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
Neurons in the cerebral cortex are generally grouped into several classes. Which of the following class of neurons is characterized by short axons and functions as interneurons, utilizing either glutamate (excitatory) or GABA (inhibitory) as their neurotransmitter?
Purkinje Cells
Granular Cells
Fusiform Cells
Pyramidal Cells
Granular Cells
Which of the following characteristics would be true of tonic receptors but not phasic receptors?
Slow adapting
Do not transmit a continuous signal
Stimulated only when stimulus strength changes
Transmit information regarding rate of change
Slow adapting
Which of the following characteristics refers to the specificity of nerve fibers for transmitting only one modality of sensation?
Differential sensitivity
Modality
Labeled line principle
Adaptability threshold
Labeled line principle
In addition to the stimuli that elicit fast pain, slow pain can also be elicited by which of the following kinds of stimuli?
Mechanical
Thermal
Pressure
Chemical
Chemical
Which of the following characterizes fast pain?
It begins about 1 second after the stimulus is applied
It is carried by alpha-delta fibers
It can be elicited by mechanical, thermal and chemical stimuli
Fibers carrying fast pain terminate in the substantia gelatinosa
It is carried by alpha-delta fibers
Thermain sensations are carried in pathways that parallel which of the following pathways?
Pain
2-point sensation
Vibration
Crude Touch
Pain
The cerebral cortex has been mapped and divided into specific areas known as Brodmann’s areas. The sensory cortex is associated with which of the following Brodmann’s Areas?
1,2,3
4
7A, 40
44
1,2,3 (“1,2,3..can’t hurt me”)
Lesions (damage) to which of the following pathways would affect the transmission of temperature stimuli?
Lateral spinothalamic pathways Anterior spinothalamic pathway Dorsal column pathways Fasciculus cuneatus pathway Fasciculus gracilis pathway
Lateral spinothalamic pathways
Although a small number of fibers in the slow-chronic paleospinothalamic pathways pass all the way to the thalamus, most fibers terminate in which of the following areas?
Somatosensory cortex
Basal nuclei
Reticular formation
Ventrobasal nuclei
Reticular formation
Which of the following is one of the major components of analgesia system?
Periaqueductal gray
Locus coeruleus
Nucleus ruber
Thalamus
Periaqueductal gray
Which of the following is NOT one of the major components of the analgesia system?
Periaqueductal gray
Raphe magnus nucleus
Nuclear Ruber
All of the above are components of the analgesia system
Nuclear Ruber
In typical sensory pathways, decussation occurs at what level?
Primary (first order) neurons
Secondary (second order neurons)
Teritaly (third order neurons
None of the above
Secondary (second order neurons)
In typical sensory pathways, tertiary (third order) neurons typically terminate in which of the following areas?
Somatosensory cortex
Reticular formation
Basal nuclei
Thalamus
Somatosensory cortex
Critical types of tactile signals, such as two-point discrimination, are transmitted through which of the following?
Dorsal column-medial lemniscal pathway
Spinoreticular pathway
Pyramidal pathway
Spinothalamic Pathway
Dorsal column-medial lemniscal pathway
In the slow-chronic paleospinothalamic pathways a small number of fibers pass all the way to the thalamus, but most fibers terminate where?
In the somatosensory cortex
In the basal nuclei
In the reticular formation
In the ventrobasal nuclei
In the reticular formation
Which of the following is NOT characteristic of the Brown-Sequard syndrome?
All motor functions are blocked on the side of the trassection below the level of transection
Sensations of pain, heat and cold are lost on the side of the transection below the level of transection
Two-point discrimination sensations are lost on the side of the transection below the level of transection
All the above are characteristics of the Brown-sequard syndrome
Sensations of pain, heat and cold are lost on the side of the transection below the level of transection
Which of the following pathways carries conscious perception rather than unconscious perception?
