Lecture 7 part II

Question 1

What happens if there is an occlusion in the anterior/posterior spinal arteries

Answer 1

Loss of spinal cord function at level of occlusion (paralysis, loss of sensation, etc)

Question 2

What happens if there is an occlusion in the posterior inferior cerebellar artery (PICA)

Answer 2

Wallenberg syndrome: Loss of pain and temperature sensation on contralateral side of body/torso, and ipsilateral side of face

Question 3

What happens if there is an occlusion in the anterior inferior cerebellar artery (AICA)

Answer 3

Lateral Pontine syndrom: sudden onset of vomiting/vertigo, Ipsilateral loss of sensation to face and ipsilateral face paralysis

Question 4

What happens if there is an occlusion in the superior cerebellar artery

Answer 4

Ipsilateral limb dysmetria, contralateral loss of sensation

Question 5

What happens if there is an occlusion in the Pontine artery

Answer 5

contralateral paralysis and loss of sensation. Often results in death, depends on size of infarct

Question 6

What happens if there is an occlusion in the labyrinthins artery

Answer 6

ipsilateral hearing loss and vertigo

Question 7

What is the circle of willis

Answer 7

Communicating branches form anastomoses between cerebral aa

Question 8

Where is the middle cerebral artery

Answer 8

along the lateral fissure (sylvian sulcus) and lateral surface of cerebral cortex

Question 9

What happens if there is a stroke in a cortical branch of the middle cerebral artery

Answer 9

Because the branches go to the lateral surface of the cortex, there is often contralateral paralysis and sensory loss, and aphasia if it was on the dominant side

Question 10

What happens if there is an occlusion in a lateral striate branch of the middle artery

Answer 10

Because they supply internal capsule and basal ganglia, hemiplegia often results

Question 11

What does the posterior cerebral artery supply

Answer 11

occipital and temporal lobes

Question 12

What happens if there is an occlusion in the posterior cerebral artery

Answer 12

Visual field defects, prosopagnosia, contralateral deficits of CN VII, X, XII, and ipsilateral deficits of CN III

Question 13

What happens if there is an occlusion in the anterior cerebral artery

Answer 13

contralateral paralysis and sensory loss in leg and foot, Abulia: lack of will or initiative. pronounced passivity, reduced social interactions, emotional responsiveness

Question 14

What direction does blood from cerebral hemispheres and brain stem drain

Answer 14

Outwards into surface veins

Question 15

How does blood get to the dural sinuses

Answer 15

cerebral veins drain it there

Question 16

What is a dural sinus

Answer 16

venous compartment within the dura mater

Question 17

What are the dural sinuses associated with the falx cerebri

Answer 17

Superior sagittal, inferior sagittal, straight

Question 18

<p>What are the dural sinuses associated with the tentorium cerebelli</p>

Answer 18

<p>Straight, confluens, transverse, sigmoid</p>

Question 19

What are the dural sinuses associated with the anterior cranial base

Answer 19

Cavernous, inferior and superior petrosal sinuses

Question 20

Where is the cavernous sinus

Answer 20

On either side of the sella tursica surrounding the pituitary gland

Question 21

What is the function of the cavernous sinus

Answer 21

Receives blood from local sinuses, orbital veins, and communicates with the pterygoid plexus in the lateral pterygoid muscles

Question 22

What is the function of the superior and inferior petrosal sinuses

Answer 22

Drain blood from cavernous sinus posteriorly into transverse sinus

Question 23

What passes through the cavernous sinus

Answer 23

Internal carotid, CN III, IV, V, VI

Question 24

What are the anterior and posterior longitudinal sinuses

Answer 24

Valveless veins around dura in spine

Question 25

What is the basivertebral vein

Answer 25

Drains the vertebral body and is route of metastasis for prostate cancer to spine

Question 26

What are emissary veins

Answer 26

Vein that allow blood to flow freely between scalp and dural sinuses

Question 27

What is the function of emissary veins

Answer 27

Helps thermoregulate the brain by shunting hot blood to the surface in hyperthermia

Question 28

What cells make up the blood brain barrier

Answer 28

endothelium, pericytes, astrocyte feet, and basal lamina

Question 29

What does the blood brain barrier filter out

Answer 29

large, water soluble molecules

Question 30

How is the blood brain barrier maintained

Answer 30

astrocyte feet induce and maintain tight junctions between capillary endothelial cells

Question 31

How does glucose and amino acids reach the brain

Answer 31

They penetrate endothelial cells via transporters

Question 32

How do gases reach the brain

Answer 32

They diffuse (as always)

Question 33

What part of the brain is not protected by the Blood brain barrier

Answer 33

The hypothalamus, area postrema and other periventricular regions (limbic system)

Question 34

What is the import of some regions of the brain not being protected by the blood brain barrier

Answer 34

passage of larger molecules, hormones can contact the hypothalamus, poisons can stimulate pathway to vomit center

Question 35

What is the blood CSF barrier

Answer 35

tight junctions between choroidal epithelial cells making it impermeable to larger molecules

Question 36

What is the brain CSF barrier

Answer 36

free movement between the brain interstitium and ventricles through ependymal cells

Question 37

What type of substance can go through any of the barriers in the brain

Answer 37

lipophilic substances like alcohol, anesthetics