Quiz 1 Flashcards
Some quiz 1 learning objectives + Cassidy's practice Qs
Lesions of thalami, or large lesions in the hemispheres above the brainstem can impair consciousness indirectly due to what?
Mass effect (putting pressure on brainstem)
What is the area between the midbrain and the pons called?
Isthmus
Rupture of a berry aneurysm would most likely cause what kind of injury?
Subarachnoid hemorrhage
A subdural hematoma is typically caused by a rupture of what?
Bridging veins
A posterior communicating aneurysm can cause what?
CN III palsy
85% of Berry aneurysms occur in the __________ circulation
anterior
True or false? All information passed between cerebral hemispheres and the spinal cords pass through the brainstem.
True
Some of the nuclei in what part of the brain contain neurotransmitters?
Brainstem
The back of the brain (where the cerebellum sits) is directionally called what (compared to the rest of the brain)?
Caudal
What is the name of the fold between the frontal and parietal lobes?
Central sulcus
What is the common excitatory NT in the CNS?
Glutamate
What is the significance of GABA?
Most common inhibitory NT in the CNS
True or false: histamine, norepinephrine, dopamine, serotonin are all NTs
True
True or false: gray matter has local synaptic communications between neurons, white matter is over long distances
True
The cerebral cortex is made up of _________ matter and wraps around the cerebral hemispheres
Gray
Why does the spinal cord end at L-1, L-2?
Bony canal (vertebra) lengthen faster than spinal cord during development.
What condition can be caused by disk herniation, tumors, trauma, epidural abscess below the L1, L2 area?
Cauda equina syndrome
What separates the temporal lobe from the frontal lobe?
The Sylvian (or lateral) fissure (a deep sulcus)
What divides the motor and sensory cortex?
Central sulcus
Where is the primary somatosensory cortex located?
Postcentral gyrus
The bumps or ridges in between the sulci are called _________
gyri
What lies in precentral gyrus in the frontal lobe?
Primary motor cortex
Where is the primary auditory cortex?
Transverse gyri of Heschl
(this is 2 fingerlike gyri inside the Sylvian fissure)
The right visual cortex innervates which visual field?
Left half of each eye
Lesions above the pyramidal decussation would mostly cause weakness where?
Contralaterally
The ______________________ cortex is less lateralized and input from opposite side is slightly stronger, but not clinically detectable
primary auditory
_______________________ is the most important motor pathway
Corticospinal tract/ “pyramidal tract”
Pyramidal decussation occurs at junction of __________ and spinal cord
medulla
The 2 main spinal cord sensory pathways are called what?
1) Posterior column pathway
2) Anterolateral pathway
What project from the cortex down to the spinal cord or brainstem?
Upper motor neurons
Ataxia, the loss of balance and coordination, can be caused by lesions where?
Cerebellum
What is the somatosensory pathway that conveys proprioception, vibration sense, and fine touch?
Posterior column pathway
True or false: your ability to sense things would be completely eliminated if the posterior column pathway was severed. Explain your answer.
False; anterior column pathway would still be working
Which somatosensory pathway detects when you have really hot coffee spilled on you? Explain why.
Anterolateral pathway; it conveys pain, temperature, and crude touch
Which is the only sensory pathway to not go through the thalamus relay center? Why?
Olfaction; goes directly to olfactory cortex
What pathway crosses over immediately?
Anterolateral
What is located in the center of the brain and receives information about light and dark and secrets melatonin as needed?
Pineal gland
True or false? Wernicke’s area is located in the dominant hemisphere area of the brain (usually left) and processes higher order information.
True
What controls autonomic functions and the limbic system, among many other things?
Hypothalamus
What causes receptive aphasia?
Damage to Wernicke’s area
What type of aphasia can damage to Broca’s area cause?
Expressive or motor aphasia
What may cause a patient to ignore objects, or even their own body parts, to one side? What is this phenomenon called?
Right parietal lesions; hemineglect
Lesions to what area may cause a patient to experience problems with personality (like lack of judgement, inappropriate joking, inhibition) and cognition?
Frontal lobe
What may cause inability to recognize faces, colors, or persistence or reappearance of an earlier viewed object?
Lesions in the visual cortex (of parieto-occipital lobe)
Seizures in what part of the brain may cause visual hallucinations?
Visual cortex (of parieto-occipital lobe)
What arteries directly supply the brain?
Internal carotid and vertebral arteries
What forms the basilar artery?
The vertebral arteries joining
What supplies the posterior of the brain?
Basilar artery
What supplies the anterior of the brain?
