USMLE Step1 Neuro Anatomy Kaplan

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Neural Crest Derivatives? 10: 1) Adrenal Meduall
2) Ganglia (Sensory + Autonomic)
3) Pigment Cells (Melanin)
4) Schwann Cells
5) Meninges (Pia + Arachnoid)
6) Pharyngeal Arches
7) Odontoblasts
8) Parafollicular (C) Cells
9) Aorticopulmonar Septum
10) Endocardial Cushions
Asymptomatic defect in vertebtral arches: Spina Bifida Occulta
Meninges project through the vertebral defect: Spina Bifida w/ Meningocele
What Labx do you ask for in Spina Bifida?: Alfa-feto protein (increased)
What happens in meningmyelocele?: Meninges and spinal cord project through vertebral defect
What are the FOUR sympathetic ganglions?: 1) Superior Cervical Ganglion
2) Middle Cervcial
3) Vertebral
4) Cervicothoracic
What level does the Lateral Horn of the Sympathetic system comprises?: T1-L2
What are the Four cranial ganglia of the Parasympathetic System?: 1) Ciliary ganglion
2) Submandibular
3) Pterygopalatine
4) Otic
What cranial nerves are Parasympathic?: 1) III
2) VII
3) IX 3,7,9
What controls the foregut and midgut in the parasympathetic?: Vagus X, at terminal ganglia
What Parasympathetic controls the Hindgut?: Pelvic Splachnic Nerves S2-S4
Ciliary Ganglion controls what CN and muscle?: Parasymp. CN III
Ciliary m.
Submandibular galgion controlled by?: Parasymp. CN VI
Submandibular and sublingual glands
Pterygopalatine ganglion is in control of?: Parasymp.
Lacrimal glands
Nasal
Oral
CN VII
Otic Ganglion controls what?: Parasymp. CV IX
Parotid Gland
Decrease in Alfa-feto Protein in Pregnancy equals?: Down Syndrome
Forebrain TEL DI Midbrain MES Hindbrain MET MI: Telencephalon
Diencephalon
Mesencephalon
Metencepahol
Myelencephalon
Telecephalon? CNS Structure + what ventricle is formed?: Cerebral Hemis. Lat. Ventri
Diecephalo? makes what structure in CNS and what Ventricles?: Thalamus, Pineal Third Vent
Gland, neurohypo
physis, hypotha-
lamus, retina
Mesencephalon? CNS/Ventricle: Midbrain Cerebral Acued.
Metencephalon: PONS Cerebellum 4th Ventri
Myelencephalon: Medulla 4th Ventri
Who makes the PONS Bridge?: Mesencephalon
What makes Craniopharyngiomas?: Remannts of Rathke's Pouch that compress optich chiasm
Anterograde movement by?: Kinesin
Retograde movement in CNS?: Dyenin
These viruses affect retrograde movement?: Herpes
Polio
Rabie
Tetanus
Oligodendrocyte vs Schwan?: Oligo can myelinate more than 1 cell, sometimes up to 50 cells!
Hair cells are derived from what layer?: Ectoderm
Substantia Nigra derives from with plate? Alar or Basal?: Basal
Polyhydramnios caused by?: Anencephaly
Oligohydramnios?: Potter's Syndrome (Bilateral Renal Agenesis), Oligohydramnios causes limb deformities and pulmonary hipoplasia
What connects the lateral ventricles?: Foramen of Monroe (Mon Roe)
What connects the 3rd ventricle with the 4th?: Acueduct of Sylvius
What connects the ventricles and the subarachnoid space? And where is this located?: Located in the 4th ventricle
Three openings:
1) Two Lateral formaina of Luschka
2) Median foramina of Magendie
Normal pH of CSF?: 7.33
CSF has higher concentrations of ____ than blood?: Cl-, Ca2+, HCO3- and glucose
How are protein levels in CSF compared to blood?: Lower
How are Sodium levesl in CSF compared to blood?: Same about 138 mEq/L
Are PMN normal in CSF?: No!!! Bacterial Meningitis
What does it mean when there is an increase in protein in CSF?: Possibly a CNS tumor
Define Hydrocephalus?: Increase in volume (excess) or pressure of CSF producing ventricular dilation
Communicating Hydrocephalus What are the underlying causes?: It is due to oversecretion of CSF by:

