Neuro Final COPY Flashcards
1
Q
To which layer(s) of the lateral geniculate nucleus does visual information from the contralateral and ipsilateral eye project?
A
Contralateral eye: Layers 1, 4, and 6.
Ipsilateral eye: Layers 2, 3, and 5.
L8b #43
2
Q
A parietal lobe lesion will affect the ________ optic radiations, causing _________ quadrantanopia.
A
superior optic radiations
inferior quadrantanopia
L8b #52
3
Q
A temporal lobe lesion will affect the ________ optic radiations, causing _______ quadrantanopia.
A
inferior optic radiations
superior quadrantanopia
L8b #52
4
Q
- ) Which type(s) of tract(s) are found in the ventral/anterior brainstem?
- ) Consequence of injury?
A
1.) Descending motor tracts (ONLY found in ventral/anterior brainstem).
2.) Paralysis only – No sensory loss.
L5a #5
5
Q
- ) What two general things are found within the tegmentum?
2. ) Where is tegmentum?
A
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
6
Q
- ) 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)?
A
1.) (a) Motor = Medial (b) Sensory = Lateral
2.) Sulcus limitans
L5a #7
7
Q
Decussation of the corticospinal tract (aka _______ ) occurs where in the brainstem?
A
aka Pyramidal decussation – Occurs in the ventral lower (caudal) medulla.
L5a #12
8
Q
Where does the sensory decussation occur in the brainstem? What are the fibers known as after they decussate?
A
Within the internal arcuate fibers of the mid/caudal-medulla.
•known as the MEDIAL LEMNISCUS after decussation.
L5a #13
9
Q
- ) Horner’s Syndrome is always _________ (laterality)?
2. ) Caused by damage to what/where?
A
1.) Ipsilateral
2.) Hypothalamospinal tract in the lateral medulla.
L5a #22
10
Q
Give the blood supply for:
- ) Upper pons
- ) Lower pons
- ) Lateral medulla
- ) Medial medulla
A
1.) Superior cerebellar artery (L5b #38)
2.) AICA
3.) PICA
4.) Anterior spinal artery
L5b #24
11
Q
Which three arteries supply the open medulla?
A
Anterior spinal, vertebral (medullary branches), PICA
L5b #24
12
Q
- ) 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?
A
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
13
Q
- ) What is Wallenberg syndrome?
- ) Clinical symptoms (6)?
- ) How is this different from AICA syndrome?
A
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
14
Q
Describe the location where the trigeminal nerve exits the brainstem
A
Externally at the junction between the middle cerebellar peduncle and basis of the pons
L5b #27
15
Q
- ) Where do the fibers for the auditory pathway cross (structure and location)?
- ) What other structure associated with the auditory pathway is in this location?
A
1.) Trapezoid body in the DORSAL tegmentum of the lower pons.
-They form the lateral lemniscus
2.) Superior olivary nucleus (L5a #32)
L5b #30
16
Q
If there is a tumor in the region of the facial colliculus, which extra-ocular muscle is affected (and via which CN)?
A
Lateral rectus (via Abducens nerve, CN VI) L5b #31
17
Q
- ) Where is the only other place in the CNS that has pseudo-unipolar neurons just like the DRG?
- ) What reflex is mediated here?
A
1.) Mesencephalic nucleus (of CN V) in the midbrain.
2.) Jaw-jerk reflex
L5b #35
18
Q
- ) Where does the trigeminal lemniscus lie?
- ) What does it carry and to where?
- ) Where are its 1st, 2nd, and 3rd order neurons?
A
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
19
Q
- ) What is another name for abnormal flexion posturing?
2. ) Cause?
A
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
20
Q
- ) What is another name for abnormal extension posturing?
2. ) Cause?
A
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
21
Q
Where does the anterior thalamic nuclei…
- ) Receive afferents from (2), and
- ) Send efferents to (1)?
- ) Grossly, forms the ________.
A
- ) 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
22
Q
What is the function of the anterior thalamic nuclei (2)?
A
Emotion and memory acquisition
L6a #18
23
Q
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.
A
- ) 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)
24
Q
The pulvinar region of ______ thalamic nuclei ( _____ tier) receives projections from _________, and projects to ________ regions concerned with ________ and __________.
A
-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
25
The ventral *anterior* thalamic nuclei are related to _______ systems, and give efferents to the _______.
LATERAL THALAMIC NUCLEI
-Related to motor systems (think SAME DA*VE* – Ventral = Efferent/Motor)
-Efferents to the frontal lobe
L6a #25
26
Name the two subdivisions of ventral posterior thalamic nuclei and give their afferents (2 and 1) and efferents (one for both).
1. ) VPL – afferents from medial lemniscus and spinothalamics.
* Bodily sensation —> Contralateral...right?*
2. ) VPM – afferents from trigeminothalamic tract (spinothalamic and principal trigeminal nuclei).
* CONTRALATERAL facial sensation*
Efferents – BOTH project to somatosensory cortex.
L6a #27
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
28
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
29
1. ) What is the role of the reticular nucleus?
2. ) How?
3. ) 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
30
1. ) 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 the subthalamic nucleus of the basal ganglia (wiki).
L6a #44
31
What is the blood supply for the subthalamic nuclei (2)?
Posterior cerebral and Posterior communicating arteries
| L6a #44
32
What three things form the epithalamus?
1.) Pineal gland
2.) Habenular nuclei
3.) Stria medullaris thalami
L6a #48
33
1. ) The pineal gland is involved in _______ production.
2. ) Input?
3. ) Secretions (2; other than #1).
