Neuroscience 3 Flashcards
What are the layers of the eyeball from outside in?
Sclera, choroid, retina, vitreous body
What is the pathway for light waves as they enter the eye?
Cornea, Aqueous humor, Lens, Vitreous humor
The opthalmic artery enters the bony orbit via the optic canal and gives off the:
central artery of the retina
Occlusion of the opthalmic artery may result in:
ipsilateral blindness
Where is the nucleus of CN III?
Tegmentum of the midbrain
CN III innervates the motor fibers of the:
Superior rectus Medial rectus Inferior rectus Inferior oblique Levator palpebrae
CN III innervated the PS fibers of the:
Ciliary muscle
Sphincter pupillae muscle
What is “down and out” and what nerve is out?
External strabismus, CN III is out, and eye is down and out due to unopposed action of superior oblique (4) and lateral rectus (6). This also can cause diplopia
What is ptosis? What CN damage is associated with it?
Droopy eyelid, CN III or Horner’s syndrome
What is mydriasis and what CN damage is associated with it?
Dilated pupil, CN III, can also have blurred vision (impaired accommodation)
Damage to CN IV can result in:
Vertical diplopia, patient can’t look down ie when going down stairs
True or False: CN IV and CN VI only have motor input.
True
What is the onlyCN to emerge on the dorsal surface of the brain stem, with contralateral projection?
Trochlear, CN IV
What is internal strabismus and what CN damage is associated with it?
Eye deviates medially due to unopposed action of medial rectus muscle, damage to CN VI - abducens
Nucleus of CN VI is located in:
the pons
Ophthalmic nerve is also known as:
V-1 of trigeminal nerve, CN V
Name the branches of the ophthalmic nerve:
- Tentorial (meningeal branch)
- Lacrimal
- Frontal
- Nasociliary
What is papilledema and what are some conditions that cause it?
Swelling of optic disc, associated with tumor, bleeds, impaired CSF reabsorption, increased CSF production, ventricular obstruction
typically bilateral with visual acuity unaffected unless extreme case
A relaxed ciliary muscle causes the lens to become __1__ and is used for __2__.
- Lens is less convex
2. Far vision focus
A contracted ciliary muscle causes the lens to become __1__ and is used for __2__.
- Lens more convex
2. Near vision focus
Gray matter is composed of:
neuronal cell bodies
White matter is composed of:
axons
Where is the limbic lobe in the brain?
Directly above the corpus collosum (cingulate gyrus)
The precentral gyrus is also known as:
primary motor cortex
The postcentral gyrus is also known as:
the primary somatosensory cortex
Warnicke’s areas includes:
the supramarginal gyrus
the planum temporale
The primary visual cortex is on the banks of the:
calcarine sulcus (covers the lingual sulcus and the cuneus)
The middle cerebral artery supplies:
Primary motor Primary somatosensory (for the above **not leg and foot) Broca's Wernicke's Primary Auditory Frontal lobe Superolateral portion of temporal lobe
The anterior cerebral artery supplies:
Primary Motor and Primary somatosensory - leg and foot areas
Medial surface of cortex
The posterior cerebral artery supplies:
Inferior and medial portions of the cerebral cortex
Primary visual cortex
Temporal lobe areas responsible for memory
Thalamus and Midbrain
The lenticulostriate arteries supply:
The basal ganglia
Internal capsule
The blood supply of the pons come from:
The basilar artery
The base of the pons contains axons of the corticospinal tract and what CN’s?
CN VI and VII
What is the blood supply of the medulla?
PICA, AICA
The CSF flows into the 4th ventricle where it exits the __1__ into the sub-arachnoid space through three holes in the lining of the ventricles and the pia mater: __2__ and __3__.
- ventricular system
- foramen of magendie (medial)
- foramina of Luschka (lateral)
Eventually, CSF is reabsorbed into the venous system through:
the arachnoid villi
The subcortical gray matter of the thalamus includes:
- Pulvinar
- Anterior tubercle
- Lateral geniculate body (visual from eye to V1)
- Medial geniculate body (auditory info from Heschel’s)
The lenticular nucleus (putamen and globus pallidus) and the striatum (putamen and caudate nucleus) make up the gray matter of the:
basal ganglia
What are the symptoms of Parkinson’s Disease:
- shuffling gait
- limb rigidity
- masked expression
- difficulty initiating movements
- pill rolling tremor of hands
Where is the lesion implicated in Parkinson’s disease found?