1) Choroid Plexus Papilloma
2) Tumor in Subarachnoid space
3) Meningitis (limits absorption into superior saggital sinus)
Noncommunicating Hydrocephalus: undersecretion/ obstruction of CSF flow
1)tumor blocking foramen Monro, cerebral aqueduct, 4th ventricle or Fomanina Magendie or Lushka.
Mechanism of Normal Pressure hydrocephalus?: - CSF not absorbed by arachnoid villi
- ventricles enlarged
- ventricles press agains cortex and skull
Symptoms of NPH (normal pressure hydrocephalus)?: 1) confusion
2) gait apraxia
3) urinary incontinence

stiff legs, dementia
confused with Alzheimer
like magnetic feet stuck to the ground
Blood-brain barrier regulated by what type of cells? What type of junctions?: - Tight Junctions in the capillary endothelium
- Astrocytes
Where is CSF produced?: Choroid Plexus
What part of hypothalamus is controlled by sympathetic?: Posterior Hypothalamus...
remember to use your posterior to be sympathetic w/ someone
Sympathetic Response? Think of the tiger chasing you: - Eyes open wide + pupil dilation (to see better)
- Perspire (to slip from it)
- Hair Sticks up (to look ferocious)
- Sphincters close (don't wanna go to the bathroom in the middle of the chase)
- Increase HR
- Epinephrine increase adrenalin
- liver increase degradation of glycogen to glucose
- pancreas
increase glucagon
decrease insulin
- Stress causes diabetes!
Horner Sx is an attack to sympathetic. What are the symptoms?: - Miosis enophthalmos
- pseudotosis
- Anhydrosis (can't sweat)
- lack of piloerection
What kind of neurons does the ventral horn contains?: Motorneurons
What kind of neurons does the dorsal horn control?: Sensory neurons
What 2 motorneurons does the ventral horn have?: Alpha and Gamma
What do alpha motorneurons control?: skeletal muscle (extrafusal fibers)
What do gamma motorneurons control?: muscle spindle contractile intrafusal fibers
Neural Systems: 3 Major Neural Systems
Motor Systems composed of?: 1) Upper Motorneuron
2) Lower Motorneuron
Where are the bodies of the upper motor neurons found?: 1) Red nucleus
2) Reticular Formation
3) Lateral Vestibular Nuclei of the brain stem.
4) Cerebral Cortex (Most Important)
What tract are the upper motor neurons run in?: Corticospinal Tract
Where is the motor cortex located in the brain? What lobe of the brain?: 1) Precentral Gyrus of the Frontal Lobe
2) Premotor Area both 60%
3) 1ry + 2ry somatosensory cortical areas of parietal lobe 40% of fibers
Where do corticospinal tract fibers exit the cerebral cortex?: In the Internal Capsule
Dorsal Horns transmit what type of stimulus?: Sensory
Ventral Horns transmit which type of stimulus?: Motor (Remember S&M)
What happens to the corticospianl tract at the lower medulla?: They cross the decussation of the pyramids continue contralaterally
Decorticate rigiditiy is caused by?: Lesions above the midbrain
A lesion below the midbrain causes what type of rigidity?: Decerebrate Rigidity
What reflexes are lost in an Upper Motorneuron Lesion? Reversal of Reflexes: 1) Babinski Reflex (extension instead of flexion)
2) Abdominal Reflex Lost
3) Cremasteric Reflex Lost
What are the two sensory systems?: 1) Dorsal Column-Medial Meniscal System

2) Anterolateral (Spinothalamic) System
Where is the 1st order neuron for the Sensory Systems?: Dorsal Root Ganglion (Pseudounipolar neuron)
Where is the 2nd order neuron?: Brain stem or Spinal Cord before crossing
Where is the 3rd order neuron?: Thalamus (T for Third)
It already has crossed to the other side
What does the Dorsal Column-medial leminiscal system convey? (DC-ML): Propioception and Stereoception
- sensory info. for discriminatory touch
- joint position
- vibratory
- pressure sensation from trunk and limbs
What type/class of fibers does the Dorsal Column (DC-ML) system have?: Class II or A-beta
Which part of the Dorsal Column is located medially? (Which Fasciculus): Fasciculus Gracilis
What does the fasciculus gracilis control? (Closest to the midline): Lower Extremities