1.) Melatonin
2.) Receives *indirect* photic input
3.) Secretes serotonin, norepi, and other peptides.
L6a #49
34
1. ) What is the main blood supply of the thalamus (and branches – 2)
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
35
1. ) What is the 1˚ blood supply for the internal capsule of the thalamus? Two 2˚ supplies?
2. ) 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
36
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)
37
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
38
List the four zones of the hypothalamus (mnemonic)
*LMPP*
1.) Lateral
2.) Medial
3.) Periventricular
4.) Pre-optic
L6b #11
39
1. ) Which hypothalamic nucleus is known as the "sexually dimorphic nucleus"?
2. ) What is the nature of this dimorphism?
3. ) 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
40
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
41
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 *TUBE*ral"
L6b #17
42
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
43
What are the three regions within the medial zone of the hypothalamus?
1.) Supraoptic
2.) Tuberal
3.) Mammillary
L6b #19
44
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
45
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
46
1. ) 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
47
1. ) What is the function of the periventricular zone?
2. ) Function analogous to what?
3. ) 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
48
What contributes the most to the blood supply of the hypothalamus?
Mostly small branches of the posterior communicating arteries.
L6b #31
49
1. ) What is the 1˚ blood supply for the pituitary and where is it from?
2. ) 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
50
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
51
What gives rise to cerebral cortex?
Pallium
52
For the four cerebral cortical lobes, list the following:
a. ) General function
b. ) On which surfaces of the brain it exists
c. ) Boundaries
1. ) Frontal (#8)
(a) Mostly motor
(b) Lateral, medial, and inferior surfaces
(c) Posteriorly by central sulcus, posterolaterally by lateral sulcus.
2. ) 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.
3. ) 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
53
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
54
1. ) In which cortical layer do thalamic afferent fibers to the cortex mostly terminate?
2. ) Projections from which location also terminate in the same place?
1.) Layer IV
2.) Basal ganglia
L7 #30
55
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
56
1. ) Where do cortical-cortical efferent projections terminate (ipsilateral and contralateral)?
2. ) 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
57
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
58
If tracts are carrying conscious sensation, they must reach the _________.
Thalamus
| L5a #6
59
Cranial nerve nuclei are ONLY located in what part of the brainstem?
Tegmentum
| L5a #5
60
The tegmentum contains _______ tracts.
Sensory/ascending tracts
| L5a #5
61
Give blood supply for:
1. ) Medial medulla (motor)
2. ) Lateral medulla (sensory)
3. ) Upper pons
4. ) Lower pons
1.) Anterior spinal artery (or...AICA, not sure)
2.) PICA
3.) Superior cerebellar aa.
4.) AICA
L5a #7
62
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
63
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
64
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
65
1. ) Sclera is contiguous with the ________ surrounding the ________ and ________.
2. ) 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
66
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
67
1. ) 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
68
1. ) 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
69
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
*P*osterior = *P*igmented
L8a #21
70
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
71
What is the maintained intra-ocular pressure range?
10-22 mmHg
| L8a #22
72
1. ) 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
73
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
74
1. ) Hyperopia (aka ______-sighted) results from a lens or cornea that is too _______.
2. ) Focal plane _______ (within or beyond) the eye globe.
3. ) 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
75
1. ) Myopia (aka ______-sighted) results from a lens or cornea that is too _______.
2. ) Focal plane _______ (within or beyond) the eye globe.
3. ) 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
76
1. ) In the case of retinal detachment, a potential space becomes realized. Between which two layers does the potential space exist?
2. ) What normally keeps these two layers apposed?
1.) Between the pigmented and nervous/neural layers of retina.
2.) Pressure in VITREOUS chamber.
L8a #35
77
Photoreceptors are _______-polarized by light.
HYPERpolarized.
| L8b #8
78
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
79
1. ) M cell ganglion cells are _____-associated, ______ conducting, ________ sensitive, and _______ insensitive.
2. ) 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
80
1. ) P cell ganglion cells are _____-associated, ______ conducting, ________ insensitive, and _______ selective.
2. ) 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
81
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
82
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
83
Where are P cells most common/most densely distributed?
In the CENTRAL RETINA
| L8b #19
84
Which visual cues are detected in the retina (4), and which are detected in the cortical areas (2)? *Indicate which Brodmann area for each of the two cortical areas*
Retina: Spacial frequency (acuity), contrast, color, and motion.
Cortical: Orientation (area 17) and binocularity (area 18).
*REMEMBER, binocularity does not occur until you reach 2˚ visual cortex!*
L8A #46
85
The outer segments of photoreceptors are actually modified ________.
Modified cilia.
| L8a #53
86
Gives the medical terms for color blindness that describe:
1. ) Lacking red cones
2. ) Lacking green cones
3. ) Lacking blue cones
1.) Protanope
2.) Deuteranope
3.) Tritanope
L8a #59
87
Which visual cues are encoded by the following:
1. ) P cells (2)
2. ) Cones (1)
3. ) Rods and M cells (1)
4. ) 1˚ cortex
5. ) 2˚ cortex
1.) Spatial frequency and Contrast
2.) Color
3.) Motion
4.) Orientation
5.) Binocularity
L8b #35
88
Concerning the Magnocellular layer of the LGN:
1. ) Size of cell bodies
2. ) Found in which LGN layer?
3. ) Detection of what
4. ) Termination of which cells
1.) Large cell bodies
2.) Layers 1-2 (just remember by alphabetical order; M before P)
3.) Motion detection
4.) Termination of M ganglion cells
L8b #42
89
Concerning the Parvocellular layer of the LGN:
1. ) Size of cell bodies
2. ) Found in which LGN layer?
