
- glial cell
- afferent neuron
- interneuron interneuron Which of the following is NOT a function of the autonomic nervous system?
- innervation of glands
- innervation of skeletal muscle
- innervation of cardiac muscle
- innervation of smooth muscle of the digestive tract innervation of skeletal muscle Which of the following is NOT a characteristic of neurons?
- They are mitotic.
- They conduct impulses.
- They have an exceptionally high metabolic rate.
- They have extreme longevity. They are mitotic Which of the following describes the nervous system integrative function?
- senses changes in the environment
- analyzes sensory information, stores information, makes decisions - responds to stimuli by gland secretion or muscle contraction analyzes sensory information, stores information, makes decisions
Nerve impulses leading to the brain carry information about cool temperatures on the skin. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
- sensory (afferent) division
- somatic nervous system
- sympathetic division
- parasympathetic division sensory (afferent) division Nerve impulses are sent to slow the heart's rate of contraction. The nerve fibers sending these signals will most likely belong to which division of the nervous system?
- sensory (afferent) division
- somatic nervous system
- sympathetic division
- parasympathetic division parasympathetic division
As you start working out, you notice that your heart rate and breathing rate start to increase. Which division of your nervous system is generating this response? Be as specific as possible.
- the sympathetic division of the autonomic nervous system
- the parasympathetic division of the autonomic nervous system
- the afferent division of the nervous system
- the somatic nervous system the sympathetic division of the autonomic nervous system Which glial cells have the most diversity of function?
- Schwann cells
- oligodendrocytes
- ependymal cells
- astrocytes astrocytes Which of the following types of glial cells monitors the health of neurons, and can transform into a special type of macrophage to protect endangered neurons?
- astrocytes Schwann cells The concentration of ions in the chemical environment surrounding the neurons must be tightly regulated for neurons to function properly. Which of the following cells is most responsible for this?
- astrocytes
- satellite cells
- oligodendrocytes
- Schwann cells astrocytes Meningitis can be caused by infection of the central nervous system by bacteria. Which cells would be most responsible for removing the infection?
- satellite cells
- Schwann cells
- microglia
- oligodendrocytes microglia
Schwann cells are functionally similar to ________.
- ependymal cells
- microglia
- oligodendrocytes
- astrocytes oligodendrocytes Which of the following pairings does not fit?
- sensory neurons: afferent neurons
- motor neurons: efferent neurons
- multipolar neurons: peripheral nervous system sensory neurons - association neuron: interneurons multipolar neurons: peripheral nervous system sensory neurons Many neurons have many short, branching extensions called dendrites. What is the benefit of these structures for a neuron?
- the number of processes extending from the cell body neuron - whether the nerve fibers are myelinated or unmyelinated
- the direction in which the nerve impulse travels relative to the central nervous system
- whether the neurons are found within the CNS or the PNS the direction in which the nerve impulse travels relative to the central nervous system Like all cells, the neurons' internal organization dictates its function. Neurons have relatively many mitochondria, an extensive network of rough endoplasmic reticulum and many clusters of ribosomes. These cellular features indicate all of the following EXCEPT ________.
- neurons have stable, relatively unchanging internal environments - neurons must meet a high demand for ATP
- neurons have a relatively high consumption of oxygen
- neurons produce many proteins neurons have stable, relatively unchanging internal environments Which of the following is NOT a function of dendrites?
- produce short-distance signals called graded potentials
- generate nerve impulses and transmit them away from the cell body - convey incoming messages toward the cell body
- provide enormous surface area for receiving signals from other neurons generate nerve impulses and transmit them away from the cell body Bipolar neurons are commonly ________.
- motor neurons
- found in ganglia
- called neuroglial cells
- found in the retina of the eye found in the retina of the eye Collections of nerve cell bodies outside the central nervous system are called ________.
- nerves
- tracts
- ganglia
- nuclei ganglia
Which of the following statements is correct regarding the polarization of a neuronal membrane and the formation of a resting membrane potential?
- As sodium leaks into the cell, the inside of the cell becomes more negative.
- As Na+ leaks across the membrane, that establishes a negative charge inside the membrane.
- Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels.
- A resting potential can be generated without the energy as an input. Sodium/Potassium pumps maintain concentration gradients; sodium and potassium move down their concentration gradients through leakage channels Which of the following does NOT describe conditions that occur during an action potential?
- The Na+/K+ pump reestablishes resting concentration gradients.
- Na+ enters the cell through voltage-gated channels, causing a reversal of the resting membrane potential.
- Na+ is used to repolarize the membrane.
- After initial depolarization, K+ now has both an electrical and a chemical gradient drawing it out of the cell. Na+ is used to repolarize the membrane
The interior surface of a neuron's plasma membrane at resting membrane potential will have a ________.
- positive charge and contains less sodium than outside of the cell - negative charge and contains more sodium than outside of the cell - positive charge and contains more sodium than outside of the cell - negative charge and contains less sodium than outside of the cell negative charge and contains less sodium than outside of the cell Which of the following correctly describes a graded potential?
- It travels long distances.
- It has a depolarization, repolarization, and hyperpolarization phase. - It is initiated by voltage changes in the membrane.
- It can have amplitudes of various sizes. It can have amplitudes of various sizes Which of the following is NOT true of graded potentials?
- They are short-lived.
- They can form on receptor endings.
- They can be called postsynaptic potentials.
You discover that a new chemical compound interacts with K+ voltage- dependent channels. What would be the effect on a neuron if the chemical came into contact with the axonal membrane?
- The cell would be unable to generate a resting potential.
- The cell would die.
- The cell would be unable to depolarize.
- The neuron would be unable to repolarize. The neuron would be unable to repolarize Which of the following is NOT a difference between graded potentials and action potentials?
- The magnitude of action potentials decrease as the impulse travels further away from the start of the impulse while graded potentials do not decrease in magnitude.
- Greater stimulus intensity results in larger graded potentials, but not larger action potentials.
- Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels.
- Graded potentials occur along dendrites, whereas action potentials occur along axons. The magnitude of action potentials decrease as the impulse travels further away from the start of the impulse while graded potentials do not decrease in magnitude
Which of the following is a factor that determines the rate of impulse propagation, or conduction velocity, along an axon?
- whether the axon is located in the central nervous system or in the peripheral nervous system
- length of the axon
- degree of myelination of the axon
- the number of axon collaterals extending from a truncated axon degree of myelination of the axon Local anesthetics block voltage-gated Na+ channels, but they do not block mechanically gated ion channels. Sensory receptors for touch (and pressure) respond to physical deformation of the receptors, resulting in the opening of specific mechanically gated ion channels. Why does injection of a local anesthetic into a finger still cause a loss of the sensation of touch from the finger?
- The local anesthetic prevents Na+ from causing the initial depolarization of this sensory receptor.
- The local anesthetic prevents any type of repolarization of this sensory receptor.
- Touch stimulation of this sensory receptor requires that there be a simultaneous opening of voltage-gated Na+ channels and mechanically gated ion channels.
- Touch stimulation of this sensory receptor will open the mechanically gated ion channels, but action potentials are still not initiated because propagation of an action potential requires the openi
