Cranial Meninges and Intracranial Circulation

Question 1

Within the cranial cavity, the dura matter is composed of which two layers?

Answer 1

Periosteal dura, and meningeal dura

Question 2

Lines the inner surface of the skull and serves as the periosteum (Endosteum)

Answer 2

PEriosteal Dura

Question 3

There is normally no space between the periosteal dura and the bone of the skull. However under abnormal circumstances (i.e. bleeding) A space is created there called the

Answer 3

Epidural (or extradural) space

Question 4

The meningeal dura is fused to the periosteal dura for much of its surface, but in some regions it separates from the periosteal dura to turn internally to form

Answer 4

Dural Septa

Question 5

The major dural septa include the

Answer 5

Falx cerebri, Falx cerebelli, and Tentorium cerebelli

Question 6

The Falx cerebri, Falx cerebelli, and Tentorium cerebelli are all composed of only

Answer 6

Meningeal dura

Question 7

Lies between the two cerebral hemispheres

Answer 7

Falx cerebri

Question 8

Lies between the two cerebellar hemispheres

Answer 8

Falx ceribelli

Question 9

Lies between the cerebellum and the occipital lobe of the cerebrum

Answer 9

Tentorium cerebelli

Question 10

Lie between periosteal dura and the meningeal dura in the regions where the two layers separate

Answer 10

Dural Venous sinuses

Question 11

Dural venous sinuses are also found within reflections of the

Answer 11

Meningeal dura

Question 12

Dural sinuses are lined with the same epithelium that is found lining the

Answer 12

Veins of the body

Question 13

Lies between the periosteal dura and meningeal dura at the root of the falx cerebri

Answer 13

Superior saggital sinus

Question 14

Lies within a reflection of the meningeal dura at the free edge of the falx cerebri

Answer 14

Inferior saggital sinus

Question 15

Lies between periosteal dura and meningeal dura at the root of the falx cerebelli

Answer 15

Occipital sinus

Question 16

Lies within

meningeal dura at the intersection of the falx cerebri and tentorium cerebelli

Answer 16

Straight sinus

Question 17

Located between periosteal and meningeal dura at the point where the superior sagittal, occipital and straight
sinuses meet

Answer 17

Confluens of sinuses

Question 18

Lies between periosteal and meningeal dura at the attachment of the
tentorium cerebelli

Answer 18

Transverse sinuses

Question 19

The anterior continuation of the transverse sinuses

-Drains into the jugular bulb

Answer 19

Sigmoid sinuses

Question 20

Lie between periosteal and meningeal dura forming the lateral walls of the pituitary fossa`

Answer 20

Cavernous sinuses

Question 21

Connects the cavernous sinus to the sigmoid sinus

Answer 21

Superior petrosal sinuses

Question 22

Drains the cavernous sinus into the jugular bulb

Answer 22

Inferior petrosal sinuses

Question 23

Carry most of the venous drainage from the brain

Answer 23

Dural sinuses

Question 24

The dural sinuses drain into the

Answer 24

Internal jugular vein

Question 25

The dural sinuses drain into the internal jugular vein and also communicate with veins of the face, scalp, and neck through

Answer 25

Emissary veins

Question 26

Do not contain valves

Answer 26

Emissary veins

Question 27

Since emissary veins do not contain valves, blood can flow in either direction. Thus, these veins can be pathways for the

Answer 27

Spread of infection from superficial regions of the face and scalp into the cranial cavity

Question 28

Intimately fused to the brain -Follows the sulci and gyri of the cerebral cortex

Answer 28

Pia matter

Question 29

Does not enter the sulci. It is adherent to the inner surface of the meningeal dura

Answer 29

Arachnoid matter

Question 30

Are the dura and arachnoid surfaces fused together?

Answer 30

No

Question 31

The arachnoid is pressed against the dura by

Answer 31

Cerebrospinal fluid pressure

Question 32

There is usually no space between the

Answer 32

Dura and arachnoid

Question 33

Highly vascularized tissue found in the ventricles of the brain -Secrete cerebrospinal fluid

Answer 33

Choroid plexuses

Question 34

The upward continuations of the central canal of the spinal cord

Answer 34

Ventricles of the brain

Question 35

How many ventricles of the brain are there

Answer 35

Four: two lateral, the midline third, and midline fourth ventricles

Question 36

The midline third ventricle is located in the

Answer 36

Diencephalon

Question 37

The midline fourth ventricle is located

Answer 37

Between the cerebellum and pons and the medulla

Question 38

CSF produced in the lateral ventricles enters the third ventricle through the

Answer 38

Interventricular foramina (of Monro)

Question 39

From the third ventricle, CSF passes to the fourth ventricle through the

Answer 39

Cerebral aqueduct (of Sylvius) -In the midbrain

Question 40

From the fourth ventricle, CSF may continue into the central canal, but mostly it enters the

Answer 40

Subarachnoid space

Question 41

CSF enters the subarachnoid space from the 4th ventricle through which three openings?

Answer 41

2 Lateral foramina (of Luschka) and 1 MEdian foramen (of Magendie)

Question 42

CSF is resorbed into the venous system at the

Answer 42

Arachnoid granulations

Question 43

Tufts of arachnoid that come into close contact with thinned out regions of the dural wall of the superior saggital sinus

Answer 43

Arachnoid granulations

Question 44

Approximately how much CSF is there in the subarachnoid space and ventricles at any one time?

