Neuro Final COPY Flashcards
To which layer(s) of the lateral geniculate nucleus does visual information from the contralateral and ipsilateral eye project?
Contralateral eye: Layers 1, 4, and 6.
Ipsilateral eye: Layers 2, 3, and 5.
L8b #43
A parietal lobe lesion will affect the ________ optic radiations, causing _________ quadrantanopia.
superior optic radiations
inferior quadrantanopia
L8b #52
A temporal lobe lesion will affect the ________ optic radiations, causing _______ quadrantanopia.
inferior optic radiations
superior quadrantanopia
L8b #52
- ) Which type(s) of tract(s) are found in the ventral/anterior brainstem?
- ) Consequence of injury?
1.) Descending motor tracts (ONLY found in ventral/anterior brainstem).
2.) Paralysis only – No sensory loss.
L5a #5
- ) What two general things are found within the tegmentum?
2. ) Where is tegmentum?
1.) (i) Ascending/sensory tracts and (ii) CN nuclei
2.) Deep to basal portion/basis —> In the midbrain, it lies between basis and tectum (only exists in the midbrain). Tectum is most dorsal part of the midbrain.
L5a #5
- ) What is the laterality of (a) motor and (b) sensory cranial nerve nuclei within the brainstem (i.e. lateral or medial)?
- ) What limits them (i.e. medial or lateral to what landmark)?
1.) (a) Motor = Medial (b) Sensory = Lateral
2.) Sulcus limitans
L5a #7
Decussation of the corticospinal tract (aka _______ ) occurs where in the brainstem?
aka Pyramidal decussation – Occurs in the ventral lower (caudal) medulla.
L5a #12
Where does the sensory decussation occur in the brainstem? What are the fibers known as after they decussate?
Within the internal arcuate fibers of the mid/caudal-medulla.
•known as the MEDIAL LEMNISCUS after decussation.
L5a #13
- ) Horner’s Syndrome is always _________ (laterality)?
2. ) Caused by damage to what/where?
1.) Ipsilateral
2.) Hypothalamospinal tract in the lateral medulla.
L5a #22
Give the blood supply for:
- ) Upper pons
- ) Lower pons
- ) Lateral medulla
- ) Medial medulla
1.) Superior cerebellar artery (L5b #38)
2.) AICA
3.) PICA
4.) Anterior spinal artery
L5b #24
Which three arteries supply the open medulla?
Anterior spinal, vertebral (medullary branches), PICA
L5b #24
- ) Occlusion of the Anterior spinal artery will cause damage to which three structures in the medulla?
- ) Clinical symptoms (3)?
- ) What is the clinical name for this problem?
1.) CN XII, pyramid, medial lemniscus
2.) Ipsilateral tongue paralysis (deviates to side of lesion), contralateral bodily paralysis (pyramid), contralateral loss of vibration, two-pt discrimination, and conscious proprioception (medial lemniscus).
3.) Medial medullary syndrome
L5a #25
- ) What is Wallenberg syndrome?
- ) Clinical symptoms (6)?
- ) How is this different from AICA syndrome?
1.) Lateral medullary/PICA syndrome
2.) (1) contralateral loss of pain and temperature sensation from the body (Spinothalamic tract/anterolateral system), (2) ipsilateral loss of pain and temperature sensation from the face (spinal trigeminal tract and nucleus), (3) some vertigo, vomiting, nausea, and nystagmus (vestibular nuclei), (4) loss of taste from the ipsilateral half of the tongue (solitary tract and nucleus), (5) hoarseness and dysphagia (nucleus ambiguus, i.e. roots of cranial nerves IX and X).
(6) Patients with the lateral medullary syndrome may also have the Horner syndrome owing to injury to hypothalamospinal fibers descending through the lateral areas of the medulla.
3.) Same, except AICA syndrome involves MOTOR CN VII NUCLEUS (L5a #43)
L5b #26, p.156 Haines, p.124 Atlas
Describe the location where the trigeminal nerve exits the brainstem
Externally at the junction between the middle cerebellar peduncle and basis of the pons
L5b #27
- ) Where do the fibers for the auditory pathway cross (structure and location)?