- Remember that you are graceful when you walk
- Also, gracilis muscle is on the medial aspect of the leg/thigh
What part of the brainstem is the 2nd order neuron located?: Medulla
Does the second order neuron for sensory pathway cross the midline?: NO! It crosses at the 3rd order neuron in the Thalamus
Where do 2nd order Dorsal Column cells synapse?: Medulla
Nucleus Gracilis
Nucleaus Cuneatus
Where do 3rd order of the Dorsal Column-Medial Leminiscus System (DC-MLS) cells synapse?: Medial Leminiscus like its name
Part of the Thalamus
in the Ventroposterolateral Nucleus (VPL)
Where can you find 2nd order neuron in the Dorsal Column pathway? What Nuclei?: Brainstem
- Medulla
Nucleus Gracilis
Nucelus Cuneatus
What pathway crosses the midline in the sensory pathways?: The 2nd order neuron always crosses... need two lines to make a cross
Where is the 3rd order neuron located in the Dorsal Column Medial Leminiscus (DC-MLS) Pathway? Which nucleus?: Brainstem
- Thalamus
- At the medial lemniscus like its name
- It is found in the Ventroposterolateral Nucleus
Where do the 3rd order Neurons project in the Dorsal Column Pathway?: To the ANTERIOR portion of the PARIETAL Lobe
- Primary somethetic (somatosensory) area
- located in the Postcentral gyrus
How do you determine a lesion to the Dorsal Column?: Loss of Joint sensation
- vibratory
- pressure sensation
- two-point discrimination
- loss of the ability to identify characteristics of an object
What is asterognosis?: Identify:
- shape
- size
- consistency
- form
of an object using the sense of TOUCH
How do you diagnose Dorsal Column Pathway lesion?: ask patient to close his eyes and place feet together
- positive if patient sways

- if patient sways with eyes open then the lesion/damage is at the cerebellum and not dorsal column
What is another name for the Anterolateral System?: Spinothalamic Tract System
What does the Anterolateral System sense?: - pain
- temperature
- crude touch sensations
Via what fibers do the dorsal root ganglia enter the spinal cord?: Dorsal Root Fibers
- via A-Delta
- Class III
- Class IV
What is the backup of the Corticospinal Tract Lesions?: The backup is that 20% of the fibers do not cross
- the conscious crosses
unconscious doesn't cross
What do direct fibers that do NOT cross controll?: They control proximal pathways giving function to the proximal extremities
What is a picture of a Monkey's Bottom w/ flowers?: Medulla Oblongata IX, X, XII
What is the function of a bipolar neuron?: They are responsible for special senses
- vision
- smell
- taste
Function of a pseudounipolar neuron?: It is a scanning neuron
Where are 3ry (Tertiary) neurons of the Dorsal Column Systems located?: Thalamus (Remember T is for Third/Tertiary and Thalamus)
They cross
What happens to all the lesions that are unilateral in the Spinal Cord or the Brain Stem?: They result in a contralateral loss of pain and temperature
Where is the 2nd Neuron located for the Anterolateral (Spinothalamic) System?: Dorsal HORN Gray Matter
What order neuron crosses in the Anterolateral AL-SpT tract?: 2nd order neuron
Where do the axons of the 2nd order neuron enter?: Ventral White Commissure
Where does the analgesia begin after a lesion of the anterolateral/spinothalamic tract?: 1 or 2 segments below the contralateral side of the lesion.
What information does the spinocerebellar pathways carry?: Unconscious propioceptive input from muscle spindles and GTOs to cerebellum
What two major spinocerebellar pathways are there?: Dorsal and Cuneocerebellar
(Dorsal and Ventral)
Where are the 2nd order neuron from the Dorsal Spinocerebellar tract found? (What nucleus) At what level?: - Clarke Nucleus