Internal carotid arteries
The _________________ vein returns the brain’s blood
internal jugular
Where does the middle meningeal artery run?
Epidural space
List the flow of CSF in order (7 steps)
1) Lateral ventricles
2) Foramen of Monro
3) Third ventricle
4) Sylvian aqueduct
5) Fourth ventricle
6) Foramen of Luschka and Magendie
7) Subarachnoid space
[Arachnoid granulations then absorb]
Bridging veins are found where?
Subdural space
What ventricle is in the diencephalon?
3rd ventricle
What ventricle is surrounded by the pons, medulla and cerebellum?
Fourth
Normal volume of CSF in an adult is _____cc, the choroid plexi produce about _______ cc/d
150cc; 500 cc/d
What houses the cauda equina?
Lumbar cistern
What tract controls voluntary movement of distal muscles (hands and limbs) and is involved in fine motor skills?
The lateral motor system, aka lateral corticospinal tract
If there’s a lesion in the lateral corticospinal tract of the brain, what would happen?
Contralateral hemiparesis, particularly affecting fine motor control
What two tracts originate in the primary motor cortex?
Lateral corticospinal tract and anterior corticospinal tract
What are the two divisions of the motor system’s tract?
Lateral (lateral corticospinal tract) and medial (anterior corticospinal tract)
Damage of what part of the motor system leads to issues of the trunk like gait disturbances, difficulty maintaining upright posture, or gross motor movement difficulties in Parkinson’s?
Medial motor system
What tract controls bending, twisting, and movements of the trunk?
Anterior corticospinal tract
What 3 things control the sympathetic and parasympathetic nervous systems?
Hypothalamus, brainstem, and amygdala
What can dysfunctions in the ANS lead to?
Autonomic neuropathies (nerve disorders) in the axon, myelin sheath, or both.
Neuropathy affecting spinal nerve roots is called _____________
radiculopathy
1) Burning, tingling pain, that often radiates down a limb or dermatome is called what?
2) What causes this?
3) What is that cause often secondary to?
1) Radiculopathy
2) ANS neuropathy affecting spinal nerve roots
3) Diabetes (most common), Lyme disease, HIV, or varicella-zoster (shingles)
Gray matter in the spinal cord is surrounded by what?
Ascending and descending white matter columns
Where do the nerve plexuses of the arms and legs originate?
Cervical and lumbosacral enlargements of the spinal cord
Vertebral arteries form what besides the basilar artery?
Both the anterior and posterior spinal arteries
What supplies most of the spinal cord with blood? What part does it not supply?
Anterior spinal artery; doesn’t supply dorsal surface
Venous return for the spinal cord occurs where?
Epidural space
Where is the corticospinal tract of the brain?
In the posterior limb of the internal capsule
A lesion/stroke of the ________________ can cause weakness of the entire contralateral side of the body from face to lower extremity
internal capsule
What are the 3 long tracts of the spinal cord?
1) Posterior column-medial leminiscal system
2) Anterolateral systems (2, includes spinothalamic tract)
3) Corticospinal tract
What are the two main somatosensory pathways?
1) Posterior column-medial leminiscal system
2) Anterolateral systems (2, includes spinothalamic tract)
A lesion of what tract will cause a loss of pain and temp sensation in the contralateral side below the level of the lesion? Why?
Spinothalamic tract; mediates pain and temp sense
What decussates at anterior commissure of spinal cord?
Anterolateral systems (includes spinothalamic tract)
What does the spinothalamic tract relay info through and to?
Through the thalamus to the primary somatosensory cortex
What tract conveys proprioception, vibration sense, and fine touch?
Posterior column-medial leminiscal system
What long tract decussates in the lower medulla?
Posterior column-medial leminiscal system
What is the most common cause of spinal cord lesions?
External compression from degenerative spinal disease, trauma, and metastatic cancer.
Vitamin B12 deficient can affect what part of the CNS?
Posterior cord
Lesions (trauma, compression, multiple sclerosis) of the ___________________ of the spinal cord causes loss of vibration sense, and proprioception below the level of the lesion. This is called _________________________
posterior columns; posterior cord syndrome
Anterior spinal artery infarcts can cause what condition that leads to loss of pain and temp sensation below the level of lesion?
Anterior cord syndrome
The cauda equina consists of nerve roots from ______ to ______ in the coccygeal tail bone end
L2 to Co1
What is responsible for the motor and sensory innervation to pelvic organs (e.g bladders and bowel), lower limbs, and perineum?