Medial lemniscal
Spinocerebellar
Spino-olivary
Spinotectal
Medial lemniscal
Which of the following areas is almost completely insensitive to visceral pain?
Ureter
Bile Duct
Liver Parenchyma
Parietal Pleura
Liver Parenchyma
The total refractive power of the human eye is about which of the following?
10 diopters
25 diopters
40 diopters
60 diopters
60 diopters
Which of the following is a measure of how much a lens bends light waves and is equal to 1 meter divided by the focal length of the lens?
Refractive index
Visual acuity
Refractive power
Depth of focus
Refractive power
What is the maximum visual acuity of the human eye for a two-point source of light?
1 nm
2 micrometer
10 millimeter
20 cm
2 micrometer
An eyeball that is too short will cause the light rays coming from distant objects to be focused behind the retina. This condition is referred to as which of the following? (Check the other terms)
Emmetropia Hyperopia Myopia Astigmatism Presbyropia
Presbyropia
An eyeball that is too long will cause the light rays coming from distant objects to be focused in front of the retina. This condition is referred to as which of the following?
Emmetropia Hyperopia Myopia Astigmatism Presbyropia
Myopia
Which of the following is a characteristic of myopia?
Ciliary muscles are contracted
All distant objects can be seen clearly
The lens system is too weak
The eyeball is too long
The eyeball is too long
The impingement of photos on a rod cell in the retina will cause rhodopsin to dissociate into which of the following?
Scotopsin and 11-cis retinal Scotopsin and 11-cis retinal Scotopsin metarhodopsin Scotopsin and all-trans retinal Iodopsin and 11-cis retinal
Scotopsin and all-trans retinal
Which of the following statements regarding ion flow through trod membranes in the dark is FALSE?
The outer rod segment is leaky to sodium ions
The inner rod segment continually pumps sodium ions to the outside
The inner rod segment is leaky to potassium ions
cGMP gated channels are open in the outer rod segment
The inside of the rod membrane has a potential of -70 mV
The inside of the rod membrane has a potential of -70 mV
In the rods, cGMP sodium gates are closed when phosphodiesterase is activated by which of the following?
Transducin Metarhodopsin Scotopsin 11-cis retinal All-trans retinal
Transducin
How much of the signal is allowed to pass to the visual cortex (gating control) is determined by which of the following?
Amacrine cells Ganglion cells Lateral geniculate nucleus Interplexiform cells Color blobs in the visual cortex
Lateral geniculate nucleus
Transmission pathways in the foveal region of the retina can be grouped into two different categories: 3-neuron and 4-neuron. Both types of pathways share the same types of neurons. The 4-neuron pathway differs from the 3-neuron pathway because it also utilized which of the following types of neurons?
Cones
Bipolar cells
Ganglion Cells
Amacrine cells
Amacrine cells
Which of the following is a characteristic of “X’ ganglion cells?
The have the smallest axon diameter of all the ganglion cells
They have broad fields in the peripheral retina
They make up approximately 5% of all the ganglion cells
They are probably responsible for all color vision
They are probably responsible for all color vision
Which of the following is NOT a characteristic of layers III-VI of the lateral geniculate nucleus?
They constitute the magnocellular region of the lateral geniculate nucleus
They are associated with accurate point-to-point transmission
Almost all their input is via X type ganglion cells
They transmit color
They constitute the magnocellular region of the lateral geniculate nucleus
Which of the following cell types respond to rapid changes in the visual image?
Bipolar cells Amacrine cells X type ganglion cells Y type ganglion cells Z type ganglion cells
Y type ganglion cells
Axons on which of the following cells make up the optic nerve?
Bipolar cells Amacrine cells Interplexiform cells Ganglion cells Rod and Cone cells
Ganglion cells
Sensory information entering the central nervous system typically decussates (crosses over) at some point in the spinal cord or brain. For visual information, the decussation occurs in the optic chiasma. How much decussation occurs in the optic chiasma?
