Exam 2 Lecture - Duke's Self Evaluation Questions Flashcards
True or False: Dendrites of neurons receive signals from other neurons.
True
Neurons that have one axon and numerous dendrites are classified as:
(A) bipolar neurons
(B) multipolar neurons
(C) unipolar neurons
(B) multipolar neurons
True or False: Axon hillock is a site that generates action potentials
True
Neuroglia that is a part of the choroid plexus comprises: (A) astrocytes (B) ependymal cells (C) microglia (D) oligodendrocytes
(B) ependymal cells
Which statement about astrocytes are NOT correct?
(A) Astrocytes form the choroid plexus
(B) Astrocytes transport glucose from capillaries to neurons
(C) Astrocytes form perivascular end feet
(D) Astrocytes continue dividing after birth
(E) Astrocytes prevent intercellular accumulation of the neurotransmitter glutamate
(A) Astrocytes DO NOT form the choroid plexus, ependymal cells do
The myelin sheath:
(A) is made by oligodendrocytes in the PNS
(B) is made by schwann cells in the CNS
(C) slows the nerve impulse traveling along axons
(D) enables faster conduction velocity
(D) enables faster conduction velocity
A nerve fiber is made of: (A) an axon only (B) an axon and schwann cells (C) an axon and endoneurium (D) an axon and epineurium
(B) an axon and schwann cells
True or False: Leucine is transported by facilitated diffusion at the blood brain barrier
True
What structure represents the blood-brain barrier? (A) choroid plexus (B) microglia (C) endothelial cells (D) astrocytes (E) meninges
(C) endothelial cells
True or False: Nerve fibers classified as A alpha are larger in diameter and faster in conduction than those fibers classified as C fibers
True
Axons in the CNS are myelinated by: (A) astrocytes (B) schwann cells (C) ependymal cells (D)oligodendrocytes
(D) oligodendrocytes
Na/K ATPase is located on which membrane of endothelial cells?
(A) luminal
(B) abluminal
(B) abluminal
Glucose in the CNS is transported by: (A) simple diffusion (B) GLUT 1 (C) Facilitated diffusion (D) Na+ dependent symport carrier (E) Na/K- ATPase
(B) GLUT1
True or false: The choroid plexus produces the CSF.
True
True or False: The CSF in the third ventricle enters the fourth ventricles via cerebral aqueduct.
True
What represents the blood-CSF barrier? (A) meninges (B) capillary endothelium of the choroid plexus (C) perivascular end feet (D) choroid epithelium (E) astrocytes
(D) choroid epithelium
The blood brain barrier is absent in the: (A) spinal cord (B) cerebellum (C) choroid plexus (D) area postrema (E) two of the above
(E) two of the above: choroid plexus and area postrema
Which of the following best describes a neuron at the resting state?
(A) Na/K ATPase pumps are not active
(B) the resting membrane potential is about +65 mV
(C) K+ ions leak out of a neuron via nongated K channels
(D) voltage gated K channels are open
(E) the resting state represents the relative refractory period
(C) K+ ions leak out of a neuron via nongated K channels
A local anesthetic, such as lidocaine, prevents generation of action potential by inactvating:
(A) receptors for GABA
(B) Nongated Na channels
(C) Voltage-gated Ca channels
(D) Voltage-gated Na channels
(E) release of the neurotransmitter acetylcholine
(D) voltage-gated Na channels
The rising phase of an action potential is triggered by:
(A) inhibitory postsynaptic potentials
(B) Na/K ATPase pumps
(C) Opening of Voltage-gated K channels
(D) Inactivation of voltage-gated Na channels
(E) activation of voltage-gated Na channels
(E) activation of voltage-gated Na channels
Graded potentials occur at:
(A) presynaptic sites
(B) postsynaptic sites
(B) postsynaptic sites
True or False: Action potentials follow the all-or-none principle
True
Which of the following is a characteristic of a graded potential?
