Neuro lecture 6

Question 1

The prosencephalon is the embryological origin for what two aspects of the brain?

Answer 1

telencephalon and diencephalon

Question 2

The rhombencephalon is the embryological origin for what three aspects of the brain?

Answer 2

metencephalon, myelencephalon and myelon

Question 3

The left and right lateral ventricles communicate with the 3rd ventricle through what foramina?

Answer 3

Foramina of Monro (also called the inter ventricular foramina)

Question 4

How does the 3rd ventricle communicate with the 4th ventricle?

Answer 4

cerebral aqueduct

Question 5

what are the four distinct parts of the lateral ventricle?

Answer 5

Anterior Frontal Horn, Body (corpus), posterior (occipital horn) and inferior (temporal) horn

Question 6

the 4th ventricle communicate with the subarachnoid space via what foramina?

Answer 6

the two foramina of Luschka (lateral) and the foramen of Magendie (midline)

Question 7

Choroid plexus occupies all ventricles of the brain however it is not present in the cerebral aqueduct, why?

Answer 7

because it is so narrow

Question 8

the choroid plexus is a rich network of blood vessels of the pia mater that form a semi-permeable filter between what two things?

Answer 8

arterial blood and CSF

Question 9

what is the function of the CSF?

Answer 9

serves to support and cushion the CNS against injury, serves nutritive functions and removes metabolic waste

Question 10

what is the normal pressure?

Answer 10

65-200mm H20

Question 11

where is CSF produced?

Answer 11

Choroid Plexus of the lateral, 3rd and 4th ventricles. Additionally by ependyma, glia, pail and arachnoid vessels

Question 12

describe the route of CSF

Answer 12

circulates from the lateral ventricles into the third ventricle via the foramina of monro, to the cerebral aqueduct, to the 4th ventricle, into the subarachnoid space via the foramina of Luschka (lateral, hence why there is two) and Magendie (medial)

Question 13

what should CSF be free of?

Answer 13

white blood cells, red blood cells, and glucose

Question 14

what does it mean if you get blood in the CSF?

Answer 14

Subarachnoid hemorrhage

Question 15

CSF is high in what contents relative to serum?

Answer 15

Na, Cl, and Mg

Question 16

what is the total volume in the ventricles and subarachnoid space of CSF?

Answer 16

140mL

Question 17

Extraventricular CSF returns to the venous system through what?

Answer 17

through small membranous villi, arachnoid granulations, located along the superior sagittal sinus.

Question 18

what structure located along the superior sagittal sinus ensures the unidirectional movement of fluid into the venous system?

Answer 18

Arachnoid villi

Question 19

there is no actual subdural or epidural spaces, so what does this mean when someone refers to these spaces?

Answer 19

the space is created as a result of trauma, infection or pathological

Question 20

Describe what happens if you develop a pineal gland tumor?

Answer 20

The cerebral aqueduct becomes blocked and therefore the CSF backs up and this enlarges the lateral and 3rd ventricles

Question 21

drainage of blood from the brain is chiefly into what?

Answer 21

venous dural sinuses, which are channels between the two layers of dura of the brain

Question 22

do venous dural sinuses have valves?

Answer 22

no

Question 23

the venous dural sinuses receive blood from what three major sources?

Answer 23

cerebral veins (major source), diploic veins and emissary veins

Question 24

venous sinuses have little tendency to collapse, why?

Answer 24

because of the fibrous consistency of the dura mater.

Question 25

the emissary veins connect what two veins?

Answer 25

extra cranial with intracranial veins

Question 26

what sinuses are considered to be the unpaired dural venous sinuses?

Answer 26

Superior longitudinal (sagittal) sinus, Inferior sagittal sinus, straight sinus and small occipital sinus

Question 27

the superior sagittal sinus is a continuation of what vein?

Answer 27

nasal vein

Question 28

what veins does the superior sagittal sinus receive blood from?

Answer 28

cerebral, diploic and emissary

Question 29

what veins does the inferior sagittal sinus receive blood from?

Answer 29

veins on the medial surface of the brain

Question 30

the straight sinus is a posterior continuation of what vein?

Answer 30

great cerebral vein of Galen this then joints the superior sagittal sinus to form the confluence of sinuses

Question 31

what are the paired dural venous sinuses?

Answer 31

Transverse Sinus, Cavernous Sinus, Sigmoid Sinus, Superior and Inferior petrosal sinus, and sphenoparietal sinuses

Question 32

describe the blood drainage into the transverse sinus?

Answer 32

receives blood from the superior sagittal sinus and straight sinus and drains into the internal jugular veins via the sigmoid sinuses

Question 33

describe the blood drainage into the cavernous sinuses?

Answer 33

receive blood from the superficial middle cerebral veins and superior ophthalmic veins and drain into the internal jugular veins and transverse sinuses

Question 34

how do the cavernous sinuses communicate?

Answer 34

via intercavernous sinuses as well as with the petrosal sinuses and the pterygoid plexus of veins.

Question 35

which sinuses are the largest and most clinically important?

Answer 35

cavernous sinuses

Question 36

where do the sigmoid sinuses review their blood from?

Answer 36

inferior cerebrum, cerebellum and emissary veins. (continuation of the transverse sinuses)

Question 37

where do the superior and inferior petrosal sinuses drain from?

Answer 37

cavernous sinuses

Question 38

where do the sphenoparietal sinuses receive their blood from?

Answer 38

superficial middle cerebral veins

Question 39

what are the veins of the spinal cord?

Answer 39

anterior median spinal vein, anterolateral spinal vein, posterolateral spinal vein, posterior median spinal vein and internal venous plexus

Question 40

there are organs surrounding the ventricular system called the circumventricular organs, do they have tight blood brain barriers?

Answer 40

no very loose

Question 41

describe the role of the pineal gland as a circumventricular organ

Answer 41

mediating circadian rhythms- melantonin

Question 42

describe the role of the area postrema as a circumventricular organ

Answer 42

body fluids (vomiting control center) and homeostasis. the location of this organ is close to CN IX AND X which controls your gag reflex, so it makes sense that it is the vomiting control center

Question 43

describe the role of the organum vasculosum as a circumventricular organ

Answer 43

balances our fluids and electrolytes. so basically the organum vasculorum is constantly checking our blood to make sure it is in balance before it goes into the ventricular circulation

Question 44

describe the role of the subfornical organ as circumventricular organ

Answer 44

thirst regulating center

Question 45

describe the role of the subcommissural organ as a circumventricular organ

Answer 45

secretes various glycol-proteins into the CSF

Question 46

describe the role of the median eminence of the third ventricle in terms of a circumventricular organ.

Answer 46

controls hypophysiotrophic hormones before they are conveyed to the pituitary gland

Question 47

what condition would you see that results from insufficient CSF absorption and therefore enlargement of ALL ventricles?

Answer 47

Communicating Hydrocephalus

Question 48

what condition results from obstruction of inter ventricular foramina, cerebral aqueduct or the foramina of Luschka and Magendie? (not all ventricles are enlarged)

Answer 48

non communicating (obstructive ) hydrocephalus

Question 49

what condition reflects a complication of infection of the middle ear, sinuses, nasopharynx, scalp or face

Answer 49

thrombosis of the dural sinus.

Question 50

If a patient presents with nausea, vomiting and a headache what is the first thing you should think of as a cause of the symptoms?

Answer 50

increased intracranial pressure