25%
50%
75%
100%
50%
In children the refractive power of the lens can be voluntarily increased from 20 to 34 diopters (an accommodation of 14 diopters). In a person fo 70 years of age, accommodation is reduced to which of the following levels?
0
15
20
27
0
The primary visual cortex is made up of how many layers?
4
6
8
12
6
Which of the following principles states that the nervous system detects sound frequencies by determination positions along the basilar membrane that are most stimulated?
Attenuation reflex
Impedance matching
Principle of Corti
Place Principle
Place Principle
Which of the following descriptions best describes the hair fibers arranged along the basilar membrane form the oval window to the apex of the cochlea?
Length of fibers increases from the oval window to the apex and diameter of the fibers decreases from the oval window to the apex
Length of fibers decreases from the oval window to the apex and diameter of the fibers increases form the oval window to the apex
Both length and diameter of the fibers increases from the oval window to the apex
Both length and diameter of the fibers decreases from the oval window to the apex
Length of fibers increases from the oval window to the apex and diameter of the fibers decreases from the oval window to the apex
The endocochlear potential of +80 mV is largely due to which of the following factors?
High concentration of potassium in the endolymph
High concentration of sodium in the endolymph
High concentration of potassium in the perilymph
Low concentration of sodium in the perilymph
High concentration of potassium in the endolymph
The tensor tympani and stapedius muscles attach to the malleus and stapedius respectfully. Which of the following represents the function of these two muscles?
Attenuation reflex
Impedance matching
Creation of “traveling wave”
Creation of endocochlear potential
Attenuation reflex → dampen the movement of the malleus and stapedius so you can ignore your own voice when you’re talking
Which is the correct conduction pathway sequence in the middle ear?
Tympanic membrane → Malleus → Incus → Stapes → Oval window
Tympanic Membrane → Malleus → Incus → Stapes → Round window
Tympanic membrane → Malleus → Stapes → Incus → Round Window
Tympanic membrane → Incus→ Malleus → Stapes → Oval window
Tympanic membrane → Malleus → Incus → Stapes → Oval window
Reissner’s membrane seperate which of the following pairs of chambers?
Scala Tympani/Scala Media
Scala Vestibuli/Scala Media
Scala tympani/scala vestibuli
None of the above
Scala Vestibuli/Scala Media
Which of the following separates the scala media from the scala vestibuli, thereby maintaining a special fluid within the scala media?
Tectorial Membrane
Reissner’s Membrane
Stria vascularis
Organ of Corti
Reissner’s Membrane
Collaterals from the auditory tracts activate the entire nervous system in response to loud noises. Where would you expect these collateral to terminate?
Cerebral Cortex
Thalamus
Red Nucleus
Reticular Activating System
Reticular Activating System
Decussation of the auditory pathways occurs in all of the places listed below except?
Trapezoid body
Lateral lemniscal nuclei
Commissure connecting the inferior colliculi
Thalamus
Thalamus
Stereocilia (hairs) of the auditory hair cells are embedded in which of the following?
Reissner’s Membrane
Basilar Membrane
Tectorial Membrane
Reticular Lamina
Tectorial Membrane
Which of the following sequences represents the correct order of structure involved in the pathway for the transmission of auditory information?
Dorsal Ventral cochlear nuclei; Superior olivary nucleus; Medial Geniculate nucleus (thalamus); Auditory cortex
Lateral Lemniscus’ nucleus; Superior olivary nucleus; Dorsal and ventral cochlear nuclei; Auditory cortex
Medial geniculate nucleus; lateral leniscus’s nucleus; Superior olivary nucleus; Dorsal and ventral cochlear nuclei
Dorsal and ventral cochlear nuclei; superior olivary nucleus; auditory cortex; medial geniculate nucleus (thalamus)
Dorsal Ventral cochlear nuclei; Superior olivary nucleus; Medial Geniculate nucleus (thalamus); Auditory cortex
