Monday, 3-28-Ventricular system and Blood vessels (Stephens)

Question 1

A lesion of the right motor cerebral cortex that causes paralysis of the left side of the body is a ___ deficit

Answer 1

contralateral

Question 2

Destruction of the posterior column of the SC on the right side that results in loss of proprioception and tactile discrimination on the right side of the body below the level of the lesion is a ___ deficit

Answer 2

ipsilateral

Question 3

The major sensory and pyramidal (motor) systems are all __ organized as are parts of the cerebral cortex

Answer 3

somatotopically

Question 4

a cartoon representation of the exaggerated proportions of the cortical map is a called ___

Answer 4

Homonculus–> certain specific portions of a pathway may convey info from specific regions of the body or face

Question 5

___ is a collection of axons, dendrites, and their sheaths in the CNS

Answer 5

white matter

Question 6

__ is a general term for a large, cord-like bundle of nerve fibers

Answer 6

Funiculus

Question 7

___ is a general term referring to a bundle of nerve fibers, which belong to a particular system in the CNS. Functionally, these may be a tract, although it may not be referred to as such.

Answer 7

Fasciculus–> important fasciculi: fasciculus gracilis, fasciculus cuneatus, medial longitudinal, and superior longitudinal fasciculus

Question 8

___ is specifically defined as a fascicles comprised of nerve fibers that have a common origin, termination, and function

Answer 8

Tract–> clinically important ones are the lateral spinothalamic tract, ventral spinothalamic tract and corticospinal tract

Question 9

___ is a bundle of crossed, secondary nerve fibers in a conscious sensory pathway. It has a very limited and specific usage.

Answer 9

Lemniscus–> 4 important ones: spinal lemniscus, medial lemniscus, trigeminal lemniscus, and lateral lemniscus

Question 10

A lesion of a a lemniscus results in ___ deficits

Answer 10

contralateral

Question 11

Unilateral space-occupying lesions of the cerebrum may cause the cingulate gyrus to herniate across the midline (midline shift) beneath the free edge of the flax. This is referred to as a ___.

Answer 11

Falx herniation

Question 12

An epidural hematoma is usually caused by rupture of the ___ a., often secondary to a fracture of the temporal bone.

Answer 12

Middle meningeal a. –> pts post-traumatic history is initial unconsciousness followed by rapid recovery. After a few hrs, the increase in supratentorial cranial volume causes displacement of brain tissue (herniation)

Question 13

During a epidural hematoma, the cerebrum can herniate under the ___ and/or through the ___

Answer 13

falx cerebri

tentorial notch (tentorial or uncal herniation)

Question 14

What is the tx for a epidural hematoma?

Answer 14

emergency operation to evacuate the hematoma or the pt will die

Question 15

Subdural hematomas are caused by rupture of the __ veins.

Answer 15

bridging –> head trauma may cause these cerebral veins to rupture as they cross the subdural space. These veins are vulnerable to sheer forces created between the movement of the brain versus the dura. Temporal onset may be delayed for days or weeks, and the progression of signs and symptoms are much more insidious. The delay is due to the slower accumulation

Question 16

In children, subdural hematomas are often associated with a ___ while in the elderly minor head trauma may result in a subdural hematoma due to ____

Answer 16

• skull fracture

- more fragile blood vessels

Question 17

Severe blows to the head may cause the sharp edge of the incisura to lacerate or contuse the brainstem. The result may be some degree of temporary or permanent coma, depending upon the amount of damage to the midbrain ___

Answer 17

reticular formation –> integrity of the midbrain RF is essential for consciousness

Question 18

In 2/3 of cases, the superior saggital sinus empties directly into the ___ sinus, and the straight sinus drains directly into the __ vein.

