Cranial Meninges and Intracranial Circulation Flashcards Preview

Structure and Function Test 1 > Cranial Meninges and Intracranial Circulation > Flashcards

Flashcards in Cranial Meninges and Intracranial Circulation Deck (80)
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1
Q

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

A

Periosteal dura, and meningeal dura

2
Q

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

A

PEriosteal Dura

3
Q

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

A

Epidural (or extradural) space

4
Q

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

A

Dural Septa

5
Q

The major dural septa include the

A

Falx cerebri, Falx cerebelli, and Tentorium cerebelli

6
Q

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

A

Meningeal dura

7
Q

Lies between the two cerebral hemispheres

A

Falx cerebri

8
Q

Lies between the two cerebellar hemispheres

A

Falx ceribelli

9
Q

Lies between the cerebellum and the occipital lobe of the cerebrum

A

Tentorium cerebelli

10
Q

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

A

Dural Venous sinuses

11
Q

Dural venous sinuses are also found within reflections of the

A

Meningeal dura

12
Q

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

A

Veins of the body

13
Q

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

A

Superior saggital sinus

14
Q

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

A

Inferior saggital sinus

15
Q

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

A

Occipital sinus

16
Q

Lies within

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

A

Straight sinus

17
Q

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

A

Confluens of sinuses

18
Q

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

A

Transverse sinuses

19
Q

The anterior continuation of the transverse sinuses

-Drains into the jugular bulb

A

Sigmoid sinuses

20
Q

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

A

Cavernous sinuses

21
Q

Connects the cavernous sinus to the sigmoid sinus

A

Superior petrosal sinuses

22
Q

Drains the cavernous sinus into the jugular bulb

A

Inferior petrosal sinuses

23
Q

Carry most of the venous drainage from the brain

A

Dural sinuses

24
Q

The dural sinuses drain into the

A

Internal jugular vein

25
Q

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

A

Emissary veins

26
Q

Do not contain valves

A

Emissary veins

27
Q

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

A

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

28
Q

Intimately fused to the brain

-Follows the sulci and gyri of the cerebral cortex

A

Pia matter

29
Q

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

A

Arachnoid matter

30
Q

Are the dura and arachnoid surfaces fused together?

A

No

31
Q

The arachnoid is pressed against the dura by

A

Cerebrospinal fluid pressure

32
Q

There is usually no space between the

A

Dura and arachnoid

33
Q

Highly vascularized tissue found in the ventricles of the brain

-Secrete cerebrospinal fluid

A

Choroid plexuses

34
Q

The upward continuations of the central canal of the spinal cord

A

Ventricles of the brain

35
Q

How many ventricles of the brain are there

A

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

36
Q

The midline third ventricle is located in the

A

Diencephalon

37
Q

The midline fourth ventricle is located

A

Between the cerebellum and pons and the medulla

38
Q

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

A

Interventricular foramina (of Monro)

39
Q

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

A

Cerebral aqueduct (of Sylvius)

-In the midbrain

40
Q

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

A

Subarachnoid space

41
Q

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

A

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

42
Q

CSF is resorbed into the venous system at the

A

Arachnoid granulations

43
Q

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

A

Arachnoid granulations

44
Q

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

A

125-150 mL

45
Q

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

A

450 - 500 mL

46
Q

CSF in the subarachnoid space normally has a pressure of bout

A

80-120 mmH20

47
Q

An abnormal increase in intracranial CSF pressure results in

A

Hydrocephalus

48
Q

What are the two major categories of hydrocephalus?

A
  1. ) Communicating hydrocephalus

2. ) Non-communicating (or obstructive) hydrocephalus

49
Q

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

A

Communicating hydrocephalus

50
Q

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

A

Non-communicating (obstructive) Hydrocephalus

51
Q

Communicating hydrocephalus is usually caused by a defect in

A

Resorption

52
Q

Non-communicating hydrocephalus is most commonly caused by

A

Narrowing of the cerebral aqueduct

53
Q

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

A

Lateral and/or median foramina or the interventricular foramen

54
Q

The brain receives its blood supply from

A

2 vertebral and 2 internal carotid arteries

55
Q

The vertebral arteries supply mostly the

A

Brainstem, cerebellum, and occipital lobe of the cerebrum

56
Q

Supply most of the remainder of the brain

A

Internal carotid arteries

57
Q

These 4 arteries anastomose with eachother to form the

A

Cerebral arterial circle (CIrcle of Willis)

58
Q

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

A

Basilar artery

59
Q

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

A

2 Posterior cerebral arteries

60
Q

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

A

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

61
Q

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

A

Right and left posterior communicating arteries

62
Q

The two anterior cerebral arteries are connected by the

-forms the communication between right and left carotid system

A

Anterior communicating artery

63
Q

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

A

Subarachnoid space

64
Q

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

A

Foramen spinosum

65
Q

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

A

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

66
Q

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

A

Epidural hematoma

67
Q

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

A

Lateral side of the head in the region of the pterion

68
Q

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

A

Lucid interval

69
Q

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

A

Unconsciousness

70
Q

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

A

Superior saggital sinus

71
Q

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

A

Dura

72
Q

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

A

Subdural hematoma

-Separates arachnoid and dura creating subdural space

73
Q

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

A

Slower leaking blood from lower pressure veins

74
Q

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?

A

Epidural hematoma

75
Q

Can cross suture lines

-Allows clinicians to differentiate between types of hematoma on imaging

A

Subdural hematoma

76
Q

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

A

Subarachnoid space

77
Q

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

A

Subarachnoid hemorrhage

78
Q

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

A

CSF

79
Q

How can a subarachnoid hemorrhage be diagnosed?

A

By presence of blood in CSF in a spinal tap

80
Q

What are some symptoms of a subarachnoid hemorrhage?

A

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

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