(A) adheres to the all or non principle of the stimulus applied at synaptic sites
(B) depolarizes or hyperpolarizes postsynaptic membrane
(C) opens voltage-gated Na channels
(D) propagates along axons
(B) depolarizes or hyperpolarizes postsynaptic membrane
True or False: The membrane of resting neurons is selectively permeable to K due to the presence of high numbers of nongated K channels.
True
True or False: An EPSP is a local hyperpolarization of the membrane.
False
True or False: An IPSP is a local depolarization of the membrae.
False
For inhibitory graded potentials (IPSPs) to occur during synaptic transmission, an inhibitory neurotransmitter must bind to the:
(A) ligand-gated receptors to trigger influx of Cl-
(B) ligand-gated receptors to trigger influx of Na
(C) voltage-gated Na channels to trigger influx of Na
(D) voltage-gated K channels to trigger influx of K
(A) ligand-gated receptors to trigger influx of Cl-
What is the result in the postsynaptic neuron when EPSPs increase but IPSPs stay the same?
(A) the likelihood of an action potential increases
(B) the likelihood of an action potential decreases
(C) the likelihood of an action potential stays the same
(D) EPSPs and IPSPs do not affect the post synaptic neuron
(A) the likelihood of an action potential increases
What triggers the depolarization phase of an action potential? (A) Na moves into the cell (B) Na moves out of the cell (C) Increased permeability of K ions (D)K moves into the cell
(A) Na moves into the cell
Hypokalemia incudes \_\_\_\_\_\_\_ of the neuronal membrane and makes neurons \_\_\_\_\_\_ \_\_\_\_\_\_. (A) hyperpolarization, more excitable (B) hyperpolarizaton, less excitable (C) depolarizatoin, more excitable (D) depolarization, less excitable
(B) hyperpolarization, less excitable
During the absolute refractory period, which gate on the voltage gated Na channel is closed? (A) activation (B) inactivation (C) both activation and inactivation (D) neither activation nor inactivation
(B) inactivation
Which neurotransmitter generates EPSPs that depolarize the post synaptic membrane during synaptic transmission? (A) glycine (B) acetylcholine (C) GABA (D) all of the above
(B) acetylcholine
The conduction of an action potential from on note of Ranvier to the next node is referred to as:
(A) EPSP
(B) Saltatory conduction
(C) Ionic conduction
(B) saltatory conduction
Depolarization during an action potential is caused by opening of which gate on the voltage gated Na channels?
(A) activation
(B) inactivation
(C) both activation and inactivation
(C) both activation and inactivation
When two action potentials arrive from two separate presynaptic neurons to the same postsynaptic neurons simultaneously, summation of postsynaptic graded potentials is called:
(A) spatial summation
(B) temporal summation
(A) spatial summation
What neurotransmitter is released at the neuromuscular synapse?
(A) norepinephrine
(B) acetylcholine
(C) glutamate
(A) norepinephrine
True or False: Acetylcholinesterase (AChE) present at the postsynaptic membrane breaks up ACh in the synaptic cleft to choline and acetate.
True
True or False: Choline is actively transported back into the presynaptic terminal for synthesis of new ACh.
True
True or False: The ion most directly responsible for neurotransmitter release is calcium.
True
Which neurotransmitter generates a graded potential that depolarizes the postsynaptic membrane during synaptic transmission? (A) glycine (B) acetylcholine (C) GABA (D) all of the above
(B) acetylcholine
Which of the following is an excitatory neurotransmitter?
(A) glycine
(B) acetylcholine
(C) GABA
(B) acetylcholine
Which of the following is an ionotropic receptor?
(A) acetylcholine
(B) norepinephrine
(C) epinephrine
(A) acetylcholine
Which statement is true about the neuromuscular synapse?
(A) Presynaptic membrane has voltage-gated Na channels
(B) Axons of the motor end plate have their cell bodies in the dorsal horn
(C) sarcolemma forms junctional folds
(D) presynaptic membrane has ligand-gated ion channels
(C) sarcolemma forms junctional folds
True or False: Enzymatic action is one of the means to clear a neurotransmitter at a synapse.