3. ) Detection of what (2)
4. ) Termination of which cells
1.) Small cell bodies
2.) Layers 3-6 (just remember by alphabetical order; P after M)
3.) Detail and color detection
4.) Termination of P ganglion cells.
L8b #42
90
1. ) Onto which layers of the Lateral Geniculate Nucleus (LGN) is information from the contralateral and ipsilateral eye projected?
2. ) Which hemiretina and visual field do those correspond to?
1.)
Contralateral eye: Layers 1, 4, and 6.
Ipsilateral eye: Layers 2, 3, and 5.
2.) Contralateral eye corresponds to nasal hemiretina/temporal visual field.
Ipsilateral eye corresponds to temporal hemiretina (on the same side as LGN), and nasal visual field.
L8b #43
*See image on #44 as well*
91
What layer is the primary thalamic recipient zone in cerebral cortex?
Layer 4
| L8b #48
92
1. ) In which layer of cortex do M geniculate cells and P geniculate cells project their axons?
2. ) In which layers are the M and P cell bodies that project back to the thalamus?
M cells: 4Cα, cell bodies in deep layer 6 (or deeper layers).
P cells: 4Cβ, cell bodies in superficial layer 6.
L8b #48
93
Structure and functional organization of cortex reflects the organization in the _____________.
Lateral geniculate nucleus (of the Thalamus).
| L8b #48
94
Where in the striated/calcarine cortex do the (1) superior and (2) inferior visual fields project to, and what part of cortex do they pass through to get there?
1.) Superior visual field projects to the INFERIOR BANK of striated/calcarine cortex, passing through the temporal cortex to get there.
2.) Inferior visual field projects to the SUPERIOR BANK of striated/calcarine cortex, passing through the parietal cortex to get there.
L8b #49
95
1. ) The thalamus and, thus, the LGN receives its blood supply from the ________ artery via the ________ arteries.
2. ) Damage to this main artery can cause what type of ocular disorder?
1.) From the middle cerebral artery (MCA) via the thalamostriate arteries.
2.) Bilateral homonymous hemianopsia
L8b #54
96
1. ) What is the blood supply for the striated/occipital cortex?
2. ) The optic radiations also pass posteriorly near this area, what is their blood supply?
1.) Posterior cerebral arteries (PCA)
2.) Anterior cerebral arteries (ACA) —> ??? HOW ???
L8b #54
97
1. ) In which cortical layers are simple and complex cells found?
2. ) What is the main difference in stimulation between the simple and complex cells?
1.) Simple = 4Cβ (same as P geniculate cells) —> Complex = 4Cα
2.) For simple cells, placement AND *orientation* is important (has distinct excitatory and inhibitory regions).
For COMPLEX cells, placement is not important, but ORIENTATION is important (i.e. if light is anywhere in the visual field, the cell will respond *provided the light has the proper orientation*) because complex cells have no clear distinct excitatory or inhibitory regions within their receptive fields.
L8b
Simple – #57
Complex – #60
98
What are the four ways that 1˚ visual cortex segregates visual information?
1.) Laterality (left vs right eye)
2.) Orientation of stimulus
3.) Spatial frequency
4.) Color
L8b #62
99
Concerning the "what" cortical stream:
1. ) Dorsal or ventral
2. ) ______-bias (rod or cone).
3. ) Associated with _____-cells of the _______ cell system.
4. ) Found through areas ____ and _____, to _______ lobe termination.
5. ) Three functions
1.) Ventral
2.) Cone-bias
3.) P-cells of the simple cell system
4.) Areas 18 and 19, to temporal lobe termination.
5.) Object identification, form and color
L8b #64
100
Concerning the "where" cortical stream:
1. ) Dorsal or ventral
2. ) ______-bias (rod or cone).
3. ) Associated with _____-cells of the _______ cell system.
4. ) Found through areas ____ and _____, to _______ lobe termination.
5. ) Two functions
1.) Dorsal
2.) Rod-bias
3.) M cells of the complex cell system
4.) Areas 5 and 7, to parietal lobe termination
*slide #64 says "through area MT" —> What is area MT?*
5.) Object's spatial location (relative to observer), and motion detection.
L8b #64
101
What is the only CN nucleus in which the ascending first order neurons are located within the CNS?
Mesencephalic nucleus of trigeminal nerve in the midbrain.
| L8a #35
102
Concerning Thalamic Intralaminar Nuclei:
1. ) Enclosed by _________.
2. ) Give the two nuclei, their relative positions, and where they project to.
1. ) Enclosed by internal medullary lamina
2. )
(i) Centromedian (CM) nucleus: Medial to VPL/VPM, lateral to parafascicular (PF) nucleus. *Projects to PUTAMEN and motor cortex*
(ii) Parafascicular (PF) nucleus: Medial to CM. *Projects to CAUDATE NUCLEUS and PREFRONTAL CORTEX*
L6a #36
103
In which layers do inter-cortical circuits typically arise (2)?
Terminate (4)?
Arise: Layers II and III
Terminate: Layers I-III, and layer V (to a lesser extent).
L7 #25
104
What are the two types of ipsilateral cortical connections?
Long fiber tracts and Short "U" association fibers
| L7 #25
105
What are the two types of contralateral cortical connections? Describe their primary difference
Commissural fibers: Homotopic connections – travels to a similar point on the opposite side.
Decussating fibers: Cross the midline, but do not connect to similar points (i.e. not homotopic), e.g. hippocampal (fornical) commissure.
