Midterm 1 study guide Flashcards
(186 cards)
1
Q
Outer‑to‑inner order of meninges
A
Dura mater → Arachnoid mater → Pia mater
2
Q
Falx cerebri separates _____
A
The two cerebral hemispheres
3
Q
Tentorium cerebelli separates
A
Occipital lobes from cerebellum
4
Q
Epidural hematoma location
A
Blood collects external to dura (commonly middle meningeal a.)
5
Q
Subdural hematoma location
A
Blood between dura & arachnoid, tears bridging veins
6
Q
Subarachnoid hemorrhage hallmark
A
“Worst headache of life,” blood in CSF, ruptured aneurysm
7
Q
Lumbar puncture needle level—adult
A
L3–L4 (or L4–L5) into lumbar cistern
8
Q
Lumbar puncture needle level—infant
A
L4–L5 or below (conus ends lower, ~L3)
9
Q
If intracranial pressure (ICP) ↑, LP is _____
A
Contraindicated (risk of herniation)
10
Q
Normal adult opening CSF pressure
A
70‑180 mm H₂O (≤ 200)
11
Q
CSF produced mainly by
A
Choroid plexus (ependymal cells)
12
Q
Route of CSF flow
A
Lat. ventricle → Foramen of Monro → 3rd V → Cerebral aqueduct → 4th V → Foramina Luschka/Magendie → Subarachnoid space → Arachnoid granulations → Dural sinuses
13
Q
Functions of CSF (all 3)
A
- Buoyancy
- Cushioning/trauma dampening
- Waste removal & chemical stability
14
Q
CSF leaves 4th ventricle via
A
Foramina of Luschka (2) & Magendie (1)
15
Q
Large molecules cross BBB easily?
A
False – tight junctions restrict them
16
Q
Pineal gland BBB status
A
Lacks BBB (True)
17
Q
About _____ % of CSF produced by choroid plexus
A
≈ 70 %
18
Q
CSF formed by filtration through _____ cells’ fenestrations
A
Choroidal capillary endothelial cells
19
Q
Brain “floats” because SG of brain ≈ CSF; effect?
A
Reduces traction on nerves/vessels
20
Q
Post‑LP “low‑pressure” headache mechanism
A
CSF leak → sagging brain → traction on pain‑sensitive dura
21
Q
Lumbar cistern extends from
A
Conus medullaris (~L1‑L2) → S2
22
Q
Filum terminale function
A
Anchors spinal cord to coccyx within dural sac
23
Q
Cauda equina defined as
A
Bundle of dorsal/ventral roots below conus in lumbar cistern
24
Q
Dural sleeves of spinal nerves formed by
A
Meningeal pia + arachnoid + dura extensions
25
Arachnoid villi function
One‑way CSF valves into superior sagittal sinus
26
“Obstructive” vs “communicating” hydrocephalus
* Block in ventricles/aqueduct
* Impaired arachnoid granulation absorption
27
Most common LP complication
Post‑dural‑puncture headache (low‑pressure)
28
Structure pierced last by LP needle
Arachnoid mater (then subarachnoid space)
29
Epidural anesthesia injected into
Extradural (epidural) space—outside dura, not into CSF
30
Key CSF lab finding in bacterial meningitis
Low glucose, high WBC (neutrophils), cloudy/turbid appearance
31
Ventral (anterior) root function
Efferent motor (GSE & pre‑ganglionic autonomic)
32
Dorsal (posterior) root function
Afferent sensory; contains dorsal root ganglion
33
Dorsal root ganglion cell type
Pseudo‑unipolar primary sensory neurons
34
Conus medullaris vertebral level (adult)
~L1–L2