Substantia nigra - basal ganglia
Uncontrollable hand writhing movements and mental status changes such as dementia siggest what diagnosis?
Huntington’s Disease (putamen and caudate nuclei)
Wild, flailing movements of the limbs are suggestive of what diagnosis of the basal ganglia?
Hemiballism (subthalamic nucleus)
The internal structures of white matter include:
- corpus callosum
- fornix
- anterior commissure
- posterior commissure
- optic tract
- optic chiasm
- optic nerve
- corona radiata
- Internal capsule
- Crus Cerebri
What is this? The funnel in which axonal tracts carry information from the thalamus to the cortex, and from the cortex to the striatum, brain stem (corticobulbar) and spinal cord (corticospinal).
Internal Capsule
Damage to what part of the internal capsule results in symptoms of sensory loss and paralysis?
Posterior Limb
What makes up the lenticulate nucleus?
Putamen, globus pallidus - part of basal ganglia
Lenticulostriate arteries and/or the anterior choroidal artery supply the:
posterior limb of the internal capsule
What is the cause of retinitis pigmentosa?
Degeneration of rods, then cones due to mutations in rhodopsin gene
What are the symptoms of macular degeneration?
Loss of central vision and acuity
What is the leading cause of vision loss?
Age-related macular degeneration
Blocked, blurred vision is a symptom of?
Diabetic retinopathy
What is the treatment for diabetic retinopathy?
Laser surgery etc.
The common retinal disorders are:
retinitic pigmentosa
macular degeneration
diabetic retinopathy
The visual system is very good at detecting spatial:
contrast
ON center cells increase their discharge rate to luminance _____ in the receptive field center
increments
____ center cells increase their discharge to luminance decrements in the receptive field center.
Off
Receptive fields of ganglion cells have a __1__. They come in 2 types: on-center and off-center ganglion cells.
- center and antagonistic surround
Where does an on-center ganglion cell cell have its excitation?
Center
Where does an an off-center ganglion cell have its excitation?
Periphery
Bipolar cells have what instead of APs?
Graded potentials
Graded depolarization of bipolar cells leads to increase ___1___ release at their synapses and ___2___ of ganglion cells they contact.
- glutamate
2. depolarization
On-center bipolar cell __1__ in light (and __2__ in dark)
- depolarizes
2. hyperpolarizes
Off-center bipolar cell __1__ in light (and __2__ in dark)
- hyperpolarizes
2. depolarizes
Center and surround receptive fields are constructed neurally where?
At the level of the retinal bipolar cells (receiving synaptic input from cones)
In hyperpolarization of off-center bipolar cells, what is hyperpolarizing and what NT release is lessening?
cones are hyperpolarizing (leads to BC hyperpolarizing), glutamate release goes down
Cone hyperpolarization in on-center bipolar cells results in:
BC depolarization (also glutamate DECREASE)
What determines the the on/off center properties of bipolar cells?
Glutamate receptors
On-center bipolar cells have what kind of glutamate receptors?
Metabotropic
Off-center bipolar cells have what kind of glutamate receptors?
Ionotropic (AMPA, kainate)
What cells connect bipolar cells to cone cells?
Horizontal cells
Horizontal cells have what kind of potentials?
Graded
Horizontal cells to what for bipolar cells?
Provide lateral inhibition/antagonism in that they tend to antagonize the bipolar cells’ response to light
Cones synapse on __1__ to form receptive field centers, and on horizontal cells to form receptive field __2__.
- bipolar cells
2. surrounds
What is the basis for trichromatic color vision?
short (blue), medium (green) and long (red) cone cells
What are cone opsins?
GPCR superfamily where the cis-11- retinal chromophore sits
No green detection comes from:
no expression of M opsin, deuteranopia
No red detection comes from:
no expression of L opsin, protanopia
What kinds of ganglion cells carry color information?
Parvocellular cells
What kind of cells are luminance encoding?
Magnocellualr cells
Blue on/yellow off cells are:
koniocellular cells