Exam 1 Flashcards
During embryologic development, six hillocks of tissue form around both sides of the first branchial groove. What do these hillocks eventually become?
pinna of the external ear
accurately describe the anterolateral (spinothalamic) pathway
It is a sensory pathway for pain and temperature entering the dorsal roots as Lissauer’s tract and with axons ascending in the anterior-lateral white matter of the spinal cord
During embryological development of the central nervous system, which secondary vesicle of the neural tube becomes the pons, cerebellum and a portion of the fourth ventricle?
metencephalon
CN II
Optic
special sensory nerve for vision
CN V
trigeminal
sensory info from face and motor innervation for mastication/chewing and to the tensor tympani
CN VI
Abducens
motor control of the lateral rectus eye muscles
CN VII
facial
sensory information from the tongue through the corda tympani and motor control for facial expression and the stapedius
CN XI
accessory
motor control of sternocleidomastoid and trapezius muscle
CN XII
Hypoglossal
motor for instrinsic and extrinsic muscles of the tongue
CN I
Olfactory–special sensory nerve for smell
CN X
Vagus–parasympathetic motor function for heart, lungs etc. and sensory
CN III
Occulomotor–special sensory nerve for eye all eye and pupil muscles
CN VIII
special sensory for auditory and vestibular input
CN IV
Trochlear–motor control of superior oblique eye muscles
CN IX
Glossopharyngeal–motor for pharynx and palate and pharynx and taste
CN VIII enters or exits the brainstem at
The pontomedullary junction or cerebellopontine angle
Which extrinsic eye muscles are innervated by CN III?
CN III innervates the superior rectus, inferior rectus, medial rectus and inferior oblique
CN IV innervates the superior oblique
CN VI innervates the lateral rectus
What is meant by the term branchiomeric nerves?
Cranial nerves that innervate branchial arch musculature such as CN V, VII, IX, X and XI
Which branchial arches play a major role in development of ear structures?
Branchial arches 1 & 2
The cerebellum is connected to the main body of the pons by 3 pairs of fiber tracts known as the
cerebellar peduncles
The outer 2-4 mm of the cerebral cortex is made up of gray matter that has been divided into horizontal layers based on the cells and functions. Which item below best describes these layers?
Six layers with layer I (one) as the most superficial and layer VI (six) the deepest layer
The superior and inferior colliculi are located in which area of the brainstem?
Tectum of the midbrain
Briefly describe what structures form the circle of Willis, including some of the arteries that create the circle, and state the importance or function of the circle of Willis related to the blood supply of the CNS.
Which type of degeneration involves the distal portion of the axon that has been severed from the cell body and leaves Schwann tubes that may aid in regeneration?
Orthograde degeneration
Which of the following pathways projects primarily from the primary motor cortex, decussating in the pyramids of the medulla, traveling to the lateral white columns in the spinal cord to the ventral gray horn and then innervating muscles to provide the main control of voluntary skilled movements?
Corticospinal tract
Which of the following pathways projects from the medial and lateral vestibular nuclei to the spinal cord to act upon interneurons and motor neurons to control antigravity muscles for postural control?
Vestibulospinal tracts
What is contained in the dorsal root ganglia?
Cell bodies for the pseudounipolar (pseuduomonopolar) sensory axons of the spinal nerves
Which answer best describes the fasciculus gracilis (FG)?
The FG carries somatosensory information including touch and proprioception from the lower extremities to the medulla as part of the dorsal column-medial lemniscus pathway.
Intensity of a stimulus is represented by frequency modulation (rate of firing) for
Action potentials
Embryologically, the central nervous system (including the brain and spinal cord), sense organs such as the cochlear and vestibular hair cells, and the skin are derived from which of the germ layers?
Ectoderm
What is the generic term that describes defects of the spinal cord, during embryologic development when the caudal neuropore does not properly close?
Spina bifida
Which inner ear fluid is able to flow through a duct to reach the subarachnoid space and is thought to be a derivative of CSF?
Perilymph
With respect to neuroembryology, the term gastrulation refers to
Formation of the three primary germ layers
During embryologic development, which germ layer gives rise to the skeletal structures, circulation structures, meninges, and cartilage (including the ossicles and temporal bone)?
mesoderm
Embyologically, development of the inner ear begins with formation of…
The otic placodes which are thickenings of ectoderm
Embryologically, what structures are derived from the neural tube and its tissues?