- ) What other structure associated with the auditory pathway is in this location?
1.) Trapezoid body in the DORSAL tegmentum of the lower pons.
-They form the lateral lemniscus
2.) Superior olivary nucleus (L5a #32)
L5b #30
If there is a tumor in the region of the facial colliculus, which extra-ocular muscle is affected (and via which CN)?
Lateral rectus (via Abducens nerve, CN VI) L5b #31
- ) Where is the only other place in the CNS that has pseudo-unipolar neurons just like the DRG?
- ) What reflex is mediated here?
1.) Mesencephalic nucleus (of CN V) in the midbrain.
2.) Jaw-jerk reflex
L5b #35
- ) Where does the trigeminal lemniscus lie?
- ) What does it carry and to where?
- ) Where are its 1st, 2nd, and 3rd order neurons?
1.) Lateral to the medial lemniscus in the UPPER PONS
2.) Carries pain and temperature from the CONTRALATERAL side of the face to the VPM nucleus of the thalamus.
3.)
1st: Peripheral ganglia associated with CNs V, VII, IX, and X.
2nd: Ipsilateral spinal trigeminal nucleus
3rd: Contralateral VPM nucleus of thalamus
L5b #37, p.164 BRS
- ) What is another name for abnormal flexion posturing?
2. ) Cause?
1.) Decorticate rigidity
flexOR = decORticate
2.) Injury superior to the level of the red nucleus (i.e. above the midbrain). Flexion of upper limbs is mediated by surviving rubrospinal tract (facilitates flexor muscle tone).
Lower limbs are extended
L5b #62-63
- ) What is another name for abnormal extension posturing?
2. ) Cause?
1.) Decerebrate rigidity
2.) Injury inferior to the level of the red nucleus in the midbrain (i.e. below the midbrain). Extension is due to unopposed action of the vestibulospinal tract.
Since rubrospinal tract is also cut, flexion of upper limbs is also lost
Mnemonic —> dEcErEbratE (lots of E’s) = ExtEnsion (more E’s than flExion).
L5b #62-63
Where does the anterior thalamic nuclei…
- ) Receive afferents from (2), and
- ) Send efferents to (1)?
- ) Grossly, forms the ________.
- ) Afferents
(i) Mammillary bodies (via mammillothalamic tract)
(ii) Hippocampus (via fornix) - ) Efferents
(i) Cingulate gyrus (via anterior limb of internal capsule)
3.) Anterior tubercle
L6a #18, p.184 BRS
What is the function of the anterior thalamic nuclei (2)?
Emotion and memory acquisition
L6a #18
List the three regions of dorsomedial thalamic nuclei, and give their relative cell size, along with their relative location (i.e. caudal, rostral, etc.). Give the two afferents for #3.
- ) Parvicellular (small cells) –located caudally
- ) Magnocellular (large cells) –located rostrally (see p.201 Haines)
- ) Paralaminar subdivision (afferents from substantia nigra and frontal lobe).
Mnemonic —> Mr. PC —> Magno–Rostral, Parvi–Caudal
L6a #19 (see images in OneNote –Visual System part 8B2)
The pulvinar region of ______ thalamic nuclei ( _____ tier) receives projections from _________, and projects to ________ regions concerned with ________ and __________.
-Lateral thalamic nuclei (dorsal tier)
-receives projections from superior colliculus (associated with eye movement/vision —> inferior colliculus is associated with audition)
-cortical regions concerned with visual functions and eye movements.
L6a #23
The ventral anterior thalamic nuclei are related to _______ systems, and give efferents to the _______.
LATERAL THALAMIC NUCLEI
-Related to motor systems (think SAME DAVE –Ventral = Efferent/Motor)
-Efferents to the frontal lobe
L6a #25
Name the two subdivisions of ventral posterior thalamic nuclei and give their afferents (2 and 1) and efferents (one for both).
- ) VPL –afferents from medial lemniscus and spinothalamics.
* Bodily sensation —>Contralateral…right?* - ) VPM –afferents from trigeminothalamic tract (spinothalamic and principal trigeminal nuclei).
