Physiology II Exam 1 Flashcards
The nucleus ruber (“red nucleus”) in the mesencephalon would be best characterized by which of the following descriptions?
A collection of myelinated axons in the midbrain
A collection of myelinated dendrites in the midbrain
A collection of cell bodies and dendrites in the midbrain
A collection of unmyelinated axons in the midbrain
A collection of cell bodies and dendrites in the midbrain
Which of the following is not a necessary component of a synapse?
Presynaptic Membrane
Postsynaptic Membrane
Synaptic Cleft
Sarcoplasmic Reticulum
Sarcoplasmic Reticulum
The thalamus is derived from which of the following brain divisions?
Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon
Diencephalon
In which of the following forms of spina bifida are only meninges found in the sac?
Occulta
Meningocele
Meningomyelocele
Myeloschisis
Meningocele
The Superior colliculi for visual reflexes and the inferior colliculi for auditory and olfactory reflexes are located in the tectum (roof) of which of the following subdivisions of the brain?
Telencephalon Diencephalon Mesencephalon Metencephalon Myelencephalon
Mesencephalon
Cell bodies of alpha motor neurons are located in which of the following areas of the spinal cord?
Dorsal (posterior) horns Ventral (anterior) horns Dorsal Root Ganglia Substania Gelantinosa Paravertebral Ganglia
Ventral (anterior) horns
Which of the following is the neurotransmitter used by many areas of the cerebral cortex and is always excitatory?
Serotonin Glutamate Dopamine GABA Glycine
Glutamate
Which of the following landmarks demarcates the sensory cortex from the motor cortex?
Lateral Sulcus
Central Sulcus
Insula
Angular Gyrus
Central Sulcus
Which of the following characteristics of dendrites is responsible for decremental conduction?
Lack of myelination
Relatively short length
Leakage of potassium ions
Leakage of sodium ions
Leakage of potassium ions
Which of the brain’s cerebral lobes is responsible for interpreting olfactory and auditory sensations?
Occipital Lobe
Frontal Lobe
Parietal Lobe
Temporal Lobe
Temporal Lobe
Which neurotransmitter is responsible for signaling by the alpha motor neuron?
Acetylcholine
Dopamine
Glycine
Glutamate
Acetylcholine
Sensory group III afferent neurons send signals to which neurons that relay signals to both ipsilateral and contralateral muscles?
Renshaw Cells
Gamma Motor Neurons
Alpha Motor Neurons
Excitatory Interneurons
Excitatory Interneurons
Electrotonic Conduction is utilized predominantly by the:
Axon
Dendrite
Axon Hillock
Synapse
Dendrite
One of the functions of the thalamus is to:
Control large skeletal muscle movements
Initiate cognitive processes
Relay all sensory information, except smell, to the cerebral cortex
Connect the nervous system to the endocrine system
Relay all sensory information, except smell, to the cerebral cortex
Which interneurons is responsible for inhibition of antagonistic muscle groups?
Renshaw cells
Ia inhibitory interneurons
Ib inhibitory interneurons
Gamma Motor Neurons
Ia inhibitory interneurons
Ionotropic receptors are characterized by which of the following?
Activation results in opening of an ion channel
Binding of a neurotransmitter directly to an ion channel
Activation results in changes in gene expression in the postsynaptic neuron
Always involves binding to a G protein for activation
Activation results in opening of an ion channel
Synaptic delay refers to the time it takes to transmit a signal from a presynaptic neuron to a postsynaptic neuron. It depends on a number of factors. Which of the following would NOT be associated with synaptic delay?
Time it takes to release the neurotransmitter from the presynaptic neuron
Time it takes for the neurotransmitter to diffuse across the synaptic cleft
Time it takes to jump from one node of Ranvier to the next one
Time it takes for the receptor to increase membrane permeability
Time it takes to jump from one node of Ranvier to the next one
A memory system that has been discovered in the sea snail Aplysia includes a facilitator terminal synapsing with a sensory neuron. If a noxious stimulus excites the facilitator terminal at the same time that the sensory terminal is stimulated the release of a neurotransmitter by the facilitator terminal causes the memory pathway through the sensory terminal to become facilitated for a period of time. The neurotransmitter released by the facilitator terminal is which of the following?
Acetylcholine
Norepinephrine
Serotonin
Dopamine
Serotonin
Damage to which of the following cortical areas would impair transmission of information from the visual cortex to the area where comprehension of the printed word occurs?
Supplemental Visual Cortex Wernicke’s area Angular gyrus Broca’s area Limbic association area
Angular gyrus
The Corpus Callosum is the major commissure between the two cerebral hemispheres. Cutting the Corpus Callosum would result in which of the following deficits?
Loss of 2-point discrimination from the right side of the brain into Wernicke’s area
Loss of transfer of visual info from the right hemisphere into Wernicke’s area
Loss of transfer of visual info from the left hemisphere into Wernicke’s area
Loss of pain sensation from the right hemisphere into Wernicke’s area
Loss of transfer of visual info from the right hemisphere into Wernicke’s area
Which of the following represents the major relay center for most afferent (sensory) pathways to the cerebral cortex? When the connections between this relay center and the cortex are cut, the functions of the corresponding cortical areas become almost entirely lost.
Thalamus
Basal Nuclei
Nucleus Ruber
Reticular Formation
Thalamus
Most output neurons from the cerebral cortex originate from which of the following cortical layers?
I and II II and III III and IV IV and V V and VI
V and VI
Which of following association areas plays the greatest single role of any part of the cerebral cortex for intelligence?
Broca’s area
Postcentral gyrus
Precentral gyrus
Wernicke’s area
Wernicke’s area
In most individuals the left cerebral hemisphere is considered dominant. Which of the following areas in the left hemisphere does not display dominance in either hemisphere?
Wernicke’s area
Primary sensory cortex
Broca’s Area
Angular Gyrus
Primary sensory cortex
Spatial summation increasing signal strength is transmitted by using progressively greater numbers of fiber.
True
False
True
In the neuronal pool, which of the following terms refers to all the output fibers that are stimulated by an incoming fiber?
Facilitated zone
Inhibition zone
Discharge zone
Converging zone
Discharge Zone
The Pacinian corpuscle is a specialized pressure receptor built around the axon of a sensory neuron. Local potentials are created when layers around the sensory nerve ending are deformed as a result of the application of pressure to the skin. Where in the transmission pathway are these local potentials converted to an axon potential?
Axon hillock
Cell body of the neuron
First Node of Ranvier
Within the capsule surrounding the end of the neuron
First Node of Ranvier
Which of the following nerve actions would be least affected in an individual with Arnold Chiari defect?
Hearing
Movement of the tongue
Movement of eye upward
Facial expression
Movement of eye upward
Many drugs are known to increase the excitability of neurons reducing the threshold for excitation of the neuron, while others are known to decrease excitability. Which of the following is one of the best known agents for increasing excitability by inhibiting the action of some normally inhibitory transmitter substances?
Caffeine
Theophylline
Theobromine
Strychnine
Strychnine
Which of the following functions as the major area for language comprehension?
Broca’s area
Medial geniculate nucleus
Thalamus
Wernicke’s area
Wernicke’s area