Central nervous system structures including structures such as the cerebrum, brainstem, cerebellum, ventricles and spinal cord
Which classification of nerve fibers have the slowest conduction velocity and are unmyelinated?
Group IV
The binding of a neurotramsmitter to a receptor site and depolarization of the post-synaptic cell membrane due to changes in the membrane permeability is an example of
Activation of ligand-gated (chemical-gated) ion channels
The two vertebral arteries merge near the pontomedullary junction to form what artery?
The basilar artery
best describe Parkinson’s disease
Damage/abnormal function in the substantia nigra resulting in movement dysfunction, resting tremor and rigidity, and cognitive changes
What is the reticular formation?
Diffusely organized groups of cell bodies throughout core of the brainstem which help with integration of many types of information
Which motor pathway carries information from the reticular formation of the pons and medulla to all levels of the spinal cord to influence muscle tone in the lower extremities?
Reticulospinal tract
Where is Rexed’s lamina I (one) in the spinal cord located?
In the initial portion of the dorsal gray horns (the most dorsal layer)
What is Scarpa’s ganglia?
The cell bodies of the bipolar afferent vestibular CN VIII fibers located in the internal auditory canal
what is the DCML
Dorsal Column-Medial Lemniscus Pathway carrying ascending/afferent sensory information regarding touch and proprioception from the body to the cortex
Some vestibular information being carried by CN VIII and coming from the vestibular nuclei is carried to the cerebellum. Which statement best describes the route and location in the cerebellum where vestibular information is processed?f
Nerve fibers carrying vestibular information reach the cerebellum via the juxtarestiform body of the inferior cerebellar peduncle and the information is processed primarily in the flocculonodular lobe.
A reduction in blood flow can be caused by a local, attached clot in a blood vessel caused by an atherosclerotic plaque. What is this vascular abnormality called?
Thrombosis
Which artery supplies blood to the area of the superior temporal gyrus and lateral fissure, including the area of the primary auditory cortex?
Middle cerebral artery
Why are hereditary metabolic defects such as Tay-Sachs disease and Niemann-Pick Disease so devastating and difficulty to treat.
The diseases involve enzyme deficiencies at the cellular level and it is difficult to treat or repair defects in cells so the diseases tend to be progressive and life-threatening over time (shortening the lifespan).
During embryologic development, what does the tubotympanic recess eventually become?
The middle ear cavity and the Eustachian tube
Which reflex refers to the response when an infant is startled and then throws out his/her arms and legs and begins to cry?
moro
best describe the location of the primary auditory cortex (A1)
A1 is located on the transverse gyri of the superior temporal gyrus of the temporal lobe, inside the lateral fissure.
In the embryo, which flexure of the developing neural tube marks the location where the future brainstem meets the future spinal cord, and this bend straightens out over time during development?
Cervical flexure
List two functions or expected actions from infants that can be used as indicators of possible abnormalities if the infant is not performing these functions.
Feeding and growing (failure to thrive is not eating and growing).
Sucking, rooting, regulating temperature, swallowing, some muscle tone and movements (not too flaccid or too rigid), sleeping, peeing and pooping regularly
accurately describes the medial lemniscus
Axons of the second order neurons leaving the nucleus gracilis and nucleus cuneatus in the medulla, crossing midline and then ascending to the thalamus
The second order neurons leaving the nucleus gracilis and nucleus cuneatus are the ML and they will cross midline and ascend as the ML to the thalamus. The fibers will synapse on a cell bodies in the thalamus and the 3rd order neuron will leave the thalamus and go through the internal capsule and then project as the thalamocortical projections through the corona radiata to the S1 area for the leg in the post-central gyrus (actually dipping down in to the longitudinal fissure).
Once a nerve reaches its threshold to fire an action potential, what is the FIRST step is a change in membrane permeability along the axon to begin the propagation of the bioelectrical change that is the action potential?
The opening of voltage-gated ion channels allowing an influx (inward flow) of Na+ to rapidly depolarize the neuron at the axon hillock
What term best describes the brief time period after the peak of an action potential during which another action potential cannot be generated no matter how much the cell membrane is depolarized?