* CONTRALATERAL facial sensation*
Efferents –BOTH project to somatosensory cortex.
L6a #27
Give the afferents and efferents for the medial geniculate body/nuclei
Afferents: Inferior colliculus (IC) via the brachium of IC.
Efferents: Temporal lobe (1˚ auditory cortex; Brodmann areas 41-42).
L6a #29
Give the afferents and efferents for the lateral geniculate body/nuclei
Afferents: Superior colliculus via brachium of the superior colliculus.
Efferents: Occipital lobe (1˚ visual cortex).
L6a #30
- ) What is the role of the reticular nucleus?
- ) How?
- ) Is there anywhere that it does not project to?
1.) Regulator of thalamic input
2.) GABA-ergic interneurons that serve as an intermediary between thalamocortical and corticothalamic projections.
3.) DOES NOT PROJECT TO CORTEX
L6a #37-38
- ) What causes HEMIBALLISMUS (give laterality as well).
2. ) What is hemiballismus?
1.) Damage to subthalamic nuclei —> CONTRALATERAL, e.g. left-sided damage = right-sided hemiballismus.
2.) Hemiballismus: The appearance of flailing, ballistic, undesired movements of the limbs. Caused in most cases by a decrease in activity of thesubthalamic nucleusof thebasal ganglia (wiki).
L6a #44
What is the blood supply for the subthalamic nuclei (2)?
Posterior cerebral and Posterior communicating arteries
L6a #44
What three things form the epithalamus?
1.) Pineal gland
2.) Habenular nuclei
3.) Stria medullaris thalami
L6a #48
- ) The pineal gland is involved in _______ production.
- ) Input?
- ) Secretions (2; other than #1).
1.) Melatonin
2.) Receives indirect photic input
3.) Secretes serotonin, norepi, and other peptides.
L6a #49
- ) What is the main blood supply of the thalamus (and branches – 2)
- ) What are the symptoms of damage?
1.) Posterior cerebral artery (PCA) –and its P1 and P2 branches.
2.) Damage via stroke or other CVAs = dysesthesias (abnormal sensations) –thalamic pain/thalamic syndrome.
L6a #51-52
- ) What is the 1˚ blood supply for the internal capsule of the thalamus? Two 2˚ supplies?
- ) CVA of 1˚ supply would cause….
1.) 1˚ = Anterior choroidal artery
2˚ = Lenticulostriate arteries, Recurrent artery of Huebner
2.) Visual and motor deficits (due to corticospinal and corticobulbar fibers within)
inteRnAL = Recurrent a. of huebner, Anterior choroidal, Lenticulostriate —> or LAR
L6a #57, plate 144 Netter, OneNote
What are the five parts of the internal capsule?
Mnemonic —> GRASP
Genu, Retrolenticular part, Anterior limb, Sublenticular part, Posterior limb
Somatotopically arranged
L6a #55-56 (good image on 56)
What are the three main/general functions of the hypothalamus?
1.) Visceromotor control
2.) Affective or Emotional behavior (limbic system)
3.) Homeostasis –H2O/electrolyte balance, food intake, temperature regulation, BP, conscious states, circadian rhythms.
L6b #3
List the four zones of the hypothalamus (mnemonic)
LMPP
1.) Lateral
2.) Medial
3.) Periventricular
4.) Pre-optic
L6b #11
- ) Which hypothalamic nucleus is known as the “sexually dimorphic nucleus”?
- ) What is the nature of this dimorphism?
- ) What do its neurons make?
1.) Medial pre-optic nucleus
2.) Can be larger in males than in females because males are always making testosterone (i.e. sex hormones), and females are not (female sex hormones are on a cycle).
3.) GnRH
L6b #14
What are the two nuclei of the pre-optic area of the hypothalamus and what is their function?
1.) Medial pre-optic nucleus (makes GnRH)
2.) Lateral pre-optic nucleus (locomotor regulation)
Lateral = Locomotor
L6b #14
What are the two nuclei of the lateral zone of the hypothalamus and what are their functions?
1.) Lateral Hypothalamic Nuclei (LHN): Feeding Center i.e. stimulation = feeding, damage = no feeding.