L7 #25
106
1. ) Concerning neocortex layers, what are the two primary ways in which the layers are distinguished?
2. ) In which layers are neuronal cell bodies almost exclusively found?
1.) Size of neuronal cell bodies, cell packing densities
2.) Layers II-VI
L7 #28
107
1. ) What are the components of the basal forebrain (5)? Indicate which are deep to the anterior perforated substance (2).
2. ) What is the NT for the Basal forebrain?
3. ) Damage to basal forebrain leads to what two things?
1.) BAI BM —> Basal nucleus (of Meynert) (deep to ant. perforated substance), nucleus Accumbens, substantia Innominata (deep to ant. perforated substance), diagonal band of Broca, Medial septal nuclei.
2.) ACh (cholinergic)
3.) Memory-cognitive deficits (confabulation), and Slow wave sleep (ACh promotes wakefulness).
L7 #31
108
What are three anatomical features associated with Alzheimer's disease?
1.) Cortical atrophy (loss of cortical mass)
2.) Amyloid plaques found in neuropil
3.) Neurofibrillary tangles (tau deficiency)
L7 #32
109
Which layer of cornea accounts for its transparency?
| Chief component?
Corneal stroma – Regular parallel arrangement of TYPE I collagen.
8a #15
110
What is characteristic of the outer most corneal epithelium?
```
Stratified squamous (5-6 layers, 7 day turnover) with MICROVILLI on superficial cells.
L8a #15
```
111
Which corneal layer provides strength and stability? What is characteristic, and what other layer shares this characteristic?
Bowmann's membrane (CT membrane), homogenous collagen fibers. ACELLULAR —> Characteristic shared by Descemet's membrane (the ACELLULAR posterior limiting lamina).
L8a #15
112
1. ) Aqueous humor is produced in the ______ chamber by the ________.
2. ) Describe its general composition
3. ) What function does it serve?
1.) Produced in the posterior chamber by the ciliary body.
2.) Acellular fluid with no protein and few electrolytes.
3.) Carries nutritional elements for the *AVASCULAR cornea and lens*
L8a #22,
pp.267-68 Haines: "Fluid is continuously produced by the epithelium over the ciliary body around the rim of the *posterior chamber* and flows through the pupillary opening into the anterior chamber."
113
What are the photopigments contained in rods and cones?
-Rods contain rhodopsin.
-Cones contain one of three opsins/pigments (iodopsins), i.e. they have different opsins for specific wavelengths/colors of light.
L8a #48
114
What is the principal visual pathway (three general steps).
| _______ —> _______ —> ________ (aka _____ or ______).
Retina —> Lateral geniculate nucleus/LGN (in the metathalamus) —> 1˚ visual cortex (aka striate cortex or Area 17).
L8a #48
115
Concerning the visual pathway, what is the hypothalamus important for?
Circadian rhythm
| L8a #48
116
Classify the visual neurons (5) as either Golgi Type I (3) or Golgi Type II (3) cells.
Golgi Type I: Ganglion cells —> M cells and P cells
Golgi Type II: Horizontal cells, Amacrine cells, Bipolar cells.
*HAB*
L8a #51
117
The inner segment of photoreceptors are ___________-rich. Why?
Mitochondria-rich —> To provide for the high energy needs of the outer segment.
L8a #53
118
The outer segments of photoreceptors are embedded in the ________ of _____________. Why (two reasons)?
Embedded in the *microvilli* of pigmented epithelial cells.
Because:
1.) Pigmented epithelium maintains the vitality of the photoreceptors.
2.) It isolates photoreceptors from one another, enabling individual photoreceptors to receive subtly different amounts of light than adjacent photoreceptors (i.e. the light will be different for each photoreceptor).
L8a #55
119
Rods have broader _______ and _______ than cones, are most active at ______ light levels, and detect ______.
-Broader receptive and spectral fields than cones.
-Most active at *scotopic* light levels.
-Detect motion.
L8a #55
120
Which are better at signal amplification, rods or cones?
Rods
| L8a #57
121
Describe rods and cones in terms of the following:
1. ) Directional selectivity
2. ) Degree of convergence in the retinal pathway (i.e. spatial integration).
1.) Rods = NOT directionally selective — Cones = Directionally selective.
2.) Rods = HIGHLY convergent retinal pathways — Cones = Less convergent retinal pathways.
*Less convergence = closer to a 1:1 receptor-to-ganglion cell ratio, which increases acuity and detail*
L8a #57
122
Which of the retinal neurons are local circuit neurons (2)?
Amacrine and horizontal cells
| L8a #60
123
Describe Müller cells, i.e. morphology, location, function (2).
Large, glia-like cells that span much of the full length of the retina (from pigmented epithelium almost to the inner limit of the retina, i.e. extend from the external to the internal limiting membranes).
(1) They phagocytize sheds discs from the outer segments of photoreceptor cells.
(2) Maintain integrity of all cells within the neural retina. The neural retina is avascular, and Müller cells are in contact with pigmented epithelium, which is in contact with the vascular choroid. This allows passage of nutrients to the cells in the neural retina.
L8a #60
124
1. ) Where in the eye are there NO photoreceptors?
| 2. ) Where is there the highest concentration of photoreceptors?
1.) Optic disc
2.) Fovea (within the macula)
L8a #61
125
What is the optic disc (structurally speaking)
The place where axons of ganglion cells exit the neural retina and form the optic nerve (CN II).
L8a #61
126
_______ is contiguous with epineurium of the optic nerve.
Sclera
| L8a #62
127
1. ) Fovea is the region where _________-to-_________ ratio approaches ________.