35
Primary spinal cord anchor inferiorly
Filum terminale internum → externum → coccyx
36
Dentate ligaments role
Lateral tooth‑like pia extensions anchor cord to dura
37
Define cervical enlargement levels & reason
C5‑T1; upper‑limb plexus supply
38
Define lumbosacral enlargement
L1‑S3; lower‑limb plexus supply
39
Cervical plexus segments
C1‑C4 (phrenic nerve C3‑C5 “keeps diaphragm alive”)
40
Brachial plexus roots
C5‑T1
41
Lumbar plexus roots
L1‑L4
42
Sacral plexus roots
L4‑S4
43
Thoracic spinal nerves (T2‑T11) form _____ not plexus
Intercostal (segmental) nerves
44
Myotatic (stretch) reflex synapses
Monosynaptic (Ia afferent → α‑motor)
45
Withdrawal (flexor) reflex
Polysynaptic; protective; often with crossed‑extensor contralateral extension
46
Golgi tendon reflex receptor
Ib afferent from Golgi tendon organ; inhibits same muscle via interneuron
47
Gamma‑loop concept
Gamma motor adjusts spindle sensitivity → Ia afferent → α‑motor for tone
48
Monosynaptic vs polysynaptic definition
One central synapse vs ≥ 2
49
Crossed‑extensor reflex importance
Maintains balance during withdrawal
50
Define dermatome
Skin area innervated by a single dorsal root
51
Define myotome
Muscle mass innervated by single ventral root
52
Autonomic outflow spinal segments
* Sympathetic T1‑L2
* Parasympathetic S2‑S4
53
Intermediolateral cell column location
T1‑L2 lateral horn – pre‑ganglionic sympathetics
54
Clarke’s column levels & function
T1‑L2; unconscious proprioception to cerebellum (dorsal spinocerebellar)
55
Why thoracic cord shows smallest diameter
Fewer limb motor neurons & smaller Gray matter
56
Anterior spinal artery supplies _____
Anterior 2/3 cord incl. corticospinal, spinothalamic
57
Posterior spinal arteries supply
Posterior 1/3—dorsal columns
58
Great radicular (Adamkiewicz) artery level
Usually L2; critical for lumbar enlargement
59
Spinal cord ischemia leads first to
Loss of motor & pain/temp (anterior syndrome)
60
Cauda equina syndrome symptoms
Saddle anesthesia, urinary retention, flaccid paralysis lower limbs
61
CN I name & function
Olfactory – smell (sensory)
62
CN II
Optic – vision (sensory)
63
CN III
Oculomotor – most extraocular muscles, parasymp pupil constrict (motor)
64
CN IV
Trochlear – superior oblique muscle (motor)
65
CN V divisions
* V1 ophthalmic (sensory)
* V2 maxillary (sensory)
* V3 mandibular (sensory & motor to mastication)
66
Muscles of mastication nerve
CN V3
67
CN VI
Abducens – lateral rectus eye muscle
68
CN VII
Facial – muscles of facial expression, taste ant 2/3 tongue (chorda tympani), parasymp lacrimal & salivary (except parotid)
69
Cranial nerve for taste anterior 2/3 tongue
Facial (CN VII via chorda tympani)
70
CN carrying general facial sensation
Trigeminal (CN V)
71
CN VIII
Vestibulocochlear – hearing & balance
72
CN IX
Glossopharyngeal – taste & sensation post 1/3 tongue, carotid body sinus, parotid gland PS
73
CN X
Vagus – parasympathetic thoraco‑abdominal, larynx muscles etc.