-Associated with the peptide OREXIN/hypocretin.
-LARGE neurons.
2.) Tuberal nuclei: Small cluster, SMALL multipolar neurons.
—> Think “Feeding TUBEral”
L6b #17
List the four nuclei of the Supraoptic region within the medial hypothalamic zone and give their functions.
Mnemonic – PASS
1.) Paraventricular: Vasopressin/ADH production
2.) Anterior: Body temperature regulation
3.) Supraoptic: Oxytocin synthesis
4.) Suprachiasmatic: Circadian pacemaker
L6b #20
What are the three regions within the medial zone of the hypothalamus?
1.) Supraoptic
2.) Tuberal
3.) Mammillary
L6b #19
What are the three nuclei (and their functions) of the tuberal region within the medial hypothalamic zone?
- DAVe*
1. ) Dorsomedial: Emotional behavior; damage = sham rage.
2.) Arcuate: Source of releasing hormone for anterior pituitary –Dopamine (inhibits pituitary secretion of prolactin), GnRH to pituitary, NPY and AgRP.
3.) Ventromedial: Satiety center; damage = overeating.
-Opposite of LHN (feeding center)-Opposite of LHN (feeding center)
L6b #21
What are the four nuclei of the mammillary region of the medial hypothalamic zone?
LIMP
1.) Lateral mammillary nuclei
2.) Intermediate mammillary nuclei
3.) Medial mammillary nuclei
-Afferents from hippocampus via fornix
-Efferents to anterior thalamic nucleus (limbic system)
4.) Posterior hypothalamic nuclei: Emotional, cardiovascular and analgesic functions.
Think – “This is the one that doesn’t seem to fit with the others”; thus, its functions seem out of place as well
L6b #24
- ) Mammillary nuclei are important in what function?
2. ) Damage results in what?
1.) Conversion of short-term memory into long-term memory.
2.) Damage causes retrograde amnesia, i.e. the inability to create new long-term memories.
L6b #26
- ) What is the function of the periventricular zone?
- ) Function analogous to what?
- ) Characteristic feature?
1.) Synthesize hormones for anterior pituitary —> Somatostatin (GHIH), TRH, and GnRH.
2.) Function is analogous to the arcuate nucleus of the tuberal region.
3.) Region of small cell-bodied neurons.
L6b #27
What contributes the most to the blood supply of the hypothalamus?
Mostly small branches of the posterior communicating arteries.
L6b #31
- ) What is the 1˚ blood supply for the pituitary and where is it from?
- ) What are the two smaller parts of the pituitary, and which pituitary lobe are they associated with?
1.) Hypophysial arteries (superior and inferior) from the internal carotid arteries.
2.) Pars tuberalis and pars intermedia; associated with the ANTERIOR lobe.
L6b #31
What is the embryologic origin of cortex? (3 stages, 3 things in the third stage)
Prosencephalon (forebrain) —> Telencephalon —> Pallium, Basal ganglia, and Basal forebrain.
L7 #5
What gives rise to cerebral cortex?
Pallium
For the four cerebral cortical lobes, list the following:
a. ) General function
b. ) On which surfaces of the brain it exists
c. ) Boundaries
- ) Frontal (#8)
(a) Mostly motor
(b) Lateral, medial, and inferior surfaces
(c) Posteriorly by central sulcus, posterolaterally by lateral sulcus. - ) Parietal (#9)
(a) Somatosensory, expressive, and integrative functions.
(b) Lateral and medial surfaces
(c) Between central sulcus and imaginary line joining the parieto-occipital notch and the pre-occipital notch. - ) Occipital (#10)
(a) Vision
(b) Lateral, medial, and inferior surfaces
(c) Behind imaginary line joining the parieto-occipital notch and the pre-occipital notch.
4.) Temporal (#11)
(a) Audition, sensory association, and memory.
(b) Lateral and inferior surfaces…NOT MEDIAL!
(c) In front of the line bordering the parietal and occipital lobes
L7 #8-11
What is the definition of decussating fibers?
Fibers that cross the midline, but don’t connect to a similar/comparable point on the other side (i.e. not homotopic).