2. ) Outside of this area, the ratio goes ________ (meaning?)
1.) Photoreceptor-to-ganglion cell ration approaches 1:1
2.) Ratio goes down (more photoreceptors per ganglion cell).
L8a #63
128
1. ) Fovea has the highest concentration of _______; _____-rich and _____-poor.
2. ) It is the region of highest _________.
1.) Highest concentration of photoreceptors; cone-rich and rod-poor.
2.) Highest visual acuity.
L8a #63
129
1. ) What is the physiological pathology of retinitis pigmentosa? Due to what?
2. ) Symptoms (5)?
1. ) Loss of rhodopsin or direct loss of photoreceptors due to AA substitution of Ala for Pro, which causes misfolding of rhodopsin protein.
2. ) Slow, progressive loss of vision (permanent), night blindness, tunnel vision (loss of peripheral vision), poor color separation. *Can also lose central, high acuity color vision as well (if cones are affected)*
130
1. ) What do the retinal layers look like in retinitis pigmentosa?
2. ) What gene can cause it?
1.) Disorganized retinal lamination (primarily photoreceptors...rods).
2.) Dysfunction of the RPE gene (or cones).
L8a #66
131
Which type of photoreceptor has the most abundant distribution in the parafoveal retina?
Rods (cones are more densely packed centrally and in the fovea).
L8a #68
132
Between which two arteries does the oculomotor nerve (CN III) lie?
Posterior cerebral arteries and Superior cerebellar arteries.
L5a #24
133
What is the function of the pontine nuclei and where are they?
Relay station for cerebropontine fibers in the basal pons.
| L5a #30
134
What is the function of the main sensory nucleus of the trigeminal nerve?
Conscious proprioception from the face.
| L5a #7
135
The internal medullary lamina splits anteriorly and partially encapsulates what structure(s)?
Anterior thalamic nuclei/Anterior tubercle
| L6a #16
136
What are the five groups of thalamic nuclei? (mnemonic)
* MARLI*
1. ) Medial thalamic nuclei (L6a #19)
2. ) Anterior thalamic nuclei (#18)
3. ) Reticular nucleus (#37)
4. ) Lateral thalamic nuclei (#21)
5. ) Intralaminar nuclei (#36)
137
Besides two nuclei, what other structure lies within the lateral hypothalamic region and what is its function?
Medial forebrain bundle: Connects hypothalamus with cranial and caudal brain regions.
L6b #16
138
Where is the feeding center and where is the satiety center?
Feeding center: Lateral hypothalamic nuclei in the lateral hypothalamic region. Associated with the peptide OREXIN.
Satiety center: Ventromedial nuclei in the Tuberal region of the Medial zone of the hypothalamus.
L6b #21
139
What does the dorsomedial hypothalamic nucleus mediate (2)? Where is it located?
Mediates emotional behavior and *sham rage.*
-Located in the Tuberal region of the Medial zone of the hypothalamus.
L6b #21
140
List the four nuclei and their functions of the mammillary region in the medial zone of the hypothalamus. *One has an aff. and an eff., one has three functions, the other two have nothing listed).
*LIMP*
1.) Lateral mammillary nucleus
2.) Intermediate mammillary nucleus
3.) Medial mammillary nucleus —> Afferent: from Hippocampus, Efferent: to Anterior thalamic nucleus
4.) Posterior hypothalamic nuclei: Emotion, cardiovascular and analgesic functions.
L6b #24
141
1. ) Damage to which hypothalamic nuclei can cause retrograde amnesia?
2. ) Why?
3. ) What is retrograde amnesia?
1.) *Mammillary nuclei* in the mammillary zone of the medial region of the hypothalamus.
2.) Because mammillary nuclei are important in the conversion of short term memory into long term memory.
3.) Inability to create new long term memories.
L6b #26
142
List the four nuclei within the supraoptic region of the medial zone of the hypothlamus. Give what they produce and/or regulate.
*PASS*
1.) Paraventricular nuclei: Produce vasopressin/ADH; water regulation.
2.) Anterior nuclei: Body temperature regulation.
3.) Suprachiasmatic nuclei: Circadian *pacemaker*
4.) Supraoptic nuclei: Produce oxytocin.
L6b #20
143
List the three nuclei within the Tuberal region of the medial zone of the hypothalamus. Give what they produce and/or regulate.
*DAVe*
1.) Dorsomedial nuclei: Emotional behavior, sham rage.
2.) Arcuate nuclei: Produces releasing hormones (4) for the anterior pituitary — (i) Dopamine: Inhibits pituitary secretion of prolactin (ii) GHRH to pituitary (growth hormone releasing hormone (iii) NPY (neuropeptide Y?) (iv) AgRP (agouti-related peptide).
3.) Ventromedial nuclei: Satiety center.
L6b #21-22
144
1. ) What is Korsakoff's syndrome?
2. ) Cause?
3. ) What is affected and consequence?
1.) Alcohol-based targeting of limbic/diencephalic structures.
2.) Alcohol
3.) Mammillary region (no new long-term memories) – Mammillary region is for converting short-term memories into long-term memories.
L6b #26
145
Describe the role of the Periventricular zone of the hypothalamus and what it produces (3). Which other nuclei is its function analogous to?
Region of small cell-bodied neurons that *synthesizes hormones for the anterior pituitary*
1.) Somatostatin (GHIH, i.e. Growth Hormone Inhibiting Hormone)
2.) TRH (thyroid hormone-releasing hormone)
3.) GnRH
*Function analogous to arcuate nuclei*
L6b #27
146
What four structures comprise the diencephalon?