Answer 18

• right transverse sinus

- left transverse sinus

Question 19

Thrombosis of the posterior portion of the superior venous sinus or right transverse sinus results in ___

Answer 19

cortical ischemia and/or necrosis

Question 20

Thrombosis of the posterior portion of the straight venous sinus or left transverse sinus results in ___

Answer 20

ischemia and/or necrosis of structures deep in the cerebrum. THIS IS USUALLY FATAL

Question 21

Increased intracranial pressure can apply a cuff-like pressure to the small veins on the optic n. via the adjacent subarachnoid extension. The decrease in venous drainage from the retina results in edema of the retina and swelling of the optic disc. This is known as ___

Answer 21

papilledema

Question 22

rupture of one of the vessels in the region directly below the arachnoid mater is known as a ___ and is indicated by the presence of erythrocytes in the CSF

Answer 22

subarachnoid hemorrhage

Question 23

If a subarachnoid hemorrhage is suspected, CSF can usually be sampled by inserting a needling to ___

Answer 23

either the cerebellomedullary or lumbar cisterns

Question 24

Describe the flow of CSF:

Answer 24

Lateral ventricles –> 3rd ventricle via right and left intraventricular foramen of Monroe –> 3rd ventricle –> 4th ventricle via cerebral aqueduct (of sylvius) –> subarachnoid space via foramina of Luschka (lateral) and Magendie (medial)

Question 25

___ is where CSF absorption occurs

___ is where CSF production occurs

Answer 25

arachnoid villi–> adjacent to superior saggital sinus

choroid plexus–> in all 4 ventricles

Question 26

___ is an excessive accumulation of CSF in the subarachnoid space with concomitant enlargement of that space by compression of the CNS. It may be supratentorial, infratentorial or both

Answer 26

external hydrocephalus

Question 27

This form of external hydrocephalus is most commonly associated with senile atrophy of the cortex (alzheimers)

Answer 27

supratentorial

Question 28

this form of external hydrocephalus is seen in combination with communicating hydrocephalus

Answer 28

infratentorial

Question 29

___ is caused by a structural blockage of CSF circulation within the ventricular system (i.e., stenosis of the aqueduct of sylvius). It results in dilation of the ventricle(s) proemial to the obstruction.

Answer 29

Internal hydrocephalus –> AKA noncommunicating hydrocephalus; may be present in combo with an infratentorial external hydrocephalus

Question 30

communicating hydrocephalus is a combo of which hydrocephali?

Answer 30

infratentorial external and internal hydrocephalus

Question 31

___ is an obstruction of the subarachnoid space at the level of the tentorial notch that may prevent the flow of CSF from infratentorial to supratentorial regions. CSF is free to move through the ventricular system into the infratentorial subarachnoid space, but it cannot circulate over the cerebrum to be resorbed at the arachnoid villi adjacent to and in the superior saggital sinus

Answer 31

communicating hydrocephalus –> result is hypertrophy of the ventricles (internal hydrocephalus) and an accumulation of CSF in the infratentorial subarachnoid space (external hydrocephalus)

Question 32

In a communicating hydrocephalus, a CSF shunt or tube is inserted into the ___ in order to drain the excess CSF

Answer 32

cerebellomedullary cistern (cisterna magna)

Question 33

Cardiac arrest, drowning, or exsanguination are common causes of ___, in which the distal areas of cerebral arterial circulation are hypo perfused, and vulnerable to watershed infarction.

Answer 33

global ischemia –> distal branches of cerebral arteries and pyramidal cells of the hippocampus are consistently damaged in severe ischemic injury.

Question 34

Following focal ischemia (stroke) the tissue surrounding the core ischemic territory is too ischemic to function, yet critically viable. Stroke therapy is directed at rescuing the ___ by improving tissue acidosis and O2 delivery.

Answer 34

ischemic penumbra

Question 35

The internal carotids and vertebrals pierce the dura, course in the ___ space and their 1st branches penetrate into the brain parenchyma. As they do so, they are surrounded by the tapered ___ space

Answer 35

• subarachnoid

- perivascular (virchow-robbin)

Question 36

List the arterial contributions to the circle of willis

Answer 36

• anterior cerebral a.
• anterior communicating a.
• posterior communicating a.
• posterior cerebral a.

Question 37

Where is the anterior choroidal a. located?

Answer 37

near the junction of the posterior communicating and ICA

Question 38

The ___ a. is prone to thrombosis due to its long course in the subarachnoid space. In elderly persons, it is also a frequent cause of vascular insufficiency to the globus pallidus and hippocampus.

Answer 38

anterior choroidal a.

Question 39

The __ artery provides important collateral circulation between anterior and posterior circulations and has the highest incidence of cerebral aneurysms (35%)

Answer 39

anterior cerebral a.