L7 #25
- ) In which cortical layer do thalamic afferent fibers to the cortex mostly terminate?
- ) Projections from which location also terminate in the same place?
1.) Layer IV
2.) Basal ganglia
L7 #30
Give the four locations from which ascending afferents reach the cerebral cortex, and their termination layers (and NT for the two that apply).
1.) Thalamic radiations (to layer IV mostly, but also I and VI).
Thalamocortical projections
2.) Basal ganglia (to layer IV).
Claustrocortical projections
3.) Non-specific projections (from monoaminergic brainstem nuclei, i.e. arise from nuclei within the brainstem) —> Uses 5HT/serotonin (from raphe nuclei), and norepinephrine (from locus cereleus). Project to ALL layers
4.) Basal forebrain: Uses ACh as NT, projects to ALL LAYERS.
Implicated in Alzheimer’s and Wernicke-Korsakoff
L7 #30
- ) Where do cortical-cortical efferent projections terminate (ipsilateral and contralateral)?
- ) Afferent?
1.) Layers II and III for BOTH ipsi- and contralateral.
2.) Same
Mnemonic (rhyme): CortiSEE (cortice) to CortiSEE uses layers two and thREE
-This is for both ipsilateral and contralateral.
L7 #34
From which layers do descending efferent projections to the cortex arise – ipsilateral (two exceptions) and contralateral. Which are the largest and longest fibers arising from cortex?
They arise from several major groupings: Brainstem (5), basal ganglia, corticothalamic, and corticospinal
Ipsilateral: Layer V (brainstem? largest and longest fibers) except claustrum and corticothalamic, which arise in layer VI
Contralateral: Layer V
L7 #34
If tracts are carrying conscious sensation, they must reach the _________.
Thalamus
L5a #6
Cranial nerve nuclei are ONLY located in what part of the brainstem?
Tegmentum
L5a #5
The tegmentum contains _______ tracts.
Sensory/ascending tracts
L5a #5
Give blood supply for:
- ) Medial medulla (motor)
- ) Lateral medulla (sensory)
- ) Upper pons
- ) Lower pons
1.) Anterior spinal artery (or…AICA, not sure)
2.) PICA
3.) Superior cerebellar aa.
4.) AICA
L5a #7
Where are the pyramids located and what do they contain? They are the site of what?
Located at the spinomedullary junction (caudal medulla) and contain descending corticospinal tracts.
Site of motor decussation
L5a #8
What five major things are in the lower medulla?
1.) Fasciculus gracilis
2.) Fasciculus cuneatus
3.) Spinal nucleus of trigeminal nerve
4.) Trigeminal tract
5.) Pyramidal decussation
L5a #12
What five major things exist at the mid-medulla?
1.) Decussation of medial lemniscus (i.e. sensory decussation).
2.) Internal arcuate fibers.
3.) Uncrossed pyramids/corticospinal tract.
4.) Spinal nucleus of trigeminal nerve
5.) Trigeminal tract
L5a #13
- ) Sclera is contiguous with the ________ surrounding the ________ and ________.
- ) What are its two primary components?
1.) contiguous with the DURA MATER surrounding the optic nerve and brain.
2.) Type 1 collagen and elastic fibers
L8a #13
What is the site of attachment for the extra-ocular muscles and where is it?
Tenon’s space – the portion of sclera between episcleral layer and substantia propria (which is continuous with the transparent middle layer of cornea).
L8a #13
- ) What are the three components of the uveal tract?
2. ) What three characteristics do they all share?
1.) Choroid, ciliary body, iris
2.) Vascular, pigmented, loose CT
L8a #17
- ) What are the four layers of choroid (outer to inner)?
2. ) What is their general organizational pattern?
1.)
(i) Halter’s layer: Large diameter blood vessels
(ii.) Sattler’s layer: Medium diameter blood vessels
(iii.) Choriocapillaris: Layer of capillaries
(iv.) Bruch’s membrane: Inner-most layer
Layers i-iii are the vascular layers
Think – The ones that have “-tler or -er” at the end go in alphabetical order, then you know the next layer in choriocapillaris because Bruch’s membrane is last because it is avascular and closest to the retina
2.) Layers with larger diameter blood vessels are towards the outside/externally (near the sclera), and layers with smaller diameter blood vessels are towards the inside/internally (near the retinal pigmented epithelium).