1.) Dorsal thalamus (thalamus)
2.) Hypothalamus
3.) Ventral thalamus (subthalamus)
4.) Epithalamus
L6a #3
147
The thalamus receives precortical input from all sensory systems except the ________ system.
the olfactory system
| p.183 BRS
148
From where does the Paralaminar subdivision of the medial thalamic nuclei receive afferents (2)?
Substantia nigra, frontal lobe
| L6a #19
149
Where is the spiral ganglion found (i.e. what is it contained within)?
Embedded in the modiolus
| L9a #25
150
Finish the statement: If there is a nucleus that has a projection from thalamus to cortex, that nucleus is going to ________________.
That nucleus is going to receive a projection from cortex TO THE SAME REGION IN THE THALAMUS.
L6a #37
151
What three things comprise the subthalamus?
1.) Subthalamic nucleus
2.) Pre-rubral area (field H of Forel)
3.) Zona Incerta
L6a #43
152
The prerubral area of the _________ is a ________-rich region that rostral to the ___________.
-Subthalamus
-Myelin-rich
-Red nucleus
L6a #46
153
Thalamic syndrome results from extensive damage to the ______________.
*posterior* thalamus
| L6a #51
154
1. ) Central pain syndrome, aka ____________ is caused by what?
2. ) Symptoms?
1.) aka Thalamic pain, usually results from damage to the DORSAL thalamus. Usually follows a stroke or ischemic attacks in the thalamus blood supply.
2.) Numbness–Pain that progressing to tingling, then various degrees of burning sensations.
*Numbness —> Pain —> Tingling —> Burning*
L6a #53
155
List the six steps to decreased feeding in the hypothalamic pathway
1.) Leptin released by adipocytes.
2.) Leptin binds Arcuate nuclei via their Leptin receptors.
3.) Arcuate nuclei release *MSH and CART* (MSH = α melanocyte-stimulating hormone, CART = cocaine-amphetamine-regulated transcript).
4.) MSH and CART reach the following: Lateral hypothalamic zone (w/ LHN, i.e. "feeding center"), Paraventricular nuclei (water regulator; ADH, vasopressin, ACTH release), and spinal cord (posterior horn).
5.) Release of *ACTH and TSH*
6.) Increased metabolism and sympathetic tone, *DECREASED FEEDING*
L6b #28
156
What are the four arteries that supply the hypothalamus (mnemonic), and which regions does each supply —> 1st (3), 2nd (3), 3rd (1), 4th (1)
*PATH*
1.) Posterior communicating artery: Tuberal and mammillary regions; portions of the lateral region.
2.) Anterior communicating artery: Supraoptic and pre-optic regions; portions of the lateral region.
3.) Thalamoperforating artery (from post. comm.): Posterior hypothalamus.
4.) Hypophysial arteries (superior and inferior; from internal carotids): To pituitary gland.
L6b #31
157
Give the three major hypothalamic afferents and how they reach it (2nd one has two paths). Which two have reciprocal connections?
* HAO —> HEYO*
1. ) Hippocampus – via fornix
2. ) Amygdala (two fiber paths) – Striae terminalis (auditory?), ventral amygdalofugal bundle
3. ) Olfactory – via *medial forebrain bundle*
*Reciprocal connections between Amygdala and Hippocampus*
L6b #33
158
List the two hypothalamic efferents (for the 1st, give the route and what it does – for the 2nd, give what it does and how).
*BP*
1.) Brainstem (via mammillotegmental tract): Control of the ANS (remember, homeostasis and visceromotor control by hypothalamus).
2.) Pituitary: Direct release of hormones via *neurohypophysis*
L6b #34
159
The internal capsule of the thalamus is a layer of ___________ that separates the _______ and _______ medially, from the ________ laterally.
is a layer of white matter (myelinated axons) that separates the caudate nucleus and thalamus medially from the *LENTIFORM nucleus* laterally.
L6b #56 (good image), p.187 BRS, OneNote
160
The hypothalamus is concerned with many _________ functions.
Autonomic functions
| L6a #4
161
Retina is considered part of the _______ because it develops as part of the ________.
CNS, because it develops as part of the diencephalon.
| L6a #6
162
The ________ completely separates both sides of the thalamus.
3rd ventricle
| L6a #11
163
What is the lateral-most structure of the thalamus? What is directly medial to it?
Reticular nucleus – External *medullary* lamina lies just medial.
L6a #11-12
164
What are the afferents for the Lateral dorsal and Lateral posterior nuclei in the dorsal tier of the lateral thalamic nuclei?
```
They both have the SAME two afferents:
1.) Parietal lobe
2.) Cingulate gyrus
*Think – LD and LP are PC*
L6a #23
```
165
In an anterior coronal MRI section of the brain, which diencephalic structure will be visible first, and which will not be visible until a more posterior section?
Hypothalamus will be visible first, and thalamus will not be visible until a bit more posterior.
*Hypothalamus lies slightly ANTERIOR/ROSTRAL to the thalamus*
L6a #32-33
166
1. ) The pineal gland receives _______ ________ input.
| 2. ) What two things does it secrete?
1.) Indirect photic input
2.) Serotonin and norepinephrine (and other peptides released into circulation).
L6a #49
167
Damage to the posterior thalamus can cause what generalized type of symptoms?
```
Abnormal sensations (dysesthesias)
L6a #51
```
168
What are the boundaries of the hypothalamus – rostral, caudal (2), external, superior, and medial
```
Rostral: LAMINA terminalis
Caudal: Midbrain tegmentum, periaqueductal gray
External: Caudal edge of mammillary body
Superior: Hypothalamic sulcus
Medial: 3rd ventricle
L6b #4-5
```
169
1. ) Distinguish between the medial and lateral regions of the hypothalamus in terms of cell and fiber density.
