Chapter 10: Cerebral Cortex

Question 1

What layer of the neocortex is the termination of the thalamocortical projections?

Answer 1

internal granular layer

Question 2

What are the 6 layers of the neocortex?

Answer 2

I. molecular
II. external granular
III. External pyramidal layer
IV. Internal granular layer
V. Internal pyramidal layer
VI. Multiform layer (layer of polymorphic cells)

Question 3

Which layer of the neocortex give rise to the corticospinal and corticobulbar tracts?

Answer 3

multiform layer

Question 4

What areas of the brain are supplied by the middle cerebral artery (MCA) supplies? (in general)

Answer 4

• lateral surface of the frontal, parietal, and upper temporal lobes
• posterior limb and genu of the internal capsule
• most of the basal ganglia

Question 5

Left sided middle cerebral artery occlusion can lead to what condition specific conditions?

Answer 5

Broca or Wernicke aphasia

Question 6

Right sided middle cerebral artery occlusion?

Answer 6

left sided neglect

Question 7

Occlusion of branches of the middle cerebral artery that supply Meyer’s loop fibers in the temporal lobe result in what condition?

Answer 7

contralateral superior quadrantanopsia

Question 8

What structures does the ACA supply?

Answer 8

medial surface of the frontal and parietal lobes; anterior 4/5 of corpus callosum; anterior limb of internal capsule

Question 9

What areas of the brain does the PCA supply?

Answer 9

supplies occipital lobe; lower temporal lobe; splenium; midbrain

Question 10

What is the most common site for an aneurysm?

Answer 10

where the anterior communicating artery joins an anterior cerebral artery

Question 11

How do thrombotic cerebral infarcts appear?

Answer 11

anemic/ pale infarct; usually atherosclerotic complication

Question 12

How do embolic cerebral infarcts appear?

Answer 12

hemorrhagic/ red infarct; from heart or atheroscelrotic plaques middle cerebral artery most vulnerable to emboli

Question 13

How do hypotension cerebral infarcts appear?

Answer 13

“watershed” areas and deep cortical layers most affected

Question 14

How do infarcts caused by hypertension appear?

Answer 14

lacunar infarcts; basal ganglia, internal capsule, and pons most affected

Question 15

Cause of epidural hematoma

Answer 15

rupture of middle meningeal artery after skull fracture

almost always traumatic

Question 16

Characteristics of an epidural hematoma?

Answer 16

lucid interval before loss of consciousness (“talk and die” syndrome)

Question 17

What is the cause of a subdural hematoma?

Answer 17

• usually caused by trauma
• rupture of bridging veins (drain brain to dural venous sinuses)

Question 18

What is the cause of subarachnoid hemorrhage?

Answer 18

ruptured berry aneurysm most commn cause

Question 19

Predisposing factors of subarachnoid hemorrhage?

Answer 19

Marfan syndrome, Ehlers-Danlos type 4, adult polyscystic kidney disease, hypertension, smoking

Question 20

What are the causes of intracerebral hemorrhage?

Answer 20

common causes: hypertension, trauma, infarction

Question 21

Primary auditory cortex corresponding Brodmann areas?

Answer 21

41 & 42

Question 22

Broca’s area corresponding Brodmann area?

Answer 22

44 & 45

Question 23

Frontal eye field corresponding Brodmann area?

Answer 23

area 8

Question 24

Premotor cortex corresponding Brodmann area?

Answer 24

area 6

Question 25

Primary motor cortex corresponding Brodmann area?

Answer 25

area 4

Question 26

Primary somatosensory cortex corresponding Brodmann area?

Answer 26

areas 3, 1, and 2

Question 27

Angular gyrus corresponding Brodmann area?

Answer 27

area 39

Question 28

Wernickes area corresponding Brodmann area?

Answer 28

area 22

Question 29

What would a lesion of the frontal eye field lead to?