L8a #19
Describe the two epithelial surfaces of the ciliary body in terms of pigmentation and their relation to the chambers of the eye.
1.) Anterior chamber surface: Non-pigmented
2.) Posterior chamber surface: Pigmented
Posterior = Pigmented
L8a #21
The canals of Schlemm are found at the junction of which two eyeball components?
Junction of ciliary body and sclera, just behind where the sclera and cornea meet.
L8a #22
What is the maintained intra-ocular pressure range?
10-22 mmHg
L8a #22
- ) The iris is an _______ extension of _______.
2. ) It delineates _______ and _________ of the __________.
1.) Anterior extension of choroid.
2.) Delineates anterior and posterior chambers of the aqueous cavity.
L8a #24
The subcapsular epithelium of the ocular lens is present ONLY on the _______ surface of the lens.
Present only on the ANTERIOR surface of the lens.
L8a #27
- ) Hyperopia (aka ______-sighted) results from a lens or cornea that is too _______.
- ) Focal plane _______ (within or beyond) the eye globe.
- ) Treatment requires ______ lens.
1.) Farsighted = lens/cornea that is too flat.
2.) Focal plane beyond the eye globe (eye globe too short).
3.) Treatment requires a CONVEX/CONVERGING lens.
L8a #32
- ) Myopia (aka ______-sighted) results from a lens or cornea that is too _______.
- ) Focal plane _______ (within or beyond) the eye globe.
- ) Treatment requires ______ lens.
1.) Nearsighted = lens/cornea that is too curved/rounded.
2.) Focal plane within the eye globe (eye globe is too long).
3.) Treatment requires a CONCAVE/DIVERGING lens.
L8a #32
- ) In the case of retinal detachment, a potential space becomes realized. Between which two layers does the potential space exist?
- ) What normally keeps these two layers apposed?
1.) Between the pigmented and nervous/neural layers of retina.
2.) Pressure in VITREOUS chamber.
L8a #35
Photoreceptors are _______-polarized by light.
HYPERpolarized.
L8b #8
Retinal ganglion cells are responsible for the _____________ receptive fields, and are specialized to emphasize ________.
responsible for the center-surround receptive fields, and are specialized to emphasize edges.
L8b #16
- ) M cell ganglion cells are _____-associated, ______ conducting, ________ sensitive, and _______ insensitive.
- ) Describe them in terms of (a) light requirement, (b) contrast detection, and (c) acuity.
1.) M cell: Rod-associated, fast conducting, motion sensitive, color insensitive.
2.) (a) low light (scotopic), (b) low contrast detection, (c) low acuity.
Mnemonic: Mr. PC —> M (cell) R (rod), P (cell) C (cone)
L8b #17
- ) P cell ganglion cells are _____-associated, ______ conducting, ________ insensitive, and _______ selective.
- ) Describe them in terms of (a) light requirement, (b) contrast detection, and (c) acuity.
1.) P cell: Cone-associated, slow conducting, motion insensitive (respond to stationary stimuli), color selective (i.e. color sensitive).
2.) (a) high light (photopic), (b) high contrast detection, (c) high acuity.
Mnemonic: Mr. PC —> M (cell) R (rod), P (cell) C (cone)
L8b #17
Describe M and P cells in terms of (4): Size of dendritic and receptive field, degree of convergence, distribution across retinal plane, and where they project to (M cells project to TWO places, P cells project to just one place).
1.) M cells: Large dendritic/receptive field, extensive convergence, more even distribution across retinal plane, project to magnocellular laminae of LGN and the superior colliculus.
2.) P cells: Small dendritic/receptive field, less convergence, most common in the central retinal plane/centrally, project ONLY to the parvocellular laminae of LGN.
L8b #18
What is the effect of a small dendritic field on the level of visual acuity?
Small dendritic field = HIGHER visual acuity (i.e. higher detail discrimination).
L8b #18