2. ) What two structures are used as a boundary between the two regions?
1.) Lateral region: Highly fibrous
Medial region: Highly cellular
2.) Mammillothalamic tract and the fornix
L6b #13
170
Aqueous humor is the fluid contained in the space between the ______ and ______.
Between the *lens and cornea*
| L8a #22
171
The lateral geniculate nucleus is found in the _________.
Metathalamus
| 8b #42
172
Associate the evolutionary division of cortex with its final adult cortical structure:
1. ) Archipallium
2. ) Paleopallium
3. ) Neopallium
1.) Hippocampus
2.) Olfactory cortex
3.) Neocortex (6-layered cortex)
L7 #5
173
What are the three general regions that immediately arise from telencephalon?
Pallium, Basal ganglia, Basal forebrain
| L7 #80
174
Concerning spiny dendrites (Type ____ Golgi neurons), _____ receive excitatory inputs, and _____ receive inhibitory inputs.
-Type I Golgi neurons
-Spines receive excitatory inputs
-Shafts receive inhibitory inputs
*Think – You get the shaft (which is a negative connotation) = inhibitory*
L7 #19
175
1. ) Pyramidal neurons are Type _____ Golgi neurons.
2. ) Their axons form ______ synapses.
3. ) Their axons exhibit ________ spiking activity.
1.) Type I Golgi neurons
2.) Asymmetric synapses
3.) Regular spiking activity
L7 #19
176
1. ) Spiny stellate neurons are Type ___ Golgi neurons.
2. ) What type of synapses do they form?
3. ) Where in cortex are they typically found (generally speaking)
1.) Type I
2.) Asymmetric axospinous synapses
3.) Found in the middle of cortex
L7 #20
177
1.) Aspiny stellate neurons are what type of Golgi neuron?
2.) They are ______ and _______ immunopositive in both their _______ and ________.
L8 #21
1.) Type II
2.) GAD and Substance P immunopositive in both their CELL BODIES and AXON TERMINALS.
L7 #21
178
What is GAD?
Glutamic acid decarboxylase (GAD): Enzyme that produces GABA (inhibitory NT used by Type II Golgi neurons).
L8 #21
179
On which part(s) of Type II (2) and Type I (1) neurons do spiny neurons project?
Aspinous neurons? – Type II (2), Type I (3)
Spiny
Type II: Dendritic shafts and cell bodies
Type I: Dendritic spines
Aspinous
Type II: Dendritic shafts and cell bodies
Type I: Dendritic shaft, cell body (including hillock), and axon initial segment.
L7 #24
180
Is there any type/region of cortex that is thicker than another?
Little variation in cortical thickness...*with one notable exception*...
MOTOR CORTEX is thicker.
L7 #28
181
In which cortical layers are the following found?
1. ) Thalamo-cortical connections
2. ) Cortico-thalamic connections
3. ) Cortical-Cortical connections
1.) Layer IV
2.) Layer VI
3.) Layers II-III
L7 #29
182
Which cortical layer is composed of mainly glial cells?
Layer I —> relatively acellular with few cell bodies.
| L7 #29
183
Explain the two types of partial seizures
1.) Simple: Person is *aware* – may involve motor, sensory, or autonomic symtoms.
2.) Complex: Person experiences *changes in awareness* and *often feels confused.*
L7 #36
184
Explain the four types of general seizures in terms of symptoms and how much of the brain is involved.
1.) Absence: Person stares blankly for ≈ 10 sec, then continues on as if nothing happened. Involves the whole brain.
2.) Tonic Clonic: Jerking movements in regions of the body, or throughout the entire body. May involve part of the brain, OR the entire brain.
3.) Atonic: Involves person suddenly falling to the ground. Involves the entire brain.
4.) Myotonic: Sudden jerk of only *one part of the body.* Involves the entire brain.
L7 #37
185
a. ) List the five common features among most seizures – indicate the feature the is common to ALL seizures.
b. ) What types of neurons are involved in seizures?
a.)
1.) Brief loss of memory
2.) Loss of consciousness
3.) Uncontrolled urination
4.) Rhythmic movements
5.) Confusion and sleepiness after seizure
*Common to ALL seizures: No recollection of what happened during the seizure* —> #'s 1 and 2 are the most common.
b.) Projection (excitatory) neurons – Not local circuit neurons because they have NO EXCITATORY ACTIVITY (#41).
L7 #37
186
Describe how areas of the brain that are affected by a seizure appear on a PET scan and why.
Affected areas appear RED during a seizure due to *high glucose activity* – During a seizure, involved cortical components use more energy (glucose). In between seizures, metabolic activity returns to normal.
187
1. ) What type of test is useful in some cases of epilepsy?
| 2. ) When is it not as useful?
1.) 2-FD-Glucose-PET
2.) Helpful in some cases, but can confuse the situation by *revealing abnormalities unrelated to epilepsy.*
L7 #38
188
1. ) What is the largest axonal pathway in the brain?
| 2. ) List its components (6) and which homonymous cortical lobes (4) they link —> *There will be three links altogether*
1.) Corpus callosum
2.)
(i) Rostrum, genu, body: Frontal lobes
(ii): Body and isthmus: Parietal lobes
(iii) Splenium: Temporal and occipital lobes
L7 #47
189
1. ) Explain language dominance in the context of handedness (3 points).