Question 40

This penetrating branch off of the anterior cerebral a. is considered one of the medial striate arteries. It penetrates the anterior perforating substance and supplies the internal capsule and corpus striatum (globus pallidus, putamen, and caudate)

Answer 40

recurrent artery of heubner

Question 41

Approximately 25% of cerebral aneurysms occur in this artery which connects the 2 anterior cerebral a.

Answer 41

anterior communicating artery

Question 42

The paracentral lobule and occlusion of the ACA or superior saggital sinus may result in what?

Answer 42

sensory and/or motor deficits in the contralateral leg and foot

Question 43

__ is a large a. that is the lateral continuation of the ICA. About 25% of all cerebral aneurysms occur along this a.

Answer 43

middle cerebral a.

Question 44

Thrombosis of the __ artery (located in central sulcus) results in contralateral spastic paralysis and/or paraesthesia of the face and upper 1/2 of the body

Answer 44

central a. (Rolando)

Question 45

Thrombosis of the ___ a. and/or a lesion of the frontal lobe results in expressive or Broca’s aphasia, a motor language disorder characterized by cryptic, telegraphic speech with a frustrating problem in initiation of speech motor patterns.

Answer 45

middle cerebral

Question 46

Obstruction of the MCA in the dominant hemisphere may result in ___, a receptive language disorder. Pts can be quite fluent (talkative) but they lack content or meaning in their spoken and written comprehension of language. Their language pattern tends to circumlocute with numerous inappropriate word choices and neologisms (new word creations)

Answer 46

Wernicke’s aphasia

Question 47

Central cord syndrome is a disruption of blood flow to the __ a.

Answer 47

anterior spinal a.

Question 48

___ supplies the posterior inferior portion of the cerebellum, the posterolateral aspect of the medulla, and the choroid plexus of the 4th ventricle

Answer 48

Posterior inferior cerebellar a. (PICA)

Question 49

Clinically, displacement of the ___ on angiograms of the posterior cranial fossa may indicate the presence of a space-occupying mass such as a tumor.

Answer 49

PICA

Question 50

Thrombosis of the PICA results in ___ syndrome

Answer 50

Lateral Medullary (Wallenburg) syndrome

Question 51

Uncal herniation may compress the ___ a. or thrombosis may occlude the __ a., causing an ischemic necrosis of the primary visual cortex (lingual and cuneus gyri), thereby resulting in contralateral homonymous hemianopsia with macular sparing

Answer 51

PCA

PCA

(Posterior cerebral a.)

Question 52

The __ a. is located in the pontobulbar sulcus next to the VI, VII, and VIII nerves, and the flocculus. It supplies the anterior inferior portion of the cerebellum, the superior and middle cerebellar peduncles, and part of the brainstem

Answer 52

anterior inferior cerebellar a.

Question 53

This a. supplies the paracentral lobule

Answer 53

anterior cerebral

Question 54

this a. supplies the primary motor cortex, premotor cortex, brocas speech area, primary somesthetic and primary auditory cortex, and Wernicke’s area

Answer 54

middle cerebral a.

Question 55

this a supplies the primary visual cortex

Answer 55

posterior cerebral a.

Question 56

this a. has penetrating branches to the central portion of the SC

Answer 56

anterior spinal a.

Question 57

this a. has penetrating branches to the posterior 1/3 of the SC

Answer 57

posterior spinal a.

Question 58

This vein courses next to the parahippocampal gyrus and receives thalamostriate and anterior septal veins, and drains into the great vein of Galen

Answer 58

Internal cerebral v.

Question 59

__ is adjacent to the cerebral peduncle, receives the middle deep cerebral and anterior cerebral veins, and drains into the great vein of Galen

Answer 59

basal v. of rosenthal

Question 60

This vein courses adjacent to the posterior portion of the corpus callosum. It receives internal cerebral and basal veins, and drains into the straight sinus

Answer 60

great v. of galen

Question 61

Since it drains most of the deep cerebrum, obstruction of the __ vein is usually fatal

Answer 61

great vein of galen

Question 62

a great vein varix may compress ___

Answer 62

the pineal body and posterior commissure