- Spinal Cord level (T1-L2)
Where are the bodies of the cuneocerebellar tact found? (What nucleus) At what level?: - External Cuneate Nucleus
- Medulla
What information is gathered from the dorsal spinocerebellar pathway?: Input from lower extremities and lower trunk
What information is gathered by the Cuneocerebellar tracts?: Propioceptive input to the cerebellum from upper extremities and upper trunk
What disease atacks the Spinocerebellar tract?: Friederich's Ataxia
What form of inheritance is Friederich's Ataxia?: Autosomal Recessive
What are the symptoms in a hemisection of the spinal cord?: 1) ipsilateral spastic paresis below injury
2) ipsilateral loss of joint position sense, tactile discrimination and vibratory sensations below lesion
3) contralateral loss of pain and temperature starting 1 or 2 segments below lesion
What is another name for hemisection of the spinal cord?: Brown-Sequard Sx
What pathways are interrupted by a hemisection?: 1) corticospinal
2) dorsal columns
3) spinothalamic (anterolateral)
What spinal cord lesion is caused by Vitamin B12 Deficiency?: Subacute Combined Degeneration
What other Diseases cause Subacute Combined Degeneration (SCD)?: - Vitamin B12
- Pernicious Anemia
- AIDS
What pathway is damaged in Polio?: LMN
What pathway is damaged in Tabes Dorsalis?: Dorsal Column
What Pathway is damaged in Amyotrophic Lateral Sclerosis?: - Corticospinal Tract
- LMN
What pathways are damaged in Anterior Spinal Artery occulsion (ASA)?: - LMN
- Spinothalamic tract (SpTh)
- Corticospinal tract (CST)
- LMN
Except Dorsal Column (DC) is spared
What pathways are damaged in Subacute combined degeneration?: - Corticospinal Tract (CT)
- Dorsal Column
- Spinocerebellar Tract
What sign do we find on Dorsal Column lesion?: Romberg's Sign (+)
What tract is damaged in Syringomyelia?: - Spinothalamic (SpTh)
- LMN
What is a late complication of Syringomyelia?: Horner Syndrome (ptosis, miosis, anhydrosis)
What tracts are damaged in Hemisection: Brown-Sequard Sx?: - DC
- CST
- SpTh
- LMN
All of them!
If lesion is above T1 then Horner Sx. (Ipsilateral)
Which side is affected in Horner Sx lesion at T1-T4? Above T1?: Contralateral side

Above T1 is ipsilateral side
What happens in Vitamin B12 Def?: Demyelination of Spinal Cord Tracts
What tracts are affected by Vitamin B12 deficiency?: - Dorsal Columns (DC)
- Spinocerebellar Tracts
- Corticospinal Tracts (CTS)
Patient with paresthesias, bilateral spastic weakness, Babinksi sign and antibodies to intrinsic factor? Diagnosis Dx:?: Dx: Subacute combined degeneration
Intrinsic Factor is deficient and wont let the ileum absorb Vitamin B12
How are Multiple Sclerosis, Vitamin B 12 deficiency and Subacute Combined Degeneration similar?: They are all conditions where CNS is demyelinated
What cells are within the white matter of spinal cord?: Oligodendrocytes
- they create the myelin for all axons inside the CNS and tracts of white matter
What tract is injured in a patients with signs of UMN and LMN?: Amyotrophic Lateral Sclerosis (ALS)
Which cells regenerate in the PNS? Why?: Cells in the Ventral Root
- they contain myelin from Schwann Cells which promote regeneration of cut axons.
What are the three Ps of Tabes Dorsalis?: 1) Pain
2) Paresthesia
3) polyuria
Argyll Robertson Pupils
Last P is Pupil Defect!
What structures degenerates in MS?: Myelin containing nerves
i.e. Optic Nerves, formed by oligodendrocytes not schwann(PNS)
What test do you find positive in MS?: Heterogeneous Immunoglobulin G Staining w/ oligoclonal banding
Charactestic of Syringomyelia?: Bilateral loss of pain and temperature
What level does the fasciculus cuneatus begins?: T5 segment
What cells are affected in LMN lesions?: Alpha motor neurons in the ventral horns
What cells manage the reflex contraction of muscle and extension of oposite muscles?: Muscle Spindles
What are does the anterior spinal artery supply?: Ventrolateral 2/3's of the spinal cord
- DC are spared
- NO problems in pain and temp.
What is affected if the spinothalamic tract on the left side is affected?: Pain and temperature sensations on the right leg
Where do axons of fasciculus cuneatus have their bodies in?: Dorsal Root Ganglia
The Brain Stem: pg. 363
What three parts make the Brainstem?: 1) midbrain
2) pons
3) medulla
What cranial nerves arise from the midbrain?: 1) oculomotor III
2) trochlear IV