The cauda equina
What controls voluntary sphincter control and sensory functions in the saddle region?
Cauda equina
Sensory loss in what region is called saddle anesthesia?
S2-S5
Impairment of _________ (perianal) can cause bladder dysfunction, constipation, fecal incontinence, and loss of erections and needs immediate treatment
S2-S4
Is the thalamus made of gray or white matter? What is it shaped like?
Gray; like eggs
What is the processing center of the brain?
Thalamus
Define dermatome
A peripheral region innervated by sensory fibers from a single nerve root level
________________ are organized in a way that allows clinicians to map sensory information to the corresponding spinal nerve, which can be useful in diagnosing certain neurological conditions.
Dermatomes
What is the T4 dermatome?
Nipple line
What is the T10 dermatome line?
Umbilicus
What is the C4 dermatome line?
Thumb
What is the S5 dermatome?
Perianal
What supplies the anterior hemispheres of the brain?
Internal carotid arteries
____________________ supply posterior hemispheres and join forming the basilar artery
Vertebral arteries
The anterior and posterior blood supplies form the ___________________ from which all major cerebral vessels arise
Circle of Willis
About __[fraction]_____of general population has a full/complete ring/ circle of willis
1/3
_______________________ come off the aorta and split into the internal and external carotid arteries
Common carotid arteries
The main arteries that supply the cerebral hemisphere are what?
The anterior, middle, and posterior cerebral arteries (ACA, MCA, and PCA)
The anterior and middle cerebral arteries are the termination of what?
Internal carotids
The ___________ join anteriorly by the anterior communicating artery
ACA (anterior cerebral arteries)
The anterior and posterior circulations are linked by the ________________________ arteries
posterior communicating
What two arteries are linked to join anterior and posterior circulation of the brain?
Internal carotid and the posterior cerebral arteries
What does the anterior cerebral artery (ACA) supply?
-Cortex on the anterior medial surface of the brain, from frontal to parietal lobe.
-Medial sensorimotor cortex.
The _____________ artery’s branches supply the cortex above and below the Sylvian fissure including the lateral temporal lobe and parts of the parietal lobe. Also includes large parts of the basal ganglia and internal capsule, and the thalamus
Middle cerebral artery (MCA)
What does the posterior cerebral artery (PCA) supply blood to?
1) Inferior and medial temporal lobes
2) Medial occipital cortex
Branches of the ____________ supply large regions of the basal ganglia and the internal capsule.
MCA
In the setting of HTN, what small vessels are prone to narrowing, which can lead to blockages causing lacunar infarctions?
MCA branches that supply large regions of the basal ganglia and the internal capsule
Define lacunar infarct
A blockage of one of the small branches (esp of the MCA) can cause an area to infarct, leaving a hole or depression in that area of the brain known as a lacunar infarct/stroke
Lacunar infarction in what area causes contralateral hemiparesis?
Posterior limb of the internal capsule (which houses motor pathways of the corticospinal tract) and thalamus
What characterizes lacunar infarct syndrome (stroke) (clinical manifestation of lacunar infarct)?
Pure motor hemiparesis; contra/unilateral face, arm, and leg weakness. Due to lacunar infarct of posterior limb of internal capsule.
What is the most common type of stroke?
Lacunar infarct syndrome
What strokes are more common, ACA, MCA, or PCA?
MCA
What type of stroke is characterized by aphasia, hemineglect, hemianopia, face/arm or face/arm/leg sensorimotor loss, and a gaze toward the side of the lesion?
MCA stroke
Define watershed infarcts
The area when the blood supply of 2 adjacent cerebral arteries is compromised, the region between the 2 vessels is at high risk for ischemia or infarction
What are two causes of watershed infarcts?
Sudden occlusion of the internal carotid or a drop in BP setting of carotid stenosis
Where is Broca’s area?
Just superior to Sylvian fissure in frontal lobe of left hemisphere
What is inferior to the lateral fissure in the temporal lobe?
Wernicke’s area
1) Define Transient Ischemic Attacks (TIAs)
2) What are their symptoms?
3) What are their causes?
1) A neurological deficit caused by cerebral ischemia that lasts <24 hours (usually closer to 10 mins)
2) Motor, sensory, visual, auditory, emotional or cognitive
3) Migraines, seizures, arrhythmias and hypoglycemia
_______% of patients with TIAs will have a stroke within ___ months and most of those within the next ______ hours
10%; 3 months; 48 hours
What is the 5th leading cause of death in the US?
Strokes
What are the two types of strokes? Define each
1) Hemorrhagic: blood vessel ruptures
2) Ischemic: lack of adequate blood supply to the brain for long enough to cause cell death.