2. ) Give an example of hemispheric hetergeneity
1.) -In 95% of right-handed people, the LEFT hemisphere has language dominance.
-For 60-70% of left-handed people, the LEFT hemisphere is also language dominant.
-In 20% of left-handed people, there is language co-dominance.
2.) Left brain = Logical, Right = Creative
L8 #49-50
190
1. ) Cortical layer IV is characteristically dense in which cortical areas? Why?
2. ) In which cortex will you find lots of big neurons around layer V?
1.) 1˚ sensory areas (auditory, visual, etc.), because layer IV is critical for *thalamo-cortical activity*
2.) 1˚ motor cortex (area 4)
L7 #58
191
What is a homunculus?
A point-to-point sensory representation/map of somatosensory cortex.
L7 #64-65
192
For which cortical activities must there be specific, reciprocal connections (give an example)? For which do you not need specific connections and why is this necessary?
Specific (point-to-point) connections: Special senses and motor activities (e.g. Thalamo-cortical systems are key for sensory systems and motor control).
Non-specific connections: Gating and facilitatory —> Allows one to have conscious perception or to not have it. Essential for conscious activities, perceptions, personality, and emotions. WHY????? Re-watch.
L7 #66-67
193
1. ) A motor seizure involves which cortex of which lobe?
| 2. ) Describe the laterality of seizures
1.) Motor seizure = Motor cortex = Frontal lobe
2.) Right-sided seizure = LEFT hemisphere.
L7 #69
194
Which surfaces and poles of cerebral hemisphere does each of the cerebral arteries supply?
Anterior cerebral: Medial and *upper-lateral* surface - Frontal pole.
Middle cerebral: Lower and lateral surfaces - Temporal pole.
Posterior cerebral: Inferior surface - Occipital pole.
L7 #74
195
1. ) What is an aneurysm and where, in general, are aneurysms most common?
2. ) What are the two patterns the blood vessel can take?
3. ) Where in the Circle of Willis do most aneurysms occur?
1.) Evagination of the arterial wall at a point of weakness. Most common where an artery branches off (structural weakness of arterial wall).
2.) Saccular (sac-like) and Fusiform (band-like).
3.) Where ACA meets ACoA (40%).
L7 #76
196
1. ) Where will deficits occur in the following occlusions:
a. ) ACA (2)
b. ) MCA (4)
2. ) In general, where else will you see reduced activity in the case of an occlusion and why? How will this manifest on a PET scan?
1.)
a.) Lower trunk and limb
b.) Arm, hand, face, and tongue
2.) Will see reduced activity in the area CONTRALATERAL to the occlusion due to *reduced cortical-cortical input via the corpus callosum* —> This will register as blue/blue-green in the contralateral homotopic cortex (while the area of affected cortex will appear black).
L7 #77
197
Where is the MLF (medial longitudinal fasciculus) found? What disease is it associated with and what does does it do?
-MLF found in upper medulla/Lower pons.
mnemonic: *Medulla/Lower (pons) = MLf*
-Associated with MS – causes demyelination of the MFL.
L5a #14, 30
198
What seven important structures are found in the upper medulla?
1.) Spinal trigeminal nucleus
2.) MLF
3.) 4th ventricle
4.) Uncrossed corticospinal tract
5.) Medial lemniscus
6.) ***Inferior olivary nucleus***
7.) ICP???
L5a #14
199
For what six things does the spinal trigeminal nucleus provide sensory innervation?
1.) Tympanic membrane
2.) Auditory tube
3.) Upper part of pharynx
4.) Tonsil
5.) Posterior 1/3 of tongue
6.) Pain and temperature from the ipsilateral face
*Just start from middle ear and work your way down —> TM, auditory tube, upper pharynx, tonsil, post. 1/3 tongue*
L5a #16
200
What is the results of lesions to the following:
1. ) Pyramid
2. ) Inferior cerebellar peduncle (and where is it?)
3. ) Dorsal nucleus of CN X
4. ) Hypothalamospinal tract (and where is it)
1.) Contralateral spastic paralysis
2.) Ataxia (upper/mid-medulla)
3.) Tachycardia
4.) Lateral medulla – *Ipsilateral* HORNER SYNDROME (always ipsilateral).
*PAMELA* = Ptosis (drooping eyelid), Anhydrosis (lack of sweating), Miosis (constricted pupil), Enophthalmos (sunken eye), Loss of ciliospinal reflex (dilation of ipsilateral pupil in response to pain stimulus on that side).
L5a #22
201
The pons is continual laterally with what structure?
Middle cerebellar peduncle
| L5a #28
202
1. ) Which nerve and muscle is compromised if the fascial colliculus is damaged?
2. ) Where is it (facial colliculus) located?
3. ) Which other nerve is present at this location, though its nucleus is not.
1.) Abducens nerve (CN VI) and Lateral rectus muscle.
2.) Lower DORSAL pons (floor of 4th ventricle)
3.) Facial nerve wraps around the abducens nucleus.
L5a #30
203
What is another name for Raymond syndrome? What structures are involved (2)?
Medial pontine syndrome: Abducent nerve (ipsilateral lateral rectus palsy) and corticospinal tract (contralateral hemiplegia/spastic paralysis).
L5a #40
204
What happens in the case of a bilateral ventral pons lesion?
Locked in syndrome – All motor activity ceases, *except for vertical eye movements.*
L5a #44
205
1. ) Where are substantia nigra and crus cerebri located?
| 2. ) What is the result of their damage?
1.) *Lower* midbrain
2.) S.nigra = Parkinson's
Crus cerebri = Contralateral spastic paralysis
L5a #55