3 and 4
What cranial nerves enter or exit the pons?: V, VI, VII, VIII

5-8
What three cranial nerves enter or exit from the medulla?: IX, X, XII
Are Motor Nuclei located medially or lateral?: Medial M=Medial M=Motor
What are some of the symptoms for a pineal tumor?: Parinaud Sx:
1) paralisis of upward gaze
2) noncummunicating hydrocephalus
What cranial nerve is affected in Neurofibromatosis II?: VIII, associated with Schwannomas
What happens to a lesion of the nucleus ambiguus?: Ipsilateral paralysis of the soft palate
- uvula deviates away from the lesion
- nasal regurgitation of liquids
- hoarseness
- difficulty swallowing
What does the solitary nucleus control?: solitary sounds like salivary and taste.
- it controls the taste and visceral sensory neurons
What cranial nerve does the spinal nucleus control?: Trigeminal nerve V
What is the major parasympathetic nucleus in the brain stem? Where is it located?: Dorsal motor nucleus in the 4th ventricle
What cranial nerves does the nucleus solitarius control?: VII, IX, X

7,9,10
What nerve is NOT affected when there is an intramedullary lesion?: Spinal Accesory Nerve (XI)
What muscles does the spinal accesory nerve innervate?: 1) sternocleidomastoid
2) trapezius
Where is the abducens nucleus found?: Floor of the 4th ventricle
- lateral to the MLF
What happens when the abducens nucleus has a lesion?: - ipsilateral facial paralisis of the VII nerve
- inability to look to the side of the lesion
Where does the facil nerve exit the brain?: pontomedullary junction
What is the superior olivary nucleus responsible for?: It receives auditory impulses from both ears by cochclear nuclei.
- cochclear nuclei at pontomedullary junction
Where are vestibular nuclei found?: posterior surface of pons
What three structures are found in the pontomedullary junction?: - Facial motor nucleus exits fibers
- cochlear nuclei
What four nerves emerge from the pons?: V-VIII
5,6,7,8
at the pontomedullary junction
What is another name for midbrain?: Mesencephalon
What structures pass through the midbrain?: - cerebral acueduct
- superior colliculi
- inferior colliculi
What is the function of the inferior colliculi?: processes auditory information received bilaterally from cochlear nuclei
What is the function of superior colliculi?: help direct movement of both eyes in gaze
What two nerve emerge from midbrain?: oculomotor III
trochlear IV
3,4
What do the cerebral peduncles contain?: Corticospinal fibers
corticobulbar fibers
How do oculomotor nucleus exists the midbrain?: ventrally in the interpenducular fossa
How do trochlear nerves exit?: posterior midline inferior to the inferior colliculi
How does the ear protect itself against damage to the inner ear from loud sounds?: It contracts the stapedius and tensor tympani muscles
What happens to the Upper Face and Lower Face in a corticobulbar lesion?: The Upper Face has normal function since it has a bilateral innervation.

The Lower Face is affected contralaterally since there is only one set of fibers going there.
What are the components of the ear?: 1) external ear
2) middle ear
3) inner ear
What structures make up the external ear?: Pinna
External Auditory Meatus
What makes up the middle ear?: - Temporal Bone
- tympanic membrane
- connecting it to the oval window
What bones are included in the middle ear?: malleus
stapes
incus
What makes up the inner ear?: - labyrinth
- channels (semicircular ducts and cochlear duct)
What is the characteristic of endolymph?: It contains the same characteristics as intracellular fluid
What is the characteristic of perilymph?: It is ionically extracellular fluid
How does sound travel from the ear to the brain?: hair cells in the organ of Corti are conected to the spiral ganglion.
- to cochlear part of CN VIII
- ventral cochlear nuclei --> Superior Olivary N. --> Inferior Colliculus --> Midbrain
What is stimulated in low-frequency sounds?: Apex of of the cochlea
What is stimulated in high-frequency sounds?: Base of the cochlea
Does perilymph move towards or away the direction of movement?: Toward
How does endolymph move?: Against the direction of movement
Static Laberynth is made up of?: Striola
Otoconia
Kinocillium
How can you tell if there is excitation from the kinocillium?: They are pointing toward the striola
What are the components of the dynamic laberynth?: Ampulla, endolymph, hair cells, crystals
What consists in a Pinealoma Sydrome?: Insomnia, headache and can't look up
What is the mechanism of damage in a pinealoma?: - Damage to the superior colliculus center for upward gaze
- pupillary constriction for accomodation
- decrease in melatonin
- decrease in sleep patterns
- headache from tumor compression
- Can't follow Upward gaze - Hydrocephalus - Headache - Pupils Accomodate but not react Diagnostic?: Pinnealoma/Parinaud Sx
What nerve is intact when you have good convergence?: III adducts well
Patient difficulty swallowing and palata droopped, what center is affected?: Nucleus Ambiguus

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Number of cards 193