What are the two main causes of ischemic strokes? Which one happens more suddenly?
1) Thrombus and embolus
2) Embolus is more sudden
What type of ischemic stroke do emboli cause?
Large vessel strokes
What are small vessel strokes also called?
Lacunar infarcts
For ________ strokes, you need to find the source to prevent additional strokes. Why?
embolic; emobli are most often blood clots and commonly come from the heart
What can cause emboli to come from the heart?
Afib or areas of damaged cardiac tissue from previous MI, where slow moving or dead areas of cardiac muscle have stagnant blood flow and create emboli
What can form on valve leaflets or artificial valves?
Valvular disease thrombi
What type of emboli can come from stenotic area of another vessel?
Artery to artery emboli
_____________ of carotids or vertebral arteries often form thrombi/clot which can embolize to the brain
Dissection (tear of the inner wall of an artery)
Carotid dissection can cause TIA or infarct in the __________ circulation
anterior
Vertebral dissection can cause TIA or infarct in the __________ circulation
posterior
Cortical signs come from _________ strokes
lobar
What are the cortical signs?
Aphasia, neglect, homonymous visual field defects, apraxia, hemiparesis, and sensory loss
Headaches occur in about ____ of ischemic stroke patients from the innervation of the blood vessels and meninges.
¼
Headaches are more commonly seen in ________ strokes and can include _______ pain if carotid or vertebral arteries are involved
hemorrhagic; neck
Strokes in younger patients are usually from?
Dissection/trauma
Stroke risk factors include?
HTN, DM, hypercholesterolemia, cigarette smoking, (+) family history, prior h/o stroke or vascular disease, Afib
Deep and superficial veins drain the brain and dump into __________ sinuses. They ultimately exit via the internal ____________ veins
dural sinuses; jugular veins
_____________ sinuses lay near the dura and collect deoxygenated blood
Cerebral venous sinuses
If a pt experiences neck stiffness or nuchal rigidity, along with a sudden horrible headache, what may be occurring?
A subarachnoid hemorrhage
What are potential symptoms of a subarachnoid hemorrhage other than a headache and nuchal rigidity?
Altered mental status, nausea, vomiting, or focal neurological deficit
What is the most common cause of subarachnoid hemorrhages?
Rupture of an intracranial aneurysm
Explain why subarachnoid hemorrhages are associated with thunderclap headaches
When there’s an aneurysm rupture at the Circle of Willis, blood fills the subarachnoid space, causing irritation to the meninges, leading to severe headache
What are the diagnostic tools for subarachnoid hemorrhages?
1) CT scan is the initial diagnostic tool (as shown in the case image)
2) If CT is negative but suspicion is high, lumbar puncture may be performed
How are subarachnoid hemorrhages treated?
Emergent neurosurgical evaluation; aneurysm may be clipped neurosurgically to prevent recurrent hemorrhage
True or false: you can’t recover from a subarachnoid hemorrhage. Explain your answer
False; varies depending on the severity of the bleed and promptness of treatment, but full recovery is possible
Give 4 differential diagnoses for subarachnoid hemorrhages/ severe headaches
1) Cervical artery dissection
2) Cerebral venous sinus thrombosis
3) Pituitary apoplexy
4) Hypertensive emergency
True or false: The complaint of “worst headache of my life” should always prompt immediate medical evaluation to rule out life-threatening conditions, particularly subarachnoid hemorrhage. Explain your answer
True; if its a subarachnoid hemorrhage their chance of recovery depends on promptness of treatment
Where are the spinothalamic tracts of the spinal cord in relation to the anterior gray matter horn?
Anterior
Where are the corticospinal tracts of the spinal cord in relation to the dorsal horn of the gray matter?
Lateral
What function does the lateral corticospinal tract control?
Movement of extremities
Where is the spinal cord the thickest?
Cervical area
True or false? The lateral corticospinal tract starts in the precentral gyrus and travels down through the spinal cord but crosses at the pyramidal decussation.
True
What percent of the corticospinal tract continues ipsilaterally after the pyramidal decussation?
15%
The 85% of the corticospinal tract that crosses over becomes the _____________ corticospinal tract; the 15% that doesn’t becomes the ___________ corticospinal tract.
85% becomes lateral corticospinal tracts; 15% becomes anterior corticospinal tract
Where does the anterolateral pathway cross the spinal cord?
Anterior commissure
What tract crosses over in the lower medulla?
Posterior column-medial leminiscal pathway
