Anatomy and Physiology 2 Flashcards
What symptoms can be seen with severe hypotension when considering the watershed zones of the brain?
upper leg/upper arm weakness
higher-order visual processing deficits
Cerebral perfusion is primarily driven by…
pCO2
How does therapeutic hyperventilation help decrease intracranial pressure?
In cases of acute cerebral edema (stroke, trauma), a decrease in pCO2 will cause a decrease in cerebral perfusion and ultimately cause vasoconstriction
What is the MC site of a berry aneurysm?
the junction of the anterior communicating artery and anterior cerebral artery
What palsy is associated with a lesion to the posterior communicating artery?
CN III palsy
What disease are Charcot-Bouchard micro aneurysms associated with?
chronic HTN
What is the condition where a patient has neuropathic pain due to thalamic lesions following a stroke?
central post-stroke pain syndrome
What vessels are ruptured in an epidural hematoma?
middle meningeal arteries
What intracranial hemorrhage shows a biconvex (lentiform) lens shape?
epidural hematoma
What vessels are ruptured in a subdural hematoma?
bridging veins
In what population are subdural hematoma more often seen?
elderly
alcoholics
blunt trauma
shaken baby
What can be seen on CT with a subdural hematoma?
crescent-shaped hemorrhage
What vessels are ruptured in a subarachnoid hemorrhage?
rupture of an aneurysm
often called “worst HA of my life” –> EMERGENCY
What is the MCC of intraparenchymal (hypertensive) hemorrhage?
systemic HTN (but also seen in amyloid antipathy, vasculitis, and neoplasms)
What are the areas most vulnerable during an ischemic stroke?
hippocampus (ischemic HYPOxia = HYPOcampus)
neocortex
cerebellum
watershed areas
How long does a patient have before irreversible brain damage during an ischemic stroke?
5 minutes
What is one contraindication for the use of tPA that can be detected using a CT?
hemorrhage
What is the MC site of hemorrhagic stroke?
basal ganglia
What type of necrosis results from an ischemic stroke?
liquefactive necrosis
What are the 3 types of ischemic strokes?
- thrombotic
- embolic
- hypoxic
What is the treatment for ischemic stroke? What is the time frame within which you can use this treatment?
tPA if used within 3-4.5 hr of onset and no hemorrhage/risk of hemorrhage
What is the definition of a transient ischemic attack?
brief, reversible episode of focal neurologic dysfunction lasting <24 hrs without acute infarction
What is the pathway of CSF through the ventricles of the brain?
CSF made in ependymal cells of choroid plexus –> lateral ventricle –> 3rd ventricle via right and left inter ventricular foramina of Monro –> 4th ventricle via cerebral aqueduct (Sylvius) –> subarachnoid space via foramina of Luschka (lateral) and foramen of Magendie (medial)
What is the pathogenesis of a communicating hydrocephalus?
Decrease CSF absorption by arachnoid granulations –> increased intracranial pressure, papilledema, and herniation
What are the signs of a normal pressure hydrocephalus?
“Wet, wobbly, and wacky”
Urinary incontinence, ataxia, and cognitive dysfunction
What is the pathogenesis of a normal pressure hydrocephalus?
- increase CSF production by choroidal tumors
2. impaired CSF absorption by arachnoid granulations damaged by tumor or meningitis
What is the key clinical feature of normal pressure hydrocephalus?
enlarged ventricles
What is interesting about hydrocephalus ex vacuo?
there is an apparent increase in CSF d/t neuronal atrophy (e.g. Alzheimer disease, advanced HIV, Pick disease)
What causes noncommunicating hydrocephalus?
structural blockage of CSF circulation within the ventricular system (e.g. stenosis of the aqueduct of Sylvius)
What many spinal nerves are there and how many for each section of the vertebral column?
31 spinal nerves in total
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
What is the pathogenesis of a herniated disc?
the nucleus pulpous (soft central disc) herniates through the annulus fibrosis (outer ring)
Usually around L4-L5 or L5-S1
At what level does the spinal cord end in an adult?
L1-L2
At what level should a lumbar puncture be performed?
L3-L4 or L4-L5
How is polio transmitted?
Fecal oral transmission
replicates in the oropharynx –> small intestine before spreading via bloodstream –> CNS –> destruction of cells in anterior horn of spinal cord
Does poliomyelitis result in UMN or LMN lesions?
LMNs - weakness, hypotonia, flaccid paralysis, fasciculations, hyporeflexia, and muscle atrophy
Also include signs of infection such as fever, HA, malaise
What is spinal muscular atrophy (Wernig- Hoffmann disease)?
congenital degeneration of anterior horns of spinal cord –> LMN
What are signs of Wernig-Hoffmann disease?
“floppy baby” with marked hypotonia and tongue fasciculations
What inheritance pattern is Wernig-Hoffmann disease?
AR
What is the genetic cause of Friedreich ataxia?
AR trinucleotide repeat disorder (GAA) on chromosome 9 in gene that encodes frataxin (iron binding protein)
What are physical findings of Friedreich ataxia?
staggering, frequent falling, nystagmus, dysarthria, pets cavus, hammer toes, hypertrophic cardiomyopathy
Friedreich is Fratastic (frataxin): he’s your favorite frat brother, always stumbling, staggering, and falling, but has a big heart
What is the cause of death with those wit Friedreich ataxia?
hypertrophic cardiomyopathy
In Brown-Sequard Syndrome, what are the two sensations that are CONTRALATERAL below the lesion?
pain and temperature sensation
What are physical signs of Horner Syndrome?