Answer 44

125-150 mL

Question 45

How much CSF is secreted in the average adult each day?

Answer 45

450 - 500 mL

Question 46

CSF in the subarachnoid space normally has a pressure of bout

Answer 46

80-120 mmH20

Question 47

An abnormal increase in intracranial CSF pressure results in

Answer 47

Hydrocephalus

Question 48

What are the two major categories of hydrocephalus?

Answer 48

1. ) Communicating hydrocephalus | 2. ) Non-communicating (or obstructive) hydrocephalus

Question 49

CSF is able to pass from the ventricles to the subarachnoid space, but resorption into the venou ssystem does not keep pace with CSF production

Answer 49

Communicating hydrocephalus

Question 50

CSF produced in the ventricles is obstructed in its passage to the subarachnoid space and thus there is diminished resorption into the venous system

Answer 50

Non-communicating (obstructive) Hydrocephalus

Question 51

Communicating hydrocephalus is usually caused by a defect in

Answer 51

Resorption

Question 52

Non-communicating hydrocephalus is most commonly caused by

Answer 52

Narrowing of the cerebral aqueduct

Question 53

Non-communicating hydrocephalus is less commonly caused by an obstruction in the

Answer 53

Lateral and/or median foramina or the interventricular foramen

Question 54

The brain receives its blood supply from

Answer 54

2 vertebral and 2 internal carotid arteries

Question 55

The vertebral arteries supply mostly the

Answer 55

Brainstem, cerebellum, and occipital lobe of the cerebrum

Question 56

Supply most of the remainder of the brain

Answer 56

Internal carotid arteries

Question 57

These 4 arteries anastomose with eachother to form the

Answer 57

Cerebral arterial circle (CIrcle of Willis)

Question 58

At the pons-medulla junction, the two vertebral arteries join to form the

Answer 58

Basilar artery

Question 59

At the pons-midbrain junction, the basilar artery divides into

Answer 59

2 Posterior cerebral arteries

Question 60

After exiting from the cavernous sinus, the internal carotid artery divides into the

Answer 60

Anterior cerebral artery, middle cerebral artery, and posterior communicating artery

Question 61

Connect the two internal carotid arteries to the two posterior cerebral arteries

Answer 61

Right and left posterior communicating arteries

Question 62

The two anterior cerebral arteries are connected by the -forms the communication between right and left carotid system

Answer 62

Anterior communicating artery

Question 63

The cerebral arteries are bound to the pia matter and therefore are in the

Answer 63

Subarachnoid space

Question 64

The middle meningeal artery (branch of the maxillary artery) enters the cranial cavity through the

Answer 64

Foramen spinosum

Question 65

Within the cranial cavity, branches of the middle meningeal artery lie between the

Answer 65

Inner surface of the skull and periosteal dura (tightly bound to the dura)

Question 66

These branches may be injured by trauma to the overlying skull resulting in arterial bleeding into the plane between the periosteal dura and the skull. This is called an

Answer 66

Epidural hematoma

Question 67

What is the most common sight of injury for an epidural hematoma?

Answer 67

Lateral side of the head in the region of the pterion

Question 68

Patients with an epidural hematoma will often have a period of time known as the

Answer 68

Lucid interval

Question 69

During this lucid period, the size of the hematoma is increasing until the increased cranial pressure again causes

Answer 69

Unconsciousness

Question 70

The cortex of the brain has venous drainage through cortical veins which drain into dural venous sinuses, primarily the

Answer 70

Superior saggital sinus

Question 71

These veins "bridge" across the subarachnoid space to penetrate the arachnoid and then the

Answer 71

Dura

Question 72

Tearing of these bridging veins by force or rapid deceleration at the site where they are anchored to the dura results in a

Answer 72

Subdural hematoma -Separates arachnoid and dura creating subdural space

Question 73

Onset of a subdural hematoma is slower than an epidural hematoma because of the

Answer 73

Slower leaking blood from lower pressure veins

Question 74

Because the periosteal dura is very tightly attached to the bone of the skull at the suture lines, what type of hematoma does not cross suture lines?

Answer 74

Epidural hematoma

Question 75

Can cross suture lines -Allows clinicians to differentiate between types of hematoma on imaging

Answer 75

Subdural hematoma

Question 76

The arteries that provide blood supply to the brain are bound in the pia matter on the surface of the brain and thus are in the

Answer 76

Subarachnoid space

Question 77

Rupture of any of these arteries as a ruptured cerebral aneurysm or head trauma will result in a

Answer 77

Subarachnoid hemorrhage

Question 78

In a subarachnoid hemorrhage, arterial blood enters the subarachnoid space and mixes with

Answer 78

CSF

Question 79

How can a subarachnoid hemorrhage be diagnosed?

Answer 79

By presence of blood in CSF in a spinal tap

Question 80

What are some symptoms of a subarachnoid hemorrhage?

Answer 80

Severe rapid onset headache (worst of life), and may have vomitin, seziures, disorientaton or other neurological signs/symptoms