True
True or False: Adrenergic beta receptors are coupled to G protein which directly stimulates adenylyl cyclase
True
One of the binding sites of norepinephrine is: (A) muscarinic receptor subtype M1 (B) muscarinic receptor subtype M2 (C) Nicotinic receptor (D) Beta 1 adrenergic receptor
(D) beta 1 adrenergic receptor
Post ganglionic parasympathetic neurons have \_\_\_\_ receptors that bind to neurotransmitter \_\_\_\_. (A) nicotinic, norepinephrine (B) adrenergic beta, norepinephrine (C) muscarinic, acetylcholine (D) adrenergic alpha, acetylcholine
(C) muscarinic, acetylcholine
Which of the following is affected in a dog with tic paralysis?
(A) sensory neurons in the dorsal horn
(B) postsynaptic acetylcholine receptors
(C) release of acetylcholine at the neuromuscular synapse
(D) release of glycine from the presynaptic sites
(E) motor neurons in the ventral horn
(C) release of acetylcholine at the neuromyscular synapse
Which of the following is affected by myasthenia gravis?
(A) acetylcholinesterase in synaptic cleft
(B) acetylcholine receptors
(C) release of acetylcholine
(D) release of GABA
(B) acetylcholine receptors
Demyelination of axons is likely to result in:
(A) increased conduction velocity of axons
(B) no apparent change in conduction speed as voltage gated Na and K channels remain available in the demylenated area
(C) significant loss of conduction of action potential
(D) increased conduction velocity due to loss of resistance imposed by myelin sheath
(C) significant loss of conduction of action potential
True or False: Pacinian corpuscles have rapid adaptation, whereas Merkel’s corpuscles have slow adaptation.
True
Pain is detected by the: (A) free nerve endings (B) Pacinian corpuscles (C) muscle spindle (D) Merkel's corpuscles (E) none of the above
(A) free nerve endings
Which statement is correct about the system that mediates signals for pain sensation?
(A) ventral roots carry pain signals to the spinal cord
(B) perikarya of the primary sensory neurons is located in the dorsal root ganglion
(C) second-order neurons are located in the ventral horn
(D) the spinothalamic tract ascends in the dorsal horn to reach the thalamus
(B) perikarya of the primary sensory neurons is located in the dorsal root ganglion
Dorsal root ganglion cells are classified as: (A) multipolar neurons (B) unipolar neurons (C) bipolar neurons (D) neuroglia
(B) unipolar neurons
The dorsal root ganglion cells mediate:
(A) motor signals only
(B) sensory signals only
(C) both motor and sensory signals
(B) sensory signals only
Which statement is correct for muscle spindles?
(A) they are composed of extrafusal muscle fibers surrounded by a connective tissue capsule
(B) they are composed of extrafusal muscle fibers with no connective tissue capsule
(C) they are composed of intrafusal muscle fibers with no connective tissue capsule
(D) they are composed of intrafusal muscle fibers surrounded by a connective tissue capsule
(E) they are composed of smooth muscle fibers surrounded by a connective tissue capsule
(D) they are composed of intrafusal muscle fibers surrounded by a connective tissue capsule
True or False: Muscle spindles are innervated by both sensory and motor nerve fibers.
True
True or False: Receptor potential increases as a function of stimulus strength.
True
True or False: Frequency of action potentials represents stimulus strength, but the relationship is not linear.
True
True or False: Receptive fields of primary sensory neurons are circular and identical in size.
False
What structure directly projects sensory signals to the cerebral cortex?
(A) dorsal root ganglia
(B) thalamus
(C) primary sensory neurons in the dorsal horns
(D) second-order neurons in the dorsal horn
(B) thalamus
Muscle spindles are: (A) nonencapsulated receptors (B) present in the tendon (C) proprioceptors (D) synonymous with motor end plates (E) synonymous with golgi-tendon organ
(C) proprioceptors
True or False: conscious proprioception can be evaluated by the proprioceptive positioning test.
True