Ptosis
Anhidrosis
Miosis
What type of lesion is Horner Syndrome associated with?
A spinal cord lesion above T1 (e.g. Pancoast Tumor, Brown-Sequard Syndrome, late-stage syringomyelia)
Match the appropriate nerve root to the reflex…
S1, 2 L3, 4 C5, 6 C7, 8 L1, 2 S3, 4
S1, 2 - achilles reflex (“buckle my shoe”)
L3, 4 - patellar reflex (“kick the door”)
C5, 6 - bicep (“pick up sticks”)
C7, 8 - tricep (“lay them straight”)
L1, 2 - cremaster reflex (“testicles move”)
S3, 4 - anal wink reflex (“winks galore”)
A positive Babinski sign indicates what type of lesion in an adult?
UMN lesion
What CNs lie medially at the brain stem?
III, VI, and XII
What is the function of the pineal gland?
melatonin secretion, circadian rhythms
What is the function of the superior colliculi?
conjugate vertical gaze center
What is the function of the inferior colliculi?
auditory
Match the following cranial nerve nuclei to its CN nerves…
midbrain
pons
medulla
spinal cord
midbrain - CN III, IV
pons - CN V, VI, VII, VIII
medulla - CN IX, X, XII
spinal cord - CN XI
What CN innervates the orbicularis oculi muscle?
CN VII
Name the afferent and efferent CNs responsible for the pupillary reflex
CN II - afferent
CN III- efferent
Name the afferent and efferent CNs responsible for the gag reflex
CN IX - afferent
CN X - efferent
What type of information is relayed to the nucleus solitarius?
visceral sensory information (e.g. taste, baroreceptors, gut distention)
CN VII, IX, and X
What type of information is relayed to the nucleus ambiguous?
Motor innervation of pharynx, larynx, and upper esophagus (e.g. swallowing, palate elevation)
CN IX, X, and XI (cranial portion)
What type of information is relayed to the dorsal motor nucleus?
sends autonomic (parasympathetic) fibers to heart, lungs, and upper GI
CN X
Match the following opening with its appropriate nerves or vessels in the middle cranial fossa
optic canal superior orbital fissure foramen rotundum foramen ovale foramen spinosum
optic canal - CN II, ophthalmic artery, and central retinal vein
superior orbital fissure - CN III, IV, V1, VI, ophthalmic vein, sympathetic fibers
foramen rotundum - CN V2
foramen ovale - CN V3
foramen spinosum - middle meningeal artery
Match the following opening with its appropriate nerves or vessels in the posterior cranial fossa
internal auditory meatus
jugular foramen
hypoglossal canal
foramen magnum
internal auditory meatus - CN VII, VIII
jugular foramen - CN IX, X, XI, jugular vein
hypoglossal canal - CN XII
foramen magnum - spinal roots of CN XI, brain stem, vertebral arteries
What is the path the blood from the eye takes to drain?
blood from eye and superficial cortex –> cavernous sinus –> internal jugular vein
What nerves go through the cavernous sinus?
CN III, IV, V1, V2, and VI and postganglionic sympathetic fibers
What will be seen with a CN V motor lesion?
jaw deviation TOWARDS the side of lesion d/t unopposed force from the opposite pterygoid muscle
What will be seen with a CN X lesion?
uvula deviates AWAY from side of lesion (weak side collapses and uvula points away)
What will be seen with a CN XI lesion?
weakness turning head to contralateral side of lesion (SCM)
shoulder droop on side of lesion (trapezius)
What will be seen with a CN XII lesion (LMN)?
tongue deviates TOWARDS side of lesion d/t weakened tongue muscles on affected side
What is the function of the 3 ossicles of the middle ear?
to conduct and amplify sound from eardrum to inner ear
ossicles = malleus, incus, and stapes
Where in the inner ear are low frequencies heard?
at apex near helicotrema
Where in the inner ear are high frequencies heard?
at base of cochlea
What are the Rinne and Weber test results from someone with conductive hearing loss?
Rinne Test - abnormal (bone > air)
Weber Test - localizes to affected ear
What are the Rinne and Weber test results from someone with sensorineural hearing loss?
Rinne Test - normal (air > bone)
Weber Test - localizes to unaffected ear
How does noise induced hearing loss occur?
damage to the stereocilliated cells in organ of Corti
An UMN facial lesion would result in what clinical findings?
contralateral paralysis of lower face
forehead SPARED d/t bilateral UMN innervation
An LMN facial lesion would result in what clinical findings?
ipsilateral paralysis of upper AND lower face
What are clinical findings of a patient with facial nerve palsy?
ipsilateral facial paralysis (dropping smile)
inability to close eye on involved side
What are diseases associated with facial nerve palsy?
MC = idiopathic (Bell palsy)
Associated diseases
- Lyme disease
- herpes simplex
- herpes zoster (less common)
- sarcoidosis
- tumors
- diabetes
What is the treatment for facial nerve palsy?
corticosteroids
What are the 4 muscles to mastication and what are they innervated by?
masseter (close jaw)
temporalis (close jaw)
medial pterygoid (close jaw)
lateral pterygoid (opens jaw)
All innervated by CN V3