74
Carotid sinus baroreceptor afferent nerve
CN IX glossopharyngeal
75
CN XI
Accessory – SCM & trapezius
76
CN XII
Hypoglossal – tongue muscles
77
Facial nerve exits skull via
Stylomastoid foramen
78
Trigeminal ganglion analogue of dorsal root ganglion
True
79
Pathways for corneal blink reflex
Afferent V1, efferent VII
80
Lesion of CN VII UMN vs LMN
UMN spares forehead (bilateral), LMN full ipsilateral face
81
Bell palsy etiology
Idiopathic CN VII LMN paralysis
82
Hypoglossal lesion sign
Tongue deviates toward lesion on protrusion
83
Jaw jerk reflex afferent/efferent
V3 / V3 (monosynaptic)
84
Gag reflex
Afferent IX, efferent X
85
Spinal accessory nerve nucleus location
Cervical cord C1‑C5 lateral ventral horn
86
Taste pathway nucleus
Nucleus of solitary tract (rostral gustatory)
87
Muscles of facial expression embryologic arch
2nd pharyngeal arch (CN VII)
88
Tensor tympani innervation
CN V3
89
Stapedius innervation
CN VII
90
Damage to CN VIII cochlear part
Sensorineural hearing loss ipsilateral
91
Damage to vestibular part
Vertigo, nystagmus
92
Jugular foramen syndrome CNs
IX, X, XI
93
Superior orbital fissure CNs
III, IV, V1, VI
94
Internal acoustic meatus CNs
VII & VIII
95
Olfactory pathway unique property
Bypasses thalamus (direct to piriform/limbic cortex)
96
CN with longest intracranial course
CN IV
97
LR6 SO4 AO3 mnemonic
Lateral rectus CN VI, Superior oblique CN IV, All others CN III
98
Trigeminal sensory nuclei
* Mesencephalic (proprio)
* Chief (touch)
* Spinal (pain/temp)
99
Facial nerve parasymp nuclei
* Superior salivatory
* Lacrimal
100
Glossopharyngeal PS nucleus
Inferior salivatory
101
Neuron cell body (soma) function
Metabolic & trophic center; protein synthesis
102
Nissl substance composition
Rough ER + ribosomes (basophilic)
103
Structures lacking Nissl
Axon hillock & axon
104
Axon hillock significance
AP initiation zone (initial segment)
105
Dendrite primary function
↑Surface area for synaptic input
106
Microtubules diameter
25 nm; transport tracks (kinesin/dynein)
107
Neurofilaments role
Structural support; abnormal in Alzheimer’s tangles
108
Fast anterograde transport speed & motor
100‑400 mm/day via kinesin
109
Fast retrograde transport speed & motor
50‑200 mm/day via dynein
110
Slow axonal transport carries
Cytoskeletal proteins (0.25‑5 mm/day)
111
Multipolar neuron example
Ventral horn α‑motor neuron
112
Bipolar neuron locations
Retina, olfactory epithelium, vestibular & cochlear ganglia
113
Pseudo‑unipolar function
Primary sensory in DRG, nodose ganglion (BP sensing)
114
Unipolar neurons in vertebrates
Very rare; autonomic ganglia in invertebrates
115
Principal (Golgi I) vs intrinsic (Golgi II)
Long‑axon projection vs short interneuron
116
Astrocyte GFAP marker
Glial fibrillary acidic protein
117
Astrocyte BBB contribution
Perivascular end‑feet around capillaries
118
K+ buffering by astrocytes
High resting conductance & gap junction coupling
119
Astrocyte glutamate uptake transporter
EAAT1/EAAT2 → converts to glutamine
120
Astrocyte gliotransmitters
* Glutamate
* D‑serine
* ATP
121
Astrocyte role in microcirculation
Ca²⁺‑dependent release of PGE₂ / 20‑HETE dilate/constrict arterioles
122
Microglia origin
Mesoderm (bone‑marrow derived)
123
Interfascicular oligodendrocyte location
White matter rows; CNS myelin
124
Oligodendrocyte vs Schwann myelin ratio
1 oligodendrocyte ∼ 60 axons; 1 Schwann per internode
125
Nodes of Ranvier property
High Na⁺‑channel density; saltatory conduction
126
What is the origin of microglia?
Mesoderm (bone‑marrow derived)
## Footnote
Microglia are immune cells in the central nervous system.
127
Where are interfascicular oligodendrocytes located?
White matter rows; CNS myelin
## Footnote
They are responsible for myelinating axons in the central nervous system.
128
What is the oligodendrocyte vs Schwann myelin ratio?
1 oligodendrocyte ∼ 60 axons; 1 Schwann per internode
## Footnote
Oligodendrocytes can myelinate multiple axons, while Schwann cells myelinate a single internode.
129
What is a property of the Nodes of Ranvier?
High Na⁺‑channel density; saltatory conduction
## Footnote
This allows for faster transmission of electrical signals in myelinated axons.
130
What is the myelin composition in the CNS vs PNS?
CNS: MBP + proteolipid; PNS: MBP + P0 glycoprotein
## Footnote
Myelin basic protein (MBP) is common in both, but they differ in additional proteins.
131
What is the pathology of multiple sclerosis?