Answer 29

inability to make voluntary eye movements toward the contralateral side Because the activity of thee intact frontal eye field in the opposite cortex would also be unopposed after such a lesion, the result is conjugate slow deviation of eyes toward side of the lesion. Intact frontal eye field in the opposite hemisphere deviates eyes away from the paralyzed limb

Question 30

What is Gerstmann Syndrome?

Answer 30

when a lesion is confined to anuglar gyrus ( found in the parietal lobe) Symptoms: produces loss of ability to comprehend written language (alexia) and to write it (agraphia) Often presents with 3 other conditions: acaclulia finger agnosia left-right disorientation

Question 31

Describe conduction aphasia?

Answer 31

* the large fiber bundle called the superior longitudinal fasiculus (or the arcuate fasiculus) is lesioned. * verbal output is fluent, but there are many parapharases and word finding pauses. * Both verbal and visual language comprehension; but if asked to repeat words or execute verbal commands cant be done.... * also poor object naming example of "disconnect syndrome" * Disconnect syndrome because of inability to send information from one cortical area to another

Question 32

Transcortical apraxia.

Answer 32

similar to conduction aphasia except 2 hemispheres are disconnected because of lesion at the corpus callosum

Question 33

Asomatognosia.

Answer 33

caused by lesions in the non-dominant right parietal lobe may result in unawareness or neglect of the contralateral half of the body

Question 34

What is visual agnosia?

Answer 34

when there is damage to parts of the temporal lobes involving the cone stream producing a visual agnosia. Inability to recognize visual patterns (including objects) in the absence of a visual field deficit lesions in the temporal lobe that also produce some destruction of adjacent occipital lobe in either hemisphere result in prosopagnosia specific inability to recognize faces

Question 35

Alexia without agraphia?

Answer 35

"higher-order" deficit associated with occipital lobe damage is alexia without agraphia (or pure word blindness) Patients unable to read at all and often have color anomia (inability to name colors) can write another example of disconnect syndrome in which information from occipital lobe is not available to the parietal or frontal lobes to understand or express what is seen involvement of splenium of corpus callosum prevent visual informatin from intact right occipital cortex from reaching languate comprehension centers in left hemisphere

Question 36

Arterial supply to the anterior limb of the internal capsule?

Answer 36

medial striate br. of ACA

Question 37

What are the tracts reaching the anterior limb of the internal capsule?

Answer 37

thalamocortical

Question 38

Arterial supply to the genu of the internal capsule?

Answer 38

lenticulostriate br. of MCA

Question 39

What are the tracts through the genu?

Answer 39

corticobulbar

Question 40

Arterial supply to the posterior limb of the internal capsule?

Answer 40

lenticulostriate branch of MCA

Question 41

Tracts through the posterior limb of the internal capusle?

Answer 41

corticospinal, all somatosensory thalamocotical projections

Question 42

Where is the second most common site of aneurysm in the brain?

Answer 42

posterior communicating artery

Question 43

Posterior communicating artery blockage can cause blockage of what cranial nerve?

Answer 43

CN III

Question 44

Gaze palsy aphasia is seen with which branch of the middle cerebral artery?

Answer 44

lenticulostriate branch

Question 45

What part of the brain is implicated in frontal lobe syndrome? What is frontal lobe syndrome?

Answer 45

prefrontal cortex; symptoms can include poor judgment, difficulty concentrating and problem solving, apathy, inappopriate social behavior

Question 46

What is the lobe implicated in contralateral asterognosis/ apraxia?

Answer 46

superior parietal lobe

Question 47

What are the lobes implicated in Gerstmann syndrome?

Answer 47

Inferior parietal lobule (angular gyrus; area 39)

Question 48

What structure is implicated in Kluver bucy syndrome?

Answer 48

amygdala

Question 49

What are some symptoms of Kluver Bucy?

Answer 49

hyperphagia, hypersexuality, visual agnosia