Absolute refractory period
best describe the resting membrane potential of a neuron
The inside of the cell is about -70 millivolts compared to the extracellular fluid due to a high concentration of sodium outside of the cell and a high concentration of potassium inside the cell
When action potentials reach the terminal bouton of a neuron, what occurs to allow for synaptic transmission of the signal to the next cell (the post-synaptic cell)?
Voltage change triggers opening of Ca++ channels at the bouton, inward flow of Ca++, and then the release of neurotransmitters into the synaptic cleft
According to the House-Brackmann Facial Paralysis Scale, which description is accurate?
a Grade I is normal function and Grade VI is total paralysis
A nonacoustic middle ear muscle reflex can be used to provide additional diagnostic information if the acoustic middle ear muscle reflex is absent. correctly list the muscles evaluated and the stimuli used to generate the nonacoustic middle ear muscle reflex
Tactile stimulation of the facial skin or a puff of air into the eye or sudden lifting of the upper eyelid can cause the stapedius and/or tensor tympani muscles to contract
If there is a patient with Bell’s Palsy, which test below might an audiologist use to help in diagnosis and assessment of recovery from the palsy?
acoustic reflex testing
There is no somatotopic mapping of body parts/areas in the pathways of the spinal cord because somatotopic mapping only begins in the primary motor and primary somotosensory cortices in the cerebrum.
False
Somatotopic mapping occurs throughout the nervous system and body: from dermatomes and myotomes through the organization of body area in the spinal cord related to sacral, lumbar, thoracic and cervical (SLTC) locations and the mapping is carried all the way to and from the cortex.
What is located directly beneath the arachnoid mater?
Subarachnoid space filled with cerebrospinal fluid
The blood-brain barrier includes
The tight junctions in the endothelial cells that line the capillaries of the central nervous system which prevent most macromolecules from entering or leaving the central nervous system
Following a skull fracture and the tearing of meningeal arteries, there may be bleeding between skull bones and the dura that can be fatal unless treated. This is known as a/an
epidural hematoma
Which branchial arches play a major role in development of ear/auditory structures?
Branchial arches 1 & 2
Briefly describe the production, flow and absorption of cerebrospinal fluid(CSF): begin with where CSF is produced, cover how it flows through the ventricular system and where/how it is absorbed.
Produced by choroid plexus in ventricles (1)
Flows from lateral through interventricular foramina to third (1)
From third to fourth through the cerebral aqueduct (1)
Out of fourth through Luschka and Magendie (1)
To subarachnoid space to be absorbed by arachnoid villi into the superior sagittal sinus and then exiting through the jugular veins (2)
What is the specific name of the condition caused when there is a build-up of CSF within the subarachnoid space due to a lack of absorption after the CSF has exited the ventricles and is flowing in the subarachnoid space?
communicating hydrocephalus
What type of cells form myelin on the axons in the central nervous system?
oligodendrocytes
The ability to sense the position of one’s limbs is known as
proprioception
Briefly describe 2 important functions of the integumentary system. (State the function and give a sentence or two about how these functions are accomplished).
Which glands of the skin release sodium chloride, urea, uric acid and other substances out through the skin and also help with heat regulation to cool the body?
Sweat glands
What is the largest bundle of axons that serves as the main interhemispheric connection between the right and left hemispheres?
corpus callosum
Which type of proprioceptors detect/measure muscle tension?
golgi tendon organs
What is the name of the structure which made from the pia extending through the cauda equina from the conus medullaris to the end of the dural sac around the spinal cord, and anchoring the spinal cord in the area of the the coccyx?
filum terminale
Separations in the layers of the dura form cavities which are part of the drainage system of the brain and are known as
venous sinuses
Which layer of the skin mainly contains adipose (fat) tissue?
hypodermis/subcutaneous
List one common excitatory neurotransmitter of the audiovestibular system.
glutamae
aspartate
Give a brief description of embryologic development for one of the following:
Outer ear
Middle ear
Inner ear
or
Central nervous system
best describe myelin formation and function
Myelin is a lipid tissue produced by specialized glial cells which wrap around neuronal axons in segments to insulate the neuron and increase transmission speed of neural signals
which of the tissue/wrapping covers many nerve fibers
perineurium
What is not a term used to refer to a collection/bundle of axons in the central nervous system?
ganglia
terms of axons: Funiculus
Peduncle
Lemniscus
fasciculus
structures related to the limbic system
hippocampus
amygdala
cingulate gyrus