Autoimmune demyelination CNS (oligodendrocytes)
## Footnote
MS leads to damage of the myelin sheath in the central nervous system.
132
What is the pathology of Guillain‑Barré syndrome?
Autoimmune demyelination PNS (Schwann)
## Footnote
GBS primarily affects the peripheral nervous system.
133
What is Wallerian degeneration?
Distal axon/terminal breakdown after injury
## Footnote
This process occurs following the injury of an axon.
134
What is chromatolysis?
Soma swelling, Nissl dispersion after axon injury near cell body
## Footnote
This reflects the response of the neuron to injury.
135
What is an example of anterograde transneuronal degeneration?
Optic nerve → lat geniculate neuron loss
## Footnote
This refers to the degeneration of neurons downstream from an injured neuron.
136
What occurs in retrograde transneuronal degeneration?
Inputs to injured neuron degenerate (e.g., cortex after thalamic lesion)
## Footnote
This affects the neurons that send signals to the injured neuron.
137
How does the rabies virus transport to the CNS?
Fast retrograde axonal to CNS + transneuronal spread
## Footnote
This facilitates the virus's movement through the nervous system.
138
What is the latency mechanism of herpes simplex virus?
Virus transported retrogradely to trigeminal ganglion
## Footnote
This allows the virus to remain dormant before reactivation.
139
What role does β‑secretase play in Alzheimer’s disease?
Cleaves APP to Aβ, promotes plaque formation
## Footnote
Amyloid plaques are a hallmark of Alzheimer's pathology.
140
What does tau hyperphosphorylation lead to?
Neurofibrillary tangles (paired helical filaments)
## Footnote
These tangles are another characteristic of Alzheimer's disease.
141
What defect is associated with amyotrophic lateral sclerosis (ALS)?
Mutant SOD1 in astrocytes → ↓EAAT2 → glutamate excitotoxicity
## Footnote
This contributes to the motor neuron degeneration seen in ALS.
142
From what cell do gliomas originate?
Astrocyte or other glia (e.g., oligodendrocyte)
## Footnote
Gliomas are brain tumors arising from glial cells.
143
What type of cell is associated with NF‑1 (von Recklinghausen) tumors?
Schwann cell (True)
## Footnote
These tumors are linked to neurofibromatosis type 1.
144
What is the mechanism of edaravone in ALS?
Free‑radical scavenger antioxidant
## Footnote
This treatment aims to reduce oxidative stress in ALS.
145
What is the benefit of plasma exchange in Guillain‑Barré syndrome?
Removes circulating antibodies against myelin
## Footnote
This can help alleviate symptoms of the condition.
146
What defines mitotic nondisjunction?
Post‑zygotic error → mosaicism
## Footnote
This can lead to genetic diversity in cell lines.
147
What causes Down syndrome?
Trisomy 21 via meiotic NDJ; ↑ maternal age
## Footnote
Nondisjunction during meiosis is a common cause.
148
What is the karyotype for Turner syndrome?
45,X (partial/complete X loss)
## Footnote
This chromosomal pattern is characteristic of Turner syndrome.
149
What is Klinefelter syndrome?
47,XXY – testicular dysgenesis
## Footnote
This genetic condition results from an extra X chromosome.
150
What gene is associated with Marfan syndrome?
Fibrillin‑1 (FBN1) autosomal dominant
## Footnote
Marfan syndrome affects connective tissue.
151
What protein family is associated with Ehlers‑Danlos syndrome?
Collagen (various types)
## Footnote
This affects the structure and function of connective tissues.
152
What does the TORCH infection acronym stand for?
Toxo, Other (syphilis, VZV), Rubella, CMV, HSV
## Footnote
These are infections that can affect fetal development.
153
What is the triad of fetal alcohol syndrome?
Growth retardation + CNS dysfunction + facial dysmorphia
## Footnote
This condition is caused by alcohol exposure during pregnancy.
154
What nutrient is important for preventing anencephaly?
Folic acid preconception & 1st trimester
## Footnote
Folic acid is crucial for neural tube development.
155
What is the definition of hemorrhage?
Discharge of blood from vascular compartment
## Footnote
This can occur due to various medical conditions.
156
What is the difference between hyperemia and congestion?
Active vs passive ↑ blood in tissue
## Footnote
Hyperemia is an active process, while congestion is passive.
157
Does edema arise when venous return is impaired?
Yes – fluid accumulates upstream
## Footnote
This can lead to swelling in affected areas.
158
What is the main site for deep venous thrombi?
Deep leg veins (popliteal, femoral)
## Footnote
These are common sites for thrombus formation.
159
What is the usual source of pulmonary embolism?
DVT fragment via IVC → right heart → lungs
## Footnote
Deep vein thrombosis is a common precursor.
160
What organ is the source of arterial thromboembolism?
Heart (mural thrombus post‑MI/AF)
## Footnote
Thrombus formation can occur after myocardial infarction.
161
What does atherosclerosis predispose to?
Arterial thrombi
## Footnote
The buildup of plaques narrows arteries and increases thrombus risk.
162
What is the cardiac output equation?
CO = HR × SV (not resp rate)
## Footnote
Cardiac output is determined by heart rate and stroke volume.
163
What type of vessel contributes to peripheral vascular resistance?
Arterioles
## Footnote
These small blood vessels regulate blood flow and pressure.
164
What component is involved in venous microcirculation?
Venules (with arterioles, capillaries)
## Footnote
Venules collect blood from capillaries and transport it back to the heart.
165
What is the size and cause of petechiae?
1‑2 mm pinpoint hemorrhages from capillary rupture
## Footnote
These small spots indicate minor bleeding.
166
What is the definition of ecchymosis?
>1 cm bruise
## Footnote
This represents larger areas of bleeding under the skin.
167
What type of tissue is the epineurium?
Dense connective tissue
## Footnote
It surrounds nerves and provides structural support.
168
What is the most common neuron type in the CNS?
Multipolar
## Footnote
Multipolar neurons have multiple processes and are found throughout the CNS.
169
What type of neuron is found in the retina?
Bipolar
## Footnote
Bipolar neurons are involved in sensory pathways.
170
How is synaptic transmission defined?
Mechanism neurons communicate across synapse
## Footnote
This is crucial for neuron-to-neuron communication.
171
What is the function of interfascicular oligodendrocytes?
Myelination in white matter
## Footnote
They support the rapid conduction of electrical impulses.
172
What is a correct statement about astrocyte properties?
Regulate synaptic transmission & neurovascular coupling
## Footnote
Astrocytes play a vital role in maintaining homeostasis in the CNS.
173
Are unipolar neurons rare in vertebrates?
Very rare in vertebrates (True)
## Footnote
Most vertebrate neurons are multipolar or bipolar.
174
Is it true that pseudo‑unipolar neurons in the nodose ganglion sense blood pressure?
True
## Footnote
These neurons play a role in sensory signaling.
175
Does Guillain‑Barré syndrome affect all ages and both sexes?
True
## Footnote
GBS is a condition that can impact anyone, regardless of age or gender.
176
Do demyelination diseases include MS & GBS?
True
## Footnote
Both conditions involve damage to the myelin sheath.
177
What is the effect of oral contraceptives on coagulation?
Increase coagulability (statement 'decrease' = False)
## Footnote
This can raise the risk of thromboembolic events.
178
Do lymphatics reabsorb interstitial fluid?
True
## Footnote
This process is essential for maintaining fluid balance in tissues.
179
What is the most common chromosomal anomaly?
Trisomy 21 (verified)
## Footnote
This is associated with Down syndrome.
180
Is nondisjunction a major cause of numeric errors?
True
## Footnote
This can lead to conditions like aneuploidy.
181
Where do vegetations typically form?
Mitral or Aortic valves
## Footnote
These can indicate infective endocarditis.
182
What is the effect of left‑ventricular failure on the lungs?
Pulmonary edema
## Footnote
This occurs due to increased pressure in the pulmonary circulation.
183
Where do deep venous thrombi typically develop?
Legs, not IVC (though may propagate)
## Footnote
They are primarily associated with venous stasis.
184
What is the blood profile associated with a mutant LDL receptor?
↑ LDL & cholesterol (familial hypercholesterolemia)
## Footnote
This genetic condition leads to high levels of low-density lipoprotein.
185
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